Generic Environmental 

Impact Statement for 

License Renewal of 

Nuclear Plants 

Supplement 43 

Regarding 

Palo Verde Nuclear 

Generating Station 

Final Report 

Office of Nuclear Reactor Regulation 

NUREG-1437 

Supplement 43 
AVAILABILITY OF REFERENCE MATERIALS

IN NRC PUBLICATIONS

NRC Reference Material

As of November 1999, you may electronically access 

NUREG-series publications and other NRC records at 

NRC=s Public Electronic Reading Room at 

http://www.nrc.gov/reading-rm.html. 

Publicly released records include, to name a few, 

NUREG-series publications; Federal Register notices; 

applicant, licensee, and vendor documents and 

correspondence; NRC correspondence and internal 

memoranda; bulletins and information notices; 

inspection and investigative reports; licensee event 

reports; and Commission papers and their 

attachments.

NRC publications in the NUREG series, NRC 

regulations, and Title 10, Energy, in the Code of 

Federal Regulations may also be purchased from one 

of these two sources.

1. The Superintendent of Documents

 U.S. Government Printing Office

 Mail Stop SSOP

 Washington, DC 20402B0001

 Internet: bookstore.gpo.gov

 Telephone: 202-512-1800

 Fax: 202-512-2250

2. The National Technical Information Service

 Springfield, VA 22161B0002

 www.ntis.gov 

 1B800B553B6847 or, locally, 703B605B6000

A single copy of each NRC draft report for comment is 

available free, to the extent of supply, upon written 

request as follows:

Address: U.S. Nuclear Regulatory Commission 

 Office of Administration

 Publications Branch 

 Washington, DC 20555-0001

E-mail: DISTRIBUTION.SERVICES@NRC.GOV

Facsimile: 301B415B2289 

Some publications in the NUREG series that are 

posted at NRC=s Web site address 

http://www.nrc.gov/reading-rm/doc-collections/nuregs

are updated periodically and may differ from the last 

printed version. Although references to material found 

on a Web site bear the date the material was 

accessed, the material available on the date cited may 

subsequently be removed from the site.

Non-NRC Reference Material

Documents available from public and special technical 

libraries include all open literature items, such as 

books, journal articles, and transactions, Federal 

Register notices, Federal and State legislation, and 

congressional reports. Such documents as theses, 

dissertations, foreign reports and translations, and

non-NRC conference proceedings may be purchased 

from their sponsoring organization.

Copies of industry codes and standards used in a 

substantive manner in the NRC regulatory process are 

maintained atC

The NRC Technical Library 

Two White Flint North

11545 Rockville Pike

Rockville, MD 20852B2738 

These standards are available in the library for 

reference use by the public. Codes and standards are 

usually copyrighted and may be purchased from the 

originating organization or, if they are American 

National Standards, fromC

American National Standards Institute

11 West 42nd Street

New York, NY 10036B8002

www.ansi.org 

212B642B4900

Legally binding regulatory requirements are stated only 

in laws; NRC regulations; licenses, including technical 

specifications; or orders, not in 

NUREG-series publications. The views expressed in 

contractor-prepared publications in this series are not 

necessarily those of the NRC.

The NUREG series comprises (1) technical and 

administrative reports and books prepared by the staff 

(NUREGBXXXX) or agency contractors 

(NUREG/CRBXXXX), (2) proceedings of conferences 

(NUREG/CPBXXXX), (3) reports resulting from 

international agreements (NUREG/IABXXXX), (4) 

brochures (NUREG/BRBXXXX), and (5) compilations 

of legal decisions and orders of the Commission and 

Atomic and Safety Licensing Boards and of Directors=

decisions under Section 2.206 of NRC=s regulations 

(NUREGB0750).
Generic Environmental 

Impact Statement for 

License Renewal of 

Nuclear Plants 

Supplement 43 

Regarding 

Palo Verde Nuclear 

Generating Station 

Final Report 

Manuscript Completed: December 2010 

Date Published: January 2011 

Office of Nuclear Reactor Regulation 

NUREG-1437 

Supplement 43 
 
December 2010 iii NUREG-1437, Supplement 43 

ABSTRACT 

This final supplemental environmental impact statement (SEIS) has been prepared in response 

to an application submitted by Arizona Public Service Company (APS) to renew the operating 

licenses for the Palo Verde Nuclear Generating Station (PVNGS) for an additional 20 years. 

This SEIS includes the analysis that evaluates the environmental impacts of the proposed 

action and alternatives to the proposed action. Alternatives considered include replacement 

power from new supercritical coal-fired generation; natural gas combined-cycle generation; new 

nuclear generation; a combination of alternatives that includes natural gas combined-cycle 

generation, energy conservation, and solar; and not renewing the license (the no-action 

alternative). 

The Nuclear Regulatory Commission’s recommendation is that the adverse environmental 

impacts of license renewal for PVNGS are not great enough to deny the option of license 

renewal for energy-planning decision makers. This determination is based on (1) the analysis 

and findings in the Generic Environmental Impact Statement for License Renewal of Nuclear 

Plants (GEIS), NUREG-1437; (2) the Environmental Report submitted by APS; (3) consultation 

with Federal, State, and local agencies; (4) the NRC staff’s own independent review; and (5) the 

NRC staff’s consideration of public comments received during the scoping process and draft 

SEIS comment period. 

December 2010 v NUREG-1437, Supplement 43 

Table of Contents 

Abstract ............................................................................................................................... iii

Executive Summary ..................................................................................................................... xi

Background .............................................................................................................................. xi

Proposed Action ....................................................................................................................... xi

Purpose and Need for Action ................................................................................................... xi

Environmental Impacts of License Renewal ............................................................................ xii

Land Use ............................................................................................................................. xii

Air Quality ............................................................................................................................ xiii

GroundWater Use and Quality ............................................................................................ xiii

Surface Water Use and Quality ........................................................................................... xiii

Aquatic Resources .............................................................................................................. xiii

Terrestrial Resources .......................................................................................................... xiii

Threatened and Endangered Species ................................................................................ xiii

Human Health .................................................................................................................... xiv

Socioeconomics ................................................................................................................. xiv

Severe Accident Mitigation Alternatives .............................................................................. xv

Alternatives .............................................................................................................................. xv

Comparison of Alternatives ..................................................................................................... xv

Recommendation ................................................................................................................... xvii

Abbreviations and Acronyms ..................................................................................................... xix

1.0 Purpose and Need for Action ............................................................................................. 1-1

1.1 Proposed Federal Action ................................................................................................ 1-1

1.2 Purpose and Need for the Proposed Federal Action ...................................................... 1-1

1.3 Major Environmental Review Milestones ........................................................................ 1-2

1.4 Generic Environmental Impact Statement ...................................................................... 1-3

1.5 Supplemental Environmental Impact Statement ............................................................ 1-5

1.6 Cooperating Agencies .................................................................................................... 1-6

1.7 Consultations .................................................................................................................. 1-6

1.8 Correspondence ............................................................................................................. 1-6

1.9 Status of Compliance ..................................................................................................... 1-8

1.10 References ................................................................................................................... 1-9

2.0 Affected Environment ......................................................................................................... 2-1

2.1 Facility Description ...................................................................................................... 2-1

2.1.1 Reactor and Containment Systems ...................................................................... 2-1

2.1.2 Radioactive Waste Management ......................................................................... 2-5

2.1.3 Nonradioactive Waste Management .................................................................... 2-6

2.1.4 Plant Operation and Maintenance ........................................................................ 2-8

2.1.5 Power Transmission System ................................................................................ 2-8

2.1.6 Cooling and Auxiliary Water Systems ................................................................ 2-14

2.1.7 Facility Water Use and Quality ........................................................................... 2-15

2.2 Surrounding Environment .......................................................................................... 2-27

2.2.1 Land Use ............................................................................................................ 2-29

2.2.2 Climate and Meteorology ................................................................................... 2-29

2.2.3 Groundwater Resources .................................................................................... 2-37

2.2.4 Surface Water Resources .................................................................................. 2-40

2.2.5 Aquatic Resources ............................................................................................. 2-41

2.2.6 Terrestrial Resources ......................................................................................... 2-42
Table of Contents 

NUREG-1437, Supplement 43 vi December 2010 

2.2.7 Threatened and Endangered Species ................................................................ 2-43

2.2.8 Socioeconomic Factors ...................................................................................... 2-51

2.2.9 Historic and Archaeological Resources .............................................................. 2-63

2.3 Related Federal Project Activities And Consultations ............................................... 2-66

2.4 References ................................................................................................................ 2-67

3.0 Environmental Impacts Of Refurbishment .......................................................................... 3-1

3.1 References ....................................................................................................................... 3-3

4.0 Environmental Impacts Of Operation ................................................................................. 4-1

4.1 Land Use ..................................................................................................................... 4-1

4.2 Air Quality .................................................................................................................... 4-1

4.3 Groundwater ................................................................................................................ 4-2

4.3.1 Generic Groundwater Issues ................................................................................ 4-2

4.3.2 Groundwater Use Conflicts (Plants That Use >100 gpm) .................................... 4-2

4.3.3 Groundwater Use Conflicts (Make-Up From a Small River) ................................. 4-2

4.3.4 Groundwater Quality Degradation (Cooling Ponds at Inland Sites) ..................... 4-3

4.4 Surface Water .............................................................................................................. 4-4

4.4.1 Generic Surface Water Issues ............................................................................. 4-4

4.4.2 Water Use Conflicts (Plants Using Make-Up Water from a Small River with Low 

Flow) .................................................................................................................... 4-5

4.5 Aquatic Resources ...................................................................................................... 4-7

4.5.1 Generic Aquatic Ecology Issues ........................................................................... 4-7

4.6 Terrestrial Resources .................................................................................................. 4-8

4.7 Threatened Or Endangered Species ........................................................................... 4-8

4.7.1 Aquatic Species .................................................................................................... 4-9

4.7.2 Terrestrial Species ............................................................................................... 4-9

4.8 Human Health ............................................................................................................ 4-10

4.8.1 Generic Human Health Issues ........................................................................... 4-10

4.8.2 Microbiological Organisms ................................................................................. 4-13

4.8.3 Electromagnetic Fields – Acute Shock ............................................................... 4-13

4.8.4 Electromagnetic Fields – Chronic Effects ........................................................... 4-14

4.9 Socioeconomics ........................................................................................................ 4-15

4.9.1 Generic Socioeconomic Issues .......................................................................... 4-15

4.9.2 Housing Impacts ................................................................................................. 4-16

4.9.3 Public Services: Public Utility Impacts ............................................................... 4-16

4.9.4 Offsite Land Use ................................................................................................. 4-17

4.9.5 Public Services: Transportation Impacts ............................................................ 4-18

4.9.6 Historic and Archaeological Resources .............................................................. 4-18

4.9.7 Environmental Justice ........................................................................................ 4-19

4.10 Evaluation of New and Potentially Significant Information ........................................ 4-26

4.11 Cumulative Impacts ................................................................................................... 4-26

4.11.1 Cumulative Impacts on Water Resources .......................................................... 4-27

4.11.2 Cumulative Impacts of Thermophilic Microbiological Organisms and 

Electromagnetic Fields ....................................................................................... 4-28

4.11.3 Cumulative Impacts on Aquatic Resources ........................................................ 4-28

4.11.4 Cumulative Impacts on Terrestrial Resources ................................................... 4-28

4.11.5 Cumulative Air Quality Impacts .......................................................................... 4-29

4.11.6 Cumulative Human Health Impacts .................................................................... 4-31

4.11.7 Cumulative Socioeconomic Impacts .................................................................. 4-31

4.11.8 Summary of Cumulative Impacts ....................................................................... 4-32

4.12 References ................................................................................................................ 4-33
Table of Contents 

December 2010 vii NUREG-1437, Supplement 43 

5.0 Environmental Impacts of Postulated Accidents................................................................. 5-1

5.1 Design-Basis Accidents ............................................................................................... 5-1

5.2 Severe Accidents ......................................................................................................... 5-2

5.2.1 Severe Accidents Initiated by Sabotage and Terrorism ....................................... 5-3

5.3 Severe Accident Mitigation Alternatives .................................................................... 5-11

5.3.1 Introduction ......................................................................................................... 5-11

5.3.2 Estimate of Risk ................................................................................................. 5-12

5.3.3 Potential Plant Improvements ............................................................................ 5-15

5.3.4 Evaluation of Risk Reduction and Costs of Improvements ................................ 5-15

5.3.5 Cost-Benefit Comparison ................................................................................... 5-15

5.3.6 Conclusions ........................................................................................................ 5-16

5.4 References ................................................................................................................ 5-17

6.0 Environmental Impacts of The Uranium Fuel Cycle, Solid Waste Management, and 

Greenhouse Gas Emissions ............................................................................................... 6-1

6.1 The Uranium Fuel Cycle and Solid Waste Management ............................................. 6-1

6.2 Greenhouse Gas Emissions ........................................................................................ 6-2

6.2.1 Existing Studies .................................................................................................... 6-3

6.2.2 Conclusions: Relative Greenhouse Gas Emissions ............................................. 6-7

6.3 References .................................................................................................................. 6-9

7.0 Environmental Impacts of Decommissioning ...................................................................... 7-1

7.1 Decommissioning ........................................................................................................ 7-1

7.2 References .................................................................................................................. 7-2

8.0 Environmental Impacts of Alternatives ............................................................................... 8-1

8.1 Supercritical Coal-Fired Generation ............................................................................ 8-3

8.1.1 Air Quality ............................................................................................................. 8-6

8.1.2 Groundwater Use and Quality ............................................................................ 8-11

8.1.3 Surface Water Use and Quality .......................................................................... 8-11

8.1.4 Aquatic and Terrestrial Ecology ......................................................................... 8-11

8.1.5 Human Health .................................................................................................... 8-12

8.1.6 Socioeconomics ................................................................................................. 8-13

8.1.7 Waste Management ........................................................................................... 8-16

8.1.8 Climate Change-Related Impacts of a Coal-Fired Alternative ............................ 8-18

8.2 Natural Gas Combined-Cycle Generation ................................................................. 8-19

8.2.1 Air Quality ........................................................................................................... 8-20

8.2.2 Groundwater Use and Quality ............................................................................ 8-22

8.2.3 Surface Water Use and Quality .......................................................................... 8-23

8.2.4 Aquatic and Terrestrial Ecology ......................................................................... 8-23

8.2.5 Human Health .................................................................................................... 8-23

8.2.6 Socioeconomics ................................................................................................. 8-24

8.2.7 Waste Management ........................................................................................... 8-27

8.2.8 Climate Change-Related Impacts of a Natural Gas Combined Cycle 

Alternative .......................................................................................................... 8-28

8.3 New Nuclear Generation ........................................................................................... 8-28

8.3.1 Air Quality ........................................................................................................... 8-29

8.3.2 Groundwater Use and Quality ............................................................................ 8-30

8.3.3 Surface Water Use and Quality .......................................................................... 8-30

8.3.4 Aquatic and Terrestrial Ecology ......................................................................... 8-30

8.3.5 Human Health .................................................................................................... 8-30

8.3.6 Socioeconomics ................................................................................................. 8-31

8.3.7 Waste Management ........................................................................................... 8-34
Table of Contents 

NUREG-1437, Supplement 43 viii December 2010 

8.3.8 Climate Change-Related Impacts of a New Nuclear Alternative ........................ 8-34

8.4 Combination Alternative ............................................................................................ 8-34

8.4.1 Impacts of the Natural Gas Combined Cycle Facility Portion of the Combination 

Alternative .......................................................................................................... 8-35

8.4.2 Impacts of the Conservation Portion of the Combination Alternative ................. 8-36

8.4.3 Impacts of the Concentrated Solar Power (CSP) Portion of the Combination 

Alternative .......................................................................................................... 8-38

8.4.4 Summary of Impacts of the Combination Alternative ......................................... 8-41

8.5 Alternatives Considered but Dismissed ..................................................................... 8-41

8.5.1 Offsite Coal-Fired, Gas-Fired, and Nuclear Capacity ......................................... 8-41

8.5.2 Coal-Fired Integrated Gasification Combined-Cycle (IGCC) .............................. 8-41

8.5.3 Energy Conservation/Energy Efficiency ............................................................. 8-43

8.5.4 Purchased Power ............................................................................................... 8-43

8.5.5 Solar Power ........................................................................................................ 8-43

8.5.6 Wind ................................................................................................................... 8-44

8.5.7 Wood Waste ....................................................................................................... 8-45

8.5.8 Hydroelectric Power ........................................................................................... 8-45

8.5.9 Wave and Ocean Energy ................................................................................... 8-46

8.5.10 Geothermal Power ............................................................................................. 8-46

8.5.11 Municipal Solid Waste ........................................................................................ 8-47

8.5.12 Biofuels ............................................................................................................... 8-48

8.5.13 Oil-Fired Power .................................................................................................. 8-48

8.5.14 Fuel Cells ........................................................................................................... 8-48

8.5.15 Delayed Retirement ............................................................................................ 8-48

8.6 No-Action Alternative ................................................................................................. 8-49

8.6.1 Air Quality ........................................................................................................... 8-50

8.6.2 Groundwater Use and Quality ............................................................................ 8-50

8.6.3 Surface Water Use and Quality .......................................................................... 8-50

8.6.4 Aquatic and Terrestrial Resources ..................................................................... 8-50

8.6.5 Human Health .................................................................................................... 8-50

8.6.6 Socioeconomics ................................................................................................. 8-51

8.6.7 Waste Management ........................................................................................... 8-52

8.7 Alternatives Summary ............................................................................................... 8-52

8.8 References ................................................................................................................ 8-55

9.0 Conclusion .......................................................................................................................... 9-1

9.1 Environmental Impacts of License Renewal ................................................................ 9-1

9.2 Comparison of Environmental Impacts of License Renewal and Alternatives ............. 9-1

9.3 Resource Commitments .............................................................................................. 9-2

9.3.1 Unavoidable Adverse Environmental Impacts ...................................................... 9-2

9.3.2 The Relationship between Local Short-Term Uses of the Environment and the 

Maintenance and Enhancement of Long-Term Productivity ................................ 9-2

9.3.3 Irreversible and Irretrievable Commitments of Resources ................................... 9-3

9.4 Recommendation ........................................................................................................ 9-4

10.0 List of Preparers ................................................................................................. 10-1

11.0 Index .................................................................................................................. 11-1

12.0 List of Agencies, Organizations, and Persons to Whom Copies of the 

Supplemental Environmental Impact Statement are Sent ................................. 12-1

Appendix A. Comments Received on the Palo Verde Nuclear Generating Station, 

Environmental Review ........................................................................................ A-1
Table of Contents 

December 2010 ix NUREG-1437, Supplement 43 

Appendix B. National Environmental Policy Act Issues for License Renewal of 

Nuclear Power Plants ......................................................................................... B-1

Appendix C. Applicable Regulations, Laws, and Agreements ................................................. C-1

Appendix D. Consultation Correspondences ........................................................................... D-1

Appendix E. Chronology of Environmental Review ................................................................. E-1

Appendix F. U.S. Nuclear Regulatory Commission Staff Evaluation of Severe Accident 

 Mitigation Alternatives for Palo Verde Nuclear Generating Station In Support of 

 License Renewal Application Review ................................................................. F-1

FIGURES 

Figure 1-1. Environmental Review Process. ............................................................................. 1-2 

Figure 1-2. Environmental Issues Evaluated During License Renewal.. .................................. 1-5 

Figure 2.1-1. Palo Verde Nuclear Generating Station 50 Mile Radius. ..................................... 2-2 

Figure 2.1-2. Palo Verde Nuclear Generating Station 6 Mile Radius. ....................................... 2-3

Figure 2.1-3. Palo Verde Nuclear Generating Station General Plant Layout. ........................... 2-4 

Figure 2.1.5-1. Palo Verde Nuclear Generating Station Transmission Lines – Arizona. ........ 2-12 

Figure 2.1.5-2. Palo Verde Nuclear Generating Station Transmission Lines – California. ..... 2-13

Figure 2.1.7-1. PVNGS Surface Impoundments, Landfills, and Monitoring Wells ................... 2-18 

Figure 2.2.1-1. Palo Verde Nuclear Generating Station Site Boundary. .................................. 2-28

Figure 2.2.2. Wind Rose at 35-foot at PVNGS 2004–2008 (APS 2008a) ............................... 2-30

Figure 2.2.3-1. Surface Features in the Vicinity of the PVNGS ............................................... 2-38

Figure 2.2.3-2. Groundwater Flow in shallow aquifer below PVNGS (APS 2009c) ................. 2-39 

Figure 4.4-1. Gila River and its Principal Tributaries ................................................................ 4-6

Figure 4.9.7-1. Minority block groups within a 50-mile radius of PVNGS (USCB 2009). ........ 4-21

Figure 4.9.7-2. Low-income block groups within 50-mile radius of PVNGS (APS 2008a). ..... 4-23 

TABLES 

Table 1-1. Licenses and Permits. ............................................................................................. 1-8

Table 2.1.5-1. PVNGS Transmission Lines ............................................................................. 2-11

Table 2.1.7-1. PVNGS Production Wells ................................................................................ 2-17

Table 2.1.7-2. Facilities Regulated by PVNGS Aquifer Protection Permit Program ............... 2-20

Table 2.1.7-3. Partial Summary of Aquifer Protection Permit Violations 2004 - 2008a

 ........... 2-25

Table 2.2.2-1. PVNGS Annual Emissions Inventory Summaries, 2004-2008......................... 2-33

Table 2.2.2-2. National Ambient Air Quality Standards (NAAQS)a ......................................... 2-35

Table 2-6. Listed Terrestrial Species ....................................................................................... 2-47

Table 2.2.8–1. APS Employee Residence by County in 2008 ................................................ 2-53

Table 2.2.8.1–1. Housing in Maricopa County ........................................................................ 2-53

Table 2.2.8.2–1. Major Maricopa County Public Water Supply Systems 

(thousand acre-feet) ................................................................................... 2-54

Table 2.2.8.2–2. Average Annual Daily Traffica (AADT) Counts in the vicinity of PVNGS ...... 2-56

Table 2.2.8.5–1. Population and Percent Growth in Maricopa County ................................... 2-58

Table 2.2.8.5–2. Demographic Population Profile in PVNGS ROI in 2000 .............................. 2-58

Table 2.2.8.5–3. Demographic Population Profile in PVNGS ROI 2006-8 Estimate ............... 2-59
Table of Contents 

NUREG-1437, Supplement 43 x December 2010 

Table 2.2.8.5–4. Seasonal Housing within 50 miles (80 km) of PVNGS, 2000 ...................... 2-60 

Table 2.2.8.5–5. Migrant Farm Worker and Temporary Farm Labor within 50 miles 

(80 km) of PVNGS, 2007 ............................................................................ 2-61

Table 2.2.8.6–1. Major Employers in the Phoenix Metropolitan Area, 2009 ........................... 2-62

Table 2.2.8.6–2. Income Information for PVNGS, 2008 ......................................................... 2-62

Table 2.2.8.6–3. Maricopa County Tax Revenues, 2005 to 2008; PVNGS Property Tax, 

2005 to 2008; and PVNGS Property Tax as a Percentage of 

Tax Revenues ............................................................................................ 2-63

Table 3-1. Category 1 Issues for Refurbishment Evaluation ..................................................... 3-2

Table 3-2. Category 2 Issues for Refurbishment Evaluation ..................................................... 3-2

Table 4-1. Land Use Issues ...................................................................................................... 4-1

Table 4-2. Air Quality Issue ....................................................................................................... 4-2

Table 4-5. Aquatic Resources Issues ....................................................................................... 4-7

Table 4-6. Terrestrial Resources Issues .................................................................................... 4-8

Table 4-8. Human Health Issues ............................................................................................ 4-10

Table 4-9. Socioeconomic Issues ........................................................................................... 4-15

Table 4-11. Summary of Cumulative Impacts on Resources Areas ........................................ 4-32

Table 5-1. Issues Related to Postulated Accidents.. ................................................................. 5-1

Table 5-3a. PVNGS Core Damage Frequency for Internal Events ......................................... 5-13

Table 5-3b. Important PVNGS Fire Compartments and their Contribution to Fire CDF ......... 5-14

Table 5-4. Breakdown of Population Dose by Containment Release Mode ........................... 5-14

Table 6-1. Issues Related to the Uranium Fuel Cycle and Solid Waste Management .............. 6-2

Table 6-2. Nuclear Greenhouse Gas Emissions Compared to Coal ......................................... 6-5

Table 6-3. Nuclear Greenhouse Gas Emissions Compared to Natural Gas .............................. 6-6

Table 6-4. Nuclear Greenhouse Gas Emissions Compared to Renewable Energy Sources .... 6-7

Table 7-1. Category 1 Issues Applicable to the Decommissioning of PVNGS Following 

the Renewal Term ................................................................................................. 7-1

Table 8-1. Summary of Environmental Impacts of the Supercritical Coal-Fired Alternative 

Compared to Continued Operation of PVNGS ...................................................... 8-6

Table 8-2. Estimated Emissions of Criteria Pollutants and Carbon Dioxide from the 

Coal-Fired Alternative .......................................................................................... 8-10

Table 8-3. Summary of Environmental Impacts of the Natural Gas 

Combined-Cycle Generation Alternative Compared to Continued Operation 

of PVNGS ............................................................................................................ 8-20

Table 8-4. Summary of Environmental Impacts of the New Nuclear Alternative 

Compared to Continued Operation of PVNGS .................................................... 8-29

Table 8-5. Summary of Environmental Impacts of the Combination Alternative 

Compared to Continued Operation of PVNGS .................................................... 8-35

Table 8-6. Summary of Environmental Impacts of No Action Compared to Continued 

Operation of PVNGS ........................................................................................... 8-49

Table 8-7. Summary of Environmental Impacts of Proposed Action and Alternatives ............. 8-54

Table 10-1. List of Preparers ................................................................................................... 10-1

Table A-1. Individuals Providing Comments During Scoping Comment Period ...................... A-2

Table B-1. Summary of Issues and Findings ............................................................................ B-1

Table C-1. Federal and State Environmental Requirements .................................................... C-1

Table D-1. Consultation Correspondences .............................................................................. D-1

Table F-1a. PVNGS Core Damage Frequency for Internal Events ......................................... F-3

Table F-1b. Important PVNGS Fire Compartments and their Contribution to Fire CDF .......... F-4

Table F-2. Breakdown of Population Dose by Containment Release Mode ............................ F-5

Table F-3. PVNGS PRA Historical Summary .......................................................................... F-7

Table F-5. SAMA Cost/Benefit Screening Analysis for PVNGS ............................................ F-23
 

December 2010 xi NUREG-1437, Supplement 43 

EXECUTIVE SUMMARY 

BACKGROUND 

By letter dated December 11, 2008, Arizona Public Service Company (APS) submitted an 

application to the U.S. Nuclear Regulatory Commission (NRC) to issue a renewed operating 

license for the Palo Verde Nuclear Generating Station (PVNGS), for an additional 20-year 

period. 

Pursuant to Title 10, Part 51.20(b)(2) of the Code of Federal Regulations (10 CFR 51.20(b)(2)), 

the Commission indicates that a renewal of a power reactor operating license requires 

preparation of an environmental impact statement (EIS) or a supplement to an existing EIS. In 

addition, 10 CFR 51.95(c) states that the Commission shall prepare an EIS, which is a 

supplement to the Commission’s Generic Environmental Impact Statement for License Renewal 

of Nuclear Plants (GEIS), NUREG-1437, published in May 1996. 

Upon acceptance of APS’s application, the NRC staff began the environmental review process 

described in 10 CFR Part 51 by publishing a Notice of Intent to prepare a supplemental 

environmental impact statement (SEIS) and conduct scoping. In preparation of this SEIS for 

PVNGS, the NRC staff performed the following: 

• conducted public scoping meetings on June 25, 2009, in Tonopah and 

Avondale, AZ 

• conducted a site audit at the plant in October 2009 

• reviewed APS’s environmental report (ER) and compared it to the GEIS 

• consulted with other agencies 

• conducted a review of the issues following the guidance set forth in 

NUREG-1555, Standard Review Plans for Environmental Reviews for 

Nuclear Power Plants, Supplement 1: Operating License Renewal

(NRC 2000) 

• considered public comments received during the scoping process and draft 

SEIS comment period. 

PROPOSED ACTION 

APS initiated the proposed Federal action by submitting an application for license renewal of 

PVNGS, for which the existing licenses, NPF-41, NPF-51, and NPF-74, expire on June 1, 2025 

(Unit 1), April 24, 2026 (Unit 2), and November 25, 2027 (Unit 3). The NRC’s Federal action is 

the decision whether to renew these licenses for an additional 20 years. 

PURPOSE AND NEED FOR ACTION 

The purpose and need for the proposed action (issuance of renewed licenses) is to provide an 

option that allows for power generation capability beyond the term of a current nuclear power 

plant operating license to meet future system generating needs, as such needs may be 

determined by State, utility, and, where authorized, Federal (other than NRC) decision makers. 

This definition of purpose and need reflects the Commission’s recognition that, unless there are 

findings in the safety review required by the Atomic Energy Act or findings in the National 
Executive Summary 

NUREG-1437, Supplement 43 xii December 2010 

Environmental Policy Act (NEPA) environmental analysis that would lead the NRC to reject a 

license renewal application, the NRC does not have a role in the energy-planning decisions of 

State regulators and utility officials as to whether a particular nuclear power plant should 

continue to operate. 

If the renewed licenses are issued, State regulatory agencies and APS will ultimately decide 

whether the plants will continue to operate based on factors such as the need for power or other 

matters within the State’s jurisdiction or the purview of the owners. If the operating licenses are 

not renewed, then the facility must be shut down on or before the expiration date of the current 

operating licenses. 

ENVIRONMENTAL IMPACTS OF LICENSE RENEWAL 

The SEIS evaluates the potential environmental impacts of the proposed action. The 

environmental impacts from the proposed action are designated as SMALL, MODERATE, or 

LARGE. As set forth in the GEIS, Category 1 (generic) issues are those that meet all of the 

following criteria: 

(1) The environmental impacts associated with the issue is determined to apply either to all 

plants or, for some issues, to plants having a specific type of cooling system or other 

specified plant or site characteristics. 

(2) A single significance level (i.e., SMALL, MODERATE, or LARGE) has been assigned to 

the impacts, except for collective offsite radiological impacts from the fuel cycle and from 

high-level waste and spent fuel disposal. 

(3) Mitigation of adverse impacts associated with the issue is considered in the analysis and 

it has been determined that additional plant-specific mitigation measures are likely not to 

be sufficiently beneficial to warrant implementation. 

For Category 1 issues, no additional site-specific analysis is required in this SEIS unless new 

and significant information is identified. Chapter 4 of this report presents the process for 

identifying new and significant information. Site-specific issues (Category 2) are those that do 

not meet one or more of the criterion for Category 1 issues; therefore, an additional 

site-specific review for these non-generic issues is required, and the results are documented in 

the SEIS. The NRC staff has reviewed APS’s established process for identifying and evaluating 

the significance of any new and significant information on the environmental impacts of license 

renewal of PVNGS. Neither APS nor the NRC identified information that is both new and 

significant related to Category 1 issues that would call into question the conclusions in the 

GEIS. Similarly, neither the scoping process nor the NRC staff has identified any new issue 

applicable to PVNGS that has a significant environmental impact. The NRC staff, therefore, 

relies upon the conclusions of the GEIS for all Category 1 issues applicable to PVNGS. 

LAND USE 

SMALL. The NRC staff did not identify any Category 2 issues for land use, nor did the staff 

identify any new and significant information during the environmental review. Therefore, for 

plant operation during the license renewal term, there are no impacts beyond those discussed in 

the GEIS. 
Executive Summary 

December 2010 xiii NUREG-1437, Supplement 43 

AIR QUALITY 

SMALL. The NRC did not identify any Category 2 issues for air quality impacts, nor did the staff 

identify any new or significant information during the environmental review. Therefore, for plant 

operation during the license renewal term, there are no impacts beyond those discussed in the 

GEIS. 

GROUNDWATER USE AND QUALITY 

SMALL. The staff did not identify any new and significant information in regard to Category 1 

groundwater issues. Potential groundwater use conflicts for PVNGS are considered a Category 

2 issue that requires a plant-specific assessment. Because PVNGS pumps groundwater at 

rates well below its authorized water right and uses less than 1 percent of annual demand for 

groundwater in the Phoenix Active Management Area, the NRC staff concludes that impacts 

due to groundwater use conflicts would be SMALL. Therefore, for plant operation during the 

license renewal term, there are no impacts beyond those discussed in the GEIS. 

SURFACE WATER USE AND QUALITY 

SMALL. PVNGS does not draw its cooling (or makeup) water directly from any natural surface 

water body. Instead, it uses treated wastewater effluent from the Phoenix area. PVNGS does 

not release cooling water to any natural surface water body. Instead, cooling water is 

discharged to man-made lined evaporation ponds with no outlet and no hydraulic connection to 

any natural water body. As a result, none of the Category 1 or 2 issues set forth in the GEIS 

apply to this facility. The staff did not identify any new information and issues during its review. 

Therefore, the NRC staff concludes that the impact of surface water use and quality are SMALL. 

AQUATIC RESOURCES 

SMALL. PVNGS does not draw its cooling (or makeup) water directly from any natural surface 

water body. Instead, it uses treated wastewater effluent from the Phoenix area. PVNGS does 

not release cooling water to any natural surface water body. Instead, cooling water is 

discharged to man-made lined evaporation ponds with no outlet and no hydraulic connection to 

any natural water body. No impingement, entrainment, or heat shock impacts to aquatic 

species result from plant operation. The staff did not identify any new information and issues 

during its review. Therefore, for plant operation during the license renewal term, there are no 

impacts beyond those discussed in the GEIS. 

TERRESTRIAL RESOURCES 

SMALL. The NRC staff identified no Category 2 issues related to terrestrial resources for 

license renewal. The NRC staff did not identify any additional new and significant information 

during review of the APS’s ER, the site audit, the scoping process, or the evaluation of other 

available information. Therefore, for plant operation during the license renewal term, there are 

no impacts beyond those discussed in the GEIS. 

THREATENED AND ENDANGERED SPECIES 

SMALL. The NRC staff identified no Category 2 issues related to threatened and endangered 

species for license renewal. The NRC staff did not identify any additional new and significant 

information during review of the APS’s ER, the site audit, the scoping process, or the evaluation 

of other available information. Therefore, for plant operation during the license renewal term, 

there are no impacts beyond those discussed in the GEIS. 
Executive Summary 

NUREG-1437, Supplement 43 xiv December 2010 

HUMAN HEALTH 

SMALL. The NRC staff’s review of the historical radioactive releases from PVNGS and the 

resultant dose calculation demonstrate that PVNGS is operating in compliance with Federal 

radiation protection standards. Continued compliance with regulatory requirements is expected 

during the license renewal term. Therefore, the impacts from radioactive effluents are not 

expected to change during the license renewal term. 

The NRC staff did not identify any new and significant information during its review. Therefore, 

for plant operation during the license renewal term, there are no impacts beyond those 

discussed in the GEIS. 

SOCIOECONOMICS 

SMALL. For Category 1 issues (public services and aesthetic impacts), the NRC staff identified 

no new and significant information during the environmental review. Therefore, there would be 

no impacts beyond those discussed in the GEIS. Category 2 socioeconomic impacts include 

housing impacts, public services (public utilities), offsite land use, public services (public 

transportation), and historic and archaeological resources. 

Since APS has no plans to add additional employees during the license renewal period except 

during outages, employment levels at PVNGS would remain relatively constant with no 

additional demand for permanent housing during the license renewal term. Based on this 

information, there would be no impact on housing during the license renewal term beyond what 

has already been experienced. 

For the same reason, demand for public water services will remain relatively unchanged with no 

additional demand. Public water systems in the region would be adequate to meet the 

demands of residential and industrial customers in the area. Therefore, there would be no 

additional impact to public water services during the license renewal term beyond what is 

currently being experienced. 

Since non-outage employment levels at PVNGS would remain relatively constant during the 

license renewal period, there would be no land use impacts related to population or tax 

revenues, and no transportation impacts. Therefore, offsite land use and transportation issues 

would remain relatively unchanged. 

No impacts to known historic and archaeological resources are expected from the continued 

operation of PVNGS during the license renewal term. This conclusion is based on the results of 

archaeological surveys conducted on the property prior to initial plant and transmission line 

construction; review of Arizona State Historic Preservation Office (SHPO) files, published 

literature, and information provided by APS; and, verified use of existing environmental 

procedures by PVNGS. 

In reviewing potential social environmental justice impacts (i.e., potential disproportionately high 

and adverse human health and environmental impacts on minority and low-income populations), 

an analysis of minority and low-income populations residing within a 50-mile (80-kilometer) 

radius of PVNGS indicated there would be no disproportionately high and adverse impacts to 

these populations from the continued operation of PVNGS during the license renewal period. 

Based on recent monitoring results, concentrations of contaminants in air, leafy vegetation, milk, 

water, sludge and sediment, in areas surrounding PVNGS have been low (at or near the 

threshold of detection) and seldom above background levels. Consequently, no 
Executive Summary 

December 2010 xv NUREG-1437, Supplement 43 

disproportionately high and adverse human health impacts are expected in special pathway 

receptor populations in the region as a result of subsistence consumption. 

SEVERE ACCIDENT MITIGATION ALTERNATIVES 

Since PVNGS had not previously considered alternatives to reduce the likelihood or potential 

consequences of a variety of highly uncommon but potentially serious accidents, NRC 

regulation 10 CFR 51.53(c)(3)(ii)(L) requires that PVNGS evaluate Severe Accident Mitigation 

Alternatives (SAMAs) in the course of the license renewal review. SAMAs are potential ways to 

reduce the risk or potential impacts of uncommon but potentially severe accidents and may 

include changes to plant components, systems, procedures, and training. 

The NRC staff reviewed the ER’s evaluation of potential SAMAs. Based on the staff’s review, 

the NRC staff concluded that none of the potentially cost-beneficial SAMAs relate to managing 

the effects of aging during the period of extended operation. Therefore, they need not be 

implemented as part of the license renewal pursuant to 10 CFR Part 54. 

ALTERNATIVES 

The NRC staff considered the environmental impacts associated with alternatives to license 

renewal. These alternatives include other methods of power generation and not renewing the 

PVNGS operating licenses (the no-action alternative). Replacement power options considered 

were supercritical coal-fired generation, natural gas combined-cycle generation, new nuclear 

generation, and a combination alternative that includes a portion of the combined-cycle 

gas-fired capacity, a conservation capacity component, and a solar power component. The 

NRC staff initially considered a number of additional alternatives for analysis as alternatives to 

license renewal of PVNGS; these were later dismissed due to technical, resource availability, or 

commercial limitations that currently exist and that the NRC staff believes are likely to continue 

to exist when the existing PVNGS licenses expire. The no-action alternative by the NRC staff 

and the effects it would have were also considered. The NRC staff evaluated each alternaqtive 

using the same impact areas that were used in evaluating impacts from license renewal. The 

results of this evaluation are summarized in the table on page 7 of this Executive Summary. 

COMPARISON OF ALTERNATIVES 

The coal-fired alternative would have the greatest overall adverse environmental impact. This 

alternative would result in MODERATE waste management and air quality impacts from 

nitrogen oxides, sulfur oxides, particulate matter, polycyclic aromatic hydrocarbons, carbon 

monoxide, carbon dioxide, and mercury (and the corresponding human health impacts). 

The gas-fired alternative would result in SMALL impacts in all areas. This alternative would 

result in substantially lower air emissions, and lesser amounts of operational wastes than the 

coal-fired alternative. Gas-fired generation would release greenhouse gases, in lesser 

quantities per unit of power produced than the coal-fired alternative, but in significantly greater 

quantities than would result from continued operation of the PVNGS reactors. 

Although impacts of installing and operating new nuclear-generating capacity on the PVNGS 

would be SMALL for all impact categories, there would be impacts during construction that 

would not occur if operation of the existing reactors were to continue under license renewal. 

The combination alternative would have lower air emissions and waste management impacts 

than both the gas-fired and coal-fired alternatives, however it would have relatively higher 
Executive Summary 

NUREG-1437, Supplement 43 xvi December 2010 

construction impacts in terms of land use, and potential disruption to historic and archaeological 

resources, mainly as a result of construction of the solar portions of the combination alternative 

which is likely to occur in areas off the PVNGS site. 

Under the No Action Alternative, plant shutdown would eliminate approximately 2200 jobs and 

would reduce tax revenue in the region. The loss of these contributions, which may not entirely 

cease until after decommissioning, would have a SMALL impact. However, the no-action 

alternative does not meet the purpose and need stated in this SEIS. 

Of the alternatives that meet the purpose and need for this SEIS, the natural gas-fired 

alternative, the new nuclear alternative, and the continued operation of PVNGS all have SMALL 

environmental impacts. Given the need to construct new facilities for gas-fired and new nuclear 

alternatives, however, NRC staff concludes that continued operation of the existing PVNGS is 

the environmentally-preferred alternative. 

Summary of Environmental Impacts of Proposed Action and Alternatives 

Alternative 

Impact Area 

Air Quality 

Groundwater 

Surface Water 

Aquatic and 

Terrestrial 

Resources 

Human Health 

Socioeconomics 

Waste Management 

License renewal SMALL SMALL SMALL SMALL SMALL SMALL SMALL 

Supercritical 

coal-fired 

alternative at 

the PVNGS site 

MODERATE SMALL SMALL SMALL SMALL SMALL to 

MODERATE MODERATE 

Gas-fired 

alternative at 

the PVNGS site 

SMALL SMALL SMALL SMALL SMALL SMALL SMALL 

New Nuclear 

alternative at 

the PVNGS site 

SMALL SMALL SMALL SMALL SMALL SMALL SMALL 

Combination of 

alternatives 

SMALL SMALL MODERATE 

to LARGE SMALL SMALL 

SMALL to 

MODERATE SMALL 

No-action 

alternative 

SMALL SMALL SMALL SMALL SMALL SMALL SMALL 
Executive Summary 

December 2010 xvii NUREG-1437, Supplement 43 

RECOMMENDATION 

The Nuclear Regulatory Commission’s recommendation is that the adverse environmental 

impacts of license renewal for PVNGS are not great enough to deny the option of license 

renewal for energy-planning decision makers. This determination is based on (1) the analysis 

and findings in the Generic Environmental Impact Statement for License Renewal of Nuclear 

Plants (GEIS), NUREG-1437; (2) the Environmental Report submitted by APS; (3) consultation 

with Federal, State, and local agencies; (4) the NRC staff’s own independent review; and (5) the 

NRC staff’s consideration of public comments received during the scoping process and draft 

SEIS comment period.
 
 

December 2010 xix NUREG-1437, Supplement 43 

ABBREVIATIONS AND ACRONYMS 

AAC Arizona Administrative Code 

AADT average annual daily traffic 

ac acre 

ADAMS Agencywide Documents Access and Management System 

ADEM Arizona Division of Emergency Management 

ADEQ Arizona Department of Environmental Quality 

ADEQPPP Arizona Department of Environmental Quality Pollution Prevention 

Program 

ADWR Arizona Department of Water Resources 

AEA Atomic Energy Act of 1954 

AEC U.S. Atomic Energy Commission 

AERC Arizona Emergency Response Commission 

AGFD Arizona Game and Fish Department 

ALARA as low as reasonably achievable 

AMA Active Management Area 

AMSL above mean sea level 

ANSI American National Standards Institute 

APE area of potential effect 

APP Aquifer Protection Permit 

APS Arizona Public Service Company 

AQL aquifer quality limit 

AQCR Air Quality Control Region 

AQRVs air quality-related values 

ARS Arizona Revised Statutes 

AWQS Arizona Water Quality Standards 

BACT best available control technology 

BP before present 

Btu British thermal unit 

Btu/ft3

 British thermal unit per cubic feet 

Btu/kWh British thermal unit per kilowatt-hour 

Btu/lb British thermal unit per pound 

BWR boiling-water reactor 
Abbreviations and Acronyms 

NUREG-1437, Supplement 43 xx December 2010 

CAA Clean Air Act 

CDFG California Department of Fish and Game 

CDF core damage frequency 

CEQ Council on Environmental Quality 

CERCLA Comprehensive Environmental Response, Compensation, and 

Liability 

CFR Code of Federal Regulations

cfs cubic feet per second 

CH4 methane 

cm centimeter 

cm/s centimeter per second 

CO carbon monoxide 

CO2 carbon dioxide 

CWA Clean Water Act 

dBA decibels adjusted 

DBA design-basis accident 

DNR Department of Natural Resources 

DOE Department of Energy 

DOT Department of Transportation 

DSEIS draft supplemental environmental impact statement 

DSM demand-side management 

E.O. Executive Order 

EDG emergency diesel generator 

EIA Energy Information Administration 

EIS environmental impact statement 

ELF-EMF extremely low frequency-electromagnetic field 

EMF electromagnetic fields 

EMS environmental management system 

EOP emergency operating procedure 

EPA Environmental Protection Agency 

EPCRA Emergency Planning and Community Right-to-Know Act 

EPRI Electric Power Research Institute 
Abbreviations and Acronyms 

December 2010 xxi NUREG-1437, Supplement 43 

EPZ emergency planning zone 

ER environmental report 

ERFDADS Emergency Response Facility Data Acquisition Display System 

ESA Endangered Species Act 

ESPS Essential Spray Pond System 

ESRP Environmental Standard Review Plan 

F&O fact and observation 

FES final environmental statement 

FLMs Federal Land Managers 

FR Federal Register

FSAR final safety analysis report 

ft foot 

ft/min feet per minute 

ft3

 cubic feet 

g Ceq/kWh grams of CO2 equivalents per kilowatt-hour 

GEIS generic environmental impact statement 

GHG greenhouse gas 

gpm gallons per minute 

GWP global warming potential 

Gy/d grays per day 

ha hectare 

HAP hazardous air pollutant 

HFC hydrofluorocarbons 

HFE hydrofluorinated ethers 

Hg mercury 

HLW high-level waste 

HVAC heating, ventilation, and air conditioning 

IAEA International Atomic Energy Agency 

IEEE Institute of Electrical and Electronics Engineers 

IGCC integrated gasification combined-cycle 

Inc. incorporated 
Abbreviations and Acronyms 

NUREG-1437, Supplement 43 xxii December 2010 

IPCC Intergovernmental Panel on Climate Change 

IPE individual plant examination 

IPEEE individual plant examination of external events 

ISFSI independent spent fuel storage installation 

J joule 

kg kilogram 

km kilometer 

km2

 square kilometer 

kmh kilometer per hour 

kPa kilopascal 

kV kilovolt 

kWh kilowatt-hour 

lb pound 

lb/MWh pound per megawatt-hour 

LERF large early release frequency 

LLC limited liability corporation 

LLMW low-level mixed waste 

LLW low-level radioactive waste 

LOCA loss-of-coolant accident 

LOOP loss of offsite power 

m meter 

m/min meter per minute 

m/s meter per second 

m3

 cubic meter 

m3

/month cubic meter per month 

m3

/s cubic meter per second 

MACCS2 MELCOR Accident Consequence Code System 2 

MAG Maricopa Association of Governments 

MCAQD Maricopa County Air Quality Department 

MDTS meteorological data transmission station 

mg/L milligrams per liter 
Abbreviations and Acronyms 

December 2010 xxiii NUREG-1437, Supplement 43 

mgd million gallons per day 

mGy milligray 

mGy/d milligray per day 

mi mile 

mi2

 square mile 

MOU Memorandum of Understanding 

mph mile per hour 

mrad millirad 

mrem millirem 

MSA Magnuson-Stevens Fishery Conservation and Management Act of 

1996 

msl mean sea level 

MSPI Mitigating System Performace Index 

mSv millisievert 

MT metric tones 

MVAC motor vehicle air conditioners 

MW megawatt 

MWd/MTU megawatt-days per metric ton uranium 

MWe megawatt-electric 

MWt megawatt-thermal 

N2O nitrous oxide 

NA not applicable 

NAAQS National Ambient Air Quality Standards 

NAS National Academy of Sciences 

NCDC National Climatic Data Center 

NEI Nuclear Energy Institute 

NEPA National Environmental Policy Act of 1969 

NESC National Electric Safety Code 

NF3 nitrogen triflouride 

ng nanograms 

NHPA National Historic Preservation Act 

NIEHS National Institute of Environmental Health Sciences 

NMFS National Marine Fisheries Service 

NO2 nitrogen dioxide 
Abbreviations and Acronyms 

NUREG-1437, Supplement 43 xxiv December 2010 

NOAA National Oceanic and Atmospheric Administration 

NOx nitrogen oxide(s) 

NOV Notices of Violation 

NPDES National Pollutant Discharge Elimination System 

NRC U.S. Nuclear Regulatory Commission 

NRHP National Register of Historic Places 

NWS National Weather Service 

ODAM Offsite Dose Assessment Manual 

ODCM Offsite Dose Calculation Manual 

OMB Office of Management and Budget 

PAH polycyclic aromatic hydrocarbon 

PCB polychlorinated biphenyl 

pCi/L picocuries per liter 

PFC perfluorocarbons 

PM particulate matter 

PM10 particulate matter, 10 microns or less in diameter 

PM2.5 particulate matter, 2.5 microns or less in diameter 

PMF probably maximum flood 

PPP Pollution Prevention Plan 

ppt parts per thousand 

PRA probabilistic risk assessment 

PSD Prevention of Significant Deterioration 

PTE potential to emit 

PVNGS Palo Verde Nuclear Generating Station 

PWR pressurized water reactor 

Rad radiation absorbed dose 

rad/d radiation absorbed dose per day 

RAI request for additional information 

RCRA Resource Conservation and Recovery Act 

RCS reactor coolant system 

Rem roentgen equivalent man 

REMP radiological environmental monitoring program 
Abbreviations and Acronyms 

December 2010 xxv NUREG-1437, Supplement 43 

RHR residual heat removal 

ROI region of influence 

ROW(s) right-of-way(s) 

RPS reactor protection system 

RPV reactor pressure vessel 

SAAQS State Ambient Air Quality Standards 

SAMA Severe Accident Mitigation Alternative 

SAR safety analysis report 

SBO station blackout 

SC species of concern 

SCE Southern California Edison 

SCR selective catalytic reduction 

SEIS supplemental environmental impact statement 

SER safety evaluation report 

SF6 sulfur hexafluoride 

SGTR steam generator tube rupture 

SHPO State Historic Preservation Office 

SIP State Implementation Plan 

SO2 sulfur dioxide 

SO3 sulfur trioxide 

SOx sulfur oxide(s) 

sq square 

SQG small quantity generator 

SRP Salt River Project 

STP Sewage Treatment Plant 

Sv sievert 

TCLP Toxicity Characteristic Leaching Procedure 

TDS total dissolved solids 

TSP total suspended particles 

TSS total suspended solids 

U Uranium 

U.S. United States 
Abbreviations and Acronyms 

NUREG-1437, Supplement 43 xxvi December 2010 

U.S.C. United States Code

USCB U.S. Census Bureau 

USDA U.S. Department of Agriculture 

USFWS U.S. Fish and Wildlife Service 

USGCRP United States Global Change Research Program 

USGS U.S. Geological Survey 

USI unresolved safety issue 

V volt 

VOC volatile organic compound 

WGA Western Governors Association 

WHO World Health Organization 

WRF Water Reclamation Facility 

WSR Water Storage Reservoir 

WTF Wastewater Treatment Facility 

yd3

 cubic yard 

yd3

/month cubic yard per month 
 

December 2010 1-1 NUREG-1437, Supplement 43

1.0 PURPOSE AND NEED FOR ACTION 

Under the U.S. Nuclear Regulatory Commission’s (NRC’s) environmental protection regulations 

in Title 10, Part 51, “Environmental Protection Regulations for Domestic Licensing and Related 

Regulatory Functions,” of the Code of Federal Regulations (10 CFR Part 51), which implement 

the National Environmental Policy Act (NEPA), renewal of a nuclear power plant operating 

license requires the preparation of an environmental impact statement (EIS). 

The Atomic Energy Act of 1954 originally specified that licenses for commercial power reactors 

be granted for up to 40 years with an option to renew for another 20 years. The 40-year 

licensing period was based on economic and antitrust considerations rather than on technical 

limitations of the nuclear facility. 

The decision to seek license renewal rests entirely with nuclear power facility owners and 

typically is based on the facility’s economic viability and the investment necessary to continue to 

meet NRC safety and environmental requirements. The NRC makes the decision to grant or 

deny a license renewal application, based on whether the applicant has demonstrated that the 

environmental and safety requirements in the agency’s regulations can be met during the period 

of extended operation. 

1.1 PROPOSED FEDERAL ACTION 

Arizona Public Service Company (APS) initiated the proposed Federal action by submitting an 

application for license renewal of Palo Verde Nuclear Generating Station (PVNGS), for which 

the existing licenses, NPF-41, NPF-51, and NPF-74, expire on June 1, 2025 (Unit 1), April 24, 

2026 (Unit 2), and November 25, 2027 (Unit 3). The NRC’s Federal action is the decision 

whether to renew these licenses for an additional 20 years. 

1.2 PURPOSE AND NEED FOR THE PROPOSED FEDERAL ACTION 

The purpose and need for the proposed action (issuance of a renewed license) is to provide an 

option that allows for power generation capability beyond the term of a current nuclear power 

plant operating license to meet future system generating needs, as such needs may be 

determined by State, utility, and, where authorized, Federal (other than NRC) decision makers. 

This definition of purpose and need reflects the Commission’s recognition that, unless there are 

findings in the safety review required by the Atomic Energy Act or findings in the NEPA 

environmental analysis that would lead the NRC to reject a license renewal application, the 

NRC does not have a role in the energy-planning decisions of State regulators and utility 

officials as to whether a particular nuclear power plant should continue to operate. 

If the renewed licenses are issued, State regulatory agencies and APS will ultimately decide 

whether the plants will continue to operate based on factors such as the need for power or other 

matters within the State’s jurisdiction or the purview of the owners. If the operating licenses are 

not renewed, then the facility must be shut down on or before the expiration date of the current 

operating license, June 1, 2025 (for Unit 1), April 24, 2026 (for Unit 2), and November 25, 2027 

(for Unit 3). 
Purpose and Need for Action 

NUREG-1437, Supplement 43 1-2 December 2010

1.3 MAJOR ENVIRONMENTAL REVIEW MILESTONES 

APS submitted an environmental report (APS 2008a) as part of its license renewal application 

(APS 2008) in December 2008. After reviewing the application and the environmental report for 

sufficiency, the NRC staff published a Notice of Acceptability and Opportunity for Hearing on 

May 15, 2009, in the Federal Register (74 FR 22978-81). Then, on May 26, 2009, the NRC 

published another notice in the Federal Register (74 FR 24884-6) on its intent to conduct 

scoping, thereby beginning the 60-day scoping period. 

The agency held two public scoping meetings on June 25, 2009, near the PVNGS site. The 

NRC report entitled, “Environmental Impact Statement Scoping Process Summary Report for 

Palo Verde Nuclear Generating Station, Units 1, 2 and 3,” dated April 2010, presents the 

comments received during the scoping 

process in their entirety (NRC 2010). 

Appendix A to this Supplemental 

Environmental Impact Statement (SEIS) 

presents the comments considered to 

be within the scope of the 

environmental license renewal review 

and the associated NRC responses. 

To independently verify information 

provided in the environmental report, 

the NRC staff conducted a site audit at 

PVNGS from October 26 – 30, 2009. 

During the site audit, staff met with plant 

personnel; reviewed specific 

documentation; toured the facility; and 

met with interested Federal, State, and 

local agencies. 

Upon completion of the scoping period 

and site audit, the staff compiled its 

findings in the draft SEIS (Figure 1-1). 

This document was made available for 

public comment for 70 days. During this 

time, NRC staff hosted two public 

meetings and collected public 

comments. Based on the information 

gathered, the staff amended the draft 

SEIS and then published this final SEIS. 

The NRC has established a license 

renewal process that can be completed 

in a reasonable period of time with clear 

requirements to ensure safe plant 

operation for up to an additional 20 

years of plant life. The safety review is 

conducted simultaneously with the 

environmental review. The staff 

documents the findings of the safety Figure 1-1. Environmental Review Process. The 

process provides opportunities for public involvement.
Purpose and Need for Action

December 2010 1-3 NUREG-1437, Supplement 43

Significance indicates the importance 

of likely environmental impacts and is 

determined by considering two 

variables: context and intensity. 

Context is the geographic, 

biophysical, and social context in 

which the effects will occur. 

Intensity refers to the severity of the 

impact, in whatever context it occurs. 

review in a safety evaluation report. The 

Commission considers the findings in both the 

supplemental EIS and the safety evaluation 

report in its decision to either grant or deny the 

issuance of a renewed license. 

1.4 GENERIC ENVIRONMENTAL 

IMPACT STATEMENT 

The NRC performed a generic assessment of 

the environmental impacts associated with 

license renewal to improve the efficiency of the 

license renewal process. NUREG-1437, 

Generic Environmental Impact Statement for 

License Renewal of Nuclear Power Plants (referred to as the GEIS), documents the results of 

NRC staff’s systematic approach to evaluating environmental consequences for renewing the 

licenses of individual nuclear power plants and operating them for an additional 20 years (NRC 

1996, 1999)1

. The NRC staff analyzed in detail and resolved those environmental issues that 

could be resolved generically in the GEIS. 

The GEIS establishes 92 separate issues for the NRC staff to independently verify. Of these, 

the staff determined that 69 are generic to all plants (Category 1), while 21 issues do not lend 

themselves to generic consideration (Category 2). Two other issues remained uncategorized; 

environmental justice and the chronic effects of electromagnetic fields must be evaluated on a 

site-specific basis. Appendix B to this report lists all 92 issues. 

For each potential environmental issue, the GEIS (1) describes the activity that affects the 

environment, (2) identifies the population or resource that is affected, (3) assesses the nature 

and magnitude of the impact on the affected population or resource, (4) characterizes the 

significance of the effect for both beneficial and adverse effects, (5) determines whether the 

results of the analysis apply to all plants, and (6) considers whether additional mitigation 

measures would be warranted for impacts that would have the same significance level for all 

plants. 

The NRC’s standard of significance for impacts was established using the Council on 

Environmental Quality terminology for “significant.” The NRC established three levels of 

significance for potential impacts—SMALL, MODERATE, and LARGE, as defined below. 

SMALL – Environmental effects are not detectable or are so minor that they will neither 

destabilize nor noticeably alter any important attribute of the resource. 

MODERATE – Environmental effects are sufficient to alter noticeably, but not to destabilize, 

important attributes of the resource. 

LARGE – Environmental effects are clearly noticeable and are sufficient to destabilize important 

attributes of the resource. 

 

1

 The NRC originally issued the GEIS in 1996 and issued Addendum 1 to the GEIS in 1999. Hereafter, 

all references to the “GEIS” include the GEIS and Addendum 1. 
Purpose and Need for Action 

NUREG-1437, Supplement 43 1-4 December 2010

The GEIS includes a determination of whether the analysis of the environmental issue could be 

applied to all plants and whether additional mitigation measures would be warranted 

(Figure 1-2). Issues are assigned a Category 1 or a Category 2 designation. As set forth in the 

GEIS, Category 1 issues are those that meet all of the following criteria: 

(1) The environmental impacts associated with the issue have been determined to apply 

either to all plants or, for some issues, to plants having a specific type of cooling system 

or other specified plant or site characteristics; 

(2) A single significance level (i.e., SMALL, MODERATE, or LARGE) has been assigned to 

the impacts (except for collective offsite radiological impacts from the fuel cycle and from 

high-level waste and spent fuel disposal); and 

(3) Mitigation of adverse impacts associated with the issue has been considered in the 

analysis, and it has been determined that additional plant-specific mitigation measures 

are likely not to be sufficiently beneficial to warrant implementation. 

For generic issues (Category 1), no additional site-specific analysis is required in this SEIS 

unless new and significant information is identified. Chapter 4 of this report presents the 

process for identifying new and significant information. Site-specific issues (Category 2) are 

those that do not meet one or more of the criterion for Category 1 issues, and therefore, 

additional site-specific review for these issues is required. The SEIS documents the results of 

that site-specific review. 
Purpose and Need for Action

December 2010 1-5 NUREG-1437, Supplement 43

Figure 1-2. Environmental Issues Evaluated During License Renewal. 92 issues were 

initially evaluated in the GEIS. A site-specific analysis is required for 23 of those 92 issues.

1.5 SUPPLEMENTAL ENVIRONMENTAL IMPACT STATEMENT 

The SEIS presents an analysis that considers the environmental effects of the continued 

operation of PVNGS, alternatives to license renewal, and mitigation measures for minimizing 

adverse environmental impacts. Chapter 8 analyzes and compares the potential environmental 

impacts from alternatives, while Chapter 9 presents the recommendation to the Commission as 

to whether or not the environmental impacts of license renewal are so great that preserving the 

option of license renewal would be unreasonable. The recommendation was made after 

consideration of comments received during the public scoping period and on the draft SEIS. 

In the preparation of this SEIS for PVNGS, the staff undertook the following activities: 

• reviewed the information provided in the APS environmental report; 

• consulted with other Federal, State, and local agencies; 

• conducted an independent review of the issues during the site audit; and 

• considered the public comments received during the scoping process and on 

the draft SEIS.
Purpose and Need for Action 

NUREG-1437, Supplement 43 1-6 December 2010

New and significant information either: 

(1) identifies a significant environmental issue 

not covered in the GEIS, or (2) was not 

considered in the analysis in the GEIS and 

leads to an impact finding that is different from 

the finding presented in the GEIS. 

New information can be identified from a 

number of sources, including the applicant, the 

NRC, other agencies, or public comments. If a 

new issue is revealed, then it is first analyzed to 

determine whether it is within the scope of the 

license renewal evaluation. If it is not 

addressed in the GEIS then the NRC 

determines its significance and documents its 

analysis in the SEIS. 

1.6 COOPERATING AGENCIES 

During the scoping process, no Federal, State, or local agencies were identified as cooperating 

agencies in the preparation of this SEIS. 

1.7 CONSULTATIONS 

The Endangered Species Act of 1973, as amended; the Magnuson-Stevens Fisheries 

Conservation and Management Act of 1996, as amended; and the National Historic 

Preservation Act of 1966 require that Federal agencies consult with applicable State and 

Federal agencies and groups before taking action that may affect endangered species, 

fisheries, or historic and archaeological resources, respectively. Below are the agencies and 

groups with whom the NRC consulted; Appendix D to this report includes copies of consultation 

documents. 

Agua Caliente Tribal Council, Palm Springs, California 

Ak Chin Indian Community Council, Maricopa, Arizona 

Arizona Game and Fish Department, Phoenix, Arizona 

Arizona Radiation Regulatory Agency, Phoenix, Arizona 

Arizona State Parks, Officer of Historic Preservation, Phoenix, Arizona 

City of Phoenix, Office of Environmental Programs, Phoenix, Arizona 

Colorado River Tribal Council, Parker, Arizona 

Fort McDowell Yavapai Tribal Council, Fountain Hills, Arizona 

Fort Yuma-Quechan Tribal Council, Yuma, Arizona 

Gila River Indian Community Council, Sacaton, Arizona 

Maricopa County Board of Supervisors, Phoenix, Arizona 

Pascua Yaqui Tribe, Tucson, Arizona 

Salt River Pima-Maricopa Indian Community Council, Scottsdale, Arizona 

San Carlos Tribal Council, San Carlos, Arizona 

Tohono O’odham Nation, Sells, Arizona 

Tonto Apache Tribe, Payson, Arizona 

U.S. Environmental Protection Agency, Region IX, Environmental Review Office 

Communities and Ecosystems Division, San Francisco, California 

U.S. Department of the Interior, U.S. Fish and Wildlife Service, Arizona Ecological 

Services Field Office, Phoenix, Arizona 

White Mountain Apache Tribe, Whiteriver, Arizona 

Yavapai-Apache Nation Tribal Council, Camp Verde, Arizona 

Yavapai-Prescott Board of Directors, Prescott, Arizona

1.8 CORRESPONDENCE 

During the course of the environmental review, the NRC staff contacted the following Federal, 
Purpose and Need for Action

December 2010 1-7 NUREG-1437, Supplement 43

State, regional, local, and tribal agencies. Appendix E to this report contains a chronological list 

of all documents sent and received during the environmental review. 

Agua Caliente Tribal Council, Palm Springs, California 

Ak Chin Indian Community Council, Maricopa, Arizona 

Arizona Game and Fish Department, Phoenix, Arizona 

Arizona Radiation Regulatory Agency, Phoenix, Arizona 

Arizona State Parks, Officer of Historic Preservation, Phoenix, Arizona 

City of Phoenix, Office of Environmental Programs, Phoenix, Arizona 

Colorado River Tribal Council, Parker, Arizona 

Fort McDowell Yavapai Tribal Council, Fountain Hills, Arizona 

Fort Yuma-Quechan Tribal Council, Yuma, Arizona 

Gila River Indian Community Council, Sacaton, Arizona 

Maricopa County Board of Supervisors, Phoenix, Arizona 

Pascua Yaqui Tribe, Tucson, Arizona 

Salt River Pima-Maricopa Indian Community Council, Scottsdale, Arizona 

San Carlos Tribal Council, San Carlos, Arizona 

Tohono O’odham Nation, Sells, Arizona 

Tonto Apache Tribe, Payson, Arizona 

U.S. Environmental Protection Agency, Region IX, Environmental Review Office 

Communities and Ecosystems Division, San Francisco, California 

U.S. Department of the Interior, U.S. Fish and Wildlife Service, Arizona Ecological 

Services Field Office, Phoenix, Arizona 

White Mountain Apache Tribe, Whiteriver, Arizona 

Yavapai-Apache Nation Tribal Council, Camp Verde, Arizona 

Yavapai-Prescott Board of Directors, Prescott, Arizona 

A list of persons who received a copy of this SEIS is provided below: 

Steve Olea 

Arizona Corporation Commission 

Senior Counsel 

Law Department, Generation 

Resources 

Southern California Edison Company 

Senior Resident Inspector, 

Palo Verde Nuclear Generating 

Station 

U.S. Nuclear Regulatory 

Commission 

Regional Administrator, Region IV, 

NRC 

Director 

Arizona Radiation Regulatory 

Agency 

Director 

Regulatory Affairs 

Palo Verde NGS 

Chairman 

Maricopa County Board of 

Supervisors 

Vice President 

Regulatory Affairs and Plant 

Improvement, PVNGS 

Director, Nuclear 

 Generation 

El Paso Electric Company 

James Ray 

Public Service Company of New 

Mexico 

Geoffrey Cook 

Southern California Edison Company 

Jeffrey Weikert 

Assistant General Counsel 

El Paso Electric Company 

Eric Tharp 

Los Angeles Department of Water & 

Power 

Southern California Public Power 

Authority 

Brian Almon 

Public Utility Commission 

William B. Travis Building 

Austin, TX 

Environmental Program Manager 

City of Phoenix 

Office of Environmental Programs 

Chairman, Ak-Chin Indian 

Community 

Tom Kelly 

Environmental Review Office 

Communities and Ecosystems 

Division 

U.S. Environmental Protection 

Agency, Region IX 

Willian R. Rhodes, Governor Joseph 

Manual, Lt. Governor 

Gila River Indian Community Council 
Purpose and Need for Action 

NUREG-1437, Supplement 43 1-8 December 2010

Barb Painter John Arminger Stephen Brittle 

Margaret Cook, Director 

Department of Environmental Quality 

of the Gila River Indian Community 

Gila River Indian Community Council 

Randall Edington 

Executive Vice President 

Nuclear/CNO 

Arizona Public Service Company 

1.9 STATUS OF COMPLIANCE 

APS is responsible for complying with all NRC regulations and other applicable Federal, State, 

and local requirements; Appendix H to the GEIS describes some of the major Federal statutes. 

Table 1-1 lists the permits and licenses issued by Federal, State, and local authorities for 

activities at PVNGS. 

Table 1-1. Licenses and Permits. Existing environmental authorizations for PVNGS. 

Permit Number Dates Responsible 

Agency 

Operating License NPF-41 

Issued: 6/1/1985 

Expires: 6/1/2025 

U.S. NRC 

Operating License NPF-51 

Issued: 4/24/1986 

Expires: 4/24/2026 

U.S. NRC 

Operating License NPF-74 

Issued: 11/25/1987 

Expires: 11/25/2027 

U.S. NRC 

Aquifer Protection Permit 

(Operate PVNGS 

Facilities) 

P-3507-100388 

Issued: 03/14/2008 

Expires: End of facility life 

Arizona Department 

of Environmental 

Quality 

Aquifer Protection Permit (Operate 

Hassayampa Pump Station Holding 

Pond) 

P-105295 

Issued: 02/02/2004 

Expires: End of facility life 

Arizona Department 

of Environmental 

Quality 

Aquifer Protection Permit 

(Operate the WRSS Pipeline 

Temporary Chlorination Station) 

P-105317 

Issued: 04/06/2005 

Expires: End of facility life 

Arizona Department 

of Environmental 

Quality 

Type 3 Reclaimed 

Water General Permit R-105317 

Issued: 06/22/2005 

Expires: 03/24/2015 

Arizona Department 

of Environmental 

Quality 

WRF Laboratory License AZ0129 

Issued: annually 

Expires: End of April of 

each year 

Arizona Department 

of Health Services 

Central Laboratory License AZ0555 

Issued: annually 

Expires: End of April of 

each year 

Arizona Department 

of Health Services 

Approval to Operate 

(Evaporation Pond 1) 

Application 

No. 07.54 

Issued: 11/27/1992 

Expires: Not Listed 

Arizona Department 

of Water Resources 

Approval to Operate 

(Evaporation Pond 2) 

Application 

No. 07.62 

Issued: 12/12/1990 

Expires: Not Listed 

Arizona Department 

of Water Resources 
Purpose and Need for Action

December 2010 1-9 NUREG-1437, Supplement 43

Permit Number Dates Responsible 

Agency 

Type 1 Non-Irrigation 

Certificate of 

Grandfathered Groundwater Right 

58-114051.0001 

Issued: 09/13/1990 

Expires: Not Listed 

Arizona Department 

of Water Resources 

Irrigation Certificate of 

Grandfathered Groundwater Right 58-114058.0000 

Issued: 12/13/1983 

Expires: Not Listed 

Arizona Department 

of Water Resources 

Notice of Registration Certificate for 

Ionizing Radiation Machine 7/1/3340 

Issued: 02/13/2007 

Expires: 04/30/2014 

Arizona Radiation 

Regulatory Agency 

Special Approval (Disposal of Water 

Reclamation Facility Sludge) 

7-368 

(Category D18) 

Issued: 09/11/2008 

Expires: 04/30/2013 

Arizona Radiation 

Regulatory Agency 

Pipeline Repair & Maintenance (Repair 

work on the WRSS Pipeline) FA20020002 

Issued: 1/7/2002 

Expires: Not Listed 

Flood Control District 

of Maricopa County 

Dust Control/Demolition 

(Annual Block Permit) E100456 

Issued: Annual 

Expires: 03/19/2011 

Maricopa County Air 

Quality Department 

Non-Title V Air Permit 030132 

Issued: 08/18/2005 

Expires: 07/31/2010 

Maricopa County Air 

Quality Department 

Landfill 00008 Issued: Annually 

Expires: 04/30/2011 

Maricopa County 

Environmental 

Services Department 

Waste Water Treatment Plant 37148 

Issued: Annually 

Expires: 12/31/2010 

Maricopa County 

Environmental 

Services Department 

Water Public/Non-Community 07412 

Issued: Annually 

Expires: 12/31/2010 

Maricopa County 

Environmental 

Services Department 

Special Use - Construct a nuclear 

power electric generation facility 

Zoning Case 

Z 76-33 

Issued: 04/15/1976 

Expires: 04/15/2051 

Maricopa County 

Planning & Zoning 

Commission Services 

Department 

Special Use - Construct additional 

Evaporation Ponds 

south of the current ponds 

Zoning Case 

Z2006106 

Issued: 12/20/2006 

Expires: 04/15/2051 

Maricopa County 

Planning and 

Development 

Department 

1.10 REFERENCES 

10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

Protection Regulations for Domestic Licensing and Related Regulatory Functions.” 

74 FR 22978-81. U.S. Nuclear Regulatory Commission, Washington, D.C., “Notice of 

Acceptance for Docketing of the Application and Notice of Opportunity for Hearing Regarding 

Renewal of Facility Operating License Nos. NPF-41, NPF-51, and NPF-74 for an Additional 

20-Year Period; Arizona Public Service Company; Palo Verde Nuclear Generating Station, 

Units 1, 2, and 3.” Federal Register: Vol. 74, No. 93, pp. 22978-81. May 15, 2009. 
Purpose and Need for Action 

NUREG-1437, Supplement 43 1-10 December 2010

74 FR 24884-6. U.S. Nuclear Regulatory Commission, Washington, D.C., “Arizona Public 

Service Company; Notice of Intent to Prepare an Environmental Impact Statement and Conduct 

Scoping Process for Palo Verde Nuclear Generating Station, Units 1, 2, and 3.” Federal 

Register: Vol. 74, No. 99, pp. 24884-6. May 26, 2009. 

Arizona Public Service Company (APS). 2008. Palo Verde Nuclear Generating Station Unit 1, 

Unit 2, and Unit 3, License Renewal Application. ADAMS Nos. ML083510611, 12, 14, 15. 

Arizona Public Service Company (APS). 2008a. Palo Verde Nuclear Generating Station, Units 

1, 2, and 3, Applicant’s Environmental Report, License Renewal Operating Stage. ADAMS No. 

ML083510615, Appendix E. 

Atomic Energy Act of 1954. 42 U.S.C. 2011, et seq. 

Endangered Species Act of 1973. 16 U.S.C. 1531, et seq. 

Magnuson-Stevens Fishery Conservation and Management Act, as amended by the 

Sustainable Fisheries Act of 1996. 16 U.S.C. 1855, et seq. 

National Environmental Policy Act of 1969. 42 U.S.C. 4321, et seq. 

National Historic Preservation Act. 16 U.S.C. 470, et seq. 

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants. NUREG-1437, Volumes 1 and 2, Washington, D.C. 

ADAMS No. ML061770605. 

U.S. Nuclear Regulatory Commission (NRC). 1999. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants, Main Report, “Section 6.3 – Transportation, Table 9.1, 

Summary of findings on NEPA issues for license renewal of nuclear power plants, Final Report.” 

NUREG-1437, Volume 1, Addendum 1, Washington, D.C. 

U.S. Nuclear Regulatory Commission (NRC). 2009. “Summary of Public Environmental 

Scoping Meetings Related to the review of the Palo Verde License Renewal Application (TAC 

NOS. ME0261, ME 0262, ME0263).” ADAMS No. ML091900138.

U.S. Nuclear Regulatory Commission (NRC). 2010. “Issuance of Environmental Scoping 

Summary Report associated with the Staff’s review of Application by Arizona Public Service 

Company for Renewal of the Operating License for Palo Verde Nuclear Generating Station, 

Units 1, 2, and 3, (TAC NOS. ME0261, ME0262, ME0263)” ADAMS Accession No. 

ML100820451. 
 

December 2010 2-1 NUREG-1437, Supplement 43

2.0 AFFECTED ENVIRONMENT 

Palo Verde Nuclear Generating Station (PVNGS) is located approximately 26 miles west of the 

nearest Phoenix metropolitan area boundary (APS 2008a). Figures 2.1-1 and 2.1-2 present the 

50-mile (80-km) and 6-mile (10-km) vicinity maps, respectively. For purposes of the evaluation 

in this report, the “affected environment” is the environment that currently exists at and around 

PVNGS. Because existing conditions are at least partially the result of past construction and 

operation at the plant, the impacts of these past and ongoing actions and how they have shaped 

the environment are presented here. Section 2.1 of this report describes the facility and its 

operation, and Section 2.2 discusses the affected environment. 

2.1 FACILITY DESCRIPTION 

PVNGS is a three-unit nuclear-powered steam electric generating facility that began commercial 

operation between January 1986 (Unit 1) and January 1988 (Unit 3). The PVNGS site 

boundary encloses approximately 4,280 acres. The site buildings and adjacent, developed 

areas comprise approximately 720 acres. There are approximately 780 surface acres of water 

on the site in various large ponds. The most conspicuous structures on the PVNGS site include 

the three reactor containment buildings, three turbine buildings, nine cooling towers (three per 

unit), plus various buildings auxiliary to the reactors (APS 2008a). Figure 2.1-3 provides a 

general layout of the PVNGS site. 

2.1.1 Reactor and Containment Systems 

PVNGS is comprised of three individual reactor units each having a Combustion Engineering 

System 80 pressurized water nuclear reactor with a turbine-generator. Each reactor produces a 

reactor core power of 3990 megawatts-thermal (MWt) and a nominal net electrical capacity of 

1346 megawatts-electric (MWe). 

The containment building is a pre-stressed, reinforced concrete cylinder with a slab base and a 

hemispherical dome. A welded steel liner is attached to the inside face of the concrete shell to 

insure a high degree of leak tightness. In addition, the 4-foot thick concrete walls serve as a 

radiation shield. 

The nuclear fuel is low-enriched uranium dioxide with enrichments less than 5 percent by weight 

uranium-235 and fuel burnup levels with a batch average less than 60,000 megawatt-days per 

metric ton uranium. Typical burnup is approximately 50,000 megawatt-days per metric ton 

uranium and maximum burnup is up to 60,000 megawatt days per metric ton uranium (APS 

2008a). 

 
Affected Environment 

NUREG-1437, Supplement 43 2-2 December 2010

Figure 2.1-1 Palo Verde Nuclear 

Generating Station 50-Mile Radius 

(Source: APS 2008a) 
Affected Environment

December 2010 2-3 NUREG-1437, Supplement 43

Figure 2.1-2 Palo Verde Nuclear 

Generating Station 6 Mile Radius 

(Source: APS 2008a)
Affected Environment 

NUREG-1437, Supplement 43 2-4 December 2010

Evaporation Ponds 

Water 

Storage 

Reservoirs

Reactor and 

Turbine Bldgs 

Cooling 

Towers

Water 

Reclamation

Facility

Main Administrative 

Buildings 

Switch 

Yard Unit 3

Unit 2

Figure 2.1-3 Palo Verde Nuclear 

Generating Station General Plant Layout 

(Source: APS 2008a) 
Affected Environment

December 2010 2-5 NUREG-1437, Supplement 43

2.1.2 Radioactive Waste Management 

PVNGS’s radioactive waste system collects, treats, stores, and disposes of radioactive and 

potentially radioactive wastes that are byproducts of plant operations. The byproducts are 

activation products resulting from the irradiation of reactor water and impurities therein 

(principally metallic corrosion products) and fission products resulting from defective fuel 

cladding or uranium contamination within the reactor coolant system. Operating procedures for 

the radioactive waste system ensure that radioactive wastes are safely processed and 

discharged from the plant within the limits set forth in 10 CFR Part 20, “Standards for Protection 

against Radiation” (APS 2008a). 

Radioactive wastes resulting from plant operations are classified as liquid, gaseous, or solid. 

Radioactive liquid wastes are generated from liquids received directly from portions of the 

reactor coolant system or were contaminated by contact with liquids from the reactor coolant 

system. Radioactive gaseous wastes are generated from gases or airborne particulates vented 

from reactor and turbine equipment containing radioactive material. Radioactive solid wastes 

are solids from the reactor coolant system, solids that contacted reactor coolant system liquids 

or gases, or solids used in the reactor coolant system or the power conversion system. 

Reactor fuel that has exhausted a certain percentage of its fissile uranium content is referred to 

as spent fuel. Spent fuel assemblies are removed from the reactor core and replaced with fresh 

fuel assemblies during routine refueling outages approximately every 18 months. Spent fuel 

assemblies are stored in the spent fuel pool and dry casks. 

The PVNGS offsite dose calculation manual (ODCM) contains the methodology and parameters 

used to calculate offsite doses resulting from radioactive effluents. The methodology is used to 

ensure that radioactive material discharged from the plant meets regulatory dose limits. The 

ODCM also contains the radioactive effluent controls and radiological environmental monitoring 

activities and descriptions of the information included in the annual radiological environmental 

operating report and annual radioactive effluent release report (APS 2008a). 

2.1.2.1 Radioactive Liquid Waste 

The PVNGS liquid drains system collects, holds, treats, processes, provides for leakage 

detection, stores, and monitors all radioactive liquid wastes. The system collects and transports 

non-corrosive, radioactive or potentially radioactive liquid wastes from equipment and floor 

drains of the containment building, the auxiliary building, the fuel building, the main steam 

support structure, the radwaste building, the hold up tank area, and the decontamination and 

laundry facilities. The wastes collected are pumped to the liquid radwaste system for 

processing (APS 2008a). 

2.1.2.2 Radioactive Gaseous Waste 

The purpose of the radioactive gaseous waste system is to collect and process radioactive and 

potentially radioactive waste gas. The system also limits the release of gaseous activity so that 

personnel exposure and activity releases in restricted and unrestricted areas are as low as is 

reasonably achievable (ALARA). The system consists of piping runs, valves, two waste gas 

compressors, a waste gas surge tank and three waste gas decay tanks (APS 2008a). 

PVNGS discharges gaseous waste in accordance with the procedures and methodology 

described in the ODCM. The radioactive gaseous waste system is used to reduce radioactive 

materials in gaseous effluents before discharge to meet the dose limits in 10 CFR Part 20 and 
Affected Environment 

NUREG-1437, Supplement 43 2-6 December 2010

the dose design objectives in Appendix I to 10 CFR Part 50. 

2.1.2.3 Radioactive Solid Waste 

The radioactive solid waste management program is designed to safely collect, process, store, 

and prepare radioactive wet and dry solid waste materials for shipment to an offsite waste 

processor or for disposal. 

Solid wastes consist mainly of dry active waste such as contaminated paper, plastic, wood, 

metals, and spent resin. Solid wastes are collected, analyzed, packaged, and shipped from the 

site according to PVNGS’s process control program. Solid wastes are prepared in accordance 

with the requirements of 10 CFR 61 relating to waste form and classification as well as sitespecific requirements at the disposal facility (APS 2008a). 

The State of South Carolina’s licensed low-level radioactive waste disposal facility, located in 

Barnwell, has limited the access from radioactive waste generators located in States that are 

not part of the Atlantic Low-Level Waste Compact. Arizona is not a member of the Atlantic LowLevel Waste Compact. This has had a minimal affect on PVNGS’s ability to handle its 

radioactive solid low-level waste. PVNGS has adequate storage capacity for its radioactive 

waste during the license renewal term (APS 2008a). 

2.1.3 Nonradioactive Waste Management 

PVNGS generates nonradioactive solid wastes as part of routine plant maintenance, cleaning 

activities, and plant operations. 

PVNGS generates solid waste that is classified as either nonhazardous or hazardous as defined 

by the Resource Conservation and Recovery Act (RCRA). The nonhazardous solid waste 

includes office trash, construction debris, kitchen waste and other rubbish material from routine 

plant maintenance, operations and cleaning activities as well as sludge material from the 

PVNGS Water Reclamation Facility. 

PVNGS maintains an onsite permitted landfill facility (Maricopa County, Environmental Services 

Department Permit Number 00008). Information provided during the site audit in October 2009 

lists this landfill as both a rubbish landfill and sludge landfill. PVNGS has also acquired a 

special approval permit (Permit Number 7-368 Category D18) from the Arizona Radiation 

Regulatory Agency for onsite landfill disposal of the sludge material generated at the PVNGS 

Water Reclamation Facility and the cooling towers (APS 2008a).

The U.S. Environmental Protection Agency (EPA) classifies certain nonradioactive solid wastes 

as hazardous based on characteristics including ignitability, corrosivity, reactivity, or toxicity 

(further information on hazardous waste is available in 40 CFR Part 261). State-level regulators 

may add wastes to EPA’s list of hazardous wastes. RCRA provides standards for the 

treatment, storage, and disposal of hazardous waste for hazardous waste generators 

(regulations are available in 40 CFR Part 262). RCRA regulations are administered in Arizona 

by the Arizona Department of Environmental Quality (ADEQ) as incorporated in Title 18 - 

Environmental Quality (Chapter 8, ADEQ Hazardous Waste Management) of the Arizona 

Administrative Code (AAC). AAC Title 18 has been periodically updated to keep current with 

Federal RCRA regulations. 

PVNGS generates a variety of hazardous waste streams including spent and expired chemicals, 

laboratory chemical wastes, spent and unused paint, thinner and solvent, universal wastes 
Affected Environment

December 2010 2-7 NUREG-1437, Supplement 43

(such as mercury-bearing or fluorescent lamps, lead-acid batteries, capacitors, ballasts, etc.), 

hydraulic cuttings, hydrazine, aerosol cans, antifreeze, rag debris, medical wastes (such as 

sharps, bio-system cartridges and unused pharmaceutical waste) and occasional projectspecific wastes. PVNGS is a small-quantity generator of hazardous waste, meaning the plant 

generates less than 1,000 kilograms (kg) of non-acute hazardous waste in a month and stores 

less than 6,000 kg of this waste at any one time. As listed in the information provided by APS 

during the site audit conducted by NRC staff, PVNGS total annual hazardous waste generation 

was approximately 6,000 lbs annually from 2005 to 2009. Most of these wastes are associated 

with paint, thinner, solvent, discarded and unused chemicals, batteries and lamps (APS 2008a). 

EPA classifies several hazardous wastes as universal wastes; these include batteries, 

pesticides, mercury-containing items, and fluorescent lamps. Arizona has incorporated, by 

reference, the EPA’s regulations (available at 40 CFR Part 273) regarding universal wastes in 

Chapter 8 of AAC Title 18. PVNGS generates fluorescent lamps, batteries and electronic 

components as universal wastes from normal facility operations, which are sent offsite to an 

EPA-approved hazardous waste disposal or recycling facility (APS 2008a). 

Used oil produced during operation of PVNGS is sent offsite to an EPA-approved used oil 

disposal facility as verified during the PVNGS Site Audit in October 2009. In 2008, PVNGS 

listed a total of 205,245 lbs (or 23,325 gallons in volume equivalent) of used oil sent offsite to an 

EPA-approved waste disposal or recycling facility (APS 2008a). 

PVNGS also generates medical wastes including sharps, pharmaceutical materials and biosystem cartridges as part of its operation. The medical wastes, typically less than 100 lbs 

annually, are shipped offsite to an EPA-approved medical waste disposal facility (APS 2008a). 

The Emergency Planning and Community Right-to-Know Act (EPCRA) requires applicable 

facilities to provide information on hazardous and toxic chemicals to emergency planning 

authorities and the EPA. PVNGS is subject to EPCRA Section 312 reporting and therefore 

submits annual reports to local emergency agencies principally to the Arizona Division of 

Emergency Management (ADEM). Copies of the EPCRA Section 312 Tier II reporting forms 

(2005 thru 2008) submitted to ADEM by APS listed, among others, the following hazardous and 

toxic chemicals including: hydrazine, ammonium hydroxide (1-30%), sodium hydroxide 

(1-100%), sodium hypochlorite (1-16%), boric acid, diesel fuel, lubricating oils, carbon dioxide, 

dimethylamine (0-2%), laminating resin 2002-3-R-A, polifloc AE 1701, sulfuric acid (1-96%), 

soda ash (1-100%), anion / cation water treatment resin, 1, 1, 1, 2 tetrafluoroethane (HFC134a), trisodium phosphate (anhydrous), nitrogen, ethanolamine (monoethanolamine)(1-80%), 

air blasting abrasives, anthracite (coal), activated carbon (charcoal), cement products, sulfuric 

acid and lead in batteries, transformer (dielectric oil), unleaded gasoline, bulab 6002, calcium 

carbonate, and many others. PVNGS annually files Tier II forms electronically in a repository 

maintained by the Arizona Emergency Response Commission (AERC) (APS 2008a). 

2.1.3.1 Pollution Prevention and Waste Minimization 

Currently, PVNGS has waste minimization measures in place as verified during the PVNGS site 

audit conducted by the NRC in October 2009. In 2004, PVNGS submitted a Pollution 

Prevention Plan to the Arizona Department of Environmental Quality Pollution Prevention 

Program (ADEQPPP) outlining the facility’s waste minimization goals and measures. Included 

in the Plan are pollution prevention opportunities to eliminate, reduce, reuse or recycle wastes, 

emissions or toxic substances. PVNGS submits an annual Pollution Prevention Plan Progress 

Report to the ADEQPPP that tracks the facility operating activities in achieving the Plan goals. 

Examples of PVNGS minimization goals include but are not limited to reduction in the use or 
Affected Environment 

NUREG-1437, Supplement 43 2-8 December 2010

generation of hydrazine, ammonium hydroxide (aqueous ammonia), mercury (in portable 

calibration instruments and fluorescent light bulbs), waste paint, and volatile organic compound 

emission at gasoline dispensing stations. PVNGS likewise maintains an environmental website 

that posts the Plan goals and the facility’s progress in achieving those goals. Employees are 

encouraged by PVNGS management to participate in the pollution prevention program by 

providing training and by implementing an Environmental Health and Safety excellence award 

program for their employees (APS 2008a). 

In support of the nonradiological waste minimization efforts, the EPA’s Office of Pollution 

Prevention and Toxics has established a clearinghouse that provides information regarding 

waste management and technical and operational approaches to pollution prevention. The 

EPA’s clearinghouse can be used as a source for additional opportunities for waste 

minimization and pollution prevention at PVNGS, as appropriate. 

2.1.4 Plant Operation and Maintenance 

Maintenance activities conducted at PVNGS include inspection, testing, and surveillance to 

maintain the current licensing basis of the facility and to ensure compliance with environmental 

and safety requirements. Various programs and activities currently exist at PVNGS to maintain, 

inspect, test, and monitor the performance of facility equipment. These maintenance activities 

include inspection requirements for reactor vessel materials, boiler and pressure vessel inservice inspection and testing, maintenance structures monitoring program, and maintenance of 

water chemistry. 

Additional programs include those implemented to meet technical specification surveillance 

requirements, those implemented in response to the NRC generic communications, and various 

periodic maintenance, testing, and inspection procedures. Certain program activities are 

performed during the operation of the unit, while others are performed during scheduled 

refueling outages. Nuclear power plants must periodically discontinue the production of 

electricity for refueling, periodic in-service inspection, and scheduled maintenance. PVNGS 

operates on an 18-month refueling cycle (APS 2008a). 

2.1.5 Power Transmission System 

Seven 525-kilovolt transmission lines connect PVNGS to the regional electric grid. Five of the 

lines are owned by Salt River Project (SRP), one is jointly owned by SRP and APS, and one of 

the lines is owned by Southern California Edison (SCE). Unless otherwise noted, the 

discussion of the power transmission system is adapted from the Environmental Report (ER) 

(APS 2008a) or information gathered at NRC’s environmental site audit conducted in October 

2009. 

The transmission lines cross through Maricopa and La Paz Counties, Arizona, and Riverside 

County, California. In total, the transmission lines associated with the operation of PVNGS 

comprise approximately 13,000 acres (526 ha) and span 530 mi (853 km) of transmission line 

rights-of-way (ROWs). Generally, the transmission line ROWs pass through regions of low 

population densities characterized by agriculture and desert habitat, much of which is Federal 

property. 

The Final Environmental Statement (FES) for the Operation of PVNGS (NRC 1982) specifies 

four 525-kilovolt and one 325-kilovolt transmission lines that were planned to connect PVGNS to 

the regional electric grid. One of the lines was not constructed, two additional lines were 
Affected Environment

December 2010 2-9 NUREG-1437, Supplement 43

constructed, and a new substation was put into service that split two previously planned lines to 

PVNGS into smaller portions. Therefore, the discussion of the transmission system in this 

Supplemental Environmental Impact Statement (SEIS) is different than the FES. 

Transmission lines considered in-scope for license renewal are therefore, the Westwing 1 and 2 

lines; the Rudd line; the Hassayampa 1, 2, and 3 lines; and the Devers line. Figures 2.1.5-1 

and 2.1.5-2 are maps of the PVNGS transmission system. Table 2.1.5-1 summarizes the 

transmission lines. The seven transmission lines are as follows: 

• Westwing 1 and Westwing 2: These lines extend northeast and then east for 

approximately 45 mi (72 km) to the Westwing Substation just outside of 

Phoenix, Arizona. These lines are contained within Maricopa County and 

share a 330-ft (100-m) wide ROW. 

• Rudd: This line extends northeast and then east for approximately 37 mi (60 

km) to the Rudd Substation in southern Phoenix, Arizona. This line is 

contained within Maricopa County, shares a 330-ft (100-m) wide ROW with 

Westwing 1 and Westwing 2 initially, and then splits off to extend eastward, at 

which point its ROW is 160-ft (49-m) wide. 

• Hassayampa 1: This line extends 3 mi (5 km) to the Hassayampa Substation 

just south of PVNGS, then extends southeast for an additional 20 mi (32 km) 

to the Jojoba Substation south of Buckeye, Arizona, and then extends an 

additional 52 mi (84 km) to the Kyrene Generating Station south of Tempe, 

Arizona. This line is contained within Maricopa County and shares a 330-ft 

(100-m) wide ROW with Hassayampa 2 to the Hassayampa Substation, and 

the ROW for the remaining 72 mi (116 km) of line varies from 75 to 200 ft (23 

to 61 m). 

• Hassayampa 2: This line extends 3 mi (5 km) to the Hassayampa Substation 

just south of PVNGS. This line is contained within Maricopa County and 

shares a 330-ft (100-m) wide ROW with Hassayampa 1. 

• Hassayampa 3: This line extends south to the Hassayampa Substation and 

continues south and then west 114 mi (183 km) to the North Gila Substation 

near Yuma, Arizona. This line is contained within Maricopa County and has a 

200-ft (61-m) wide ROW. 

• Devers: This line extends west for approximately 235 mi (378 km) to the 

Devers Substation north of Palm Springs, California. This line traverses 

Maricopa and La Paz Counties, Arizona, and Riverside County, California, 

and has a 200-ft (61-m) wide ROW that varies slightly in width in certain 

areas. 

SRP, APS, and SCE follow vegetative maintenance plans to promote low-growing vegetation 

and minimize vegetation-related interference with transmission systems. The majority of ROWs 

associated with PVNGS consist of desert habitat or agricultural land, which require minimal 

maintenance. Generally, trees and tall shrubs are removed in the wire zone, the area 

immediately beneath conductors, and only tall-growing tree species are removed in the border 

zone, the area on either side of the wire zone. Herbicides, when necessary, are applied by 

personnel with an Arizona Pesticide Applicator License. All herbicides used near waterways or 

in wetland areas are EPA-approved for aquatic application. SRP, APS, and SCE perform 

regular flyovers to identify areas that require maintenance, followed by a ground inspection in 

selected areas to identify any conflicts with lines and to plan future maintenance needs. 
Affected Environment 

NUREG-1437, Supplement 43 2-10 December 2010

Vegetative maintenance is generally conducted on a five year cycle. 

Saguaro cactii (Carnegiea gigantean) near power lines require special treatment because the 

species is capable of conducting electricity due to their high water content and can pose a 

safety threat. Saguaros that are close enough to lines to pose this risk are transplanted outside 

of the border zone or trimmed. 

All transmission lines will remain a permanent part of the transmission system and will be 

maintained by SRP, APS, and SCE, regardless of PVNGS continued operation. 
Affected Environment

December 2010 2-11 NUREG-1437, Supplement 43

Table 2.1.5-1 PVNGS Transmission Lines 

 Approximate 

Distance 

ROW 

Width(a) 

ROW Area(b) 

Line Owner kV mi (km) ft (m) ac (ha) 

Westwing 1 Salt River Project 525 45 (72) 330 (100) 1800 (730)

Westwing 2 Salt River Project 525 45 (72) 330 (100) 1800 (730)

Rudd APS and Salt River 

Project 

525 37 (60) 160 (49) 720 (290) 

Hassayampa 1 Salt River Project 525 75 (121) 75 to 200 (23 

to 61) 

1250 (506)(c)

Hassayampa 2 Salt River Project 525 3 (5) 330 (100) 120 (50) 

Hassayampa 3 Salt River Project 525 114 (183) 200 (61) 2800 (1100) 

Devers Southern California 

Edison 

525 235 (378) 200 (61) 5700 (2300) 

(a) Value given represents the typical width or typical width range along line, though ROW width 

may vary at intervals along the length of the line. 

(b) Values given for ROW area are not mutually exclusive as West Wing 1 and West Wing 2 share 

a ROW, as do Hassayampa 1 and Hassayampa 2, and the Rudd line ROW splits off from the 

West Wing 1 and West Wing 2 ROW. 

(c) Value represents the calculated average ROW area. 

Source: APS 2008a 

 
Affected Environment 

NUREG-1437, Supplement 43 2-12 December 2010 Figure 2.1.5-1 Transmission Lines – Arizona (APS 2008a) 
Affected Environment

December 2010 2-13 NUREG-1437, Supplement 43 Figure 2.1.5-2 Transmission Lines – California (APS 2008a)
Affected Environment 

NUREG-1437, Supplement 43 2-14 December 2010

2.1.6 Cooling and Auxiliary Water Systems 

Water systems at PVNGS are supplied by two sources. The main source is wastewater effluent 

from Phoenix-area wastewater treatment plants. This water is pumped to the on-site Water 

Reclamation Facility (WRF) where it is treated to meet the plant’s water quality requirements. 

The other source is groundwater from onsite production wells (discussed in Section 2.1.7). 

2.1.6.1 Circulating Water System 

The Circulating Water System for each generating unit consists of a main condenser, cooling 

towers, circulating water pumps, a chemical injection system, and makeup and blowdown 

systems. The Circulating Water System removes waste heat by circulating cooling water 

through the main condenser in each unit by four 25-percent capacity, vertical, wet-pit pumps, 

each with a capacity of 140,000 gpm (and a total capacity of 560,000 gpm). Waste heat is then 

rejected to the atmosphere via three round mechanical draft cooling towers. System blowdown 

is discharged to above grade evaporation ponds. 

Cooling water is predominantly made up of tertiary treated effluent from the WRF that is stored 

in two lined water storage reservoirs. Water in the reservoirs may also contain secondary 

treated effluent from the Sewage Treatment Plant and untreated groundwater from the regional 

aquifer (ADEQ 2009a). 

Makeup water to replace evaporative and blowdown losses is provided mainly by the WRF; both 

the Domestic Water System and the Demineralized Water System, which mainly use 

groundwater, can also supply makeup water (APS 2008b). 

2.1.6.2 Essential Spray Pond System 

Each generating unit has an ultimate heat sink consisting of two independent Essential Spray 

Ponds. The Essential Spray Pond System (ESPS) provides cooling water for normal and 

emergency shutdown and has a storage capacity that enables it to operate continuously for 26 

days without a makeup water supply. During normal plant operations, the ESPS may support 

several auxiliary systems (APS 2008b). 

2.1.6.3 Water Reclamation Facility 

The WRF is an advanced wastewater treatment plant that uses a multi-phase, biochemical 

treatment process. Its main function is to provide makeup cooling water, but it also supplies 

domestic, demineralized, and fire protection water for PVNGS and sends some of its treated 

water (about 3 to 7 million gpd) (11.4 to 26.5 million liters per day) to the Redhawk Power Plant, 

a nearby gas-fired power plant owned by Pinnacle West, the parent corporation of APS. WRFtreated water is also used for dust suppression at PVNGS. At the WRF, water undergoes 

biological nitrification, lime treatment, filtration, and chlorination. Treated water is then stored in 

lined water storage reservoirs. Sludge from the treatment processes is centrifuged, dried, and 

sent to the onsite Sludge Disposal Landfill. The WRF also treats wastewater from the PVNGS 

Sewage Treatment Plant (STP) and groundwater from onsite production wells. The WRF 

produces an estimated 45,000 gpm (170.3 cubic meters per minute) or 65 million gpd (246 

million liters per day) (ADEQ 2009a). 
Affected Environment

December 2010 2-15 NUREG-1437, Supplement 43

2.1.6.4 Evaporation Ponds 

Evaporation Ponds 1 and 2 are above-grade, double-lined surface impoundments on the 

southern portion of PVNGS. The ponds are authorized to receive and evaporate Circulating 

Water System blowdown, nonhazardous reject water from the WRF, and nonhazardous 

wastewater from other onsite sources. 

Evaporation Pond 3 is an above-grade, tripled-lined wastewater impoundment located to the 

south of Evaporation Pond 1. The pond is divided into two cells, 3A (west) and 3B (east), that 

operate independently. It is authorized to receive cooling tower blow-down and wastewater 

from the generating units (ADEQ 2009a). 

2.1.6.5 Fire Protection Water System 

The fire protection water system consists of two 500,000-gallon (1,893-cubic meter) fire water 

reserve tanks, an electric-driven pump, two diesel engine driven pumps, one jockey pump, and 

related piping, valves, hydrants, and hose stations. The system provides water for all plant 

areas requiring fire protection and is shared by Units 1, 2, and 3 (APS 2008b). The source of 

the water stored in the fire reserve tanks is groundwater transferred from two onsite production 

wells (Gunter 2006). The WRF also provides water to this system (ADEQ 2009a). 

2.1.6.6 Domestic and Demineralized Water Systems 

Groundwater from two onsite production wells is transferred to two 27,000-gallon (102-cubic 

meter) well water reserve tanks for storage. These tanks provide water to the Domestic Water 

System where it is filtered and undergoes reverse osmosis and chlorination to produce potable 

water that is stored and distributed throughout PVNGS. Water from the Domestic Water 

System is also sent to the Demineralized Water System where it is further processed to remove 

dissolved gases and solids, then stored and transferred to each generating unit and to common 

facilities in the Chemical Production System. The WRF also provides water to these systems 

(ADEQ 2009a). Both the Domestic Water System and the Demineralized Water System can 

supply reactor makeup water (APS 2008b).

2.1.7 Facility Water Use and Quality 

PVNGS does not use public water supplies for plant operations, but instead relies on 

wastewater effluents from several area municipalities and groundwater from onsite production 

wells. 

2.1.7.1 Recycled Water Use 

PVNGS purchases wastewater effluents from Phoenix-area wastewater treatment plants for 

beneficial use as cooling water and safety-related makeup water for the Essential Spray Ponds. 

Treated effluent from the Phoenix 91st Avenue Wastewater Treatment Plant, the Tolleson 

Wastewater Treatment Plant, and the Goodyear Wastewater Treatment Plant is conveyed by 

gravity through a 28-mile (58-kilometer) long underground pipeline (the Water Reclamation 

Supply System) until it reaches a low point near the Hassayampa River. From there it is 

pumped 8 miles via the Hassayampa Pump Station to the onsite Water Reclamation Facility 

(WRF) where it is treated to meet the plant’s water quality requirements. The treated water is 

then stored in two onsite storage reservoirs to ensure a continuous supply of water during 

interruptions or reductions in water flowing to the WRF (APS 2008b; ADEQ 2009a). According 
Affected Environment 

NUREG-1437, Supplement 43 2-16 December 2010

to the Arizona Department of Water Resources (ADWR) (ADWR 2008), PVNGS is the largest 

user of treated wastewater effluent in the Phoenix Active Management Area (AMA), using on 

average about 53,000 acre-feet (65.4 million cubic meters) per year (APS 2008a). 

2.1.7.2 Groundwater Use 

PVNGS maintains three onsite production wells (Table 2.1.7-1). These wells are completed in 

the regional aquifer and are permitted and regulated by the State of Arizona. The average 

annual pump rate for these wells from 2001 through 2005 was 1,232 gpm (4.7 cubic meters per 

minute) (Gunter 2006). The total annual pump rates for these wells during 2006, 2007, and 

2008 were 1,535 gpm (5.8 cubic meters per minute), 1,108 gpm (4.2 cubic meters per minute), 

and 1,262 gpm (4.8 cubic meters per minute) (APS 2007a; APS 2008a; and APS 2009a). 

These pump rates are well below the 3,206 gpm (5,171 acre-feet per year) (6.4 million cubic 

meters per year) authorized by the ADWR as part of the plant’s grandfathered nonirrigation 

groundwater right within the Phoenix AMA (ADWR 1990). 

Groundwater from the Alpha and Bravo wells is transferred to two 500,000-gallon (1,893-cubic 

meter) fire water reserve tanks and two 27,000-gallon (102-cubic meter) well water reserve 

tanks for storage. The well water reserve tanks provide water to the Domestic Water System 

where it is filtered and undergoes reverse osmosis and chlorination to produce potable water 

that is stored and distributed throughout PVNGS. Water from the Domestic Water System is 

also sent to the Demineralized Water System where it is further processed to remove dissolved 

gases and solids, then stored and transferred to each generating unit and to common facilities 

in the Chemical Production System. Both the Domestic Water System and the Demineralized 

Water System can supply reactor makeup water (APS 2008b). 

Groundwater from the Range well was used for potable water at the firing range (APS 2004). A 

new production well (Charlie well) is planned for first use in the summer of 2010. Groundwater 

from this well will be used for dust control for 4 to 5 years and then Charlie may replace Bravo 

well. 
Affected Environment

December 2010 2-17 NUREG-1437, Supplement 43

Table 2.1.7-1 PVNGS Production Wells 

Well Water Uses 

Well 

Depth (ft) 

Water 

Level (ft) 

Pump 

Capacity 

(gpm) 

Maximum Water 

Demand (gpm)a

Range wellb Industrial 340 195 10 0.058 (2006) 

Alpha wellb

Bravo wellb

Charlie wellb

Potable; demineralized 

Water; fire protection and 

dust control 

Potable; demineralized water; 

fire protection and dust control 

Dust control starting summer 

2010 

1,413 

1,050 

1,360 

220 

205 

204 

2,000 

2,000 

750 

1,114 (2008) 

1,208 (2006) 

Not applicable 

(a) Values represent the maximum annual water usage during the period 2006 through 2008; year in parentheses is 

the year during which the maximum annual usage was recorded. 

(b) The Range well is classified as an exempt well by the ADWR. An exempt well is used for non-irrigation purposes 

and has a maximum pump capacity of 35 gpm (133 liters per minute) or less. Wells with this classification do not 

need a groundwater withdrawal authority (i.e., groundwater right or permit). The Alpha, Bravo and Charlie wells 

are classified by the ADWR as nonexempt wells because their pump capacity is greater than 35 gpm (133 liters 

per minute) and they are used for industrial purposes (ADWR 2009a). 

Source: APS 1982a, APS 1982b, APS 2004, APS 2007a, APS 2008c, APS 2009d, and ADWR 2009b. 
Affected Environment 

NUREG-1437, Supplement 43 2-18 December 2010

 Figure 2.1.7-1 PVNGS Surface Impoundments, Landfills, and Monitoring Wells 

(Source: APS 2009b) 
Affected Environment

December 2010 2-19 NUREG-1437, Supplement 43

2.1.7.3 Surface Water Use 

PVNGS does not draw its cooling (or makeup) water directly from any natural surface water 

body. 

2.1.7.4 Groundwater Quality 

Groundwater quality throughout Maricopa County is characterized as fair to good; although in 

some areas, treatment for fluoride and total dissolved solids (TDS) is required before it can be 

used for drinking water. Poor quality water has been observed in the Upper Alluvial Unit, 

especially in the East and West Salt River Valley sub-basins. In these sub-basins, 

contaminants include TDS, sulfates, nitrates, volatile organic compounds (VOCs), pesticides, 

and metals. The major sources of these contaminants are industry, agriculture, dry well 

injections, unregulated landfills, and leaking underground storage tanks (Maricopa County 

2001). 

PVNGS maintains a groundwater monitoring program to comply with the requirements of 

Aquifer Protection Permit (APP) No. P-100388 LTF 48337, issued by the Arizona Department 

of Environmental Quality (ADEQ) (ADEQ 2009a). The APP authorizes the operation of seven 

surface impoundments (including two unlined sedimentation basins) and two landfills at PVNGS 

(Figure 2.1.7-1). The facilities regulated by the permit are described below and their monitoring 

requirements are listed in Table 2.1.7-2. Groundwater monitoring well locations are shown in 

Figure 2.1.7-1. These wells are located and routinely sampled to characterize ambient 

(background) conditions, ensure compliance with the APP, and provide an early warning system 

in the event of a release. Water elevations are also measured to provide data for quarterly 

contour maps and hydrographs for the shallow aquifer. In addition to groundwater monitoring, 

APS conducts leak detection monitoring for the two water storage reservoirs and the 

evaporation ponds. The purpose of leak detection monitoring is to ensure immediate 

identification of potential damage to the liner systems that could result in releases above the 

discharge limits specified in the APP (ADEQ 2009a; APS 2009f). 

85-Acre and 45-Acre Water Storage Reservoirs 

The 85-acre (34.4-hectare) Water Storage Reservoir (WSR) is located in the northern portion of 

PVNGS, on the southeast side of the WRF; the 45-acre (18.2-hectare) WSR is located to the 

north of the 85-acre (34.4-hectare) WSR (Figure 2.1.7-1). The synthetic-lined impoundments 

receive tertiary treated effluent from the WRF and store it for use as cooling water for the 

generating station. The 85-acre (34.4-hectare) WSR has a maximum depth of about 30.5 feet 

(9.3 meters) (from the top of primary liner) and is designed to store 788 million gallons (2.98 

billion liters) of cooling water at its maximum operation elevation. The 45-acre (18.2 hectare) 

WSR has a maximum depth of about 46 feet (14 meters) (from the top of the primary liner) and 

is designed to store 373 million gallons (1.41 billion liters) of cooling water at its maximum 

operation elevation. Each WSR has a design flow of 60,000 gpm (227 cubic meters per minute) 

with a peak design flow of 72,000 gpm (273 cubic meters per minute). Each WSR has a 

double-liner system with a leakage collection and recovery system installed above an 

underdrain system that allows groundwater to be pumped and removed from underlying soils to 

protect the liner system. Authorized discharges to the WSRs include final treated water from 

the WRF, secondary treated effluent from the Sewage Treatment Plant (emergency only), 

nonhazardous low volume wastewaters during WRF outages, and untreated 

 
Affected Environment 

NUREG-1437, Supplement 43 2-20 December 2010

Table 2.1.7-2 Facilities Regulated by PVNGS Aquifer Protection Permit Program 

Facility Monitoring Requirements 

85-acre and 45-acre Water Storage 

Reservoirs 

• Operational (compliance) monitoring: 

- Maintenance and visual inspectiona

- Leak collection and recovery system sump (weekly) 

- Fluid level (weekly and after significant storms) 

- Flow at discharge point (daily) 

- Flow meters and other measuring devices (monthly) 

• Contingency discharge monitoring (in the event of unauthorized discharge 

or other violation) 

Evaporation Ponds 1 and 2 • Routine discharge monitoring (weekly, monthly, annually) 

• Operational (compliance) monitoring: 

- Maintenance and visual inspectiona

- Leak collection and recovery system sump (weekly) 

- Fluid level (weekly and after significant storms) 

- Flow at discharge point (monthly) 

- Flow meters and other measuring devices (monthly) 

• Contingency discharge monitoring (in the event of unauthorized discharge 

or other violation) 

Evaporation Pond 3 (Cells 3A and 

3B) 

• Monitoring of transfer of wastewater between cells (at pump location) 

• Operational (compliance) monitoring: 

- Maintenance and visual inspectiona

- Leak collection and recovery system sump (daily) 

- Fluid level (weekly and after significant storms) 

- Flow at discharge point (daily) 

- Flow meters and other measuring devices (monthly) 

• Contingency discharge monitoring (in the event of unauthorized discharge 

or other violation) 

Sludge Disposal Landfill (Cooling 

Tower and WRF Sludge) 

• Sludge monitoring prior to disposal on a per disposal event basis 

• Stormwater run-on/run-off control (monthly) 

• RCRA TCLPb

 metals monitoring 

• Contingency monitoring (in the event of unauthorized material disposal or 

other violation) 

Rubbish Landfill • Stormwater run-on/run-off control (monthly) 

• Contingency monitoring (in the event of unauthorized material disposal or 

other violation) 

Sedimentation Basin 1 & 2 No monitoring requirements unless an unauthorized discharge occurs. 

(a) Visual inspection includes freeboard, upper liner integrity, liner leakage rate, and dam and berm integrity. 

(b) RCRA TCLP (Toxicity Characteristic Leaching Procedure) analytes include pH, arsenic, barium, cadmium, 

total chromium, lead, mercury, selenium, and silver. The TCLP test is used to determine whether a solid 

waste is hazardous in terms of its leaching potential as defined by the Resource Conservation and 

Recovery Act (RCRA).

Source: ADEQ 2009a. 

groundwater from the regional aquifer. The ADEQ has also authorized the use of water from 

both WSRs for cooling tower makeup water and dust suppression (ADEQ 2009a; APS 2009c). 

The original 85-acre (34.4-hectare) WSR had a surface area of 80 acres (32.4 hectares) and a 

maximum design storage capacity of 670 million gallons (2.54 billion liters). In October 2004, 

the APS observed that the liner for this reservoir had developed leaks that required repair. To 
Affected Environment

December 2010 2-21 NUREG-1437, Supplement 43

facilitate the repair work, the 45-acre (18.2-hectare) WSR was constructed and put into service 

so that the 80-acre (32.4-hectare) WSR could be drained and repaired. During the repair 

project, the inner wall slope was changed from 3:1 to 4:1 and a new double liner with a leachate 

collection system was installed. The change in wall slope increased the surface area of the 

reservoir to 85 acres (34.4 hectares). The WSR was put back into service in early 2008 and is 

now referred to as the 85-acre (34.4-hectare) WSR. APS submitted its final corrective action 

report to the ADEQ on June 12, 2009 (Eroh 2009). 

Evaporation Ponds 

Evaporation Ponds 1 and 2 are above-grade, lined surface impoundments on the southern 

portion of PVNGS (Figure 2.1.7-1). The ponds are authorized to receive and evaporate 

circulating water system blowdown, nonhazardous reject water from the WRF and 

nonhazardous wastewater from other onsite sources. Each pond has a toe drain leakage 

collection system and a vadose zone monitoring system for dam safety. Evaporation Pond 1 

has a surface area of about 250 acres and ranges in depth from 19 to 32 feet (6 to 10 meters); it 

is designed to hold 1,793 million gallons at its maximum elevation. Evaporation Pond 2 has a 

surface area of about 220 acres and ranges in depth from 24 to 36 feet (7.3 to 11 meters); it is 

designed to hold 1,923 million gallons at its maximum elevation. The estimated average annual 

flow rate to the ponds is 3,125 gpm (11.8 cubic meters per minute) (ADEQ 2009a). 

Evaporation Pond 3 is an above-grade, tripled-lined wastewater impoundment located to the 

south of Evaporation Pond 1 (Figure 2.1.7-1). The pond is divided into two cells, 3A (west) and 

3B (east), that operate independently. Each cell is equipped with a liner leakage monitoring 

system. The pond has a total surface area of about 185 acres, a maximum depth of about 

71 feet (23 meters), and is designed to hold 2,132 million gallons at its maximum elevation. 

Evaporation Pond 3 is authorized to receive cooling tower blow-down and wastewater from the 

generating units; organic solvents and hazardous substances are prohibited. Fluids from other 

regulated ponds may be temporarily discharged to Evaporation Pond 3 as part of maintenance, 

repair, or contingency response actions (ADEQ 2009a). 

Sludge Disposal Landfill 

The Sludge Disposal Landfill is located on the east-central portion of PVNGS, just south of the 

85-acre WSR (Figure 2.1.7-1). It is an active, unlined solid waste disposal facility used for the 

surface drying and landfilling of sludge from the WRF and the cooling towers. The sludge is 

covered with a foot (0.3 meter) of soil with each application. The landfill covers about 213 acres 

and is operated in accordance with Arizona Revised Statutes (ARS) §49-762.07 (E) and (F) 

(ADEQ 2009a). 

Rubbish Landfill 

The Rubbish Landfill is located on the east-central portion of PVNGS, south of the WSR (Figure 

2.1.7-1). It is an active, unlined trench-type solid waste disposal facility that receives 

noncombustible, nonhazardous, nonradioactive, and nonputrescible solid waste generated at 

PVNGS; it is authorized to receive landscape-trimming material. The landfill covers an area of 

about 100 acres and is operated in accordance with ARS §49-762.07 (E) and (F) (ADEQ 

2009a). 

Sedimentation Basins 1 and 2 are located to the north of the evaporation ponds 

(Figure 2.1.7-1). The basins are nonengineered, unlined earthen containment ponds designed 
Affected Environment 

NUREG-1437, Supplement 43 2-22 December 2010

to collect stormwater and non-stormwater discharges. They are normally dry except during and 

after storm events. Sedimentation Basin 1 collects drainage from the western portion of 

PVNGS; it is about 1,000 feet long (305 meters) and 15 acres in area. Sedimentation Basin 2 

collects drainage from the eastern portion of PVNGS; it is about 3,000 feet (914 meters) long 

and 60 acres in area. Both basins meet the criteria for exemption from APP regulation ARS 

§§49-250(B)(23). In the past, both sedimentation basins have received discharges that are not 

listed under the exemption for stormwater impoundments. These have included demineralized 

water from the generating units, cooling water, cooling tower overflow, spray pond water, and 

oil/water separator discharge, among others. APS is required by the ADEQ to act immediately 

to correct any condition resulting in an unauthorized, non-exempt discharge and to report the 

incident in accordance with the emergency response and contingency requirements and the 

permit violation reporting specifications outlined in Sections 12.4 and 13.3 of the APP. These 

discharges and their associated corrective actions are provided in Table 2.1.7-3 (ADEQ 2009a). 

Aquifer Protection Permit Exempt Faciities 

The East and West Retention Basins were located to the north of Sedimentation Basin 1 (Figure 

2.1.7-1). These gunite-lined2

 impoundments once received nonhazardous wastewater from the 

oily and nonradioactive wastewater collection and transfer system (floor and equipment drains) 

and from the Sewage Treatment Plant (STP) during periods when the WRF was offline and not 

able to receive STP discharge. The contents of the basins were tested for pH, hydrazine 

(a compound used to prevent scaling and corrosion), visible oil, and radioactivity and treated as 

necessary before being discharged to the evaporation ponds. During construction joint repairs 

conducted in 2005, APS observed water beneath the gunite flowing to the surface, but not in the 

leak detection system beneath the retention basins. This water was sampled and found to have 

low levels of tritium. As a result of these observations, APS designed and constructed two new 

aboveground, epoxy-lined concrete tanks to replace the existing retention basins. The 

construction of the new tanks was completed in March 2007, at which time the retention basins 

were taken offline. APS began removing the retention basins in June 2007 under the 

compliance schedule in the APP. It submitted its final closure report to the ADEQ in July 2008 

(APS 2008c). The new concrete tanks are exempt from regulation under the APP 

(ADEQ 2009a). 

Other water-related PVNGS facilities that are exempt from the APP are the WRF, the STP, 

retention tanks, the Essential Spray Ponds (aboveground tanks), the cooling towers and 

concrete aprons (located on concrete pads), the Concrete/Inert Material Landfill, the 

Independent Spent Fuel Storage Installation (in concrete casks on a concrete pad), the truck 

washing station, and the Fire Training Facility. While discharge from the STP is not exempt, it is 

not regulated by the APP because it is typically directed to either the exempt retention tanks or 

to the headworks of the WRF (ADEQ 2009).

Aquifer Protection Permit Compliance

The monitoring and compliance activities required by the APP to protect the aquifer in the 

vicinity of PVNGS are documented in annual reports to the ADEQ. These reports include the 

results of groundwater monitoring, impoundment monitoring, sludge monitoring, and compliance 

status (including permit violations), and document the maintenance and repair activities for the 

 

2

 Gunite is a concrete mixture that is pneumatically applied over steel reinforcements. Under the gunite 

layer was a 6-inch layer of sand over a 0.45 millimeter Hypalon® liner (APS 2008c). 
Affected Environment

December 2010 2-23 NUREG-1437, Supplement 43

surface impoundments over the past year. The results of the 2008 monitoring and compliance 

activities are summarized below. The PVNGS 2004 through 2008 Annual Monitoring and 

Compliance Reports containing information on parameters tested for and concentrations found 

in the ponds are available at ADAMS Accession Nos. ML101540025, ML101540061, 

ML101540107, ML101550312, and ML101550341. 

In addition to the annual reports, PVNGS is also required to submit a 5-year monitoring 

evaluation report that evaluates groundwater and wastewater monitoring data over the prior 5-

year period to determine whether changes are needed in the groundwater monitoring program. 

The latest 5-year report, evaluates data from 2004 through 2008 and its recommendations are 

provided in the following sections (APS 2009c). 

Water Storage Reservoirs

Concentrations of chemical parameters in the 85-acre WSR, such as sodium, potassium, 

chloride, and sulfate, were stable over the reporting period (2004 to 2008) and well-correlated 

with the chemical parameters found in evaporation ponds, although concentrations in the 

evaporation ponds were typically two orders of magnitude higher due to the concentrating action 

of the cooling tower recycling process and the effect of evaporation that occurs in the ponds by 

design. The correlation shows that water in the WSR and water in the evaporation ponds, 

which derives from water in the WSR, remains chemically similar over time. 

APS recommended using potassium as an indicator of a release from the WSR and the 

evaporation ponds. Potassium in the WSR and evaporation ponds derives from human sources 

(e.g., water softening, sweat, urine) and its form is chemically distinct from the naturallyoccurring and fertilizer-related potassium found in groundwater from the shallow aquifer. This 

recommendation is undergoing ADEQ review (APS 2009c). 

Evaporation Ponds

In 2008, weekly water samples collected from Evaporation Ponds 1 and 2 were composited on 

a monthly basis and analyzed for the indicator parameters (inorganics and organics) specified in 

Table 17.2-7 of the APP (ADEQ 2009). Weekly samples were also composited on a quarterly 

basis and analyzed for tritium. None of the radiological parameters were found to exceed the 

alert levels required by the APP, although tritium was detected in all quarterly samples from 

both evaporation ponds. Iodine-131 was detected in monthly samples collected in February, 

March, and November from Evaporation Pond 1 (APS 2009f). Due to elevated TDS 

concentrations (relative to the surrounding shallow aquifer) and the presence of tritium in the 

evaporation ponds, APS recommended that monitoring of groundwater near the evaporation 

ponds include quarterly sampling for tritium and TDS (APS 2009c). 

Sedimentation Basins

An unintended non-stormwater release to Sedimentation Basin 2 in December 2008 triggered a 

sampling event in accordance with requirements of the APP. A composite sample was 

analyzed for the parameters listed in Table 17.3-3 (Plant Upset Releases to Unlined Facilities) 

of the APP. None of the analytes were found to exceed Arizona Water Quality Standards 

(AWQS) or alert levels required by the APP (APS 2009f). 

Cooling Tower and Wastewater Treatment Facility Sludge

The APP requires that cooling tower and WTF (Wastewater Treatment Facility) sludge be 
Affected Environment 

NUREG-1437, Supplement 43 2-24 December 2010

analyzed prior to disposal in the Sludge Disposal Landfill. Wastewater Treatment Facility (WTF) 

sludge is analyzed twice a year. In 2008, eight cooling tower sludge samples were collected: 

one from the canal and one from each of the three cooling towers in Unit 3 (for a total of four 

samples in March) and one from the canal and one from each of the three cooling towers in Unit 

2 (for a total of four samples in May). These samples were analyzed for Resource Conservation 

and Recovery Act (RCRA) Toxicity Characteristic Leaching Procedure (TCLP) metals as 

specified in Table 17.2-4 of the APP. None of the samples were found to have TCLP metals 

above their laboratory reporting limits, and none of the TCLP metals exceeded their respective 

alert limits. 

Indicator Parameters

Levels of indicator parameters in monitoring wells sampled in 2008 were for the most part 

unchanged from previous years, though some wells did show elevated levels of boron and 

chloride. Boron is a naturally-occurring element derived from the weathering of volcanic rocks 

and clay-rich sedimentary rocks (APS 2009b). Chloride is also known to be high in the shallow 

aquifer due to historical agricultural practices in the area. Tritium was not detected in any wells 

in 2008 (APS 2009f). 

Water Level Data for the Shallow and Regional Aquifers

In general, water level elevations measured in the shallow aquifer during 2008 were consistent 

with historical shallow groundwater data. Water level elevations measured in the regional 

aquifer indicate the general groundwater flow direction is south-southwest. This current flow 

gradient is controlled by pumping in the Centennial Wash area to the south-southwest and by 

pumping by other power plants south of PVNGS (APS 2009f). 

Permit Violations

A partial summary of APP violations between 2004 and 2008 is provided in Table 2.1.7-3. 

During this period, most discharge-related violations involved unauthorized releases to 

Sedimentation Basin 2 during storm events. Corrective actions were taken in each event to 

address the source of the release. These most often included a combination of sampling and 

reporting, but in some cases also required design modification and repairs. 

 
Affected Environment

December 2010 2-25 NUREG-1437, Supplement 43

Table 2.1.7-3 Partial Summary of Aquifer Protection Permit Violations 2004 - 2008a

Year Day Affected Facility Event/Corrective Action 

2008 Dec 26 Sedimentation Basin 2 Overflow of the Unit 3, B Spray Pond Filters Head 

Tank during precipitation event. Estimated release of 

1,400 gallons (5,300 liters) over a period of about 6 

hours. Corrective action was to backwash the Spray 

Pond Filters at greater frequency and duration to 

improve effectiveness of the filters and reduce foam 

buildup. Analytical results did not exceed the alert 

levels specified in Table 16.3-3 of the APP. No 

changes in monitoring were made. 

2006 Jul 7b Sedimentation Basin 2 Overflow of North Yard sump during precipitation 

event. Corrective action was to install a permanent 

design change to reroute the Turbine Building roof 

drains away from the yard sumps to the cooling tower 

canals to eliminate the overloading of sumps during 

precipitation events. Completed March 13, 2007. 

2005 Aug 2c Sedimentation Basin 2 Overflow of Unit 1 yard sump during storm event. 

Corrective action included sampling the basin and 

Unit 1 HVAC NA02B to evaluate releases. Proposal 

to reroute turbine building roof drains from yard 

sumps submitted to ADEQ on December 22, 2005. 

2004 Feb 11 Sedimentation Basin 2 WRF pipeline rupture disc failure. Corrective action 

was to shutdown the Hassayampa Pump Station and 

close the isolation valve for the rupture disc. 

Temporary dirt dam was installed downstream to 

contain the concrete dam overflow. Design 

modification to install new piping to allow releases to 

be returned and maintained in the WRF. 

2004 Apr 2 Sedimentation Basin 2 Manhole and evaporator cooler release during storm 

event. Corrective action was to reinforce and 

upgrade administrative procedures. 

2004 Nov 7 Sedimentation Basin 2 Overflow of Unit 1 yard sump during storm event. 

Corrective action was to evaluate several design 

modification options to prevent recurrence. 

2004 Nov 7 Sedimentation Basin 2 Unit 3 secondary closed loop cooling water release 

during storm event. Corrective action was to install 

swagelock plug valves in Unit 3 to prevent future 

occurrences. 

2004 Nov 12 Sedimentation Basin 2 Unit 3 temporary cooling tower cooling water release 

during a storm event. Corrective action included 

rebuilding pump with new seals and instituting new 

procedures requiring that pumps be tested prior to 

use to demonstrate their performance. 
Affected Environment 

NUREG-1437, Supplement 43 2-26 December 2010

Year Day Affected Facility Event/Corrective Action 

2004 Unknown Sedimentation Basin 2 Failure of WRS liner. Tears and separations in the 

liner were discovered during inspection. Corrective 

action included sampling reservoir, making 5-day 

notification call, and repairing some tears. Signed 

Consent Order P-153-04 to provide a corrective 

action plan for the monitoring of the WRS and repair 

of the reservoir liner. 

(a) Only permit violations related to unauthorized releases are listed here. Types of violations not 

listed include: (1) failure to submit 5-day notification of performance standard exceedance; (2) 

failure to report performance standard exceedance; and, (3) failure to provide 30-day notification 

of failure to sample. 

(b) Similar events occurred on July 25, August 9, August 14, September 9 and14 in 2005. 

(c) Similar events occurred on August 8, October 17, October 18 in 2004. 

Source: APS 2009e, APS 2008f, APS 2007b, APS 2006c, and APS 2005. 

Subsurface Assessment of Tritium 

In 2006, APS discovered tritium in a PVNGS Unit 3 subsurface concrete pipe vault at 

concentrations with the potential to exceed the aquifer quality limit (AQL) as provided in the APP 

(APS 2006a). Tritium was confirmed in subsurface water, but its origin was unknown at that 

time. Since then, APS has conducted a number of investigations to characterize the extent of 

the release and to determine its source. These investigations involved identifying and leaktesting underground piping in the area where the tritiated water was found; digging a series of 

test holes to characterize the extent of tritiated water in the soil; examining other process 

systems involving tritiated water; and reviewing the operational history of the station. 

Initial investigations have found the extent of tritiated water to be limited to the vicinity of the 

PVNGS Units 2 and 3, with only the Unit 3 Radiological Controlled Area Yard having tritium 

above action levels. Tritiated water is confined to areas within small shallow basins formed by 

low permeability compacted soil and foundation structures; these features also limit its 

migration. No leaks from underground pipes associated with the Fire Protection, Essential 

Spray Ponds, Liquid Radwaste, and Chemical and Volume Control Systems were detected. 

Other sources such as those related to leaks in piping, tanks, or sumps near the affected area 

were also evaluated; no leaks were detected. Based on its ongoing investigations (of other 

tritium sources and migration pathways) and the results of dispersion modeling analysis, APS 

reports the most probable sources of tritium are washout related to past operations of the Boric 

Acid Concentrator when it may have operated during rain events (this practice was discontinued 

in the 1990s); wash down from roofs or washout from rain during times when tritium 

condensation from the ventilation system was present; and possibly small historic spills within 

the area of the small basins (APS 2006a; APS 2006b). 

A total of 16 new monitoring wells, to depths of up to 50 feet, were installed to monitor for tritium 

releases at Units 1, 2, and 3. Three wells were installed near Unit 1, five near Unit 2, and eight 

near Unit 3. Three downgradient wells (APP-9, APP-10, and APP-12) were also drilled to 

depths of 110 to 180 feet to monitor for tritium downgradient of Units 1, 2, and 3. To date, there 

has been no detectable tritium in these downgradient wells. Asphalt repairs and sealing around 

structures have been completed (APS 2008g, APS 2009e). APS continues to submit quarterly 

progress reports to ADEQ. 
Affected Environment

December 2010 2-27 NUREG-1437, Supplement 43

2.1.7.5 Surface Water Quality 

PVNGS does not release cooling water (or cooling water blowdown) effluents to any natural 

surface water body. Instead, these effluents are discharged to man-made lined evaporation 

ponds with no outlet and no hydraulic connection to any natural water body. The evaporation 

ponds are monitored in accordance with APP No. P-100388 LTF 48337 (Section 2.1.7.4).

2.2 SURROUNDING ENVIRONMENT 

PVNGS is in the west-central part of Maricopa County in southwest Arizona and is located 

about 45 miles (72 km) west of central Phoenix. The general area is located in the Sonoran 

Desert, which covers the southwest part of Arizona, southern California, and northwestern 

Mexican states. The topography around PVNGS is relatively flat terrain at an elevation of about 

950 feet (290 meters), and its surrounding area consists of scattered low hills and buttes. 

Scattered hills with peak elevations of about 1,400 feet (427 meters) are located about 3 miles 

(5 km) west of the site. The Palo Verde Hills, located about 5 miles (8 km) northwest of the site, 

are the highest hills with peaks reaching a maximum elevation of more than 2,100 feet 

(640 meters). 

The nearest population center to PVNGS is the Phoenix metropolitan area (Figure 2.1-1), which 

includes the following major cities: Phoenix, Tempe, Mesa, Glendale, Peoria, Scottsdale, and 

Sun City. The nearest town is Wintersburg (Figure 2.1-2) (APS 2008a). 

 
Affected Environment 

NUREG-1437, Supplement 43 2-28 December 2010

(Source: APS 2008a) 

Figure 2.2.1-1 Palo Verde Nuclear 

Generating Station Site Boundary 
Affected Environment

December 2010 2-29 NUREG-1437, Supplement 43

2.2.1 Land Use 

The PVNGS site occupies 4,280 acres (1732 hectares), about 17 percent (728 acres 

[294 hectares]) of which is developed. A 20-acre (8-hectare) Independent Spent Fuel Storage 

Installation facility is located northeast of the switchyard. There are 780 surface acres 

(247 hectares) of water, including three evaporation ponds covering 650 acres (194 hectares). 

The two reservoirs of the Water Reclamation Facility, which store water reclaimed from 

wastewater effluent to provide cooling water for the plant, cover 130 acres (53 hectares) 

(APS 2008a). The undeveloped area is open desert habitat. 

Interstate Highway 10 is located 6 miles (10 km) northeast of PVNGS at its closest point and 

State Route 80 is located 7 miles (11 km) southeast. An east-west railroad corridor is located 

approximately 4 miles (6 km) south-southwest of the site. Public access to the plant site is 

restricted, with no unauthorized public access or activity allowed on APS property. The site 

boundary, as shown in Figure 2.2.1-1, is posted and fenced to prevent public access. No public 

roads, railways, or waterways traverse PVNGS. 

2.2.2 Climate and Meteorology 

The area around PVNGS has a desert-like arid climate characterized by hot summers, mild 

winters, light precipitation, a high rate of evaporation, low relative humidity, abundant sunshine, 

and large temperature ranges (NCDC 2009a). The area is characterized by light winds. Based 

on 2004–2008 wind measurements at PVNGS, average wind speed at a height of 35 feet 

(10.7 meters) is about 6.7 miles per hour (mph) (10.8 km/hour) (APS 2008a), as shown in 

Figure 2.2.2. Average wind speeds are the highest in spring and summer at 7.4 mph 

(11.9 km/hour), lower in fall at 6.1 mph (9.8 km/hour), and lowest in winter at 5.7 mph 

(9.2 km/hour). At PVNGS, the prevailing wind direction is from the southwest about 15 percent 

of the time. Winds blow from the southwest during April through August and from the north 

during October through February, with a transition between southwest and north in March and 

September. Prevailing wind directions are greatly influenced by local topography (NCDC 

2009a). 

In Arizona, topography plays a large role in determining the temperature of any specific location. 

Hot temperatures over 100°F (37.8°C) are common throughout the summer months at the lower 

elevations in the southwest of the State. For the 1893–2003 period, the annual average 

temperature at Buckeye, which is located about 14 miles (22.5 km) east of PVNGS, was 69.9°F 

(21.1°C) (WRCC 2009). January was the coldest month with an average minimum of 34.6°F 

(1.4°C), and July was the warmest month with an average maximum of 107.1°F (41.7°C). In 

summer, daytime maximum temperatures frequently exceed 110°F (43.3°C) in the afternoon 

and remain above 85°F (29.4°C) throughout the night. On average, for more than twelve days 

in December and January, minimum temperatures are below freezing. For the same period, the 

highest temperatures reached 125°F (51.7°C) in July 1995 and the lowest reached 11°F 

(–11.7°C) in January 1913. Annually, about 175 days have maximum temperatures greater 

than or equal to 90°F (32.2°C), while about 36 days have minimum temperatures at or below 

freezing. 

Throughout Arizona, precipitation patterns largely depend on elevation and the season of the 

year. Rain comes mostly in two distinct seasons (winter and summer monsoon seasons) 

(NCDC 2009b). From November to March, periodic rains are associated with 
Affected Environment 

NUREG-1437, Supplement 43 2-30 December 2010

Figure 2.2.2 Wind Rose at 35-foot at PVNGS 2004–2008 (APS 2008a) 
Affected Environment

December 2010 2-31 NUREG-1437, Supplement 43

winter storms originating from the Pacific Ocean. The summer monsoon usually begins early in 

July and lasts until mid-September. The intense summer heat causes air pressure over land to 

drop, forming an area of low pressure that allows cooler and more humid air over the ocean to 

be drawn into the area. This cooler and more humid air from the ocean overriding the hotter 

and drier air on land becomes unstable, triggering thunderstorms. Moisture sources include the 

Gulf of Mexico, the Pacific Ocean off the west coast of Mexico, and the Gulf of California. 

These summer thunderstorms, which peak in July and August, are often accompanied by strong 

winds and periods of blowing dust along with occasional hail. Typically, May and June are the 

driest months. For the 1893–2003 period, annual precipitation at Buckeye averaged about 

7.59 inches (19.3 centimeters) (WRCC 2009). Seasonal precipitation was highest at 

2.50 inches (6.35 centimeters) in winter, followed by summer at 2.07 inches (5.26 centimeters), 

and reached a low of 1.13 inches (2.87 centimeters) in spring. Trace amounts of snow occur as 

early as December or as late as March, but measurable snowfall in the desert areas of southern 

Arizona including PVNGS is a rarity (NCDC 2009a). 

Severe weather events, such as dust storms, thunderstorm winds, flash floods, and tornadoes, 

have been reported for Maricopa County (NCDC 2009c). On occasion, high winds in 

combination with dry and loose soil conditions result in blowing dust, which typically occurs 

during the afternoons of hot summer days. Dust storms can deteriorate air quality and visibility, 

creating traffic hazards. Dust storms can also have adverse effects on health, particularly for 

the young, the elderly, and people with asthma or other respiratory problems. Winds 

accompanying heavy thunderstorms mostly occur in the late afternoon during July through 

September. For the period 1950–2009, more than 10 thunderstorm wind events per year 

occurred on average in Maricopa County, sometimes reaching peak gusts of about 115 mph 

(185 km per hour) in local areas. These thunderstorm winds caused some deaths and injuries 

and considerable property damage. 

Flash flooding, due to excessive rain falling in a small area during a short period, causes 

considerable local damage in Arizona. Flash floods are usually associated with summer 

monsoon thunderstorms or the remnants of tropical storms. Between 1950 and 2009, Maricopa 

County experienced more than five floods per year, and these floods caused some deaths and 

injuries and considerable damage to property and crops. Tornadoes in Maricopa County occur 

less frequently and are less destructive than those in the central United States. For the period 

1950–2009, a total of 57 tornadoes (about one tornado per year) were reported in Maricopa 

County. However, most of the tornadoes were relatively weak. These tornadoes caused 

property damage and 57 injuries, but no deaths were reported. 

2.2.2.1 Air Quality Impacts 

The Maricopa County Air Quality Department (MCAQD) is a regulatory agency whose primary 

responsibility is to ensure that Federal clean air standards are achieved and maintained. In 

doing so, the MCAQD administers several programs, such as air permits to regulate air 

emission sources including fugitive dust and open burning, air monitoring for compliance with 

the National Ambient Air Quality Standards (NAAQS), and vehicle repair and retrofit. Currently, 

more than 20 air monitoring stations are established in downtown Phoenix and the surrounding 

areas in Maricopa County. Buckeye, located about 14 miles (22.5 km) east of PVNGS, is the 

nearest air monitoring station where particulate matter with an aerodynamic diameter of 

10 microns or less (PM10), carbon monoxide (CO), nitrogen dioxide (NO2), and ozone (O3) are 

monitored. 

PVNGS is not listed as a Major Source but instead is a Synthetic Minor Source with respect to 
Affected Environment 

NUREG-1437, Supplement 43 2-32 December 2010

its potential to emit (PTE)3 criteria pollutants or hazardous air pollutants (HAPs)4 and is not 

required to secure a Title V permit for all stationary sources of air pollution. However, PVNGS is 

required to obtain and maintain a Non-Title V permit from the MCAQD for its stationary emission 

sources. PVNGS received a Non-Title V (Synthetic Minor) air quality permit (Permit No. 

030132) from the MCAQD on August 18, 2005 (MCAQD 2005). (Non-Title V permits are issued 

to sources having actual emissions that are at least 50 percent of the Major Source emissions 

thresholds.) Permit stipulations include regulating source-specific emission limits, monitoring, 

operational requirements, recordkeeping, and reporting. 

PVNGS has a number of sources of criteria pollutants and HAPs: fuel burning equipment 

(including boilers), internal combustion engines and turbines (including emergency generators 

and two blackout gas turbine generators), petroleum storage tanks, spray coating (including 

spray booth), solvent cleaning equipment, abrasive blasting equipment, water reclamation 

equipment (including lime, soda ash, and salt storage silos), cooling towers, steam generator 

cleaning equipment, and other miscellaneous equipment. Lime/soda ash/salt operations 

release primarily particulate matter, and cooling towers release particulate matter (chemically 

treated cooling water) as drift along with the volatile organic compound (VOC) chloroform, 

present in the cooling water as a by-product from disinfection of the water by chlorination. 

Combustion sources emit most of the criteria pollutants (to be discussed below), VOCs, and a 

small amount of HAPs, such as chloroform, ethyl benzene, methyl isobutyl ketone, toluene, and 

xylene. Fuel storage tanks and chemical use operations account for evaporative VOC 

emissions. Emissions inventory data reported to the MCAQD for calendar years 2004 through 

2008 are presented in Table 2.2.2-1, which includes permitted, total (permitted and permitexempted), and allowable emissions from PVNGS specified in the permit. During the period 

2004–2008, emissions of criteria pollutants, VOCs, and HAPs varied from year to year, but all 

reported emissions (permitted source emissions only) on a calendar-year total basis were under 

the thresholds specified in the permit on a 12-month rolling total basis, except for the Notice of 

Violations to be discussed below. For the same period, there were no air emissions from 

accidental releases and no lead emissions were reported to be released from PVNGS. As 

shown in Table 2.2.2-1, annual emissions for carbon dioxide (CO2), a primary greenhouse gas, 

were estimated by NRC staff for combustion sources at PVNGS for the 2004-2008 period. 

These estimates were based on EPA’s AP-42 emission factor for uncontrolled gasoline and 

diesel industrial engines (Section 3.3, Table 3.3-1, EPA 2010a) and annual diesel consumption 

data from the applicant. Estimated annual CO2 emissions are well below the EPA’s mandatory 

reporting threshold of 25,000 metric tons CO2 equivalent per year (74 FR 56264). 

Since the issuance of the permit (August 18, 2005), the MCAQD has issued three Notices of 

Violation (NOVs) to PVNGS (Bement 2008). The first NOV related to failure to comply with 

trackout requirements pursuant to Maricopa County Air Pollution Control Regulation, on October 

 

3 Per 40 CFR 52.21(b)(4), ”potential to emit means the maximum capacity of a stationary source to emit a pollutant 

under its physical and operational design. Any physical or operational limitation on the capacity of the source to 

emit a pollutant, including air pollution control equipment and restrictions on hours of operation or on the type or 

amount of material combusted, stored, or processed, shall be treated as part of its design if the limitations or the 

effect it would have on the emissions is federally enforceable.”

4 Under the Title V operating permit program, the EPA defines a Major Source as a stationary source with the 

potential to emit (PTE) more than 100 tons per year of any criteria pollutant, more than 10 ton per year of any 

single HAP, or 25 tons per year of any combination of HAPs. Major Sources are required to obtain a Title V 

permit. A Synthetic Minor Source is one that can apply administrative controls on its sources to keep emissions 

of criteria pollutants and HAPs below the above limits. Synthetic Minor Sources are not required to obtain a 

Title V permit, but may nevertheless be required to obtain a non-Title V permit from an EPA-authorized State or 

local air program regulatory authority.
Affected Environment

December 2010 2-33 NUREG-1437, Supplement 43

26, 2006. This occurred during an earthmoving operation when a contractor for APS was 

working along the water reclamation supply line. Two of the NOVs were related to cooling tower 

PM10 emission tests: (1) for failure to comply with the permit condition that requires APS Palo 

Verde to limit PM10 emissions to less than 54.0 tons on a 12-month rolling total basis (on 

November 22, 2006) 

Table 2.2.2-1 PVNGS Annual Emissions Inventory Summaries, 2004-2008 

Annual Emissions (tons/yr)a,b

Year CO NOx PM10 SOx VOCs HAPs NHx CO2

c

2004 

13.19 

(17.32)d

50.11 

(58.21) 

34.05 

(34.62) 

0.69 

(0.75) 

29.03 

(29.62) –

e 7.47 2,986 

2005 16.38 

(24.61) 

62.03 

(82.63) 

30.83 

(31.08) 

1.02 

(1.27) 

26.90 

(28.76) 4.08/2.22f 5.71 3,306 

2006 18.53 

(26.46) 

70.42 

(89.51) 

27.74 

(27.97) 

1.15 

(1.38) 

18.32 

(20.06) 3.76/2.23 1.58 3,733 

2007 14.40 

(49.13) 

54.08 

(97.82) 

4.91 

(7.99) 

0.89 

(1.43) 

26.72 

(31.47) 3.35/1.30 3.42 2,861 

2008 15.33 

(38.22) 

58.22 

(96.75) 

4.01 

(6.71) 

0.96 

(1.43) 

21.97 

(25.80) 3.18/1.33 2.69 3,121 

Permittedg 45.0 95.0 54.0 4.0 35.0 8.0/3.0 – – 

a

 CO = carbon monoxide; CO2 = carbon dioxide; HAPs = hazardous air pollutants; NHx = ammonia and 

ammonium compounds; NOx = nitrogen oxides; PM2.5 = particulate matter ≤2.5 μm; PM10 = particulate matter 

≤10 μm; SOx = sulfur oxides; and VOCs = volatile organic compounds. 

b

 To convert “ton” to “metric ton,” multiply by 0.9072. 

c

 Estimated by NRC Staff using EPA’s AP-42 emission factor for uncontrolled gasoline and diesel industrial 

engines (Section 3.3, Table 3.3-1) and annual diesel consumption data from the applicant. 

d

 Values in parentheses denote total emissions including permitted and permit-exempted sources. 

e

 Not available. 

f

 Total HAPs emissions/highest single HAP emission. Every year chloroform has the highest emission (about 39 

to 59 percent of total HAPs emission), followed by xylene (about 33 to 41 percent of total HAPs emission), 

among HAPs included in the annual HAPs report (chloroform, ethyl benzene, methyl isobutyl ketone, toluene, 

and xylene). 

g

 Twelve-month rolling total emissions. 

Source: APS 2005, 2006, 2007, 2008, 2009b and EPA 2010a. 

and (2) for failure to comply with the permit condition that requires APS Palo Verde to limit PM10

emissions to less than 5.6 tons per month (on November 2, 2007). On February 28, 2008, 

these three NOVs were resolved with Maricopa County. 

Each of the emergency generators is enrolled in a preventative maintenance program, the 

specific steps of which are outlined in an APS internal procedure. The program requires 

periodic operation for brief periods during nonemergency conditions to ensure each generator’s 

continuous operability. On average, each generator runs approximately 100 hours each year, 
Affected Environment 

NUREG-1437, Supplement 43 2-34 December 2010

notwithstanding responses to power outages. All generators use ultra-low-sulfur diesel (sulfur 

content of 15 ppm or less) provided through a local commercial vendor. PVNGS maintains 

records of all generator operation (by recording hours of operation from nonresettable meters) in 

order to demonstrate continued eligibility for emergency generator status exemptions contained 

in Federal and Maricopa County regulations. 

Internal procedures are in place to ensure proper management of refrigerants present in 

heating, ventilating, and air-conditioning (HVAC) equipment and in industrial chillers and 

coolers. HVAC equipment and industrial chillers containing refrigerants are maintained by APS 

employees with the required EPA training and certification for handling ozone-depleting 

substances. Maintenance and repair actions are documented by a work order system in which 

a technician specifies the nature of the activity, the repair that was accomplished, and the 

amount of refrigerant introduced to complete the repair, if necessary. A commercial software 

program is used to track refrigerant leakage rates to maintain compliance with leakage rate 

limitations in Federal regulations. Other properly certified technicians service the air 

conditioners in APS-owned vehicles in the onsite garage. All vehicles now use R-134a 

exclusively in their motor vehicle air conditioners (MVACs). Health physics technicians support 

the servicing and repair of refrigerant-containing equipment located in the industrial area of the 

facility by performing surveys for radioactive contamination of components removed from that 

equipment (e.g., air filters), whenever the potential for radioactive contamination exists. 

Under the Clean Air Act (CAA), the U.S. Environmental Protection Agency (EPA) has set 

NAAQS for pollutants considered harmful to public health and the environment (40 CFR Part 

50) (EPA 2010b). NAAQS is established for criteria pollutants — CO, lead (Pb), NO2, PM10, 

particulate matter with an aerodynamic diameter of 2.5 microns or less (PM2.5), O3, and sulfur 

dioxide (SO2), as shown in Table 2.2.2-2. The CAA established two types of NAAQS: primary 

standards to protect public health including sensitive populations (e.g., the young, the elderly, 

those with respiratory disease) and secondary standards to protect public welfare, including 

protection against degraded visibility and damage to animals, crops, vegetation, and buildings. 

Some States established State Ambient Air Quality Standards (SAAQS), which can adopt the 

Federal standards or be more stringent than the NAAQS. The State of Arizona has no SAAQS 

but instead has adopted the NAAQS. 

Maricopa County is located in the Maricopa Intrastate Air Quality Control Region (AQCR) 

(40 CFR 81.36). The Maricopa AQCR is designated as a basic (subpart 1)5

 nonattainment area 

for 8-hour ozone and a serious nonattainment area for PM10 (40 CFR 81.303). The Maricopa 

AQCR is also designated as a serious maintenance area for CO. PVNGS is outside of the PM10

nonattainment area and the CO maintenance area, but is about 2.5 miles (4.0 km) inside of the 

8-hour ozone nonattainment area (ADEQ 2009). The remaining portions of Maricopa County 

are designated as an attainment area for all criteria pollutants.6

 

5 An area designated as a basic (or subpart 1) nonattainment is required to attain the standard within 5 to 10 years 

after its designation.

6 Areas considered to have air quality as good as or better than NAAQS are designated by EPA as “attainment 

areas”. Areas where air quality is worse than NAAQS are designated by EPA as “nonattainment areas.” Areas 

that previously were nonattainment areas but where air quality has since improved to meet the NAAQS are 

redesignated “maintenance areas” and are subject to an air quality maintenance plan. 
Affected Environment

December 2010 2-35 NUREG-1437, Supplement 43

Table 2.2.2-2 National Ambient Air Quality Standards (NAAQS)a

NAAQS 

Pollutantb Averaging Time Value Typec

CO 1-hour 35 ppm (40 mg/m3) P 

8-hour 9 ppm (10 mg/m3) P 

Pb Quarterly average 1.5 μg/m3 P, S 

Rolling 3-month average 0.15 μg/m3 P, S 

NO2 1-hour 100 ppb P 

Annual (arithmetic mean) 53 ppb P, S 

PM10 24-hour 150 μg/m3 P, S 

PM2.5 24-hour 35 μg/m3 P, S 

Annual (arithmetic mean) 15.0 μg/m3 P, S 

O3 1-hour 0.12 ppmd P, S 

8-hour 0.08 ppm (1997 standard) P, S 

8-hour 0.075 ppm (2008 standard) P, S 

SO2 1-hour 75 ppb P 

3-hour 0.5 ppm S 

24-hour 0.14 ppm P 

Annual (arithmetic mean) 0.03 ppm P 

(a) Refer to 40 CFR Part 50 for detailed information on attainment determination and reference method 

for monitoring. 

(b) CO = carbon monoxide; NO2 = nitrogen dioxide; O3 = ozone; Pb = lead; PM2.5 = particulate matter 

≤2.5 μm; PM10 = particulate matter ≤10 μm; and SO2 = sulfur dioxide. 

(c) P = primary standards, which set limits to protect public health; S = secondary standards, which set 

limits to protect public welfare including protection against degraded visibility, damage to animals, 

crops, vegetation, and buildings. 

(d) EPA revoked the 1-hour ozone standard in all areas, although some areas have continuing 

obligations under that standard (“anti-backsliding”). 

Source: EPA 2010b. 

The Clean Air Act requires states with areas failing to meet the NAAQS to produce a State 

Implementation Plan (SIP). A SIP is an enforceable plan developed at the state and local level, 

submitted to and approved by EPA that explains how the area will comply with the NAAQS 

according to the Clean Air Act. The Maricopa Association of Governments (MAG), together with 

the Arizona Department of Environmental Quality, is responsible for Arizona SIP requirements 

in the Maricopa County nonattainment areas. The MAG has an EPA approved eight-hour 

Ozone Plan for the Maricopa Nonattainment Area that includes PVNGS as part the SIP 

(MCAQD, 2010; ADEQ, 2010a). 

In recent years, five revisions to the NAAQS have been promulgated. Effective 

December 18, 2006, EPA revoked the annual PM10 standard of 50 micrograms per cubic meter 

(μg/m3) and revised the 24-hour PM2.5 standard from the original level of 65 μg/m3 to 35 μg/m3

(71 FR 61144). In Maricopa County, 24-hour and annual PM10 concentrations have exceeded 

their respective standards. The 2006–2008 monitoring data show Maricopa County to be in 

attainment for 24-hour and annual PM2.5 NAAQS, and thus Maricopa County would not be 

expected to be classified as a nonattainment area for PM2.5 in the near future (EPA 2009b). 

Effective May 27, 2008, the EPA revised the 8-hour ozone standards from 0.08 ppm to 

0.075 ppm (73 FR 16436), but the nonattainment status for Maricopa County will continue to be 
Affected Environment 

NUREG-1437, Supplement 43 2-36 December 2010

the same under the new standard (Wardwell 2009). Effective January 12, 2009, the EPA 

revised the Pb standard from a calendar-quarter average of 1.5 μg/m3

 to a rolling 3-month 

average of 0.15 μg/m3 (73 FR 66964). A designation letter sent by the Arizona Department of 

Environmental Quality to the EPA recommends an “unclassifiable” status for Maricopa County. 

Effective April 12, 2010, the EPA introduced the 1-hour NO2 standard of 100 ppb (75 FR 6474), 

and, effective August 23, 2010, the EPA established the 1-hour SO2 standard of 75 ppb (75 FR 

35520). Currently, no measurement data to determine the attainment/nonattainment status for 

these standards are available. 

In addition to capping increases in criteria pollutant concentrations below the levels set by the 

NAAQS, the Prevention of Significant Deterioration (PSD) regulations (40 CFR 52.21) mandate 

stringent control technology requirements for new and modified major sources. As a matter of 

policy, EPA recommends that the permitting authority notify the Federal Land Managers (FLMs) 

when a proposed PSD source would locate within 62 miles (100 km) of a Class I area. If the 

source's emissions are considerably large, EPA recommends that sources beyond 62 miles 

(100 km) be brought to the attention of the FLMs. The FLMs then become responsible for 

demonstrating that the source's emissions could have an adverse effect on air quality-related 

values (AQRVs), such as scenic, cultural, biological, and recreational resources. There are 

several Class I areas around PVNGS, none of which are situated within the 62-mile (100 km) 

range. The nearest Class I areas include the Superstition Wilderness Area, the Mazatzal 

Wilderness Area, and the Pine Mountain Wilderness Area, about 80 miles (129 km) east, 

northeast, and northeast, respectively, of PVNGS (40 CFR 81.421). All these Class I areas are 

managed by the U.S. Forest Service. Considering the locations and elevations of these Class I 

areas, prevailing wind directions, distances from PVNGS, and minor nature of air emissions 

from PVNGS, there is little likelihood that activities at PVNGS can adversely impact air quality 

and AQRVs in any of these Class I areas. 

The meteorological tower is located approximately 2,200 feet (671 meters) and 3,500 feet 

(1,067 meters) west-northwest of the Unit 2 cooling tower and the reactor building, respectively. 

Land areas and topography immediately surrounding the tower, as well as the distance of the 

tower from the reactor building and other permanent structures, suggest that no significant 

interferences to air flow exist that would compromise the quality of recovered meteorological 

data. Two trains of instruments, designated as primary and redundant, are mounted on the 

meteorological tower. A lower set of instruments, located at a height of 35 feet (10.7 meters), 

records wind speed and direction, standard deviation of wind direction, temperature, and dew 

point. The upper set of instruments, located at a height of 200 feet (61.0 meters), also records 

wind speed and direction, standard deviation of wind direction, and temperature. Precipitation 

data from a rain gauge are also collected near the base of the tower. 

Sensor information from the tower is converted to digital data by four separate reliable digital 

processor systems, and transmitted by two separate serial links to the meteorological data 

transmission station (MDTS) translator/server (DataLink). After being converted to a form 

recognizable to the Emergency Response Facility Data Acquisition Display System (ERFDADS) 

server, these data is displayed on all ERFDADS terminals and made available for time-history 

displays in the control room, emergency response facilities, and at external locations. These 

data serve as inputs to the plume dispersion models to estimate offsite exposures under 

emergency situations. To guarantee operational reliability, redundant power is supplied to the 

meteorological instruments and their respective data recorders. 

The meteorological data collection program at PVNGS is subject to detailed APS quality 

assurance and quality control procedures. Meteorological instruments are calibrated at 
Affected Environment

December 2010 2-37 NUREG-1437, Supplement 43

scheduled intervals and are subjected to routine inspection and maintenance in accordance with 

the manufacturer’s specifications and written internal procedures that require visual inspections 

of the meteorological instruments, verification of the performance through measurements, and 

documentation of the status of the key performance indicators. 

2.2.3 Groundwater Resources 

PVNGS is located on a desert alluvial plain in the Hassayampa River valley in an area that was 

once irrigated (cotton) cropland (APS 2001). The site is within the Lower Hassayampa Subbasin of the Phoenix Active Management Area (AMA). The Phoenix AMA is one of five AMAs 

established as part of the Arizona 1980 Groundwater Management Act (ARS §§ 45-401 et seq.) 

and regulated by the Arizona Department of Water Resources (ADWR 2009). The 

Hassayampa Sub-basin covers an area of about 1,200 sq mi (3,108 sq km) and is bounded on 

the north by the Vulture Mountains and the Wickenburg Mountains; on the east by the White 

Tank Mountains; on the south by the Buckeye Hills and the Gila Bend Mountains; and on the 

west by the Big Horn Mountains, the Belmont Mountains, and the Palo Verde Hills 

(Figure 2.2.3-1). The Lower Hassayampa Sub-basin covers about 400 sq mi (1,036 sq km) of 

the southern Hassayampa Sub-basin (APS 2001). 

Groundwater in the Lower Hassayampa Sub-basin occurs regionally in basin-fill alluvial 

sediments and locally in the thin layers of more recent stream alluvium. Groundwater in the 

region is predominantly under unconfined (water table) conditions, but may be under confined 

(artesian) conditions locally. Both confined and perched (saturated zones above the water 

table) conditions occur in the vicinity of PVNGS (Long 1982; ADEQ 2009a). An estimated 

4.8 million acre-feet (5.92 billion cubic meters) of groundwater were available to a depth of 

1,200 feet (366 meters) in the Hassayampa Sub-basin in 1995 (Maricopa County 2001). 

Groundwater flow is generally to the southwest toward cones of depression in the Tonopah 

Desert and Centennial Wash area (ADWR 2008). 

Basin-fill sediments in the Lower Hassayampa Sub-basin are divided into three major 

hydrogeologic units: the Upper Alluvial Unit, the Middle Fine-Grained Unit, and the Lower 

Coarse-Grained Unit. The Upper Alluvial Unit, also referred to as the shallow aquifer, occurs in 

areas along the Hassayampa and Gila Rivers. The unit is 30 to 60 feet (9.1 to 18.3 meters) 

thick and is predominantly made up of silty and gravelly sands with discontinuous lenses of clay 

and silty clay. Groundwater in the upper unit is unconfined in most of the sub-basin. Perched 

groundwater was identified at depths of 13 to 90 feet (4 to 27.4 meters) below PVNGS in the 

early 1980s, but has been declining since that time, due to cessation of irrigation practices. 

Groundwater measurements suggest groundwater flow in the shallow aquifer radiates outward 

from the center of PVNGS (Figure 2.2.3-2). This flow pattern has been present since at least 

1985. It is thought to be due mainly to the 25 years of heavy irrigation that occurred at the site 

prior to construction and the low permeability of the Middle Fine-Grained Unit which impedes 

the downward movement of groundwater (APS 2009c). Wells along the PVNGS site’s 

perimeter have groundwater elevations between those measured for the intermediate and 

shallow aquifers at the center of the site; this is likely due to a steeply sloping gradient in the 

shallow aquifer and downward movement of groundwater from the shallow and intermediate 

aquifers. The term “uppermost” aquifer is often used in place of “shallow aquifer” because the 

shallow and intermediate aquifers may be in hydraulic communication along the perimeter, 

(Long 1982; APS 2001; ADEQ 2009a). 
Affected Environment 

NUREG-1437, Supplement 43 2-38 December 2010

Figure 2.2.3-1 Surface Features in the Vicinity of the PVNGS 
Affected Environment

December 2010 2-39 NUREG-1437, Supplement 43

Figure 2.2.3-2 Groundwater Flow in shallow aquifer below PVNGS (APS 2009c) 
Affected Environment 

NUREG-1437, Supplement 43 2-40 December 2010

The Middle Fine-Grained Unit is 230 to 300 feet (70.1 to 91.4 meters) thick and consists of 

massive, continuous layers of clay and silty clay interbedded with thinner discontinuous lenses 

of clayey silt, clayey sand, and silty sand. It includes the Palo Verde Clay, a 60- to 80-foot 

(18.3- to 24.4-meter) clay unit that acts as a confining layer to the regional aquifer in the vicinity 

of the Palo Verde Hills (to the west) and a perching layer at PVNGS. The Palo Verde Clay is 

continuous throughout PVNGS and extends at least 5 mi (8 km) to the southeast and northeast. 

The intermediate aquifer is the portion of the Middle Fine-Grained Unit that lies between the 

Palo Verde Clay and the shallow aquifer (Long 1982; APS 2001; ADEQ 2009a). 

The Lower Coarse-Grained Unit ranges in thickness from about 100 feet (30.5 meters) to as 

much as 1,400 feet (427 meters) near PVNGS. The unit is predominantly made up of silty sand, 

sand, and gravelly sand and deeper, more consolidated alluvial fan deposits. Together, the 

middle and lower units (and various local bedrock units) comprise the regional aquifer and are 

the main water-bearing units in the area (Long 1982). The regional aquifer in the area of 

PVNGS is under confined to semi-confined conditions (ADEQ 2009a). Recharge to the regional 

aquifer is primarily from underflow from the Upper Hassayampa Sub-basin. Maricopa County 

estimates the annual rate of recharge to the Hassayampa Sub-basin to be on the order of 

29,000 acre-feet (35.8 million cubic meters) (MC 2001). Infiltration of precipitation, surface 

runoff, and irrigation return flow are less important sources of recharge because the lowpermeability clays of the middle unit impede the downward migration of water. Groundwater 

flow in the regional aquifer below the portion of PVNGS just south of the evaporation ponds is to 

the south-southwest (APS 2001; ADEQ 2009a). 

2.2.4 Surface Water Resources 

PVNGS is located in the Hassayampa Sub-basin that is drained by the Hassayampa River, an 

ephemeral river that enters the sub-basin from the northeast and joins the Gila River east of 

Arlington (Figure 2.2.3-1). The Gila River flows westward with effluent from the west Phoenix 

metropolitan area, crossing the southeastern tip of the sub-basin and joining the Colorado River 

near Yuma, Arizona. Flow in the Gila River is perennial below the 91st Avenue and 23rd Avenue 

Wastewater Treatment Plants, but is ephemeral along most other stretches, flowing only during 

rainfall events. Local ephemeral drainages include Centennial Wash, Winters Wash, and East 

Wash. The East Wash does not show up on regional maps but has been mapped by the 

PVNGS staff (see Figure 2.1.7-1). It has been rerouted to a new drainage ditch running along 

the east side of PVNGS (APS 2008b). 

There are no dams on the Hassayampa River, Winters Wash, or East Wash. Centennial Wash 

has several small detention dams. The largest is located about 45 mi (72 km) upstream from 

PVNGS and has a capacity of about 100 acre-feet (123,348 cubic meters). There are several 

large water-storage dams on the Gila River upstream from the site (APS 2008b). 

With the exception of East Wash, there are no natural surface water bodies on or immediately 

adjacent to PVNGS. The facility does not draw its cooling (or makeup) water from any natural 

surface water body in the area. It also does not release cooling water (or cooling water 

blowdown) effluents to any natural surface water body. Instead, these effluents are discharged 

to man-made lined evaporation ponds with no outlet and no hydraulic connection to any natural 

water body (discussed in Section 2.1.7). 
Affected Environment

December 2010 2-41 NUREG-1437, Supplement 43

2.2.5 Aquatic Resources 

APS purchases wastewater from Phoenix-area treatment plants for cooling water. PVNGS is 

the only nuclear plant in the U.S. that does not draw directly from a natural surface water body. 

Phoenix’s 91st Avenue and Tolleson treatment plants supply the majority of wastewater, 

followed by the city of Goodyear’s treatment plant. PVNGS uses about 53,000 acre-feet 

(17 x 109

 gal or 65 x 106 m3) of wastewater annually (ADWR 2008a). 

PVNGS has constructed surface water bodies, described in Section 2.1.7, that APS did not 

intend to support natural populations (APS 2008a). PVNGS treats incoming wastewater from 

Phoenix area sewage treatment plants at its Water Reclamation Facility before pumping it to 

two large, lined storage reservoirs. The treatment process includes chlorination, which kills 

many microscopic organisms. The storage reservoirs support few aquatic organisms and no 

brine shrimp. The liner prevents colonization by rooted aquatic plants that might provide food 

for ducks and other wildfowl, although birds do use the reservoirs (APS 2008a). 

Cooling tower blowdown is released to three evaporation ponds rather than to natural surface 

water bodies. The blowdown recirculates through many cooling cycles in the cooling towers, 

and so dissolved solid levels are high when the blowdown is released to the evaporation ponds. 

In terms of salinity, concentrations in the evaporation ponds in 2005 ranged from about 

38 to 94 parts per thousand (ppt) (APS 2008a). For perspective, this range exceeds the typical 

range of open ocean salinities, about 33 to 37 ppt, and overlaps the range of typical salinities in 

Utah’s Great Salt Lake, from below 50 to 270 ppt (Utah Government Services 2010). 

Evaporation Pond 1 was constructed in 1981. It is 250 acres and fairly uniform in depth and 

chemical composition. Evaporation Pond 2 was constructed in 1987. It is 230 acres and 

shallower at the north end, which has resulted in stratification and a difference between surface 

and bottom chemical samples (Hillmer 1996). Evaporation Pond 3 was constructed in 2009. It 

is 180 acres and divided into two cells, 3A (west) and 3B (east), that operate independently. 

Biological sampling of Evaporation Ponds 1 and 2 was performed in 1995 and 1996 (Hillmer 

1996). The two ponds developed different but relatively simple aquatic communities that 

changed with the seasons. Various algae formed the base of the food webs: typically 

filamentous and single cell blue-green algae (Cyanobacteria), centric and pennate diatoms 

(Bacillariophyceae), flagellated and colonial green algae and desmids (green algae or 

Chlorophyta), and others. Single-celled animals observed include amoebae, ciliates, and 

others. 

Brine shrimp (Crustacea: Artemia salina) fed on protozoa and algae in the water column, and 

abundant water boatmen (Insecta: Trichocorixa sp.) live on the surface. This genus of water 

boatmen is predaceous and has been observed eating the brine shrimp in the evaporation 

ponds. Birds, in turn, have been observed eating the water boatmen in the ponds. Damselflies 

and dragonflies (Insecta, Odonata) have been observed around the storage reservoirs. Ducks 

and other wildfowl have been observed on and around the ponds. Hilmer (1996) did not 

mention collecting brine flies, which are an ecologically important component of natural inland 

saline lakes such as Mono Lake and the Great Salt Lake. 

In 1995-96, PVNGS conducted a biological and chemical study of its evaporation ponds in 

response to a die-off of waterfowl (discussed in Section 2.2.6) that were found primarily in the 

PVNGS evaporation ponds between November 1994 and January 1995. In this study, Hillmer 

(1996) characterized the food web as being typical of coastal and estuarine basins and of inland 
Affected Environment 

NUREG-1437, Supplement 43 2-42 December 2010

saline lakes such as Mono Lake. He reported that the algae in the reservoirs and evaporation 

ponds were not commonly toxic. Although he did not investigate bioaccumulation of 

contaminants and biomagnification up the food chain, he concluded that with the exception of 

selenium, heavy metals and contaminants that are typically of concern for these processes had 

not been detected in the ponds. 

These biological observations are over a decade and a half old. The chemical and physical 

environment of the reservoirs and ponds should not have changed, however, and would support 

only a limited group of species. The NRC staff therefore believes the observations in Hillmer 

(1996) adequately characterize the structure and function of the aquatic biological communities 

in the reservoirs and evaporation ponds today. 

2.2.6 Terrestrial Resources 

PVNGS lies in the largest and driest subdivision of the Sonoran Desert, and many plants are 

restricted to drainage cuts. This subdivision contains the lower drainages of both the Colorado 

River and the Gila River. The valley is dominated by shrubs, principally creosote bush (Larrea 

divaricata) and white bursage (Ambrosia dumosa) (CSDS 2009). 

The Sonoran Desert has the most vegetative diversity of any desert worldwide. The Saguaro 

cactus (Carnegiea gigantean), the largest of cacti species, is only found within the Sonoran 

Desert, specifically those portions in southern Arizona, southeastern California, and northern 

Mexico (NPS 2003). Other common cacti include cholla cactus (Opuntia fulgida), organ pipe 

(Lemaireocereus thurderi), silver dollar cactus (O. chlorotica), and jojoba (Simmondsia 

chinensis); (WWF 2001). 

Annual and biennial herbs and grasses make up the majority of vegetation. Typical native plant 

communities include creosote bush plains, saltbush plains, mesquite washes, creosote bushsaltbush plains, and creosote bush-cacti hills (NRC 1975). Creosote bush, burrobush 

(Ambrosia dumosa), and saltbush (Atriplex spp.) are the most common shrubs on PVNGS (APS 

2008a). 

The Sonoran Desert, as a whole, contains relatively high wildlife biodiversity. An estimated 130 

mammal species, 20 amphibian species, 150 reptile species, 25 fish species, and 500 bird 

species inhabit this region. Common wildlife include Sonoran pronghorn antelope (Antilocapra 

sonoriensis), desert bighorn sheep (Ovis canadensis), Bailey’s pocket mice (Perognathus 

baileyi), black-tailed jackrabbits (Lepus californicus), round-tailed ground squirrels 

(Spermophilus tereticaudus), California leaf-nosed bats (Macrotus californicus), mountain lions 

(Felis concolor), and coyotes (Canis lantrans) (WWF 2001). 

Fifty-eight known species of reptiles are found in the United States portions of the Sonoran 

Desert, including the Sonoran desert tortoise (Gopherus agassizii), Gila monster (Heloderma 

suspectum), and tiger salamander (Ambystoma tigrinum) (WWF 2001). A variety of reptiles are 

known to inhabit PVNGS and vicinity, specifically, including the western whiptail lizard 

(Cnemidophorus tigris), western diamondback rattlesnake (Crotelus atrox), chuckwalla 

(Sauromalus obesus), and horned lizard (Phrynosoma; APS 2008a, NRC 1975). 

Forty-one percent of all terrestrial bird species in the United States inhabit, pass or migrate 

through the Sonoran Desert making it one of the most diverse birding areas in the country 

(WWF 2001). Species commonly found in this region include the roadrunner (Geococcyx 

californianus), cactus wren (Calypte costae), black-tailed gnatcatcher (Polioptila melanura), 
Affected Environment

December 2010 2-43 NUREG-1437, Supplement 43

phainopepla (Phainopepla nitens), Gila woodpecker (Melanerpes uropygualis), and Costa’s 

hummingbird (Calypte costae) (WWF 2001). 

In November 1994 through January 1995, PVNGS identified 829 dead waterfowl in the PVNGS 

evaporation ponds and Water Storage Reservoir, the majority of which were Northern shovelers 

(Anas clypeata) and ruddy ducks (Oxyura jamaicensis) (APS 2008a). In response to the die-off, 

APS partnered with the Arizona Game and Fish Department, the USFWS, the USGS National 

Wildlife Health Center, and multiple university labs to determine the cause of the event and to 

prevent future waterfowl die-offs at PVNGS (APS 2008a). A sampling program that lasted more 

than one year was conducted to identify biological toxins or chemical concentrations that may 

have lead to the avian mortalities. University of Arizona and USGS’s National Wildlife Heath 

Center also performed necropsies to identify any bacterial infections, viruses, or chemical toxins 

that may have caused the bird mortalities. As a result of sampling program and necropsy study, 

Hillmer (1996) concluded that neither biological conditions (resident algae and micro-organisms) 

nor chemical parameters in the evaporation ponds had caused the mortality. The study noted 

that within the Pacific Flyway, four other major migratory bird die-offs had occurred within the 

same timeframe as the PVNGS die-off that included Northern shovelers and/or ruddy ducks 

(Hillmer 1996). These die-offs were attributed to either Botulism type C or Avian Cholera. 

Though Hillmer (1996) was unable to conclusively determine the cause of the PVNGS die-off to 

be disease-related, University of Arizona laboratory personnel suspected Avian Botulism as a 

likely cause and also noted that the birds were likely infected prior to arriving at PVNGS (Hillmer 

1996). No other bird die-off event has occurred at PVNGS before or since the 1994-95 event 

(APS 2008a).

PVNGS-associated transmission lines cross agricultural land, open range areas, and desert 

habitat, much of which has been disturbed by cattle grazing (APS 2008a). The Devers line, 

which extends west from PVNGS for approximately 235 mi (378 km), passes through two 

wildlife refuges: the northern portion of Kofa National Wildlife Refuge in La Paz County, Arizona, 

and the northeastern portion of Coachella Valley National Wildlife Refuge in Riverside County, 

California. The Kofa National Wildlife Refuge covers 665,400 ac (270,000 ha) of pristine desert 

and contains the Kofa and Castle Dorm Mountains, which provides good habitat for the desert 

bighorn sheep (USFWS 2008d). The refuge is also home to the only species of native palm in 

Arizona, the California fan palm (Washintonia filifera); (USFWS 2008d). The Coachella Valley 

National Wildlife Refuge covers 3709 ac (1500 ha) of desert habitat (USFWS 2008a). The 

refuge contains Federally designated critical habitat for the Coachella Valley fringe-toed lizard 

(Uma inornata) and contains one of the few remaining undeveloped sand dune ecosystems 

within the Coachella Valley (USFWS 2008a). The Devers line also passes near two other 

significant ecological areas: the Chuckwalla Mountains Wilderness Area in Riverside, California, 

which is just south of the line, and Joshua Tree National Park, which is just north of the line. 

The Devers line passes through Federally designated critical habitat for the Mojave population 

of Sonoran desert tortoises and is located in and slightly north of the Chuckwalla Mountains 

Wilderness Area. 

The Sierra Estrella Wilderness, a 14,400-ac (5830-ha) Congressionally designated wilderness 

area, lies south of the Rudd line and about 15 mi (24 km) southwest of Phoenix, Arizona (BLM 

2008). This area contains the Sierra Estrella mountain range with numerous ridgelines and 

rocky canyons. Mountain peaks harbor shrub live oak (Quercus turbinella) and juniper 

(Juniperus) as well as a remnant population of desert bighorn sheep (BLM 2008). 

2.2.7 Threatened and Endangered Species 

Table 2-6 lists threatened, endangered, or candidate species known to occur in Maricopa 
Affected Environment 

NUREG-1437, Supplement 43 2-44 December 2010

County, Arizona, in which PVNGS is located, or La Paz County, Arizona, or Riverside County, 

California, through which transmission line ROWs associated with PVNGS traverse. 

2.2.7.1 Aquatic Species 

PVNGS does not draw water from any natural surface water body but instead relies on 

wastewater effluents from several area municipalities and groundwater from onsite production 

wells. After use by PVNGS, the water flows to evaporation ponds and is not returned to any 

natural surface water body. This method of water use does not require a direct intake or 

discharge to natural surface water bodies, and therefore, no threatened or endangered aquatic 

species are directly affected. 

2.2.7.2 Terrestrial Species 

Two Federally listed species, the southwestern willow flycatcher (Dendrocygna autumnalis) and 

the Yuma clapper rail (Rallus longirostris yumanensis), and one candidate species, the western 

yellow-billed cuckoo (Coccyzus americanus occidentalis), potentially occur on or in the vicinity 

of PVNGS. Additionally, the Devers transmission line ROW crosses Federally designated 

critical habitat for the Mojave population of the Sonoran desert tortoise (Gopherus agassizii) and 

Federally designated critical habitat for the Coachella Valley fringe-toed lizard (Uma inornata). 

These species are discussed in the following paragraphs. 

Southwestern Willow Flycatcher 

The southwestern willow flycatcher is Federally listed as endangered and state-listed as a 

wildlife species of special concern in Arizona and endangered in California. The species is 

brownish-olive to grey-green in color with light wingbars and pale rings around the eyes and is 

about 6 in. (15 cm) in length (USFWS 2009). This subspecies of the willow flycatcher has a 

distinctive song and occurs most commonly in riparian habitat in desert regions of the 

southwestern U.S. The southwestern willow flycatcher breeds near surface water, along rivers 

and streams, or near wetlands in late spring and lays three to four eggs from late May to early 

June (Ellis et al. 2008). Its breeding range includes Arizona, New Mexico, and southern 

California, portions of southern Nevada and Utah, and southwest Colorado (USFWS 2004). 

The species migrates to rainforest habitat in Mexico and Central and South America in the 

winter (USFWS 2004). Degradation and loss of riparian habitat as well as brood parasitism by 

the brown-headed cowbird (Molothrus ater) are thought to be the main causes of decline of this 

species. Impoundments and overuse of riparian habitat has altered up to 90 percent of the 

southwestern willow flycatcher’s historical habitat (USFWS 2004). The AGFD have records of 

this species potentially occurring within a 3-mi (1.8-km) radius of the PVNGS transmission lines 

(AGFD 2009). 

Yuma Clapper Rail 

The yuma clapper rail is Federally listed as endangered and state-listed as a wildlife species of 

special concern in Arizona and threatened in California. The species is brown in color with 

barred flanks and a long, thin orange bill. It is the largest rail in western North America with an 

adult length of 14 to 16 in. (36 to 41 cm) (CDPR Undated; Pattern 2007). The Yuma clapper rail 

is the only subspecies of the clapper rail to occur inland and to inhabit freshwater marshes; it 

also inhabits brackish marshes within its known range in Mexico (Patten 2007). Its range 

extends from Topock Marsh along the Lower Colorado River southward to the Salton Sea 

(Patten 2007). The species generally feeds on crayfish and other crustaceans along marsh 

borders and open water and nests in mature stands of cattail and bulrush (CDPR Undated). 
Affected Environment

December 2010 2-45 NUREG-1437, Supplement 43

Breeding season extends from March through July, and females lay clutches that vary greatly in 

size from 5 to 14 eggs with a typical clutch size of 8 to 10 eggs (Patten 2007). Degradation and 

loss of marsh habitat, river water damming and diversion, dredging operations, and erosion 

control programs have reduced available nesting habitat for the Yuma clapper rail (CDPR 

Undated). Because wetlands and marshes serve as sinks for a variety of contaminants, Yuma 

clapper rail eggs and tissues have been documented to have relatively high levels of selenium, 

mercury, dichlorodiphenylethane (DDE), polychlorinated biphenyls (PCBs), and other 

contaminants that can cause hatching defects and other interferences with reproductive 

success (Conway and Eddleman 2000). The Arizona Game and Fish Department (AGFD) have 

records of this species potentially occurring within a 3-mi (1.8-km) radius of the PVNGS 

transmission lines (AGFD 2009). 

Western Yellow-billed Cuckoo 

The western yellow-billed cuckoo is a candidate species for Federal listing and state-listed as 

endangered in California (it is not listed in Arizona). The species is grey-brown in color with a 

white underbelly, red primary flight feathers, and black and white patterned tail feathers. Adults 

have a yellow ring around the eye and more distinctive tail patterning than juveniles. Western 

yellow-billed cuckoos inhabit larger riparian areas, especially those with cottonwoods (Populus

spp.) and willows (Salix spp.). Western yellow-billed cuckoos feed by foliage gleaning, and 

cottonwoods have been shown to serve as important foraging habitat in areas of California 

where the species has been studied (Laymon 2004). The species’ distribution includes most of 

North America and ranges from southern Canada to northern Mexico, though the breeding 

range only extends northward to the Sacramento Valley (USFWS 2007). Individuals migrate to 

South America during the winter and range from Columbia to Venezuela (USFWS 2007). The 

western yellow-billed cuckoo requires riparian patches to be a minimum of 20 to 40 ha (50 to 

100 ac) in size for successful breeding (Laymon 2004). Loss of riparian habitat, damming, 

stream channelization, and livestock grazing are the main threats this species’ habitat. The 

dramatic decline observed in this species within California is attributed directly to breeding 

habitat loss from alteration or removal of riparian habitat for agriculture, urban development, and 

flood control (USFWS 2007). The Arizona Game and Fish Department (AGFD) have records of 

this species potentially occurring within a 3-mi (1.8-km) radius of the PVNGS transmission lines 

(AGFD 2009). 

Sonoran Desert Tortoise 

The Sonoran Desert tortoise is Federally listed as threatened, Arizona state-listed as a wildlife 

species of concern, and California state-listed as threatened. The species is long-lived with an 

average lifespan of 48 to 53 years of age for individuals in the eastern Mojave Desert. Females 

lay up to three clutches per year of four to six eggs each in burrows or under shrubs. Only an 

estimated 2 to 5 percent of hatchlings reach maturity. Common predators of hatchlings and 

juvenile desert tortoises include gila monsters (Heloderma suspectum), coachwhip snakes 

(Mastiocophis flagellum), and ravens (Corvus corax). The desert tortoise reaches maturity at 

about 15 to 16 years, at which point individuals are about 8 in. (20 cm) in length. Desert 

tortoises are most commonly found on valley bottoms and south-facing slopes. The species 

forages on grass, leaves, stems, flowers, and fruit. Threats to this species’ continued existence 

include habitat loss and degradation, overgrazing, and direct human-induced mortality from 

vehicle collisions. (Meyer 2008) 

One PVNGS-associated transmission line, the Devers line, passes through Federally 

designated critical habitat for the Mojave population of desert tortoise located in and slightly 

north of the Chuckwalla Mountains Wilderness Area. 
Affected Environment 

NUREG-1437, Supplement 43 2-46 December 2010

Coachella Valley Fringe-Toed Lizard 

The Coachella Valley fringe-toed lizard is Federally listed as threatened, Arizona state-listed as 

a wildlife species of concern, and California state-listed as endangered. The species is 6 to 9 

in. (15 to 23 cm) in length with a white to sand-colored back and belly, eye markings, and a 

wedged-shaped nose. The species occurs in blowsand habitat in drainage bottoms within the 

Coachella Valley, California. Breeding occurs from April to August, but little is known about its 

egg laying habits. The species eats small insects, leaves, buds, and seeds of native plants. 

Loss and degradation of habitat are the major threats to this species’ continued existence. 

(USFWS 2008a) 

One PVNGS-associated transmission line, the Devers line, crosses through the Coachella 

Valley National Wildlife Refuge, which contains Federally designated critical habitat for the 

Coachella Valley fringe-toed lizard. The Devers line ROW does not directly intersect this 

species’ critical habitat. 
Affected Environment

December 2010 2-47 NUREG-1437, Supplement 43

Table 2-6. Listed Terrestrial Species. The species below are Federally listed, Arizona-listed, 

and/or California-listed, as threatened, endangered, or candidate species. These species may 

occur on the PVNGS site or within the transmission line rights-of-way.

Scientific Name Common Name Federal (a) AZ(b) CA(c) Habitat 

Amphibians 

Ambystoma californiense California tiger 

salamander 

T - SSC large, fishless vernal pools 

Batrachoseps aridus desert slender 

salamander 

E - CE moist cliff sides within Sonoran 

desert scrub 

Bufo californicus arroyo toad E - SSC desert washes; riparian areas 

with sandy streambanks 

Bufo microscaphus Arizona toad - - - riparian areas 

Ensatina klauberi large-blotched 

salamander 

- - SSC oak woodland; chapparal 

Gastrophryne olivacea Great Plains narrowmouthed toad 

- WSC - montane woodlands; 

grasslands; desert 

Lithobates yavapaiensis lowland leopard frog - WSC SSC desert, grassland, and 

woodland near rivers or 

streams 

Rana draytonii California red-legged 

frog 

T - SSC lowland forests; grasslands 

Rana muscosa Sierra Madre yellowlegged frog 

E - SSC montaine riparian areas; wet 

meadows 

Scaphiopus couchii Couch's spadefoot - - SSC desert; grasslands; prairie; 

mesquite 

Spea hammondii western spadefoot - - SSC sandy or gravelly soils in 

mixed woodland, grasslands, 

and chapparal 

Taricha torosa torosa coast range newt - - SSC wet forests; chapparal; rolling 

grasslands 

Birds 

Aechmophorus clarkii Clark's grebe - WSC - inland lakes 

Agelaius tricolor tricolored blackbird - - SSC grasslands; coastal areas 

Ardea alba great egret - WSC - large lakes; wetland habitat 

Asio otus long-eared owl - - SSC coniferous forest edges 

Athene cunicularia burrowing owl - - SSC grasslands; rangelands; desert 

habitat 

Buteogallus anthracinus common black-hawk - WSC - coastal areas; mangrove 

swamps 

Campylorhynchus 

brunneicapillus sandiegensis 

coastal cactus wren - - SSC arid regions containing yucca, 

mesquite, or saguaro cactii 

Charadrius alexandrinus 

nivosus 

western snowy plover T WSC SSC sandy coasts; brackish inland 

lakes 

Circus cyaneus northern harrier - - SSC open country; moorlands; bogs 

Coccyzus americanus yellow-billed cuckoo C WSC - deciduous forest 

Coccyzus americanus 

occidentalis 

western yellow-billed 

cuckoo 

C - CE deciduous forest 

Colaptes chrysoides gilded flicker - - CE desert habitat containing 

saguaro cactii 

Cypseloides niger black swift - - SSC high cliff faces near water 

Dendrocygna autumnalis black-bellied whistlingduck 

- WSC - shallow freshwater ponds, 

lakes, and marshes 

Dendroica petechia brewsteri yellow warbler - - SSC open, wet woodland and 

shrubland 

Dendroica petechia sonorana Sonoran yellow warbler - - SSC open, wet woodland and 

shrubland 

Egretta thula snowy egret - WSC - inland and coastal wetlands 

Empidonax traillii extimus southwestern willow 

flycatcher 

E WSC CE riparian areas near desert 

habitat 

Falco peregrinus anatum American peregrine 

falcon 

- WSC - grasslands; meadowlands 

Gelochelidon nilotica gull-billed tern - - SSC lakes, marshes, and coastal 

habitat 

Glaucidium brasilianum 

cactorum 

cactus ferruginous 

pygmy-owl 

- WSC - semi-open wooded habitat 
Affected Environment 

NUREG-1437, Supplement 43 2-48 December 2010

Scientific Name Common Name Federal (a) AZ(b) CA(c) Habitat 

Haliaeetus leucocephalus bald eagle D WSC CE forested areas near open 

water 

Icteria virens yellow-breasted chat - - SSC dense, brushy areas 

Ictinia mississippiensis Mississippi kite - WSC - forests and savannahs 

bordering urban areas 

Ixobrychus exilis least bittern - WSC - wetlands; coastal plains 

Lanius ludovicianus loggerhead shrike - - SSC edge habitats; agricultural 

areas 

Laterallus jamaicensis 

coturniculus 

California black rail - WSC - salt and freshwater wetlands; 

wet meadows 

Megaceryle alcyon belted kingfisher - WSC - wetlands; riparian and coastal 

areas near estuaries and other 

waterbodies 

Melanerpes uropygialis Gila woodpecker - - CE low desert scrub in Sonoran 

desert 

Micrathene whitneyi elf owl - - CE dense mesquite; wooded 

canyons 

Pandion haliaetus osprey - WSC - forested areas near open 

water 

Pelecanus occidentalis brown pelican E - - sandy beaches; lagoons; 

coastal areas 

Piranga rubra summer tanager - - SSC open wooded areas containing 

oaks 

Plegadis chihi white-faced ibis - - - marshes containing shrubs or 

low trees 

Polioptila californica californica coastal California 

gnatcatcher 

T - SSC low-elevation, relatively flat 

coasts 

Progne subis purple martin - - SSC open areas adjacent to 

developed land 

Pyrocephalus rubinus vermilion flycatcher - - SSC desert; arid scrubland; 

farmland 

Rallus longirostris yumanensis Yuma clapper rail E WSC CT inland freshwater and brackish 

marshes 

Rynchops niger black skimmer - - SSC coastal sandy banks and 

beaches 

Sterna antillarum browni California least tern E - - tidal flats and coastal beaches 

Strix occidentalis lucida Mexian spotted owl T WSC - mature forests; steep canyons 

Toxostoma bendirei Bendire's thrasher - - SSC sparse desert shrubland; 

degraded grasslands 

Toxostoma crissale Crissal thrasher - - SSC dense shrubby vegetation near 

streams and washes 

Toxostoma lecontei Le Conte's thrasher - - SSC peatlands; wet meadows 

Vireo bellii arizonae Arizona bell's vireo - - CE low, dense shrubland 

Vireo bellii pusillus least Bell's vireo E - CE low, dense shrubland 

Insects 

Cicindela oregona maricopa Maricopa tiger beetle - - - stream edges; sandy 

reservoirs 

Dinacoma caseyi Casey's June beetle C - - sandy soil in arid, alluvial 

plains 

Euphydryas editha quino Quino checkerspot 

butterfly 

E - - scrubland 

Rhaphiomidas terminatus 

abdominalis 

Delhi Sands flowerloving fly E - - inland dunes 

Sonorella allynsmithi squaw park talussnail - - - steep slopes containing 

limestone talus 

Mammals 

Antilocarpa americana 

sonoriensis 

Sonoran pronghorn E WSC - Sonoran desert 

Antrozous pallidus pallid bat - - SSC rocky outcrops; caves and 

mine tunnels 

Chaetodipus californicus 

femoralis 

Dulzura pocket mouse - - SSC chaparral 

Chaetodipus fallax fallax northwestern San 

Diego pocket mouse 

- - SSC chaparral; coastal sage scrub 

Chaetodipus fallax pallidus pallid San Diego - - SSC chaparral 
Affected Environment

December 2010 2-49 NUREG-1437, Supplement 43

Scientific Name Common Name Federal (a) AZ(b) CA(c) Habitat 

pocket mouse 

Corynorhinus townsendii Townsend's big-eared 

bat 

- - SSC arid scrublands or pine forests 

near caves 

Dipodomys merriami parvus San Bernardino 

kangaroo rat 

E - SSC alluvial sage scrub 

Dipodomys stephensi Stephens' kangaroo rat E - CT flat to rolling grasslands 

Euderma maculatum spotted bat - - SSC desert scrub; open forest 

Eumops perotis californicus greater western 

bonneted bat 

- - SSC cliff faces near ponds or 

natural springs 

Glaucomys sabrinus 

californicus 

San Bernardino flying 

squirrel 

- - SSC coniferous or mixed 

coniferous/deciduous forest 

Lasiurus blossevillii western red bat - WSC - desert scrub; riparian areas 

Lasiurus xanthinus western yellow bat - WSC - riparian areas; palm groves 

Leptonycteris curasoae 

yerbabuenae 

lesser long-nosed bat E - - desert habitat containing 

saguaro and agaves 

Lepus californicus bennettii San Diego black-tailed 

jackrabbit 

- - SSC open plains and fields; desert; 

grasslands 

Macrotus californicus California leaf-nosed 

bat 

- WSC SSC Sonora and Mojave Desert 

scrub 

Myotis occultus Arizona Myotis - - SSC desert riparian areas 

Myotis velifer cave myotis - - SSC caves and rock crevices near 

desert scrub, wash, or riparian 

areas 

Myotis yumanensis Yuma myotis - - - open forests and woodlands 

near water 

Neotoma lepida intermedia San Diego desert 

woodrat 

- - SSC chaparral; sagebrush; desert 

Nyctinomops femorosaccus pocketed free-tailed bat - - SSC pinyon-juniper woodlands; 

desert scrub 

Nyctinomops macrotis big free-tailed bat - - SSC desert scrub; arid, rocky 

habitat 

Onychomys torridus ramona southern grasshopper 

mouse 

- - SSC coastal scrub; mixed 

chaparral; sagebrush 

 

Ovis canadensis peninsular bighorn 

sheep 

E - CT arid, rocky desert slopes; 

canyons 

Panthera onca jaguar E - - highly variable: dense 

rainforest to dryer open terrain 

Perognathus longimembris 

bangsi 

Palm Springs pocket 

mouse 

- - SSC level to sloping terrain with 

sandy soils 

Perognathus longimembris 

brevinasus 

Los Angeles pocket 

mouse 

- - SSC arid grasslands; coastal sage 

scrub 

Perognathus longimembris 

internationalis 

Jacumba pocket 

mouse 

- - SSC sage scrub 

Sigmodon arizonae plenus Colorado River cotton 

rat 

- - SSC arid grasslands near ponds or 

irrigated fields 

Spermophilus tereticaudus 

chlorus 

Palm Springs roundtailed ground squirrel C - SSC mesquite habitat; sand fields 

Taxidea taxus American badger - - SSC plains; prairie; farmland; 

woodland edges 

Plants 

Abutilon parishii Pima Indian mallow - SR - higher elevation Sonoran 

desert scrub; rocky hillsides; 

cliff bases 

Agave arizonica Arizona agave - HS - chaparral; higher elevation 

juniper grasslands 

Agave delamateri Tonto Basin agave - HS - chaparral; upland pinyonjuniper woodlands 

Agave murpheyi hohokam agave - HS - alluvial terraces on desert 

scrub slopes 

Agave toumeyana var. bella tourney agave - SR - rocky hillsides; chaparral; 

highland desert 

Allium bigelovii bigelow onion - SR - Open, sloping grasslands and 

chaparral with rocky soil 

Allium munzii Munz's onion E - CT coastal sage scrub habitat with 

rolling terrain 
Affected Environment 

NUREG-1437, Supplement 43 2-50 December 2010

Scientific Name Common Name Federal (a) AZ(b) CA(c) Habitat 

Ambrosia pumila San Diego ambrosia E - - creek beds; floodplains 

Arenaria paludicola marsh sandwort E - CE freshwater marshes; boggy 

meadows 

Astragalus lentiginosus var. 

coachellae 

Coachella Valley milkvetch E - - sand dunes and flats near 

sandy washes 

Astragalus tricarinatus triple-ribbed milk-vetch E - - dry washes with sandy or 

gravelly soils 

Atriplex coronata var. notatior San Jacinto Valley 

crownscale 

E - - vernal pools and floodplains 

with silt and clay soils 

Berberis nevinii Nevin's barberry E - CE chaparral; desert scrub 

Brodiaea filifolia thread-leaved brodiaea T - CE grasslands and vernal pools 

with clay soils 

Ceanothus ophiochilus Vail Lake ceanothus T - CE rocky northeast-facing slopes 

in chamise chaparral 

Cordylanthus maritimus ssp. 

maritimus 

salt marsh bird's-beak E - CE tidal wetlands 

Deinandra mohavensis Mojave tarplant - - CE desert edge chaparral; arid 

coastal slopes 

Dodecahema leptoceras slender-horned 

spineflower 

E - CE floodplains with sandy to silty 

alluvial soils 

 

Echinomastus erectocentrus 

var. acunensis 

acuna cactus C HS - well-drained areas and gravel 

ridges near desert washes 

Eriastrum densifolium ssp. 

sanctorum 

Santa Ana River 

woollystar 

E - CE Santa Ana River wash 

Erigeron parishii Parish's daisy T - - desert washes or canyon 

bottoms with loose alluvial 

deposits 

Erigeron piscaticus Fish Creek fleabane - SR - upper floodplain terraces in 

shady canyon bottoms 

Eriogeonum ripleyi ripley wild-buckwheat - SR - tertiary lakebeds with welldrained soils 

Eryngium aristulatum var. 

parishii 

San Diego buttoncelery E - CE vernal pools with gravelly loam 

soils 

Ferocactus cylindraceus var. 

cylindraceus 

California barrel cactus - SR - creosote bush scrub; Joshua 

Tree woodlands 

Ferocactus cylindraceus var. 

eastwoodie 

golden barrel cactus - SR - Mojave and Sonoran desert 

Ferocactus emoryi Emory's barrel-cactus - SR - Mojave and Sonoran desert 

Fremontodendron californicum flannel bush - SR - dry slopes in chaparral and 

pinyon-juniper woodlands 

Limnanthes gracilis ssp. 

parishii 

Parish's meadowfoam - CE lake shores; wet meadows 

Mammillaria viridiflora varied fishhood cactus - SR - rocky gorges; scrubland 

Navarretia fossalis Moran's navarretia T - freshwater marshes; vernal 

pools 

Opuntia echinocarpa straw-top cholla - SR - creosote bush scrub; Joshua 

Tree woodlands 

Opuntia engelmannii var. 

flavispina 

cactus apple - SR - mid-elevation desert 

Orcuttia californica California Orcutt grass E - CE vernal pools 

Perityle saxicola Fish Creek rock daisy - - - arid cliffsides 

Phacelia stellaris Brand's phacelia C - - sandy openings in coastal 

sage scrub habitat 

Pholisma arenarium scaly sand plant - HS - coastal creosote bush 

scrublands 

Purshia subintegra Arizona cliffrose E HS - arid, rocky limestone slopes 

Stenocereus thurberi organ pipe cactus - SR - south-facing desert slopes 

Trichostema austromontanum 

ssp. compactum 

Hidden Lake bluecurls T - - Hidden Lake vernal pool in 

Mount San Jacinto State 

Wilderness 

Tumamoca macdougalii tumamoc globeberry - SR - upland Sonoran desert 

scrubland 

Verbesina dissita big-leaved crown beard T - - southern maritime chaparral 

Reptiles 
Affected Environment

December 2010 2-51 NUREG-1437, Supplement 43

Scientific Name Common Name Federal (a) AZ(b) CA(c) Habitat 

Actinemys marmorata pallida southwestern pond 

turtle 

- - SSC valleys with slow-moving 

waterways 

Anniella pulchra pulchra silvery legless lizard - - SSC loose, moist soils of chaparral, 

desert scrub, and desert 

washes 

 

 

Aspidoscelis hyperythra orange-throated 

whiptail 

- - SSC semi-arid washes, chaparral, 

and streamsides with loose 

soil 

Aspidoscelis xanthonota redback whiptail - - - upland Sonoran desert 

scrublands 

 

Charina trivirgata gracia desert rosy boa - - - scrublands; rocky desert; 

canyons 

Charina trivirgata trivergata Mexican rosy boa - - - riparian areas; scrublands; 

rocky desert; canyons 

Charina umbratica southern rubber boa - - CT oak-conifer and mixed-conifer 

forests 

Crotalus ruber ruber northern red diamond 

rattlesnake 

- - SSC desert slopes; arid coastal 

areas 

Eumeces gilberti arizonensis Arizona skink - WSC - mesquite riparian drainages; 

woodlands near streams 

Eumeces skiltonianus 

interparietalis 

Coronado skink - - SSC grasslands; woodlands; 

chaparral 

Gopherus agassizii Sonoran desert tortoise T WSC CT Mojave and Sonoran desert 

Heloderma suspectum cinctum banded gila monster - - SSC rocky scrublands; semi-desert 

grasslands 

Phrynosoma coronatum 

(blainvillii population) 

San Diego horned 

lizard 

- - SSC 

Phrynosoma mcallii flat-tailed horned lizard - - SSC desert scrub; desert washes 

Salvadora hexalepis virgultea coast patch-nosed 

snake 

- - SSC creosote desert flats; 

sagebrush; chaparral 

Sauromalus ater Arizona chuckwalla - - - rocky, desert outcrops 

Thamnophis eques megalops northern Mexican 

gartersnake 

- WSC - desert scrub or semidesert 

grasslands near rivers or 

streams 

Thamnophis hammondii two-striped garter 

snake 

- - SSC desert regions near semipermanent to permanent water 

bodies 

Uma inornata Coachella Valley 

fringe-toed lizard 

T WSC CE sand dune habitat 

Uma scoparia Mojave fringe-toed 

lizard 

- - SSC sand dune habitat 

(a) C = Candidate for Federal listing; E = Federally Endangered; T = Federally Threatened 

(b) HS = Highly Safeguarded: no collection allowed (Arizona Department of Agriculture); SR = Salvage 

Restricted: collection only with permit (Arizona Department of Agriculture); WSS = Wildlife of Special 

Concern (Arizona Game and Fish Department) 

(c) CE = California State Endangered; CT = California State Threatened; SSC = California Species of Special 

Concern 

Sources: AGFD 2008; AGFD 2009; CDFG 2009; USFWS 2008b; USFWS 2008c; USFWS 2008e 

2.2.8 Socioeconomic Factors 

This section describes current socioeconomic factors that have the potential to be directly or 

indirectly affected by changes in operations at PVNGS. The nuclear plant and the people and 

communities that support it can be described as a dynamic socioeconomic system. The 

communities provide the people, goods, and services required by power plant operations. The 

nuclear power plant, in turn, creates the demand for people, goods, and services and pays for 

them in the form of wages, salaries, and benefits, and payments for goods and services. 
Affected Environment 

NUREG-1437, Supplement 43 2-52 December 2010

Income from wages and salaries and payments for goods and services is then spent on other 

goods and services within the community, thus creating additional opportunities for employment 

and income. The measure of the community’s ability to support the operational demands of 

PVNGS depends on the ability of the community to respond to changing socioeconomic 

conditions at the power plant. 

The socioeconomics region of influence (ROI) for PVNGS is defined as the area in which plant 

employees and their families reside, spend their income, and use their benefits, thereby 

affecting the economic conditions of the region. The PVNGS ROI consists of Maricopa County, 

and includes the cities of Phoenix, Tempe, Mesa, Glendale, Peoria, Scottsdale, and Sun City. 

The nearest incorporated city is Buckeye (estimated 2006 population of 29,615) located about 

16 miles (26 kilometers) east of PVNGS, while the nearest town is Wintersburg, approximately 

1.5 miles (2 kilometers) northwest of the site. 

APS employs approximately 2,200 permanent workers and approximately 620 long-term 

contract employees at PVNGS (APS 2008a). Approximately 98 percent live in Maricopa 

County, Arizona (Table 2.2.8–1). The remaining two percent of the APS workforce are divided 

among 13 Arizona counties, with between 1 and 8 employees per county. Given the residential 

locations of APS employees, the most significant impacts of plant operations are likely to occur 

in Maricopa County. The focus of the analysis in this document is therefore based in this 

county. 
Affected Environment

December 2010 2-53 NUREG-1437, Supplement 43

Table 2.2.8–1 APS Employee Residence by County in 2008 

County 

Number of PVNGS 

Personnel 

Percentage 

of Total 

Maricopa 2,156 98 

Other 44 2 

Total 2,200 100 

Source: APS 2008a 

Refueling outages at the PVNGS normally occur at 18-month intervals for each unit or one unit 

every six months on a rotating basis. During each six-month refueling outage, site employment 

increases by as many as 350 workers for approximately 45 days. Most of these workers are 

assumed to be located in the same geographic areas as the permanent PVNGS staff. The 

following sections describe housing, public services, offsite land use, visual aesthetics and 

noise, population demography, and the economy in the ROI surrounding PVNGS. 

2.2.8.1 Housing 

Table 2.2.8.1–1 lists the total number of occupied housing units, vacancy rates, and median 

value in the ROI. According to the 2000 Census, there were more than 1,250,000 housing units 

in the ROI, about 1,133,000 of which were occupied. The median value of owner-occupied 

units was $129,200. The vacancy rate was 9.4 percent, partly because of the large number of 

seasonal and recreational housing units in the county. 

By 2008, the estimated total number of housing units in Maricopa County had grown by 286,144 

units to 1,536,375, while the total number of occupied units grew by 205,162 units to 1,338,048. 

As a result, the number of available vacant housing units increased by almost 80,982 units to 

198,327, or 12.9 percent of all housing units. 

Table 2.2.8.1–1 Housing in Maricopa County 

Maricopa

2000

Total 1,250,231 

Occupied housing units 1,132,886 

Vacant units 117,345 

Vacancy rate (percent) 9.4 

Median value (dollars) 129,200 

2006–2008; three-year estimate

Total 1,536,375 

Occupied housing units 1,338,048 

Vacant units 198,327 

Vacancy rate (percent) 12.9 

Median value (dollars) 263,600 

Sources: USCB 2009a–d. 
Affected Environment 

NUREG-1437, Supplement 43 2-54 December 2010

2.2.8.2 Public Services 

This section presents a discussion of public services, including water supply, education, and 

transportation. 

Water Supply 

To relieve the growing problem of groundwater overdraft in parts of Arizona, the Arizona 

Department of Water Resources (ADWR) has designated Active Management Areas (AMAs) 

where groundwater overdraft concerns are the most significant (ADWR 2006). Much of 

Maricopa County is within the Phoenix AMA, which consists of seven groundwater basins and 

covers 5,646 square miles (14,623 square kilometers). An annual average of 2.3 million acrefeet (2.8 billion cubic meters) of water is used in the AMA (ADWR 2006), including 

1.4 million acre-feet (1.7 billion cubic meters) of water from the Colorado River, Salt River, and 

Verde River, water retrieved from treated effluent from the Phoenix metropolitan area, and 

900,000 acre-feet (1.1 billion cubic meters) coming from groundwater sources. The Phoenix 

AMA annual water overdraft is currently about 251,000 acre-feet (310 million cubic meters) 

(ADWR 2006). 

Although there is a mix of water uses in the Phoenix AMA, municipal and industrial uses are the 

most significant. Water storage reservoirs have been constructed on the Gila River and four 

principal tributaries that drain the Phoenix AMA–the Salt, Verde, Gila, and Agua Fria rivers 

(ADWR, 2006). Table 2.2.8.2–1 provides details on the largest municipal surface water supply 

systems in Maricopa County.

Table 2.2.8.2–1 Major Maricopa County Public Water Supply Systems (thousand acrefeet) 

Water Supplier a Water Sourcea

Average Daily 

Production (2005)b 

Maximum Daily 

Production (2006) b

City of Phoenix Surface Water 302.4 450.1 

City of Mesa Surface Water 90.9 121.9 

City of Scottsdale Surface Water 76.0 106.4 

City of Chandler Surface Water 54.2 77.5 

City of Tempe Surface Water 49.8 77.2 

City of Glendale Surface Water 44.4 64.2 

City of Gilbert Surface Water 37.1 44.1 

City of Peoria Surface Water 21.8 41.7 

(a) EPA 2009 

(b) APS 2008a 

 
Affected Environment

December 2010 2-55 NUREG-1437, Supplement 43

Education 

Four school districts are located in the vicinity of PVNGS. Combined, the districts have 19 

schools and in 2008 had 17,386 students and 861 teachers. The four districts are listed below, 

along with the number of schools in each and the number of students and teachers in 2008 

(NCES 2009): 

• Buckeye Elementary School District: 6 schools, 4,510 students, 202 teachers. 

• Buckeye Union High School District: 4 schools, 3,088 students, 152 teachers. 

• Liberty Elementary School District: 5 schools, 3,834 students, 222 teachers. 

• Agua Fria Union High School District: 4 schools, 5,954 students, 285 teachers. 

Transportation 

Road access to PVNGS is via Wintersburg Road, which intersects with Salome Highway a few 

miles north of the plant and, about 6 miles (10 kilometers) north, intersects with Interstate 

Highway 10 (I-10). Employees traveling from the north, northwest, and west use Salome 

Highway or I-10 to reach PVNGS, while employees traveling from the southwest and south use 

Elliot and Wintersburg Roads. Employees traveling from the northeast, east, southeast, and 

south would use Salome Highway or I-10. Some congestion occurs on the PVNGS access road 

during shift changes while vehicles pass through the security gate, although this congestion 

generally does not extend to Wintersburg Road (APS 2008a). PVNGS supports an employee 

van pool program, providing approximately 150 ten-passenger vans to groups of employees 

who pay a fee for their use, thereby reducing congestion and traffic volume. 

Table 2.2.8.2–2 lists roadways in the vicinity of PVNGS and the annual average daily traffic 

volumes (AADT) on these road segments. Traffic volumes in the vicinity of PVNGS are low, 

although traffic volumes on road segments have increased somewhat over the period 2005 

to 2008.
Affected Environment 

NUREG-1437, Supplement 43 2-56 December 2010

Table 2.2.8.2–2 Average Annual Daily Traffica (AADT) Counts in the vicinity of PVNGS

 Roadway and Location AADT 

I-10, Exit 94, 411th Avenue to Exit 98, Wintersburg Road/383rd Avenue 23,101b

I-10, Exit 98, Wintersburg Road/383rd Avenue to Exit 103, 339th Avenue 28,321b 

355th Avenue at West Salome Highway 462c

West Salome Highway at 379th Avenue 1,381c

West Salome Highway at Wintersburg Road/383rd Avenue 1,947c

West Salome Highway at 411th Avenue 722c

West Elliot Road, at 355th Avenue 466c

West Elliot Road at Wintersburg Road/383rd Avenue, eastbound 489c

West Elliot Road at Wintersburg Road/(383rd Avenue, westbound 265c

(a) Annual average daily traffic represents traffic volume during the average 24-hour day. 

(b) 2008 data. 

(c) 2009 data. 

Sources: ADOT 2009; MCDOT 2009 

2.2.8.3 Offsite Land Use 

A majority of PVNGS workers live in Maricopa County (approximately 98 percent) and PVNGS 

pays property taxes to Maricopa County. Therefore, this section provides information on offsite 

land use in that county. 

The Phoenix metropolitan region has two primary long-range planning and policy development 

organizations: the Maricopa County Planning and Development Department and the Maricopa 

Association of Governments (MAG). Local and regional planners use comprehensive land-use 

planning, zoning, and subdivision regulations to control development, encouraging growth in 

areas where public facilities such as water and sewer systems exist or are scheduled to be built 

in the future. They also promote the preservation of community natural resources, but use no 

growth control measures. 

Maricopa County covers 9,203 square miles (23,835 square kilometers) of land (USCB 2009f). 

Over the last several decades, urban development has occurred primarily in the West Valley, 

northern Pinal County, and the North Valley, although some suburban development has 

occurred to some extent throughout the ROI. From 2000 to 2004, the urbanized portion of the 

region expanded by 55,000 acres (22,259 hectares) (MAG 2005). 

With few topographical constraints, much of this development has been in the form of master 

planned communities, especially in northern Maricopa County. Active, planned, and proposed 

developments in Maricopa County are capable of accommodating an additional 100,000 people 

annually for 20 more years (MAG 2005). The highest concentrations of commercial 

development are located along the major transportation corridors (MAG 2005). Concentrations 
Affected Environment

December 2010 2-57 NUREG-1437, Supplement 43

of regional open space are located in the mountains, throughout the West Valley, and in 

northeastern and southern Maricopa County. Land in the immediate vicinity of PVNGS is 

primarily rural, consisting of open space and scattered low-density residential developments 

with lower-priced single family housing. Little industrial or commercial activity occurs in the 

plant vicinity (APS 2008a).

2.2.8.4 Visual Aesthetics and Noise 

Power generation facilities at PVNGS are situated in the northwest corner of the property. The 

major structures at the site constitute a significant feature of the landscape within the immediate 

viewshed of the site and include several buildings ranging in height from 64 to 250 feet (20 to 76 

meters) (NRC 1982). APS sought to diminish the profile of the structures of PVNGS through the 

use of desert beige and sage green paint and siding and plain concrete exteriors. Elevated 

evaporation ponds (42 feet [13 meters] in height) are located in the central and southern 

sections of the property, and water storage reservoirs are located in the northeast corner. 

Three natural gas-fired combined-cycle power generation plants are located approximately 

2.5 to 3 miles (4 to 5 kilometers) south of PVNGS. The land around PVNGS consists of 

relatively flat desert terrain with small hills and buttes; the Palo Verde Hills rise abruptly to nearly 

2,200 feet (671 meters) approximately 6 miles (10 kilometers) northwest of the site (NRC 1982). 

As indicated above, land use in the immediate vicinity of PVNGS is primarily open space and 

scattered low-density residential developments (APS 2008a) in addition to power generation. 

The plume from the nine PVNGS 64-foot-high (20-meter-high) cooling towers can be visible to a 

height of approximately 870 feet (265 meters) on an average summer morning, and estimated 

to be 1,900 feet (580 meters) during an average winter morning. 

PVNGS can be seen from Wintersburg Road, which runs north to south along the west edge of 

the site, and Elliot Road, which runs east to west at the southern end of the site. PVNGS can 

also be seen from Interstate Highway 10 located 6 miles (10 kilometers) northeast of the site at 

its closest point and from State Route 80 located seven miles south east of the site. 

Noise from nuclear plant operations can be detected offsite. Sources of noise at PVNGS 

include the turbines, construction activities, and large pump motors. Given the industrial nature 

of the station, noise emissions from the station are generally nothing more than an intermittent 

minor nuisance. However, noise levels may sometimes exceed the 55 dBA level that the U.S. 

Environmental Protection Agency (EPA) uses as a threshold level to protect against excess 

noise during outdoor activities (EPA 1974). According to the EPA this threshold does “not 

constitute a standard, specification, or regulation,” but was intended to provide a basis for state 

and local governments establishing noise standards. To date, no noise complaints associated 

with operations at PVNGS have been reported from neighboring communities. 

2.2.8.5 Demography 

In 2000, approximately 16,000 persons lived within a 20-mile (32-kilometer) radius of PVNGS, 

which equates to a population density of 13 persons per square mile (APS 2008a). This is a 

Category 1 density (less than 40 persons per square mile within 20 miles [32 kilometers] and no 

community with 25,000 or more persons within 20 miles [32 kilometers]) using the generic 

environmental impact statement (GEIS) measure of sparseness. At the same time, about 

1,572,110 people lived within a 50-mile (80-kilometer) radius of the plant, for a density of 200 

persons per square mile (APS 2008a). This translates to a Category 4 density (greater than or 
Affected Environment 

NUREG-1437, Supplement 43 2-58 December 2010

equal to 190 persons per square mile within 50 miles [80 kilometers]). Therefore, PVNGS is 

located in a medium-density population area based on the NRC sparseness and proximity 

matrix. 

Table 2.2.8.5–1 shows population projections and growth rates from 1970 to 2030 for Maricopa 

County. The growth rate in Maricopa County since 1970 has been substantial, and population 

growth is projected to continue through 2050. 

Table 2.2.8.5–1 Population and Percent Growth in Maricopa County 

Year Population Percent Growtha

1970 967,522 ----- 

1980 1,509,052 56.0 

1990 2,122,101 40.6 

2000 3,072,172 44.8 

2008 3,954,598 28.7 

2010 4,217,427 37.3 

2020 5,276,074 25.1 

2030 6,207,980 17.7 

2040 7,009,664 12.9 

2050 7,661,423 9.3 

— = No data available. 

(a) Percent growth rate is calculated over the previous decade. 

Sources: Population data for 1970 through 1990 (USCB 2009e); 2000 and 2008 estimate (USCB 2009f); projected 

population data for 2010 to 2050 (ADES 2006) 

The 2000 demographic profile of the ROI population is provided in Table 2.2.8.5–2. Persons 

self-designated as minority individuals constituted 33.8 percent of the total population. This 

minority population is composed largely of Hispanic or Latino persons. 

Table 2.2.8.5–2 Demographic Population Profile in PVNGS ROI in 2000 

Maricopa County Percent

Total Population 3,072,149 -- 

White 2,376,359 77.4 

Race (Not-Hispanic or Latino)

Black or African American 114,551 3.7 

American Indian and Alaska Native 56,706 1.8 

Asian 66,445 2.2 

Native Hawaiian and Other Pacific Islander 4,406 0.1 

Some other race 364,213 11.9 

Two or more races 89,469 2.9 

Ethnicity

Hispanic or Latino 763,341 24.8 

Minority Population (including Hispanic or Latino ethnicity)

Total minority population 1,459,131 47.5 

Source: USCB (2009g) 

 
Affected Environment

December 2010 2-59 NUREG-1437, Supplement 43

According to the U.S. Census Bureau’s 2006-2008 American Community Survey 3-Year 

Estimates, minority populations were estimated to have increased by approximately 525,000 

persons and comprised 40.5 percent of the county population (see Table 2.2.8.5–3). Most of 

this increase was due to an estimated influx of Hispanic or Latinos (over 406,000 persons), an 

increase in population of over 53 percent from 2000. The next largest increase in minority 

population was Asian, an increase of approximately 44,000 persons or 68 percent from 2000. 

Table 2.2.8.5–3 Demographic Population Profile in PVNGS ROI 2006-8 Estimate 

Maricopa County Percent

Total Population 3,862,036 -- 

Race (percent of total population, Not-Hispanic or Latino)

White 2,299,208 59.5 

Black or African American 158,092 4.1 

American Indian and Alaska Native 61,869 1.6 

Asian 108,145 2.8 

Native Hawaiian and Other Pacific Islander 6,147 0.2 

Some other race 4,086 0.2 

Two or more races 52,997 1.4 

Ethnicity

Hispanic or Latino 1,169,740 30.3 

Minority Population (including Hispanic or Latino ethnicity)

Total minority population 1,562,828 40.5 

Source: USCB 2009h 

Transient Population 

Within 50 miles (80 kilometers) of PVNGS, colleges and recreational opportunities attract daily 

and seasonal visitors who create demand for temporary housing and services. In 2009, about 

99,324 students were attending four-year colleges and universities within 50 miles 

(80 kilometers) of PVNGS (NCES 2009). 

In 2000, four percent of all housing units in Maricopa County were considered temporary 

housing for seasonal, recreational, or occasional use; with higher percentages elsewhere within 

50 miles (80 kilometers) of the plant (La Paz County 34.6 percent, Yuma County 15.7 percent 

and Pinal County 14.5 percent). Table 2.2.8.5–4 provides information on seasonal housing 

within 50 miles (80 kilometers) of PVNGS.
Affected Environment 

NUREG-1437, Supplement 43 2-60 December 2010

Table 2.2.8.5–4 Seasonal Housing within 50 miles (80 km) of PVNGS, 2000 

Countya Number of Housing Units 

Housing Units for Seasonal, 

Recreational, or Occasional Use Percent 

La Paz 15,133 5,237 34.6 

Maricopa 1,250,231 49,584 4.0 

Pinal 81,154 11,764 14.5 

Yavapai 81,730 6,048 7.4 

Yuma 74,140 11,662 15.7 

Total 1,502,388 84,295 5.6 

(a) Counties within 50 miles (80 km) of PVNGS with at least one block group located within the 50-mile 

(80-km) radius. 

Source: USCB 2009a 

Migrant Farm Workers 

Migrant farm workers are individuals whose employment requires travel to harvest agricultural 

crops. These workers may or may not have a permanent residence. Some migrant workers 

may follow the harvesting of crops throughout the rural areas of the Southwest. Others may be 

permanent residents near PVNGS who travel from farm to farm harvesting crops. 

Migrant workers may be members of minority or low-income populations. Migrant workers may 

not be included in the local Census because they travel and can spend a significant amount of 

time in an area without being actual residents. If uncounted, these workers would be 

“underrepresented” in U.S. Census Bureau minority and low-income population counts. 

The 2007 Census of Agriculture collected information on migrant farm and temporary labor. 

Table 2.2.8.5–5 provides information on migrant farm workers and temporary (less than 150 

days) farm labor within 50 miles (80 km) of PVNGS. According to the 2007 Census of 

Agriculture, Maricopa County hosts relatively small numbers of migrant workers, with 467 

temporary farm laborers employed on 136 farms in the county (USDA 2009). 
Affected Environment

December 2010 2-61 NUREG-1437, Supplement 43

Table 2.2.8.5–5 Migrant Farm Worker and Temporary Farm Labor within 50 miles 

(80 km) of PVNGS, 2007

Countya

Number of Farm 

Workers Working for 

Less that 150 Days 

Number of Farms 

Hiring Workers for 

Less than 150 Days 

Number of Farms 

Reporting Migrant 

Farm Labor 

Number of Farms with 

Hired Farm Labor 

La Paz 128 15 2 46 

Maricopa 467 136 40 526 

Pinal 124 51 37 279 

Yavapai 199 81 10 185 

Yuma 318 81 49 244 

Total 1,236 364 138 1,280 

(a) Counties within 50 mi of PVNGS with at least one block group located within the 50-mile (80-kilometer) 

radius 

Source: USDA 2009 

2.2.8.6 Economy 

This section discusses of the economy, including employment and income, unemployment, and 

taxes, within the ROI. 

Employment and Income 

Between 2000 and 2008, the civilian labor force in Maricopa County increased at an annual 

average rate of 2.9 percent to 1,999,092 (USDOL 2009). In 2007, retail, health care and social 

assistance, and construction employment represented the largest sectors of employment in 

Maricopa County, followed closely by waste management services and accommodation and 

food services (USCB 2009i). The largest employer in the Greater Phoenix area (Maricopa 

County and Pinal County) in 2009 was the State of Arizona with 50,936 employees (Table 

2.2.8.6-1). The majority of employment in the Greater Phoenix area is located in the cities of 

Chandler, Glendale, Guadalupe, Mesa, Phoenix, Scottsdale, and Tempe (GPEC 2009a). 
Affected Environment 

NUREG-1437, Supplement 43 2-62 December 2010

Table 2.2.8.6-1 Major Employers in the Phoenix Metropolitan Area, 2009

Firm Number of Employees 

State of Arizona 50,936 

Wal-Mart Stores, Inc. 32,814 

Banner Health 23,100 

City of Phoenix 17,068 

Maricopa County 14,014 

Wells Fargo 14,000 

Arizona State University 13,005 

Honeywell Aerospace 12,600 

U.S. Postal Service 10,545 

Basha’s Inc. 10,460 

Source: GPEC 2009b 

Estimated income information for the PVNGS ROI is presented in Table 2.2.8.6-2. According to 

the U.S. Census Bureau’s 2008 estimates, both the median household and per capita incomes 

in Maricopa County were above the Arizona average. In 2008, 13.0 percent of the population in 

Maricopa County was living below the official poverty level (USCB 2009f). 

Table 2.2.8.6-2 Income Information for PVNGS, 2008 

Maricopa County Arizona

Median household income (dollars) a 56,555 51,124 

Per capita income (dollars) a 27,745 25,639 

Percent of persons below the poverty line 13.0 14.3 

(a) In 2008 inflation-adjusted dollars. 

Sources: USCB 2009f; USDOC 2009 

Unemployment 

According to the U.S. Census Bureau’s 2008 estimates, the annual unemployment average for 

Maricopa County was 4.9 percent, which was lower than the annual unemployment average of 

5.6 percent for the state as a whole (USDOL 2009). 

Taxes 

The owners of PVNGS pay annual property taxes to Maricopa County. From 2004 through 

2008, Maricopa County collected between $46.8 and $53.0 million annually in property tax 

revenues from all PVNGS owners (see Table 2.2.8.6–3). The county retains a portion of 

revenues to fund county government operations and disburses the remainder to certain local tax 

jurisdictions, including Ruth Fisher Elementary School District, Arlington Elementary School 

District, Buckeye Union High School District, and Maricopa County Junior College District. For 

the years 2004 through 2008, property taxes paid by PVNGS have represented 1.1 to 

1.6 percent of Maricopa County’s total property tax revenues. 
Affected Environment

December 2010 2-63 NUREG-1437, Supplement 43

Although the deregulation of energy markets in Arizona began in 1998, electricity markets are 

only partially deregulated, and consequently, open access to utility providers does not exist for 

all electricity consumers (Macfie 2008). Any changes in assessed valuation of plant property 

and equipment that may occur in the future could affect property tax payments to Maricopa 

County and other jurisdictions in the county, including school districts. However, any changes 

to PVNGS property tax rates due to deregulation would be independent of license renewal. 

Table 2.2.8.6–3 Maricopa County Tax Revenues, 2005 to 2008; PVNGS Property Tax, 

2005 to 2008; and PVNGS Property Tax as a Percentage of Tax Revenues 

Year

Maricopa County Total 

Tax Revenues 

(in millions of dollars) 

Property Tax Paid by 

PVNGS 

(in millions of dollars)

PVNGS Property Tax as 

Percentage of Total County 

Tax Revenues 

2004 3,299 51.1 1.6 

2005 3,539 53.0 1.5 

2006 3,709 46.8 1.3 

2007 3,981 49.2 1.2 

2008 4,271 48.1 1.1 

Source: APS 2009a, b 

2.2.9 Historic and Archaeological Resources 

This section discusses the cultural background and known historic and archaeological 

resources in and around PVNGS. 

2.2.9.1 Cultural Background 

The area in and around PVNGS has the potential for significant prehistoric and historic 

resources. Human occupation in this region is categorized based on the following chronological 

sequence: Paleoindian (12,000 years before present (BP) to 9500 BP), Archaic (9500 BP to 

1500 BP), Hohokam Culture (1700 BP to 600 BP), Pima Culture (600 BP to 400 BP [i.e., AD 

1400 to 1600]), and Historic (AD 1600 to present) periods. 

In general, the Paleoindian Period is characterized by highly mobile bands of hunters and 

gatherers, hunting small game and now-extinct megafauna (e.g., mastodon, saber-tooth tiger, 

and camel) and gathering wild plants. A typical Paleoindian site might consist of an isolated 

stone point or knife (of a style characteristic of the period) near a former Pleistocene-age water 

source. Known Paleoindian sites in the area have been found predominantly in southern 

Arizona; none have been recorded in the vicinity of PVNGS (ACS 2006). 

The Archaic Period represents a transition from a highly mobile to more sedentary existence. It 

is also a period of increased local resource exploitation (e.g., hunting deer, waterfowl, and small 

mammals; and gathering nuts and seeds), more advanced tool development, construction of 

more permanent settlements, cultivation of maize, and increased complexity in social 

organization. Few Archaic sites have been recorded in this region and none have been 

recorded near PVNGS (ACS 2006). 
Affected Environment 

NUREG-1437, Supplement 43 2-64 December 2010

The Hohokam Culture practiced farming, built canals for irrigation and culturally dominated 

southern Arizona (300 BC to AD 1400). The early Pioneer Period (300 BC to AD 700) was a 

period of agricultural development with evidence of pottery and the establishment of village 

settlements. The Colonial and Sedentary Period (AD 700 to 1150) introduced irrigation 

systems, arts and crafts industry, public architecture (e.g., ball courts, mounds), ritualized 

burials, and geographic expansion. The Classic Period (AD 1150 to 1390) was a period of 

shifting settlement patterns and architectural styles from pit house structures to above ground 

walled villages, and a reorganization of trade networks. Burial patterns and the arts and crafts 

industry also experienced change. Between 1390 and 1450 some of these more organized 

practices (e.g., large-scale irrigation, rituals) seem to have disappeared in the Lower Salt and 

Middle Gila River Valleys and may represent a separate period, called the Polvorón Phase. 

The Protohistoric Period is the transition period between Hohokam Classic Period to Spanish 

Mission Period. During this period, most activity is replaced by the Pima Culture (AD 1400 to 

1600), descendants of the Hohokam Culture. The Papago Indians (Tohono O’odham) and the 

Pima Indians are two Pima Culture groups in the region. Descendants of these groups can be 

linked to the Hopi, Yuman, Piman speakers, and Zuni (ACS 2006). PVNGS is located between 

the areas where the Western Yavapai historically would hunt and gather to the north and the 

where the Maricopa and Pima Indians would practice agriculture to the south (Stein 1981a). 

The Historic Period in this region begins with the arrival of Spanish conquistadors searching for 

precious metals. The area was claimed by Spain in 1537, but the first documented Spaniards in 

the area are Fray Marcos de Niza and Francisco Coronado in 1539 and 1540 on their searches 

to find Cibola, the seven cities of gold. The Spanish controlled the area until 1821, when 

Mexico gained its independence. The first settlers came in 1846 in association with the 

Mexican-American War. The Arizona lands north of the Gila River became part of the United 

States under the Treaty of Guadalupe Hidalgo in 1848. Arizona lands south of the Gila River 

did not belong to the United States until after the Gadsen Purchase in 1853. The paths traveled 

by General Stephen Kearney and Lt. Colonel Philip Cooke in the Mexican-American War later 

became the main routes for future travel and settlement in Arizona, such as those during the 

gold rush in the 1850s. The U.S. military also established a presence during this time due to 

increased conflict with Native Americans resulting from increased mining activities in the area. 

The increase in settlement meant an increased need for goods and services and spurred the 

development of irrigated farming along the Gila River. Phoenix was founded in 1865, and the 

Southern Pacific Railroad was operating in the area by 1882 (APS 2008a). 

A cattle ranch was established in 1885 on land adjacent to what is now the present-day location 

of PVNGS. In 1920, the town of Wintersburg was settled in the same location. The town was 

initially a farming community established by World War I-veteran homesteaders, some claiming 

lands under the homestead and desert land statutes for future sale, and some hoping to receive 

government assistance in receiving irrigated water. Between 1920 and 1927, the attempts to 

farm and raise livestock were not successful, and, of the ten initial claims, all of them failed. 

The first successful claim was made in 1927 with a patent issued in 1932. Over the next 20 

years, only about 50 percent of the attempted claims were successful. The eventual growth of 

the town as it is today is related to the development of PVNGS in the mid-1970s, as many 

employees made Wintersburg their home (ACS 2006; Stein 1981b). 

Construction of PVNGS began in 1975 and was completed in 1988. PVNGS is one of the 

largest power producers in the United States, producing nearly 4000 megawatts of electricity 

and serving over four million people. It is the largest nuclear generation facility in the United 

States. It is also the only nuclear plant in the United States that is not located on a large natural 
Affected Environment

December 2010 2-65 NUREG-1437, Supplement 43

body of water. It meets its cooling water needs uniquely, using treated effluent (sewage) from 

Phoenix area municipalities. 

Three hundred twenty-eight properties are listed on the National Register of Historic Places

(NRHP) within Maricopa County, but only one of them is within a six-mile radius of PVNGS. 

The property listed that is nearest PVNGS is the Hassayampa River Bridge. 

2.2.9.2 Historic and Archaeological Resources 

PVNGS encompasses approximately 4,280 acres (1,732 hectares) of land. Approximately 728 

acres (294 hectares) of the site are developed or maintained (Section 2.2.1). Prior to the 

construction of the plant (between 1950 and 1970), approximately 60 percent of the site was 

under cotton cultivation. 

An archaeological survey of 9,300 acres (3,760 hectares) in the Palo Verde Hills area was 

conducted in 1973, prior to the selection of the PVNGS plant site. The survey identified 53 

archaeological sites. Thirteen of the 53 sites were located within the 3,880-acre (1570-hectare) 

site ultimately chosen for the plant. No sites were recorded in the area previously cultivated. Of 

the 13 sites recorded, seven were identified as prehistoric, five were historic, and one contained 

both prehistoric and historic components. A follow-up mitigation study was conducted in 1975 

that completed data recovery at each of the 13 sites and concluded that the PVNGS site was 

likely a hunting and gathering locality for aboriginal groups (Stein 1981a, b). Expansion of the 

evaporation pond capacity at the facility in 2006 resulted in the purchase and survey of an 

additional 526 acres (213 hectares) of private land. The 2006 archaeological survey identified 

four historic sites; none is eligible for listing on the NRHP (ACS 2006). 

Archaeological surveys of the Salt River Project’s Westwing and Kyrene (Hassayampa #1) 

transmission lines were completed in the 1970s, in addition to data recovery at sites that would 

be impacted during construction. Along the Kyrene line, 10 sites and 43 isolated artifacts were 

recorded (Powers, Keane, and Weaver 1978) and four of the sites were investigated further to 

mitigate the impacts of construction (Yablon 1982). Along the Westwing lines, seven sites and 

26 isolated artifacts were recorded (Stein, Granger, and Freeman 1977), and two of the sites 

underwent data recovery to mitigate the impacts of construction (Yablon 1979). The Rudd 

transmission line, also known as the Southwest Valley line, was surveyed in 2001 and 2002; the 

surveys identified 3 historic structures and 3 previously recorded sites on private land 

(Dobschuetz and Darrington 2002) and 3 archaeological sites on state land (Hackbarth 2001). 

All three structures and five of the archaeological sites were either determined eligible for listing 

on the NRHP previously or were treated as eligible for purposes of the project. A treatment plan 

was developed for the eight eligible properties in 2002. A survey was also conducted along the 

Southern California Edison Palo Verde-Devers line; 35 sites and 40 isolated finds were 

recorded (Carrico, Quillen, and Gallegos 1982). As a result of further studies on the 35 sites, 

two districts were listed on the NRHP (North Chuckwalla Mountains Quarry District and North 

Chuckwalla Mountains Petroglyph District). Mitigation of adverse effects on the two districts 

was achieved through some project redesign and construction of barriers to limit access to the 

sites (Eckhardt, Walker, and Carrico 2005). An archaeological survey was conducted along the 

APS North Gila (Hassayampa #3) transmission line prior to construction of the line (Effland and 

Green 1983). APS is conducting a four-year phased archaeological survey of its transmission 

lines; the survey is scheduled to be completed in 2011. 

Agency consultation undertaken by the U.S. Atomic Energy Commission (AEC) in November 

1973 for issuance of an operating license for PVNGS generated a response letter from the 
Affected Environment 

NUREG-1437, Supplement 43 2-66 December 2010

Arizona State Parks, dated December 14, 1973. The letter indicated that the property had been 

surveyed and that no sites meeting eligibility criteria for inclusion in the NRHP had been 

identified (McCarthy 1973). 

APS contacted the Arizona State Historic Preservation Office (SHPO) on September 28, 2007, 

requesting information on historic and archaeological resources located in the vicinity of the 

PVNGS and associated transmission lines (Fox 2007). The letter to the SHPO stated that the 

operation of PVNGS through the license renewal term will not have an adverse effect on any 

historic or cultural property in the region. In a letter dated October 29, 2007, the Arizona SHPO 

concurred with the no adverse effect determination as long as no land disturbance occurs 

(Howard 2007). 

Correspondence between the Arizona SHPO and the NRC, dated May 21, 2009, is provided in 

Appendix E (Wrona 2009). 

Government-to-Government consultation with appropriate Federally recognized Native 

American Tribes has been initiated. Copies of the consultation letters, dated June 1, 2009, and 

September 22, 2009) are provided in Appendix E. To date, no known sites of significance to 

Native Americans have been identified at PVNGS. 

2.3 RELATED FEDERAL PROJECT ACTIVITIES AND CONSULTATIONS 

The NRC staff reviewed the possibility that activities of other Federal agencies might impact the 

renewal of the operating license for PVNGS. Any such activity could result in cumulative 

environmental impacts and the possible need for a Federal agency to become a cooperating 

agency in the preparation of the PVNGS SEIS. 

The NRC has determined that there are no Federal projects that would make it desirable for 

another Federal agency to become a cooperating agency in the preparation of the SEIS. 

Federal lands, facilities, national wildlife refuges, forests, and parks within 50 miles of PVNGS 

are listed below. 

U.S. Bureau of Land Management land (in addition to Public Domain Land) 

• Anza National Historic Trail 

• Big Horn Mountains Wilderness 

• Eagletail Mountain Wilderness 

• Harquahala Mountain Wilderness 

• Hassayampa River Canyon Wilderness 

• Hells Canyon Wilderness 

• Hummingbird Springs Wilderness 

• North Maricopa Mountains Wilderness 

• Sierra Estrella Wilderness 

• Signal Mountain Wilderness 

• Sonoran Desert National Monument 

• South Maricopa Mountains Wilderness 

• Woolsey Peak Wilderness 

U.S. Bureau of Indian Affairs land 

• Gila Bend Indian Reservation 

• Gila River Indian Reservation 
Affected Environment

December 2010 2-67 NUREG-1437, Supplement 43

• Maricopa Indian Reservation 

U.S. Department of Defense land 

• Barry M. Goldwater Air Force Range 

• Buckeye National Guard Target Range 

• Luke Air Force Base 

• Luke Air Force Auxiliary Field 

• Yuma Proving Grounds 

U.S. Fish and Wildlife Service land 

• Kofa National Wildlife Refuge 

NRC is required under Section 102(2)(c) of the National Environmental Policy Act of 1969 

(NEPA) to consult with and obtain the comments of any Federal agency that has jurisdiction by 

law or special expertise with respect to any environmental impact involved. The NRC has 

consulted with the U.S. Fish and Wildlife Service. Federal Agency consultation correspondence 

is presented in Appendix D. 

2.4 REFERENCES 

10 CFR Part 20. Code of Federal Regulations, Title 10, Energy, Part 20, “Standards for 

Protection Against Radiation.” 

10 CFR Part 50. Code of Federal Regulations, Title 10, Energy, Part 50, “Domestic Licensing of 

Production and Utilization Facilities.” 

10 CFR Part 61. Code of Federal Regulations, Title 10, Energy, Part 61, “Licensing 

Requirements for Land Disposal of Radioactive Waste.” 

10 CFR Part 71. Code of Federal Regulations, Title 10, Energy, Part 71, “Packaging and 

Transportation of Radioactive Material.” 

40 CFR Part 190. Code of Federal Regulations, Title 40, Protection of Environment, Part 190, 

“Environmental Radiation Protection Standards for Nuclear Power Operations.” 

American Association for the Advancement of Science (AAAS). 2000. “Population and 

Conservation in the Sonoran Desert” in AAAS Atlas of Population and Environment. Available 

URL: http://www.ourplanet.com/aaas/pages/case06.html (accessed March 23, 2009). 

Archaeological Consulting Services, Ltd. (ACS). 2006. Cultural Resources Survey of Palo 

Verde Nuclear Generating Station’s New Evaporation Pond, South of Wintersburg, Maricopa 

County, Arizona, Tempe, Arizona, January 5, 2006. 

Arizona Department of Economic Security (ADES). 2006. Maricopa County Population 

Projections 2006 – 2055. Excel spreadsheet. Available at 

http://www.azcommerce.com/doclib/econinfo/FILES/2006MaricopaProjections.xls. March 31. 

Accessed March 24, 2010. 

Arizona Department of Environmental Quality (ADEQ). 2009. eMaps. Available at 

http://gisweb.azdeq.gov/arcgis/emaps/?topic=nonattain. Accessed November 30. 

Arizona Department of Environmental Quality (ADEQ). 2009a. Palo Verde Aquifer Protection 

Permit (Area-Wide) No. P-100388. May 1. ADAMS No. ML101660749 
Affected Environment 

NUREG-1437, Supplement 43 2-68 December 2010

Arizona Department of Environmental Quality (ADEQ). 2010a. Air Quality Plans: NonAttainment Areas and Attainment Areas with Maintenance Plans. Available at 

http://www.azdeq.gov/environ/air/plan/notmeet.html. Accessed April 30. 

Arizona Department of Environmental Quality (ADEQ). 2010b. Boundary Recommendations 

for the 2008 8-Hour Ozone National Ambient Air Quality Standards, March 12, 2009. Available 

at http://www.azdeq.gov/environ/air/plan/download/FINAL_2008_ozone_standard.pdf. 

Accessed April 30. 

Arizona Department of Transportation (ADOT). 2009. State Highway Traffic Log. Available at 

http://tpd.azdot.gov/data/documents/SHSAADT060509.pdf. 

Arizona Department of Water Resources (ADWR). 1990. Certificate of Grandfathered 

Groundwater Right. County of Maricopa. Sept. 13, 1990. [PV-276]. ADAMS No. 

ML101530153. 

Arizona Department of Water Resources (ADWR). 2006. “ABCs of Water.” “About 

ADWR.History.” “AMAs.” “Phoenix AMA.” Available at http://www.azwater.gov/dwr/default.htm. 

December. 

Arizona Department of Water Resources (ADWR). 2008. Arizona Water Atlas, Volume 8 – 

Active Management Area Planning Area. Draft. July. Final is available: 

http://azwater.gov/azdwr/statewideplanning/wateratlas/activemanagementareas/documents/volu

me_8_final.pdf 

Arizona Department of Water Resources (ADWR). 2009. Active Management Areas (AMAs) 

and Irrigation Non-Expansion Areas (INAs). Available at http://www.azwater.gov/ 

AzDWR/WaterManagement/AMAs/default.htm. 

Arizona Department of Water Resources (ADWR). 2009a. A Practical Guide to Drilling a Well 

in Arizona. Available at http://www.azwater.gov/azdwr/WaterManagement/Wells/ 

documents/wellguide.pdf. Accessed Dec. 10, 2009. 

Arizona Department of Water Resources (ADWR). 2009b. Well Registry Web Application. 

Available at https://gisweb.azwater.gov/WellRegistry/SearchWellReg.aspx. Accessed Dec. 10, 

2009. 

Arizona Game and Fish Department (AGFD). 2008. Arizona’s Natural Heritage Program: 

Heritage Data Management System (HDMS) – Element Status Designations by County, Taxon, 

Scientific Name. Available URL: 

http://www.gf.state.az.us/w_c/edits/documents/allspecies_bycounty.pdf (accessed January 28, 

2009). 

Arizona Invasive Species Advisory Council (AISAC). 2008. Arizona Invasive Species 

Management Plan. June 30, 2008. Phoenix. Available at 

http://www.governor.state.az.us/AIS/Documents/AISMP2008.pdf. Accessed on January 19, 

2010. 

Arizona Invasive Species Advisory Council (AISAC). 2010. Frequently asked questions 

(FAQs). Arizona Game and Fish Department and Arizona Department of Agriculture. Available 

at http://az.gov/invasivespecies/faqs.html. Accessed on January 19, 2010. 

Arizona Public Service Company (APS). 1982a. Registration of Existing Wells (27DDC). Filed 

with the Arizona Department of Water Resources on June 10, 1982. [PV-404] ADAMS No. 

ML101530195. 
Affected Environment

December 2010 2-69 NUREG-1437, Supplement 43

Arizona Public Service Company (APS). 1982b. Registration of Existing Wells (34ABB). Filed 

with the Arizona Department of Water Resources on June 10, 1982. [PV-405] ADAMS No. 

ML101530212. 

Arizona Public Service Company (APS). 2001. 2000 Annual Groundwater Report, Palo Verde 

Nuclear Generating Station. April 2001. ADAMS No. ML101540020. 

Arizona Public Service Company (APS). 2004. Pump Installation Completion Report for 

PVNGS Firing Range Well. Filed with the Arizona Department of Water Resources on Aug. 3, 

2004. [PV-406] ADAMS No. ML101530219. 

Arizona Public Service Company (APS). 2005. 2004 Annual Monitoring and Compliance 

Report, APP No. P-100388, May 13, 2005. [PV-062] ADAMS No. ML101540025. 

Arizona Public Service Company (APS). 2005a. Palo Verde Nuclear Generating Station 2004 

Air Emissions Inventory Summary. Reported to Maricopa County Air Quality Department, 

Phoenix, Arizona, on April 27, 2005. ADAMS No. ML103160322. 

Arizona Public Service Company (APS). 2006. Palo Verde Nuclear Generating Station 2005 

Air Emissions Inventory Summary. Reported to Maricopa County Air Quality Department, 

Phoenix, Arizona, on May 12, 2006. ADAMS No. ML103160321. 

Arizona Public Service Company (APS). 2006a. Notification of Discharge of Non-Hazardous 

Materials (Tritium) 30 Day Report. Letter with report to the ADEQ. April 3. ADAMS No. 

ML101610776. 

Arizona Public Service Company (APS). 2006b. Update to the Notification of Discharge of 

Non-Hazardous Materials (Tritium) 30 Day Report Work Plan – Completion of Tasks 1a, 1b, 1c, 

1d, 2a, and 2b. June 1, 2006. ADAMS No. ML101540298. 

Arizona Public Service Company (APS). 2006c. 2005 Annual Monitoring and Compliance 

Report, APP No. P-100388, May 15, 2006. [PV-063] ADAMS No. ML101540061. 

Arizona Public Service Company (APS). 2007. Palo Verde Nuclear Generating Station 2006 

Annual Air Emissions Inventory Summary. Reported to Maricopa County Air Quality 

Department, Phoenix, Arizona, on July 27, 2007. ADAMS No. ML103160305. 

Arizona Public Service Company (APS). 2007a. 2006 Annual Water Withdrawal and Use 

Report – Groundwater Right 58-114051.0001. Filed with the Arizona Department of Water 

Resources on March 12, 2007. ADAMS No. ML101590175. 

Arizona Public Service Company (APS). 2007b. 2006 Annual Monitoring and Compliance 

Report, APP No. P-100388, May 14, 2007. [PV-238] ADAMS No. ML101540107. 

Arizona Public Service Company (APS). 2008a. Palo Verde Nuclear Generating Station, Units 

1, 2, and 3, Applicant’s Environmental Report, License Renewal Operating Stage. December. 

ADAMS No. ML083510615, Appendix E. 

Arizona Public Service Company (APS). 2008b. Updated Final Safety Analysis Report, Palo 

Verde Nuclear Generating Station Units 1, 2, and 3, Revision 14B. Feb. ADAMS No. 

ML083510615, Appendix A. 

Arizona Public Service Company (APS). 2008c. 2007 Annual Water Withdrawal and Use 

Report – Groundwater Right 58-114051.0001. Filed with the Arizona Department of Water 

Resources on March 28, 2008. ADAMS No. ML101550146. 

Arizona Public Service Company (APS). 2008d. Palo Verde Nuclear Generating Station 2007 

Annual Air Emissions Inventory. Reported to Maricopa County Air Quality Department, 

Phoenix, Arizona, on April 30. ADAMS No. ML103160290. 
Affected Environment 

NUREG-1437, Supplement 43 2-70 December 2010

Arizona Public Service Company (APS). 2008e. Final Report – Closure Report Arizona Public 

Service Palo Verde Nuclear Generating Station, Tonopah, Arizona. July 2008. ADAMS No. 

ML101550260. 

Arizona Public Service Company (APS). 2008f. 2007 Annual Monitoring and Compliance 

Report APP No. P-100388. May 15, 2008. ADAMS No. ML101550312. 

Arizona Public Service Company (APS). 2008g. Update to the Notification of Discharge of NonHazardous Materials (Tritium) 90-Day Report: Well Installation Report – Monitoring Wells in the 

Protected Area. Jan. 11, 2008. ADAMS No. ML101550232. 

Arizona Public Service Company (APS). 2009a. Hourly Meteorological Data Set at the Palo 

Verde Nuclear Generating Station, 2004-2008. Tonopah, Arizona. Obtained on October 28 

during environmental audit. 

Arizona Public Service Company (APS). 2009b. Palo Verde Nuclear Generating Station 2008 

Annual Air Emissions Inventory. Reported to Maricopa County Air Quality Department, 

Phoenix, Arizona on April 24, 2009. ADAMS No. ML101550316. 

Arizona Public Service Company (APS). 2009c. 5-Year Monitoring Program Evaluation Report 

– Palo Verde Nuclear Generating Station. May 15, 2009. ADAMS No. ML101550329. 

Arizona Public Service Company (APS). 2009d. 2008 Annual Water Withdrawal and Use 

Report – Groundwater Right 58-114051.0001. Filed with the Arizona Department of Water 

Resources on March 31, 2009. ADAMS No. ML101590117. 

Arizona Public Service Company (APS). 2009e. 2008 Annual Monitoring and Compliance 

Report – Palo Verde Nuclear Generating Station APP Permit No. P-100388. May 13. ADAMS 

No. ML101550341. 

Bement, R.S. 2008. Letter from R.S. Bement, Palo Verde Nuclear Vice President, to Maricopa 

County Environmental Services, Air Quality Department, Enforcement Division. “Subject: Order 

of Abatement by Consent- Number NV-006-08-GJV,” dated February 19, 2008. ADAMS No. 

ML101590128. 

Blinn, W. and N.L. Poff. 2005. Colorado River Basin. Pages 483-538 in A.C. Benke and C.E. 

Cushing (eds.), Rivers of North America. Academic Press, New York. 

Bureau of Land Management (BLM). 2008. “Sierra Estrella Wilderness Area.” Available URL: 

http://www.blm.gov/az/st/en/prog/blm_special_areas/wildareas/sierra_estrella.html (accessed 

February 6, 2009). 

California Department of Fish and Game (CDFG). 2009. California Natural Diversity Database 

Quick Viewer – Species by County. Available URL: 

http://imaps.dfg.ca.gov/viewers/cnddb_quickviewer/app.asp (accessed February 2, 2009). 

California Department of Pesticide Regulation. (CDPR) Undated. “Yuma Clapper Rail.” 

Available URL: http://www.cdpr.ca.gov/docs/endspec/espdfs/ycrbio.pdf (accessed March 10, 

2009). 

Carrico, R.L., D.K. Quillen, and D.R. Gallegos. 1982. Cultural Resources Inventory and 

National Register Assessment of the Southern California Edison Palo Verde to Devers 

Transmission Line Corridor (California Portion). Prepared by WESTEC Services, Inc. San 

Diego, California. 

Center for Sonoran Desert Studies (CSDS). 2009. “Sonoran Desert Regional Natural History 

and Image Galleries.” Arizona-Sonora Desert Museum. Available URL: 

http://www.desertmuseum.org/desert/sonora.php (accessed February 4, 2009). 
Affected Environment

December 2010 2-71 NUREG-1437, Supplement 43

City of Phoenix. 2005. Water Resources Plan update 2005. Water Services Department, 

Water Resources and Development Planning Section. Available at 

http://phoenix.rhinonet.com/wrdp/wrplan.shtml. Accessed on January 6, 2010. 

City of Phoenix. 2010. Tres Rios Wetlands. Available at 

http://phoenix.gov/TRESRIOS/index.html. Updated 2010. Accessed January 6, 2010. 

Conway, C. J. and W. R. Eddleman. 2000. “Yuma Clapper Rail” in Endangered Animals: A 

Reference Guide to Conflicting Issues. R. P. Reading and B. Miller, ed. Westport, CT: 

Greenwood Publishing Group, Inc. 

Dobschuetz, K., and G. Darrington. 2002. A Cultural Resource Survey for the Proposed 

Southwest Valley 500kV Transmission Line Project, Maricopa County, Arizona. Environmental 

Planning Group Cultural Resources Services Technical Paper No. 7. Prepared 

by Environmental Planning Group, Phoenix, Arizona. May. 

Eckhardt, W.T., K.E. Walker, and R.L. Carrico. 2005. Cultural Resources Inventory of the 

Proposed Devers to Palo Verde II 500kV Transmission Line, Riverside County, California. 

Prepared by Mooney/Hayes Associates, LLC. San Diego, California. February. 

Effland, R. W. and M. Green. 1983. Cultural Resource Investigations for the Yuma 500 kV 

Transmission Line, Arizona Public Service Company. Cultural Resources Report No. 14. 

Archaeological Consulting Services, Tempe, Arizona. 

Ellis, L. A., D. M. Weddle, S. D. Stump, H. C. English, and A. E. Graber. 2008. Southwestern 

Willow Flycatcher Final Survey and Nest Monitoring Report. Wildlife. Available URL: 

http://sbsc.wr.usgs.gov/cprs/research/projects/swwf/Reports/AGFD_2008_SWWF_ReportBulletin_10-with_Appendices.pdf (accessed March 9, 2009). 

Eroh, M.P. 2009. Final Corrective Action Plan Report for 80-Acre WSR. Submitted to the 

Arizona Department of Environmental Quality, Phoenix, Arizona. June 12. [PV-415] 

Fox, E. 2007. Letter from Edward Fox, Vice President, Arizona Public Service Company, 

Phoenix, Arizona, to James Garrison, State Historic Preservation Officer, Arizona State Parks, 

Phoenix, Arizona. September 28. ADAMS No. ML101610759 

Greater Phoenix Economic Council (GPEC). 2009a. Greater Phoenix Maps. Available at 

http://www.gpec.org/Site_Selection-Maps.aspx. 

Greater Phoenix Economic Council (GPEC). 2009b. Largest Employers in Greater Phoenix. 

Excel spreadsheet. Available at http://www.gpec.org/Leading_Employers.aspx. 

Gunter, G., 2006, Calculation Package Groundwater and Treated Effluent Use, Tetra Tech, SC. 

91st Avenue Wastewater Treatment Plant 25-Year Facility Master Plan (2005-2030). ADAMS 

No. ML101590643. 

Hackbarth, M.R. 2001. Archaeological Survey of State Land within the Proposed Arizona 

Public Service and Salt River Project's Southwest Valley 500kV Transmission Line, Maricopa 

County, Arizona. Prepared by Northland Research, Inc., Tempe and Flagstaff, Arizona. 

August. 

Hillmer, T. 1996. Evaporation Pond Investigation Report. Produced by EH&S for Arizona 

Public Service Company. ADAMS Nos. ML101380158, ML101380163, ML101380198, 

ML101380203 

Howard, A. 2007. Letter from Ann Howard, Arizona State Historic Preservation Officer to 

Edward Fox, Vice President, Communications, Environment, and Safety, Arizona Public Service 

Company, Phoenix, Arizona. October 29. ADAMS No. ML101610759 
Affected Environment 

NUREG-1437, Supplement 43 2-72 December 2010

Laymon, S. A. 2004. “Yellow-billed Cuckoo (Coccycus americanus). Available URL: 

http://www.prbo.org/calpif/htmldocs/species/riparian/yellow-billed_cuckoo.htm (accessed March 

10, 2009). 

Long, M.R. 1982. Maps Showing Groundwater Conditions in the Hassayampa Sub-Basin of 

the Phoenix Active Management Area, Maricopa and Yavapai Counties, Arizona. DWR 

Hydrologic Map Series Report No. 10. Arizona Department of Water Resources in cooperation 

with the U.S. Geological Survey. 

Macfie, B. 2008. The impact of utility deregulation in Arizona. Contemporary Economic Policy, 

April. Available at http://findarticles.com/p/articles/mi_hb5823/is_2_26/ai_n29431385/. 

Maricopa County (MC). 2001. 2020 Eye to the Future – Water Resources. August. 

Maricopa Association of Governments (MAG). 2005. Regional Report. A Resource for Policy 

Makers in the Maricopa Region. Available at http://www.mag.maricopa.gov/publications.cms. 

Maricopa Association of Governments (MAG). 2010. Eight-hour Ozone Plan for the Maricopa 

Nonattainment Area, June 2007. Available at 

http://www.mag.maricopa.gov/pdf/cms.resource/ES_2007_8-HourOzonePlan.pdf. Accessed on 

April 30. 

Maricopa County Air Quality Department (MCAQD). 2005. Air Quality Permit for Arizona Public 

Service, PVNGS, Tonopah, Arizona. Issued August 18. ADAMS No. ML101620032 

Maricopa County Air Quality Department (MCAQD). 2010. State Implementation Plan. 

Available at 

http://www.maricopa.gov/aq/divisions/planning_analysis/state_implementation_plan.aspx.

Accessed April 30. 

McCarthy, D. 1973. Letter from Dennis McCarthy, State Parks Director, State Historic 

Preservation Officer, Arizona State Parks, Phoenix, Arizona, to Edward H. Peplow, Jr., 

Scottsdale, Arizona. December 14. 

Meyer, Rachelle. 2008. “Gopherus agassizii” in Fire Effects Information System. U.S. 

Department of Agriculture, U.S. Forest Service, Rocky Mountain Research Station, and Fire 

Sciences Laboratory. December 28, 2008. Available URL: 

http://www.fs.fed.us/database/feis/animals/reptile/goag/all.html (accessed December 28, 2009). 

National Climatic Data Center (NCDC). 2009a. 2008 Local Climatological Data Annual 

Summary with Comparative Data, Phoenix, Arizona (KPHX). National Oceanic and 

Atmospheric Administration. Available at http://www7.ncdc.noaa.gov/IPS/lcd/lcd.html. 

Accessed November 10, 2009. 

Maricopa County Department of Transportation (MCDOT). 2009. Traffic Counts. Available at 

http://www.mcdot.maricopa.gov/manuals/trafCounts/index.htm. 

National Center for Education Statistics (NCES). 2009. Search for Public School Districts. 

U.S. Department of Education. Available at http://www.nces.ed.gov/ccd/districtsearch/. 

National Climatic Data Center (NCDC). 2009b. Climates of the States (CLIM60): Climate of 

Arizona. National Oceanic and Atmospheric Administration, Satellite and Information Service. 

Available at http://cdo.ncdc.noaa.gov/cgi-bin/climatenormals/climatenormals.pl. Accessed 

November 28, 2009. 

National Climatic Data Center (NCDC). 2009c. Storm Events. National Oceanic and 

Atmospheric Administration, Satellite and Information Service. Available at 

http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwEvent~Storms. Accessed November 28, 2009. 
Affected Environment

December 2010 2-73 NUREG-1437, Supplement 43

National Climatic Data Center (NCDC). 2009d. The Enhanced Fujita Tornado Scale. National 

Oceanic and Atmospheric Administration, Satellite and Information Service. Available at 

http://www.ncdc.noaa.gov/oa/satellite/satelliteseye/educational/fujita.html. Accessed December 

3, 2009. 

National Climatic Data Center (NCDC). 2009e. U.S. Tornado Climatology. National Oceanic 

and Atmospheric Administration, Satellite and Information Service. Available at 

http://www.ncdc.noaa.gov/oa/climate/severeweather/tornadoes.html. Accessed December 3, 

2009. 

National Oceanic and Atmospheric Administration (NOAA). 2009. Top Arizona 

Hurricane/Tropical Storm Events, National Weather Service. Western Region Headquarters, 

Salt Lake City, Utah. Available at http://www.wrh.noaa.gov/psr/tropics/hurricanes.htm. 

Accessed November 28, 2009. 

National Park Service (NPS). 2003. “Saguaro National Park: The Saguaro Cactus.” Available 

URL: http://www.nps.gov/archive/sagu/guides/saguarocactus.pdf (accessed February 5, 2009). 

Patten, M. A. 2007. “Yuma Clapper Rail, Rallus longirostris yumanensis.” U.S. Bureau of Land 

Management. Available URL: http://www.blm.gov/ca/pdfs/cdd_pdfs/claprail1.PDF (accessed 

March 10, 2009). 

Powers, M.A., M.J. Keane, and D.E. Weaver, Jr. 1978. Final Report for An Archaeological 

Survey of the Palo Verde to Kyrene 500 KV Transmission Line, Maricopa County, Arizona, 

prepared by Museum of Northern Arizona, Flagstaff, Arizona, August 25. 

Stein, P.H. 1981a. The Palo Verde Archaeological Investigations, Part 1: Aboriginal Resources 

at the Palo Verde Plant Site, Museum of Northern Arizona Research Paper 21, Museum of 

Northern Arizona Press, Flagstaff, Arizona. ADAMS No. ML101590412. 

Stein, P.H. 1981b. The Palo Verde Archaeological Investigations, Part 2: Wintersburg: An 

Archaeological, Archival, and Folk Account of Homesteading in Arizona, Museum of Northern 

Arizona Research Paper 21, Museum of Northern Arizona Press, Flagstaff, Arizona. ADAMS 

No. ML101590412. 

Stein, P.H., S. Granger, and C.L. Freeman. 1977. Final Report for Palo Verde to Westwing 

Transmission System: An Intensive Survey for the Transmission Line and Access Roads, 

prepared by Museum of Northern Arizona, Flagstaff, Arizona, August. 

USACE and USBR (U.S. Army Corps of Engineers and U.S. Bureau of Reclamation). March 

2002. Final Environmental Assessment and Finding of No Significant Impact for Rio Grande 

Habitat Restoration Project, Los Lunas, New Mexico. 

U.S. Bureau of the Census (USCB). 2009a. QT-H1 General Housing Characteristics: 2000. 

Available at http://factfinder.census.gov/servlet/STTable?_bm=y&-context=st&-

qr_name=ACS_2008_3YR_G00_S2501&-ds_name=ACS_2008_3YR_G00_&-tree_id=3308&-

redoLog=true&-_caller=geoselect&-geo_id=05000US04013&-format=&-_lang=en. 

U.S. Bureau of the Census (USCB). 2009b. QT-H14: Value, Mortgage Status and Selected 

Conditions: 2000. Available at http://factfinder.census.gov/servlet/QTTable?_bm=y&-

context=qt&-qr_name=DEC_2000_SF3_U_QTH14&-ds_name=DEC_2000_SF3_U&-

tree_id=403&-redoLog=true&-all_geo_types=N&-_caller=geoselect&-geo_id=05000US12017&-

search_results=01000US&-format=&-_lang=en. 

U.S. Bureau of the Census (USCB). 2009c. Arizona -- County GCT-T9-R. Housing Units. 

Available at http://factfinder.census.gov/servlet/GCTTable?_bm=y&-context=gct&-
Affected Environment 

NUREG-1437, Supplement 43 2-74 December 2010

ds_name=PEP_2008_EST&-mt_name=PEP_2008_EST_GCTT9R_U40SH&-tree_id=808&-

redoLog=true&-_caller=geoselect&-geo_id=04000US04&-format=ST-2|ST-2S|ST-2Sh&-

_lang=en. 

U.S. Bureau of the Census (USCB). 2009d. 2008 American Community Survey. S2504. 

Physical Housing Characteristics for Occupied Housing Units. Available at 

http://factfinder.census.gov/servlet/STTable?_bm=y&-context=st&-

qr_name=ACS_2007_3YR_G00_S2504&-ds_name=ACS_2007_3YR_G00_&-tree_id=3307&-

redoLog=true&-_caller=geoselect&-geo_id=05000US12017&-format=&-_lang=en. 

U.S. Bureau of the Census (USCB). 2009e. Arizona: Population of Counties by Decennial 

Census: 1900 to 1990. Available at http://www.census.gov/population/cencounts/az190090.txt. 

U.S. Bureau of the Census (USCB). 2009f. State and County QuickFacts – Maricopa County, 

Arizona. Available at http://quickfacts.census.gov/qfd/states/04/04013.html. Accessed March 

24, 2010. 

U.S. Bureau of the Census (USCB). 2009g. QT-P4. Race, Combinations of Two Races, and 

Not Hispanic or Latino: 2000. Data Set: Census 2000 Summary File 1 (SF 1) 100-Percent Data 

Geographic Area: Maricopa County, Arizona. Available at 

http://factfinder.census.gov/servlet/QTTable?_bm=y&-context=qt&-

qr_name=DEC_2000_SF1_U_QTP4&-ds_name=DEC_2000_SF1_U&-CONTEXT=qt&-

tree_id=4001&-all_geo_types=N&-geo_id=05000US04013&-search_results=01000US&-

format=&-_lang=en. Accessed March 24, 2010. 

U.S. Bureau of the Census (USCB). 2009h. Maricopa County, Arizona, ACS Demographic and 

Housing Estimates: 2006-2008 . Available at 

http://factfinder.census.gov/servlet/ADPTable?_bm=y&-geo_id=05000US04013&-

qr_name=ACS_2008_3YR_G00_DP3YR5&-ds_name=ACS_2008_3YR_G00_&-_lang=en&-

redoLog=false&-_sse=on. Accessed on March 24, 2010. 

U.S. Bureau of the Census (USCB). 2009i. “County Business Patterns, 2007.” Available at 

http://www.census.gov/ftp/pub/epcd/cbp/view/cbpview.html. 

U.S. Department of Agriculture (USDA). 2009. 2007 Census of Agriculture. Hired Farm Labor 

–Workers and Payroll: 2007. Available at 

http://www.agcensus.usda.gov/Publications/2007/Full_Report/Volume_1,_Chapter_2_County_L

evel/Arizona/st04_2_007_007.pdf. 

U.S. Department of Commerce (USDOC). 2009. “Local Area Personal Income.” Bureau of 

Economic Analysis. Available at http://www.bea.gov/regional/reis/ 

U.S. Department of Labor (USDOL). 2009. Local Area Unemployment Statistics. Available at 

http://www.bls.gov/lau/#tables 

U.S. Environmental Protection Agency (EPA). 1974. “Information on Levels of Environmental 

Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety.” 

Report 550/9-74-004, Washington, D.C. Available online at 

http://www.nonoise.org/library/levels74/levels74.htm. March. (See also "EPA Identifies Noise 

Levels Affecting Health and Welfare." September 21, 2007. Available online at

http://www.epa.gov/history/topics/noise/01.htm.) Accessed March 2, 2009. 

U.S. Environmental Protection Agency (EPA). 2009. U.S. Environmental Protection Agency 

Local Drinking Water Information. “List of Water Systems in Safe Drinking Water Information 

System database for Maricopa County.” Available at 

http://oaspub.epa.gov/enviro/sdw_query_v2.get_list?wsys_name=&fac_search=fac_beginning&f
Affected Environment

December 2010 2-75 NUREG-1437, Supplement 43

ac_county=MARICOPA&pop_serv=100001&sys_status=active&pop_serv=&wsys_id=&fac_stat

e=AZ&last_fac_name=&page=1&query_results=&total_rows_found=. 

U.S. Environmental Protection Agency (EPA). 2009b. AirData: Access to Air Pollution Data. 

Available at http://www.epa.gov/oar/data/. Accessed November 11, 2009. 

U.S. Environmental Protection Agency (EPA). 2010a. Compilation of Air Pollutant Emission 

Factors, Volume 1: Stationary Point and Area Sources. AP 42, Fifth Edition.

Available at http://www.epa.gov/ttn/chief/ap42/index.html. Accessed November 12, 2010. 

U.S. Environmental Protection Agency (EPA). 2010b. National Ambient Air Quality Standards 

(NAAQS). Available at http://www.epa.gov/air/criteria.html. Last updated June 3, 2010. 

Accessed November 12, 2010. 

(U.S. Fish and Wildlife Service. (USFWS). 2001a. “Biological opinion on the transportation and 

delivery of Central Arizona Project water to the Gila River basin in Arizona and New Mexico” 

2-21-90-F-119a. April 17, 2001. Available at 

http://www.usbr.gov/lc/phoenix/biology/azfish/biologicalop.html. Accessed January 8, 2010. 

[web page Updated June 29, 2005] 

U.S. Fish and Wildlife Service. (USFWS). 2004. “Southwestern Willow Flycatcher.” Available 

URL: http://www.usbr.gov/uc/albuq/rm/mrg/fact/swwf_fact.pdf (accessed March 9, 2009). 

U.S. Fish and Wildlife Service. (USFWS). 2007. “Species Account: Yellow-billed Cuckoo, 

Coccyzus americanus.” Available URL: 

http://www.fws.gov/sacramento/es/animal_spp_acct/yellow-billed_cuckoo.pdf (accessed March 

10, 2009). 

U.S. Fish and Wildlife Service. (USFWS). 2008a. “Coachella Valley National Wildlife Refuge.” 

Available URL: http://www.fws.gov/saltonsea/Coachella/CV_index.html (accessed February 5, 

2009). 

U.S. Fish and Wildlife Service. (USFWS). 2008b. “County Species List: La Paz County.” 

Available URL: http://www.fws.gov/southwest/es/arizona/Documents/CountyLists/LaPaz.pdf 

(accessed January 29, 2009). 

U.S. Fish and Wildlife Service. (USFWS). 2008c. “County Species List: Maricopa County.” 

Available URL: http://www.fws.gov/southwest/es/arizona/Documents/CountyLists/Maricopa.pdf 

(accessed January 29, 2009). 

U.S. Fish and Wildlife Service. (USFWS). 2008d. “Kofa National Wildlife Refuge.” Available 

URL: http://www.fws.gov/southwest/refuges/arizona/kofa/ (accessed February 5, 2009). 

U.S. Fish and Wildlife Service. (USFWS). 2008e. “Threatened and Endangered Species: 

Species by County.” Available URL: 

http://www.fws.gov/carlsbad/TEspecies/CFWO_Species_List.htm (accessed January 30, 2009). 

U.S. Fish and Wildlife Service. (USFWS). 2009. “Southwestern Willow Flycatcher (Empidonax 

traillii extimus).” Available URL: 

http://ecos.fws.gov/speciesProfile/SpeciesReport.do?spcode=B094 (accessed March 9, 2009). 

U.S. Geological Survey (USGS). 2004. “Geological Provinces of the United States: Basin and 

Range Province.” Available URL: http://geomaps.wr.usgs.gov/parks/province/basinrange.html 

(accessed February 4, 2009). 

U.S. Geological Survey (USGS). 2009. Nonindigenous aquatic species. Available at 

http://nas3.er.usgs.gov/. Accessed on January 19, 2010. 
Affected Environment 

NUREG-1437, Supplement 43 2-76 December 2010

U.S. Nuclear Regulatory Commission (NRC). 1975. Final Environmental Statement Related to 

Construction of Palo Verde Nuclear Generating Station, Units 1, 2, and 3, Docket Nos. STN 50-

528, STN 50-529, and STN 50-530. NUREG-75/078. Office of Nuclear Reactor Regulation, 

Washington, D.C. September, pages 2-1, 5, 18-20. ADAMS No. ML101590158. 

U.S. Nuclear Regulatory Commission (NRC). 1982. Final Environmental Statement Related to 

the Operation of Palo Verde Nuclear Generating Station, Units 1, 2, and 3, Docket Nos. STN 

50-528, STN 50-529, and STN 50-530. NUREG-0841. Office of Nuclear Reactor Regulation, 

Washington, D.C. February. ADAMS No. ML090160247. 

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants. NUREG-1437, Volumes 1 and 2, Washington, DC. 

ADAMS No. ML061770605. 

Utah Government Services. 2010. Great Salt Lake. Available at 

http://geology.utah.gov/online/PI-39/pi39pg9.htm. Accessed on January 19, 2010. 

West Regional Climate Center (WRCC). 2009. Western U.S. Climate Historical Summaries. 

Available at http://www.wrcc.dri.edu/Climsum.html. Accessed November 28, 2009. 

World Wildlife Fund. (WWF). 2001. “Sonoran Desert (NA1310).” Available URL: 

http://www.worldwildlife.org/wildworld/profiles/terrestrial/na/na1310_full.html (accessed February 

5, 2009). 

Wrona, D.J. 2009. Letter from David Wrona, Chief Projects Branch 2, Division of License 

Renewal, Office of Nuclear Reactor Regulation, to James Garrison, State Historic Preservation 

Officer, Arizona State Parks, Phoenix, Arizona. May 21. ADAMS No. ML091070394. 

Yablon, R.K. 1979. Final Report for Archaeological Investigations at NA15,137 and NA15,142: 

Two Sites Along the Palo Verde to Westwing Transmission System, prepared by Museum of 

Northern Arizona, Flagstaff, Arizona, July 5. 

Yablon, R.K. 1982. Final Report for Archaeological Investigations of Four Sites along the Palo 

Verde to Kyrene 500 KV Transmission System, Maricopa County, Arizona, prepared by 

Museum of Northern Arizona, Flagstaff, Arizona, January 15. 
 

December 2010 3-1 NUREG-1437, Supplement 43

3.0 ENVIRONMENTAL IMPACTS OF REFURBISHMENT 

Environmental issues associated with refurbishment activities are discussed in NUREG-1437, 

“Generic Environmental Impact Statement (GEIS) for License Renewal of Nuclear Plants, 

Volumes 1 and 2 (NRC 1996). The GEIS includes a determination of whether or not the 

analysis of the environmental issues can be applied to all plants and whether or not additional 

mitigation measures are warranted. Issues are then assigned a Category 1 or a Category 2 

designation. As set forth in the GEIS, Category 1 issues are those that meet all of the following 

criteria: 

(1) The environmental impacts associated with the issue have been determined to apply to 

all plants, or for some issues, apply only to plants having a specific type of cooling 

system or other specified plant or site characteristics. 

(2) A single significance level (SMALL, MODERATE, or LARGE) has been assigned to the 

impacts (except for collective offsite radiological impacts from the fuel cycle and from 

high-level waste and spent fuel disposal). 

(3) Mitigation of adverse impacts associated with the issue has been considered in the 

analysis. It has been determined that additional plant-specific mitigation measures are 

likely not to be sufficiently beneficial to warrant implementation. 

For issues that meet the three Category 1 criteria, no additional plant-specific analysis is 

required in this supplemental environmental impact statement (SEIS) unless new and significant 

information is identified. 

Category 2 issues are those that do not meet one or more of the criteria for Category 1, 

therefore, an additional plant-specific review of these issues is required. 

License renewal actions include refurbishment for the extended plant life. These actions may 

have an impact on the environment that requires evaluation, depending on the type of action 

and the plant-specific design. Environmental issues associated with refurbishment, which were 

determined to be Category 1 issues, are listed in Table 3-1. 

Environmental issues related to refurbishment considered in the GEIS that are inconclusive for 

all plants, or for specific classes of plants, are Category 2 issues. These are listed in Table 3-2. 

The potential environmental effects of refurbishment actions are identified, and the analysis will 

be summarized within this section, if such actions are planned. Arizona Public Service 

Company (APS) indicated that it has performed an evaluation of systems, structures, and 

components pursuant to Section 54.21 of Title 10 of the Code of Federal Regulations (10 CFR 

54.21) to identify the need to undertake any major refurbishment activities that are necessary to 

support continued operation of PVNGS during the requested 20-year period of extended 

operation. Items that are subject to aging and might require refurbishment to support continued 

operation during the renewal period are listed in Table B.2 of the GEIS. 
Environmental Impacts of Refurbishment 

NUREG-1437, Supplement 43 3-2 December 2010

Table 3-1. Category 1 Issues for Refurbishment Evaluation 

ISSUE—10 CFR Part 51, Subpart A, Appendix B, Table B-1 GEIS Sections 

Surface Water Quality, Hydrology, and Use (for all plants) 

Impacts of refurbishment on surface water quality 3.4.1 

Impacts of refurbishment on surface water use 3.4.1 

Aquatic Ecology (for all plants) 

Refurbishment 3.5 

Ground Water Use and Quality 

Impacts of refurbishment on ground water use and quality 3.4.2 

Land Use 

Onsite land use 3.2 

Human Health 

Radiation exposures to the public during refurbishment 3.8.1 

Occupational radiation exposures during refurbishment 3.8.2 

Socioeconomics 

Public services: public safety, social services, and tourism and recreation 3.7.4; 3.7.4.3; 

 3.7.4.4; 3.7.4.6 

Aesthetic impacts (refurbishment) 3.7.8 

Table 3-2. Category 2 Issues for Refurbishment Evaluation 

ISSUE–10 CFR Part 51, Subpart 

A, Appendix B, 

Table B-1 

GEIS 

Sections 

10 CFR 51.53 

(c)(3)(ii) Subparagraph 

Terrestrial Resources 

Refurbishment impacts 3.6 E 

Threatened or Endangered Species (for all plants) 

Threatened or endangered species 3.9 E 

Air Quality 

Air quality during refurbishment 

(nonattainment and maintenance 

areas) 

3.3 F 

Socioeconomics 

Housing impacts 3.7.2 I 

Public services: public utilities 3.7.4.5 I 

Public services: education 

(refurbishment) 3.7.4.1 I 

Offsite land use (refurbishment) 3.7.5 I 

Public services, transportation 3.7.4.2 J 

Historic and archaeological 

resources 

3.7.7 K 

Environmental Justice 

Environmental justice Not addressed Not addressed 
Environmental Impacts of Refurbishment

December 2010 3-3 NUREG-1437, Supplement 43

The results of the evaluation of systems, structures, and components for PVNGS, as required 

by 10 CFR 54.21, do not identify the need to undertake any major refurbishment or replacement 

actions associated with license renewal to support the continued operation of PVNGS beyond 

the end of the existing operating license. 

3.1 REFERENCES 

10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

Protection Regulations for Domestic Licensing and Related Regulatory Functions.” 10 CFR 

Part 54. Code of Federal Regulations, Title 10, Energy, Part 54, “Requirements for Renewal of 

Operating Licenses for Nuclear Power Plants.” 

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants. NUREG-1437, Volumes 1 and 2, Office of Nuclear 

Regulatory Research, Washington, D.C. ADAMS Accession Nos. ML040690705 and 

ML040690738 

U.S. Nuclear Regulatory Commission (NRC). 1999. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plant. NUREG-1437, Volume 1, Addendum 1, Office of Nuclear 

Reactor Regulation, Washington, D.C.ADAMS Accession No. ML0400690720. 

 

December 2010 4-1 NUREG-1437, Supplement 43

4.0 ENVIRONMENTAL IMPACTS OF OPERATION 

This chapter addresses potential environmental impacts related to the period of extended 

operation of Palo Verde Nuclear Generating Station (PVNGS). These impacts are grouped and 

presented according to resource. Generic issues (Category 1) rely on the analysis provided in 

the generic environmental impact statement (GEIS) prepared by the U.S. Nuclear Regulatory 

Commission (NRC) (NRC 1996, 1999) and are discussed briefly. Category 1 issues have a 

significance level of SMALL. NRC staff analyzed site-specific issues (Category 2) for PVNGS 

and assigned them a significance level of SMALL, MODERATE, or LARGE. Some remaining 

issues are not applicable to PVNGS because of site characteristics or plant features. Section 

1.4 of this report explains the criteria for Category 1 and Category 2 issues and defines the 

impact designations of SMALL, MODERATE, and LARGE.

4.1 LAND USE 

Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B–1, which are applicable 

to onsite land use and power line right-of-way impacts during the renewal term are listed in 

Table 4.1. As stated in the GEIS, the impacts associated with these Category 1 issues were 

determined to be SMALL, and plant-specific mitigation measures would not be sufficiently 

beneficial to be warranted. Section 2.2.1 of this document describes the land use around 

PVNGS. 

The NRC staff reviewed and evaluated the PVNGS Environmental Report (ER) (APS 2008a), 

scoping comments, other available information, and visited PVNGS in search of new and 

significant information that would change the conclusions presented in the GEIS. No new and 

significant information was identified during this review and evaluation. Therefore, it is expected 

that there would be no impacts related to these Category 1 issues during the renewal term 

beyond those discussed in the GEIS. 

Table 4-1. Land Use Issues 

Issues GEIS Section Category 

Onsite land use 4.5.3 1 

Power line right-of-way 4.5.3 1 

4.2 AIR QUALITY 

The air quality issue applicable to PVNGS is listed in Table 4-2. Based on the information in the 

GEIS, the Commission found that “production of ozone and oxides of nitrogen is insignificant 

and does not contribute measurably to ambient levels of these gases.” This was considered a 

Category 1 issue. No Category 2 issues have been identified for air quality. The NRC staff did 

not identify any new and significant information during the review of PVNGS ER, the site audit, 

or the scoping process. Therefore, there are no impacts related to this issue beyond those 

discussed in the GEIS. For this issue, the GEIS concluded that the impacts are SMALL, and 

additional site-specific mitigation measures are not likely to be sufficiently beneficial to be 

warranted. Section 2.2.2 of this document describes the air quality around PVNGS. 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-2 December 2010

Table 4-2. Air Quality Issue 

Issues GEIS Section Category 

Air Quality Effects of Transmission Lines 4.5.2 1 

4.3 GROUNDWATER 

4.3.1 Generic Groundwater Issues 

None of the Category 1 issues set forth in the GEIS apply to PVNGS. Category 2 issues related 

to groundwater use that are applicable to PVNGS during the renewal term are discussed in the 

sections that follow. 

4.3.2 Groundwater Use Conflicts (Plants That Use >100 gpm) 

For power plants that pump more than 100 gallons per minute (gpm) (379 liters per minute) of 

groundwater from onsite wells, groundwater use conflicts with nearby groundwater users are 

considered a Category 2 issue that requires a plant-specific assessment before license renewal. 

As described in Section 2.1.7.2, PVNGS maintains three onsite production wells, two of which 

pump more than 100 gpm. The highest total annual pump rate for these wells during 2006, 

2007, and 2008 was 1,535 gpm (5,811 liters per minute). This pump rate is well below the 

3,206 gpm (5,171 acre-feet per year) (6.4 million cubic meters per year) authorized by the 

Arizona Department of Water Resources (ADWR) as part of the plant’s grandfathered 

nonirrigation groundwater right within the Phoenix Active Management Area (AMA) (ADWR 

1999). 

The total annual water demand for groundwater in the Phoenix AMA is 2.3 million acre-feet 

(ADWR 2009). Using the PVNGS highest total annual pump rate of 1,535 gpm or 2,476 acrefeet per year (reported for 2006 through 2008), it is estimated that PVNGS uses less than 1 

percent of the annual demand for groundwater in the Phoenix AMA. 

Because PVNGS pumps groundwater at rates well below its authorized water right and uses 

less than 1 percent of the annual demand for groundwater in the Phoenix AMA, the NRC staff 

concludes that impacts due to groundwater use conflicts would be SMALL, and no additional 

mitigation is warranted. 

4.3.3 Groundwater Use Conflicts (Make-Up From a Small River) 

Groundwater use conflicts are considered a Category 2 issue for power plants with cooling 

ponds or cooling towers using make-up water from a small river with low flow, i.e., less than 

3.15 × 1012 cubic feet per year (8.92 × 1010 cubic meters per year) because consumptive use of 

water from small rivers could adversely impact aquifer recharge (10 CFR 51.53(a)(3)(ii)(A)). 

PVNGS uses a closed-loop cooling system with cooling towers. Although it does not directly 

draw river water for its cooling water system, it does rely on treated effluent from the Phoenix 

area. Because PVNGS diverts treated effluent that would otherwise be discharged to the Gila 

River, which is a small river, the potential for groundwater use conflicts is of concern. 

Natural recharge in the Phoenix AMA occurs along mountain fronts and streambeds and is 

estimated to be about 24,100 acre-feet (30 million cubic meters) per year. Although the AMA 

has deep alluvial aquifers and significant volumes of water in storage, its low recharge rates and 
Environmental Impacts of Operation

December 2010 4-3 NUREG-1437, Supplement 43

large pumping volumes have left its aquifers in an overdraft condition. The Arizona Water Atlas 

(ADWR 2008) defines overdraft as a condition where groundwater is pumped in excess of safeyield. An AMA has achieved safe-yield when it can maintain a long-term balance between the 

annual amount of groundwater withdrawn and the annual amount of natural and artificial 

groundwater recharge. Currently, the ADWR has a management goal of achieving safe-yield in 

the Phoenix AMA by 2025 through recharge, replenishment, retirement of agricultural pumpage, 

and conservation, and providing incentives to industrial and agricultural users to increase their 

use of renewable water supplies (such as treated wastewater effluent). As a result, the use of 

renewable water supplies, such as that by PVNGS, has increased over the past 20 years. 

Efforts to improve access and facilitate full utilization of renewable water supplies in the Phoenix 

AMA are currently under way (ADWR 2009, 1999). 

Although flow in the Gila River is primarily ephemeral between the Ashurst-Hayden Diversion 

Dam and the river’s confluence with the Salt River (Figure 4.4-1), it is primarily perennial 

downstream of the confluence due to effluent discharges from wastewater treatment plants. At 

Estrella Parkway near Goodyear (Station No. 09514100), just downstream of the confluence, 

the average annual flow of the Gila River is 2.64 × 1010 cubic feet (7.48 × 108

 cubic meters) 

(USGS 2006). As a result, the river does provide groundwater recharge to the Upper Alluvial 

Unit aquifer. Loss of Gila River water due to the diversion of treated effluent to PVNGS is about 

53,000 acre-feet (65 million cubic meters) annually (APS 2008a). While this represents about a 

10 per cent loss for the Gila River, it supports the ADWR’s management goal of increasing the 

use of renewable water supplies in the Phoenix AMA to preserve its groundwater resources, 

even though such use reduces the perennial flow and recharge capacity of the river. Also it 

represents only a small portion (about 2.5 percent) of the total annual water demand (2.3 million 

acre-feet [2.84 billion cubic meters]) in the Phoenix AMA (ADWR 2009). For these reasons, the 

NRC staff concludes that impacts due to groundwater use conflicts would also be SMALL, and 

no additional mitigation is warranted. 

4.3.4 Groundwater Quality Degradation (Cooling Ponds at Inland Sites) 

Closed-cycle cooling ponds at inland power plants have the potential to degrade groundwater 

quality because evaporation from ponds concentrates dissolved solids and settles suspended 

solids, and pond effluents could seep into the underlying aquifer. As a result, the quality of 

groundwater in the vicinity of the ponds is a Category 2 issue that requires a plant-specific 

assessment before license renewal. 

4.3.4.1 Evaporation Ponds 

Evaporation ponds at PVNGS store and evaporate cooling tower blowdown water. Cooling 

water is cycled a minimum of 15 times before discharging to the evaporation ponds to ensure 

maximum utilization in accordance with ADWR water conservation requirements for the Phoenix 

AMA. Evaporation Ponds 1 and 2 are above-grade, double-lined surface impoundments with 

underdrain and toe-drain leakage collection systems. These ponds are also authorized to 

receive nonhazardous reject water from the Water Reclamation Facility (WRF) and other onsite 

sources. Evaporation Pond 3 is a new pond, constructed in 2009. It is an above-grade, triplelined surface impoundment, divided into two cells (3A and 3B) that operate independently. 

Each cell is equipped with a liner leakage monitoring system. Evaporation Pond 3 is also 

authorized to receive fluids from other regulated ponds during maintenance and repair activities 

and as part of contingency response actions. All evaporation ponds are regulated under the 

facility’s Aquifer Protection Permit (APP) (No. 100388 LTF 48337) issued by the Arizona 

Department of Environmental Quality (ADEQ) (ADEQ 2009a). 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-4 December 2010

The dissolved solids content of pond influent ranges from about 7,000 mg/L to 24,000 mg/L. It 

is estimated that the influent carries about 100 tons (90.7 tonnes) of solids (dry weight) per day 

per unit (Evaporation Ponds 1 and 2). Each evaporation pond has a reserve storage capacity of 

1.5 feet (0.46 meter) of pond depth to contain a 6-hour thunderstorm probable maximum 

precipitation and a minimum 5 feet (1.5 meters) freeboard is provided to accommodate waves 

and runup (APS 2008a). 

In 2008, a total of 929 million gallons (3.52 million cubic meters) were discharged to Evaporation 

Ponds 1 and 2. Water samples collected from Evaporation Ponds 1 and 2 had detectable 

amounts of two radionuclides (tritium and Iodine-131); however, no radionuclides were found to 

exceed the alert levels required by the APP. Tritium was not detected in any aquifer monitoring 

wells at PVNGS in 2008 (APS 2009). Iodine-131 is present in the influent to PVNGS due to its 

use in medical procedures in the Phoenix area and therefore detectable in the evaporation 

ponds. 

Because the evaporation ponds are designed to retain wastewater and residual solids and are 

equipped with leakage collection systems, and because PVNGS is in compliance with the 

requirements of its APP, the NRC staff concludes that the potential impacts to groundwater 

quality as a result of the operation of evaporation ponds at PVNGS are SMALL, and no 

additional mitigation is warranted. 

4.3.4.2 Water Storage Reservoirs 

The 85-acre (34.4 hectare (ha)) and 45-acre (18.2 ha) Water Storage Reservoirs (WSRs) 

located in the northern portion of the PVNGS site are synthetic-lined impoundments that receive 

tertiary treated effluent from the WRF and store it for use as makeup water for the cooling water 

system. Makeup water replaces water losses due to evaporation, blowdown, and drift from the 

unit cooling towers (APS 2008). Each WSR has a double-liner system with a leakage collection 

and recovery system above an underdrain system that allows groundwater to be pumped and 

removed from underlying soils to protect the liner system. The WSRs are also authorized to 

receive secondary treated effluent from the Sewage Treatment Plant (STP), nonhazardous lowvolume wastewaters during WRF outages, and untreated groundwater from the regional aquifer. 

Both WSRs are regulated under the facility’s APP (No. 100388 LTF 48337) (ADEQ 2009a). 

The APP requires that each WSR has a minimum freeboard of 2 feet (0.6 meter) to prevent 

overtopping and stipulates that fluid in the collection sumps be monitored for liner leaks. In 

2008, a total of 22,737 million gallons (86.1 million cubic meters) flowed into the WSRs from 

three Phoenix-area wastewater treatment plants and the STP. No exceedances of alert levels 

(due to overtopping or leakage) and no unauthorized discharges to either WSR were reported 

(APS 2009). 

Because each WSR is designed to retain treated water and equipped with a leakage collection 

system, and PVNGS is in compliance with the requirements of its APP, the NRC staff concludes 

that the potential impacts to groundwater quality as a result of the operation of WSRs at PVNGS 

are SMALL, and no additional mitigation is warranted. 

4.4 SURFACE WATER 

4.4.1 Generic Surface Water Issues 

PVNGS does not draw its cooling (or makeup) water from any natural surface water body in the 
Environmental Impacts of Operation

December 2010 4-5 NUREG-1437, Supplement 43

area. Instead, it uses treated wastewater effluent from the Phoenix area. 

PVNGS does not release cooling water to any natural surface water body. Instead, cooling 

water is discharged to man-made lined evaporation ponds with no outlet and no hydraulic 

connection to any natural water body. As a result, none of the Category 1 issues set forth in the 

GEIS apply to this facility. 

4.4.2 Water Use Conflicts (Plants Using Make-Up Water from a Small River with Low 

Flow) 

For power plants with cooling ponds or cooling towers using makeup water from a small river 

with low flow, i.e., less than the 3.15 × 1012 cubic feet per year (8.92 × 1010 cubic meters per 

year), water use conflicts are considered a Category 2 issue that require plant-specific 

assessment (10 CFR 51.53). PVNGS uses a closed-loop cooling system with cooling towers. 

Since PVNGS uses treated wastewater effluent that might otherwise be discharged to the Gila 

River, which is a small river, the potential for water use conflicts is of concern. 

The Phoenix area is drained by the Gila River and its principal tributaries: the Salt River, the 

Verde River, the Agua Fria River, and the Hassayampa River (Figure 4.4-1). Diversion dams 

have been constructed on all these rivers for the purpose of regulating flow and storing water to 

meet high-use demand (mainly irrigation). All of the streams and washes in the area are 

ephemeral, either naturally or due to upstream diversion. Flow in the Gila River is primarily 

ephemeral between the Ashurst-Hayden Diversion Dam and the river’s confluence with the Salt 

River. Downstream of the confluence, the Gila River is primarily perennial due to effluent 

discharges from wastewater treatment plants. At Estrella Parkway near Goodyear (Station No. 

09514100), just downstream of the confluence, the average annual flow is 2.64 × 1010 cubic feet 

(7.48 × 108

 cubic meters) (USGS 2006). 

Most of the treated wastewater effluent in the Phoenix AMA is generated at the 91st Avenue 

Wastewater Treatment Plant. The treatment plant processes about 139,000 acre-feet 

(171.5 million cubic meters) of wastewater annually from Glendale, Mesa, Phoenix, Scottsdale, 

and Tempe (ADWR 2008). Treated effluent is used by local municipalities and industries, and 

for urban and agricultural irrigation. In 2008, PVNGS received about 59,249 acre-feet (73.1 

million cubic meters) (43 percent) of the 91st Avenue Wastewater Treatment Plant’s treated 

effluent for use in its cooling water system (APS 2009). Currently, the volume of available 

treated effluent exceeds demand, especially during winter months; unused effluent is 

discharged to the Salt and Gila Rivers, creating perennial flow in these rivers (ADWR 2008). To 

conserve its drinking water supplies, the city of Phoenix is investigating ways to fully utilize 

treated effluent (City of Phoenix 2005). 

The annual flow volumes of treated effluent from the 91st Avenue Wastewater Treatment Plant 

are projected to increase to 264,260 to 297,840 acre-feet (326 to 367 million cubic meters) by 

2030 as the treatment plant expands to meet demand (SROG 2005). Given PVNGS’s current 

annual usage of 59,249 acre-feet (73.1 million cubic meters), the proportion of treated effluent 

from the 91st Avenue Wastewater Treatment Plant being used by the nuclear plant is expected 

to decrease from 43 percent (2009) to about 20 to 22 percent in 2030. Based on this estimate, 

the NRC staff concludes that the potential impacts of water use conflicts are SMALL, and no 

additional mitigation is warranted. 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-6 December 2010 Figure 4.4-1 Gila River and its Principal Tributaries 
Environmental Impacts of Operation

December 2010 4-7 NUREG-1437, Supplement 43

4.5 AQUATIC RESOURCES 

Table 4.5 lists the issues related to aquatic resources applicable to PVNGS. All issues are 

generic (Category 1) and addressed in the GEIS, Section 4.2 and 4.3. Section 2.1.6 of this 

document describes PVNGS’s cooling water system, and Section 2.2.5 describes the aquatic 

resources. 

Table 4-5. Aquatic Resources Issues

Issues GEIS Sections Category 

For All Plants 

Accumulation of contaminants in sediments or biota 4.2.1.2.4 1 

Entrainment of phytoplankton and zooplankton 4.2.2.1.1 1 

Cold shock 4.2.2.1.5 1 

Thermal plume barrier to migrating fish 4.2.2.1.6 1 

Distribution of aquatic organisms 4.2.2.1.6 1 

Premature emergence of aquatic insects 4.2.2.1.7 1 

Gas supersaturation (gas bubble disease) 4.2.2.1.8 1 

Low dissolved oxygen in the discharge 4.2.2.1.9 1 

Losses from predation, parasitism, and disease among 

organisms exposed to sublethal stresses 

4.2.2.1.10 1 

Stimulation of nuisance organisms 4.2.2.1.11 1 

For Plants with Cooling-Tower-Based Heat Dissipation Systems 

Entrainment of fish and shellfish in early life stages 4.3.3 1 

Impingement of fish and shellfish 4.3.3 1 

Heat shock 4.3.3 1 

4.5.1 Generic Aquatic Ecology Issues 

No new and significant information was identified during the review of the APS’s ER (APS 

2008a), the site audit, or the scoping process. Therefore, no impacts related to these issues 

occur beyond those discussed in the GEIS. PVNGS uses treated wastewater effluent to supply 

makeup water for its cooling towers and blowdown flows to evaporation ponds, so no 

impingement, entrainment, or heat shock impacts to aquatic species result from plant operation. 

For these issues, the GEIS concluded that the impacts are SMALL, and additional site-specific 

mitigation measures are not likely to be sufficiently beneficial to warrant implementation. 

4.5.1.1 Water Diversion 

The NRC’s Final Environmental Statement (NRC 1982) for PVNGS and the applicant’s ER 

(APS 2008a) both address the potential effects of water diversion on aquatic communities. 

These reports address the potential impact to natural resources that results from PVNGS using 

about 53,000 acre-feet (65 million cubic meters) of wastewater annually that are lost to 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-8 December 2010

evaporation. None of this diverted wastewater is discharged after use to a natural water body to 

support aquatic and riparian communities. The reports do not question that natural habitat has 

been lost due to water diversion. NRC 1982 concluded, however, that “this diversion will not 

adversely affect characteristic desert aquatic population structure because the existing stream 

management programs and water quality do not allow such communities to develop.” 

In relation to the present application, NRC staff considers the potential use of cooling water 

blowdown to support aquatic resources impractical and speculative. First, practically no natural 

surface water bodies occur on or adjacent to the site that could receive the blowdown. Second, 

salt and other dissolved material in the cooling tower blowdown is highly concentrated; 

therefore, the blowdown would require extensive treatment before release to support natural 

resource communities. Furthermore, it is not clear whether wastewater diverted to PVNGS 

would be used to support natural resources or support irrigation, municipal, and industrial uses. 

Therefore, NRC staff concludes that water diversion during the period of relicensing will not 

adversely affect aquatic resources. 

4.6 TERRESTRIAL RESOURCES 

The issues related to terrestrial resources applicable to PVNGS are listed in Table 4.6. There 

are no Category 2 issues related to terrestrial resources. The NRC did not identify any new and 

significant information during the review of the applicant’s ER (APS 2008a), the site audit, or the 

scoping process. The 1994-95 waterfowl die-off discussed in Section 2.2.6 is not considered 

new and significant for the purposes of this SEIS because in the investigative study that PVNGS 

initiated in response to the die-off event, Hillmer (1996) did not conclusively link the cause of the 

event with PVNGS operation. The cause of the die-off was suspected to be Avian Botulism, 

which was likely contracted by the birds before arriving at PVNGS (Hillmer 1996). Therefore, 

there are no impacts related to the Category 1 terrestrial resource issues beyond those 

discussed in the GEIS. For these issues, the GEIS concluded that the impacts are SMALL, and 

additional site-specific mitigation measures are not likely to be sufficiently beneficial to warrant 

implementation. Section 2.2.6 provides a description of the terrestrial resources at PVNGS and 

in the surrounding area. 

Table 4-6. Terrestrial Resources Issues 

Issues GEIS Section Category 

Cooling tower impacts on crops and ornamental vegetation 4.3.4 1 

Cooling tower impacts on native plants 4.3.5.1 1 

Bird collisions with cooling towers 4.3.5.2 1 

Power line right-of-way management (cutting herbicide application) 4.5.6.1 1 

Bird collisions with power lines 4.5.6.1 1 

Impacts of electromagnetic fields on flora and fauna (plants, 

agricultural crops, honeybees, wildlife, livestock) 4.5.6.3 1 

Floodplains and wetland on power line right-of-way 4.5.7 1 

4.7 THREATENED OR ENDANGERED SPECIES 

The impact to threatened and endangered species is a site-specific, or Category 2 issue. It 
Environmental Impacts of Operation

December 2010 4-9 NUREG-1437, Supplement 43

requires consultation with the appropriate agencies to determine whether threatened or 

endangered species are present and whether they would be adversely affected by continued 

operation of PVNGS during the license renewal term. The characteristics and habitats of 

threatened and endangered species in the vicinity of PVNGS are discussed in Sections 2.2.6 

and 2.2.7 of this document. 

The NRC contacted the U. S. Fish and Wildlife Service (USFWS) on June 12, 2009, regarding 

threatened and endangered species at PVNGS (letter provided in Appendix D). A description of 

the site and the in-scope transmission lines and a preliminary assessment of the Federal 

threatened, endangered, and candidate species potentially occurring on or near PVNGS was 

provided in this letter. The USFWS responded to this request on July 16, 2009 (letter provided 

in Appendix D). 

The NRC contacted the Arizona Game and Fish Department (AGFD) on June 12, 2009, to 

request data to aid in determining which State-listed species may be affected by continued 

operation of PVNGS and associated transmission line rights-of-way (ROWs) (letter provided in 

Appendix D). On July 16, 2009, the AGFD provided information on State-listed species known 

to occur within 5 miles (8 km) of PVNGS and species with the potential to occur within the 

vicinity of the transmission lines associated with PVNGS (letter provided in Appendix D). 

4.7.1 Aquatic Species 

With the exception of East Wash, there are no natural surface water bodies on or immediately 

adjacent to PVNGS. PVNGS does not draw its cooling (or makeup) water from any natural 

surface water body in the area. It also does not release cooling water (or cooling water 

blowdown) effluents to any natural surface water body. Therefore, the NRC staff concludes that 

there is no adverse impacts to aquatic species during the license renewal term.

4.7.2 Terrestrial Species 

Currently, no Federally-listed threatened or endangered terrestrial species are known to occur 

on the PVNGS site. Operation of PVNGS and its associated transmission lines are not 

expected to adversely affect any threatened or endangered terrestrial species during the license 

renewal term. 

One PVNGS-associated transmission line, the Devers line, crosses Federally-designated critical 

habitat for the Mojave population of desert tortoise (Gopherus agassizii) located in and slightly 

north of the Chuckwalla Mountains Wilderness Area. The desert tortoise is Federally listed as 

threatened, Arizona state-listed as a wildlife species of concern, and California state-listed as 

threatened. Southern California Edison (SCE), which owns and maintains the Devers line, has 

an Endangered Species Awareness Program and maintains a comprehensive field guide 

entitled Endangered Species Alert Program Manual: Species Accounts and Procedures (SCE 

2006) to ensure that employees are properly trained to identify and take appropriate precautions 

when working in desert tortoise habitat (SCE 2009). 

The Devers line also crosses through Coachella Valley National Wildlife Refuge, which contains 

Federally-designated critical habitat for the Coachella Valley fringe-toed lizard (Uma inornata); 

however, the line’s ROW does not directly intersect this species’ critical habitat. 

The NRC staff concludes that adverse impacts to threatened and endangered species during 

the license renewal term would be SMALL. A potential mitigation measure that could further 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-10 December 2010

reduce this SMALL impact would be for APS to report existence of any Federally- or State-listed 

endangered or threatened species within or near the transmission line ROWs to the AGFD, 

California Department of Fish and Game (CDFG) and/or USFWS if any such species are 

identified during the renewal term. In particular, if any evidence of injury or mortality of 

migratory birds, State-listed species, or Federally-listed threatened or endangered species is 

observed within the corridor during the renewal period, coordination with the appropriate state or 

Federal agency would minimize impacts to the species and, in the case of Federally-listed 

species, ensure compliance with the Endangered Species Act. 

4.8 HUMAN HEALTH 

The human health issues applicable to PVNGS are discussed below and listed in Table 4-8 for 

Category 1, Category 2, and uncategorized issues. Table B-1 of Appendix B to Subpart A of 

10 CFR Part 51 contains more information on these issues. 

Table 4-8. Human Health Issues 

Issues GEIS Section Category 

Microbiological organisms (occupational health) 4.3.6 1 

Microbiological organisms (public health, for plants using 

small rivers) 4.3.6 2 

Noise 4.3.7 1 

Radiation exposures to public (license renewal term) 4.6.1, 4.6.2 1 

Occupation radiation exposures (license renewal term) 4.6.3 1 

Electromagnetic fields – acute effects (electric shock) 4.5.4.1 2 

Electromagnetic fields – chronic effects 4.5.4.2 Uncategorized 

4.8.1 Generic Human Health Issues 

NRC staff did not identify any new and significant information during its review of the PVNGS 

ER, the site audit, or the scoping process associated with the human health issues listed in 

Table 4-8. Therefore, there are no impacts related to these issues beyond those discussed in 

the GEIS. For these issues, the GEIS concluded that the impacts are SMALL, and additional 

site-specific mitigation measures are not likely to be sufficiently beneficial to be warranted. The 

information presented below is a discussion of selected radiological programs conducted at 

PVNGS. 

4.8.1.1 Radiological Environmental Monitoring Program 

The Radiological Environmental Monitoring Program (REMP) was established for PVNGS by 

APS in 1979, approximately six years prior to initial criticality of the first of the three reactors. 

The REMP is designed to assess the radiological impact, if any, to its employees, the public, 

and the environment in the environs around the plant site. The REMP is performed in 

accordance with NRC requirements to provide a complete environmental monitoring program 

for nuclear reactors and with concern for maintaining the quality of the local environment. An 

annual radiological environmental operating report is issued which contains a discussion and 
Environmental Impacts of Operation

December 2010 4-11 NUREG-1437, Supplement 43

summary of the results of the monitoring. The report contains data on the monitoring performed 

for the year, graphs which trend the data from prior years, and a comparison to pre-plant 

operation baseline data. The objectives of the REMP include the following: 

• To determine baseline radiation levels in the environs prior to plant operation and to 

compare the findings with measurements obtained during reactor operations. 

• To monitor potential radiological exposure pathways to the public. 

• To determine the radiological impact on the environment caused by the operation of 

PVNGS. 

The REMP collects samples of environmental media in the environs around the site to analyze 

and measure the radioactivity levels that may be present. The media samples are 

representative of the radiation exposure pathways to the public from all plant radioactive 

effluents. The assessment program consists of routine measurements of environmental 

radiation and of radionuclide concentrations in media such as air, groundwater, drinking water, 

surface water, vegetation, milk, sludge, and sediment. To ensure the REMP samples the 

appropriate environmental media, a land use census is performed annually to identify the 

nearest milk animals, residents, and gardens. This information is used to evaluate the potential 

dose to members of the public for those exposure pathways that exist in the environs around 

PVNGS. There is also an onsite groundwater protection program designed to monitor the onsite 

plant environment to aid in the early detection of leaks from plant systems and pipes containing 

radioactive liquid. Monitoring wells monitor onsite subsurface water. These wells are monitored 

monthly and quarterly for chemical and radioactive material. These wells are part of the State of 

Arizona Area-Wide Aquifer Protection Permit No. P-100388 and contain specific regulatory 

criteria for groundwater protection (ADEQ 2009a). Additional information on the groundwater 

protection program is contained in Section 2.1.7 of this document. 

The staff reviewed PVNGS radiological environmental operating reports for 2005 through 2009 

to look for unusual trends in the data or significant impacts to the environment (APS 2006X2, 

2007Y3, 2008h, 2009f, 2010a). No unusual trends were observed, and the data showed no 

measurable impact to the environment from the operations at PVNGS. 

4.8.1.2 Radioactive Effluent Release Program 

All nuclear plants were licensed with the expectation that they would release radioactive 

material to both the air and water during normal operation. However, NRC regulations require 

that radioactive gaseous and liquid releases from nuclear power plants must meet radiation 

dose-based limits specified in 10 CFR Part 20, and the as-low-as-is-reasonably-achievable 

(ALARA) criteria in Appendix I to 10 CFR Part 50. Regulatory limits are placed on the radiation 

dose that members of the public can receive from radioactive material released by a nuclear 

power plant. In addition, nuclear power plants are required to file an annual report to the NRC 

which lists the types and quantities of radioactive effluents released into the environment. The 

radioactive effluent release and radiological environmental monitoring reports are available for 

review by the public through the ADAMS electronic reading room available through the NRC 

website. 

The NRC staff reviewed the annual radioactive effluent release reports for 2005 through 2009 

(APS 2006Y2, 2007Y3, 2008h, 2009f, 2010b). The review focused on the calculated doses to a 

member of the public from radioactive gaseous effluents released from PVNGS. There are no 

radioactive liquid effluent release pathways that impact members of the public. The doses were 

compared to the radiation protection standards in 10 CFR 20.1301 and the ALARA dose design 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-12 December 2010

objectives in Appendix I to 10 CFR Part 50. 

Dose estimates for members of the public are calculated based on radioactive gaseous effluent 

release data and atmospheric transport models. The 2009 annual radioactive material release 

report (APS 2010b) contains a detailed presentation of the radioactive gaseous effluents and 

the resultant calculated doses. The following summarizes the calculated annual dose to a 

member of the public located outside the PVNGS site boundary from radioactive gaseous 

effluents released during 2009: 

Unit 1

• The air dose at the site boundary from gamma radiation in gaseous effluents was 

2.40 x 10-2 mrad (2.40 x 10-4 mGy), which is well below the 10 mrad (0.1 mGy) dose 

criterion in Appendix I to 10 CFR Part 50. 

• The air dose at the site boundary from beta radiation in gaseous effluents was 

8.89 x 10-3 mrad (8.89 x 10-5 mGy), which is well below the 20 mrad (0.2 mGy) dose 

criterion in Appendix I to 10 CFR Part 50. 

• The organ (teen whole body) dose to an offsite member of the public from radioactive 

iodine and radioactive material in particulate form from gaseous effluents was 1.11 x 10-1

mrem (1.11 x 10-3 mSv), which is well below the 15 mrem (0.15 mSv) dose criterion in 

Appendix I to 10 CFR Part 50. 

Unit 2

• The air dose at the site boundary from gamma radiation in gaseous effluents was 

2.46 x 10-3 mrad (2.46 x 10-5 mGy), which is well below the 10 mrad (0.1 mGy) dose 

criterion in Appendix I to 10 CFR Part 50. 

• The air dose at the site boundary from beta radiation in gaseous effluents was 

1.12 x 10-3 mrad (1.12 x 10-5 mGy), which is well below the 20 mrad (0.2 mGy) dose 

criterion in Appendix I to 10 CFR Part 50. 

• The organ (teen thyroid) dose to an offsite member of the public from radioactive iodine 

and radioactive material in particulate form from gaseous effluents was 2.43 x 10-1

mrem (2.43 x 10-3 mSv), which is well below the 15 mrem (0.15 mSv) dose criterion in 

Appendix I to 10 CFR Part 50. 

Unit 3

• The air dose at the site boundary from gamma radiation in gaseous effluents was 

7.65 x 10-3 mrad (7.65 x 10-5 mGy), which is well below the 10 mrad (0.1 mGy) dose 

criterion in Appendix I to 10 CFR Part 50. 

• The air dose at the site boundary from beta radiation in gaseous effluents was 

9.99 x 10-3 mrad (9.99 x 10-5 mGy), which is well below the 20 mrad (0.2 mGy) dose 

criterion in Appendix I to 10 CFR Part 50. 

• The organ (teen thyroid) dose to an offsite member of the public from radioactive iodine 
Environmental Impacts of Operation

December 2010 4-13 NUREG-1437, Supplement 43

and radioactive material in particulate form from gaseous effluents was 1.92 x 10-1 mrem 

(1.93 x 10-3 mSv), which is well below the 15 mrem (0.15 mSv) dose criterion in 

Appendix I to 10 CFR Part 50. 

Based on the staff’s review of the PVNGS radioactive waste system performance in controlling 

radioactive effluents and the resultant doses to members of the public in compliance with the 

ALARA criteria, the NRC staff found the 2009 radiological dose data consistent with the 

historical doses. While small differences in the annual doses was observed, this is attributable 

to the amount of radioactive effluents discharged based on the plant’s operating history (e.g., 

power level, number and duration of refueling and maintenance outages, and fuel performance). 

The doses, for all years reviewed, comply with Federal radiation protection standards contained 

in Appendix I to 10 CFR Part 50, 10 CFR Part 20, and 40 CFR Part 190. 

Routine plant operational and maintenance activities currently performed will continue during 

the license renewal term. Based on the past performance of the radioactive waste system to 

maintain the dose from radioactive effluents to be ALARA, similar performance is expected 

during the license renewal term. 

The radiological impacts from the current operation of PVNGS are not expected to change 

significantly. Continued compliance with regulatory requirements is expected during the license 

renewal term; therefore, the impacts from radioactive effluents would be SMALL. 

4.8.2 Microbiological Organisms 

PVNGS does not draw water from any natural surface water body in the area. It also does not 

release water to any natural surface water body. Therefore, the staff concludes that there would 

be no adverse impacts on public health from thermophilic microbiological organisms from 

continued operation of PVNGS in the license renewal period.

4.8.3 Electromagnetic Fields – Acute Shock 

Based on the GEIS, the Commission found that electric shock resulting from direct access to 

energized conductors or from induced charges in metallic structures has not been a problem at 

most operating plants and generally is not expected to be a problem during the period of 

extended operation. However, a site-specific review is required to determine the significance of 

the electric shock potential along the portions of the transmission lines within the scope of the 

Supplemental EIS. 

The GEIS states that it is not possible to determine the significance of the electric shock 

potential without a review of the conformance of each nuclear plant transmission line with 

National Electrical Safety Code (NESC) (IEEE 2007) criteria. Evaluation of individual plant 

transmission lines is necessary because the issue of electric shock safety was not addressed in 

the licensing process for some plants. For other plants, land use in the vicinity of transmission 

lines may have changed, or power distribution companies may have chosen to upgrade line 

voltage. To comply with 10 CFR 51.53(c)(3)(ii)(H), the applicant must provide an assessment of 

the potential shock hazard if the transmission lines that were constructed for the specific 

purpose of connecting the plant to the transmission system do not meet the recommendations 

of the NESC for preventing electric shock from induced currents. 

All transmission lines associated with PVNGS were constructed in accordance with NESC and 

industry guidance in effect at that time (NRC 1982). This guidance states that the minimum 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-14 December 2010

clearance for a line must limit induced currents due to static effects to 5 mA. APS has reviewed 

the transmission lines for compliance with this criterion (APS 2008a) and indicated that all 

transmission lines within the scope of this review have been restudied and the results show 

there are no locations under the transmission lines that have the capacity to induce more than 5 

mA in a vehicle parked beneath the line. No induced shock hazard to the public should occur, 

since the lines are operating within original design specifications and meet current NESC 

clearance standards. 

APS, Salt River Project and Southern California Edison implement transmission line 

assessment procedures at PVNGS to ensure continued monitoring and documenting of current 

conditions of the transmissions lines, maintenance and compliance with current standards. 

Routine aerial inspections and ground inspections are conducted to identify any ground 

clearance problems and the integrity of the transmission line structures (APS 2008a). 

NRC staff has reviewed the available information, including the applicant’s evaluation and 

computational results. Based on this information, the NRC staff evaluated the potential impacts 

for electric shock resulting from operation of PVNGS and its associated transmission lines. 

NRC staff concludes that the potential impacts from electric shock during the renewal period 

would be SMALL. 

NRC staff identified a variety of measures that could mitigate potential acute electromagnetic 

field impacts resulting from continued operation of the PVNGS transmission lines. These 

mitigation measures would include erecting barriers along the length of the transmission line to 

prevent unauthorized access to the ground beneath the conductors and installing road signs at 

road crossings. These mitigation measures could reduce human health impacts by minimizing 

public exposures to electric shock hazards. NRC staff did not identify any cost benefit studies 

applicable to the mitigation measures mentioned above. 

4.8.4 Electromagnetic Fields – Chronic Effects 

In the GEIS, the chronic effects of 60-Hz electromagnetic fields from power lines were not 

designated as Category 1 or 2, and will not be until a scientific consensus is reached on the 

health implications of these fields. 

The potential for chronic effects from these fields continues to be studied and is not known at 

this time. The National Institute of Environmental Health Sciences (NIEHS) directs related 

research through the U.S. Department of Energy (DOE). A report by NIEHS (NIEHS 1999) 

contains the following conclusion which is supported by recently published Environmental 

Health Criteria Monograph No.238 (WHO 2007a): 

The NIEHS concludes that ELF-EMF [extremely low frequency-electromagnetic field] 

exposure cannot be recognized as entirely safe because of weak scientific evidence that 

exposure may pose a leukemia hazard. In our opinion, this finding is insufficient to 

warrant aggressive regulatory concern. However, because virtually everyone in the 

United States uses electricity and therefore is routinely exposed to ELF-EMF, passive 

regulatory action is warranted such as a continued emphasis on educating both the 

public and the regulated community on means aimed at reducing exposures. The 

NIEHS does not believe that other cancers or non-cancer health outcomes provide 

sufficient evidence of a risk to currently warrant concern. 

This statement is not sufficient to cause NRC staff to change its position with respect to the 
Environmental Impacts of Operation

December 2010 4-15 NUREG-1437, Supplement 43

chronic effects of electromagnetic fields. This position is expressed in footnote 5 To Table B-1 

of Appendix B to Subpart A of 10 CFR Part 51 as follows: 

If in the future, the Commission finds that, contrary to current indications, a consensus 

has been reached by appropriate Federal health agencies that there are adverse health 

effects from electromagnetic fields, the Commission will require applicants to submit 

plant-specific reviews of these health effects as part of their license renewal applications. 

Until such time, applicants for license renewal are not required to submit information on 

this issue. 

NRC staff considers the GEIS finding of “Uncertain” still appropriate and will continue to follow 

developments on this issue. 

4.9 SOCIOECONOMICS 

The socioeconomic issues applicable to PVNGS are shown in Table 4.9 for Category 1, 

Category 2, and uncategorized issues. Section 2.2.9 of this report describes the socioeconomic 

conditions near PVNGS. 

Table 4-9. Socioeconomic Issues 

Issues GEIS Section Category 

Housing Impacts 4.7.1 2 

Public Services: public safety, social 

services, and tourism and recreation 

4.7.3; 4.7.3.3; 4.7.3.4; 4.7.3.6 1 

Public Services: public utilities 4.7.3.5 2 

Public Services: education (license 

renewal term) 

4.7.3.1 1 

Offsite Land Use (license renewal 

term) 

4.7.4 2 

Public Services: transportation 4.7.3.2 2 

Historic and Archaeological 

Resources 

4.7.7 2 

Aesthetic Impacts (license renewal 

term) 

4.7.6 1 

Aesthetic impacts of transmission 

lines (license renewal term) 

4.5.8 1 

Environmental Justice Not addressed(a) Uncategorized(a)

(a) Guidance related to environmental justice was not in place at the time the GEIS and the associated revisions 

to 10 CFR Part 51 were prepared. Therefore, environmental justice must be addressed in plant-specific 

reviews. 

4.9.1 Generic Socioeconomic Issues 

NRC staff reviewed and evaluated the PVNGS ER (APS 2008a), scoping comments, other 

available information, and visited the plant site and did not identify any new and significant 

information that would change the conclusions presented in the GEIS. Therefore, it is expected 

that there would be no impacts related to the Category 1 issues during the period of extended 

operation beyond those discussed in the GEIS. For PVNGS, the NRC incorporates the GEIS 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-16 December 2010

conclusions by reference. Impacts for Category 2 and uncategorized issues are discussed in 

Sections 4.9.2 through 4.9.7. 

4.9.2 Housing Impacts 

Appendix C of the GEIS presents a population characterization method based on two factors, 

sparseness and proximity (GEIS, Section C.1.4). Sparseness measures population density 

within 20 miles of the site, and proximity measures population density and city size within 

50 miles. Each factor has categories of density and size (GEIS, Table C.1). A matrix is used to 

rank the population category as low, medium, or high (GEIS, Figure C.1). 

In 2000, approximately 16,000 persons lived within a 20-mile (32-km) radius of PVNGS, which 

equates to a population density of 13 persons per square mile (APS 2008a). This translates to 

a Category 1 density using the GEIS measure of sparseness (less than 40 persons per square 

mile within 20 miles and no community with 25,000 or more persons within 20 miles). At the 

same time, approximately 1,572,110 persons lived within a 50-mile (80-km) radius of the plant, 

for a density of 200 persons per square mile (APS 2008a). This translates to a Category 4 

density using the GEIS measure of proximity (greater than or equal to 190 persons per square 

mile within 50 miles). Therefore, PVNGS is located in a medium population area based on the 

NRC sparseness and proximity matrix. 

Table B-1 of 10 CFR Part 51, Subpart A, Appendix B, states that impacts on housing availability 

are expected to be of small significance in a medium population area where growth-control 

measures are not in effect. Maricopa County, in which PVNGS is located, is not subject to 

growth-control measures that would limit housing development. Therefore, the PVNGS 

employment-related impact on housing availability would likely be small. Since APS has no 

plans to add non-outage employees during the license renewal period, employment levels at 

PVNGS would remain relatively constant with no additional demand for permanent housing 

during the license renewal term. In addition, the number of available housing units has kept 

pace with growth in the area population. Based on this information, there would be no impact 

on housing during the license renewal term beyond what has already been experienced.

4.9.3 Public Services: Public Utility Impacts 

Impacts on public utility services are considered SMALL if there is little or no change in the 

ability of the system to respond to demand and thus there is no need to add capital facilities. 

Impacts are considered MODERATE if service capabilities are overtaxed during periods of peak 

demand. Impacts are considered LARGE if services (e.g., water, sewer) are substantially 

degraded and additional capacity is needed to meet ongoing demand. The GEIS indicated that, 

in the absence of new and significant information to the contrary, the only impacts on public 

utilities that could be significant are impacts on public water supplies. 

Analysis of impacts on the public water and sewer systems considered both plant demand and 

plant-related population growth. Section 2.1.3 of this document describes the PVNGS use of 

water. 

As previously discussed in Section 2.2.8.2, PVNGS provides pump seal cooling, sanitation, fire 

protection and potable water for drinking through the onsite groundwater well system. Since 

APS has no plans to add non-outage employees during the license renewal period, employment 

levels at PVNGS would remain relatively unchanged with no additional demand for public water 

services. Public water systems in the region would be adequate to meet the demands of 
Environmental Impacts of Operation

December 2010 4-17 NUREG-1437, Supplement 43

residential and industrial customers in the area. Therefore, there would be no additional impact 

to public water services during the license renewal term beyond what is currently being 

experienced. 

4.9.4 Offsite Land Use 

Offsite land use during the license renewal term is a Category 2 issue (10 CFR Part 51.4 

Subpart A, Appendix B, Table B-1). Table B-1 notes that “significant changes in land use may 

be associated with population and tax revenue changes resulting from license renewal.” 

Section 4.7.4 of the GEIS defines the magnitude of land use changes as a result of plant 

operation during the license renewal term as follows: 

 • SMALL—little new development and minimal changes to an area’s land use pattern 

 • MODERATE—considerable new development and some changes to the land use pattern 

 • LARGE—large-scale new development and major changes in the land use pattern 

Tax revenue can affect land use because it enables local jurisdictions to provide the public 

services (e.g., transportation and utilities) necessary to support development. Section 4.7.4.1 of 

the GEIS states that the assessment of tax-driven land use impacts during the license renewal 

term should consider (1) the size of the plant’s payments relative to the community’s total 

revenues, (2) the nature of the community’s existing land use pattern, and (3) the extent to 

which the community already has public services in place to support and guide development. If 

the plant’s tax payments are projected to be small relative to the community’s total revenue, tax 

driven land use changes during the plant’s license renewal term would be SMALL, especially 

where the community has pre-established patterns of development and has provided adequate 

public services to support and guide development. Section 4.7.2.1 of the GEIS states that if tax 

payments by the plant owner are less than 10 percent of the taxing jurisdiction’s revenue, the 

significance level would be SMALL. If tax payments are 10 to 20 percent of the community’s 

total revenue, new tax-driven land use changes would be MODERATE. If tax payments are 

greater than 20 percent of the community’s total revenue, new tax-driven land use changes 

would be LARGE. This would be especially true if the community has no pre-established 

pattern of development or has not provided adequate public services to support and guide 

development. 

4.9.4.1 Population-Related Impacts 

Since APS has indicated that it has no plans to add non-outage employees during the license 

renewal period, there would be no noticeable change in land use conditions in the vicinity of 

PVNGS. Therefore, there would be no population-related land use impacts during the license 

renewal term beyond those already being experienced. 

4.9.4.2 Tax-Revenue-Related Impacts 

As discussed in Section 2.2.8.6, APS pays annual real estate taxes to Maricopa County. For 

the 4-year period from 2005 through 2008, PVNGS tax payments to Maricopa County 

represented between 1.1 and 1.6 percent of the county’s total tax revenue collections. 

Since APS has no plans to add non-outage employees during the license renewal period, 

employment levels at the PVNGS would remain relatively unchanged. There would be no 

change in the assessed value of PVNGS, and annual property tax payments to Maricopa 

County would be expected to remain relatively unchanged throughout the license renewal 

period. Based on this information, there would be no tax-revenue-related offsite land use 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-18 December 2010

impacts during the license renewal term beyond those already being experienced. 

4.9.5 Public Services: Transportation Impacts 

Table B-1 in 10 CFR Part 51 states the following: 

Transportation impacts (level of service) of highway traffic generated...during the term of 

the renewed license are generally expected to be of small significance. However, the 

increase in traffic associated with additional workers and the local road and traffic control 

conditions may lead to impacts of moderate or large significance at some sites. 

The regulation in 10 CFR 51.53(c)(3)(ii)(J) requires all applicants to assess the impacts of 

highway traffic generated by the proposed project on the level of service of local highways 

during the term of the renewed license. Since APS has no plans to add non-outage employees 

during the license renewal period, traffic volume and levels of service on roadways in the vicinity 

of PVNGS would not change. Therefore, there would be no transportation impacts during the 

license renewal term beyond those already being experienced. 

4.9.6 Historic and Archaeological Resources 

The National Historic Preservation Act of 1966 (NHPA), as amended through 2000, requires 

Federal agencies to take into account the potential effects of their undertakings on historic 

properties. Historic properties are defined as resources that are eligible for listing on the 

National Register of Historic Places. The criteria for eligibility include (1) association with 

significant events in history; (2) association with the lives of persons significant in the past; 

(3) embodiment of distinctive characteristics of type, period, and construction; and 

(4) association with or potential to yield important information (ACHP 2008). The historic 

preservation review process mandated by Section 106 of the NHPA is outlined in regulations 

issued by the Advisory Council on Historic Preservation in Title 36, “Parks, Forests, and Public 

Property,” Part 800, “Protection of Historic Properties,” of the Code of Federal Regulations 

(36 CFR Part 800). The renewal of a nuclear power plant operating license is a Federal action 

that could potentially affect either known or currently undiscovered historic properties located on 

or near the plant site and its associated transmission corridors. In accordance with the 

provisions of the NHPA, the NRC is required to identify historic properties in the area of 

potential effect. If no historic properties are present or affected, the NRC is required to notify 

the State Historic Preservation Office (SHPO) before proceeding. If it is determined that historic 

properties are present, the NRC is required to assess and resolve possible adverse effects of 

license renewal. 

APS has formal guidelines in its Environmental Review and Evaluation Manual (91DP-0EN02) 

for protecting archaeological resources and consulting with the SHPO prior to ground disturbing 

activities. Another procedure, Excavation, Placement and Backfill (37DP-9ZZ11) requires work 

to be stopped if an artifact of possible historical or archaeological interest is found during 

earthmoving activities. Arizona State burial law also requires a work stoppage if any human 

remains are unexpectedly uncovered. The NRC staff reviewed these procedures and examples 

of how APS applied these procedures during the site audit. 

Similar reviews of vegetation management plans for transmission lines were conducted. APS 

procedures incorporate Federal and State regulations regarding protection of archaeological 

sites from potential impacts of ground-disturbing activities along the transmission lines, including 

California Code of Regulations, Title 14, Section 15000 et seq., “Guidelines for Implementation 

of the California Environmental Quality Act,” and the National Historic Preservation Act. APS 
Environmental Impacts of Operation

December 2010 4-19 NUREG-1437, Supplement 43

procedures require surveys prior to mechanical clearing of vegetation. APS is currently 

conducting a four-year program (2007–2011) to complete cultural resource surveys of all of its 

transmission corridors to expedite future vegetation management along these transmission 

lines. The Salt River Project (SRP) owns and operates several of the transmission lines 

associated with PVNGS. SRP’s Vegetation Management Plan states archaeological studies are 

conducted prior to mechanical clearing when required by the landholding Federal agency. 

Records on file at the AZ SHPO and the AZSITE database pertaining to the PVNGS property 

were reviewed by a qualified archaeologist from Argonne National Laboratory under contract 

with the NRC. Locations recorded in the AZSITE database corresponded to site locations that 

were identified during the initial survey and mitigated in 1975 (Stein 1981a,b). 

Based on its review of agency files, published literature, and information provided by APS, staff 

concludes that potential impacts from license renewal of PVNGS on historic and archaeological 

resources would be SMALL. This conclusion is based on the results of archaeological surveys 

conducted on the property prior to initial plant and transmission line construction and verified 

use of existing environmental procedures by PVNGS. 

4.9.7 Environmental Justice 

Under Executive Order (E.O.) 12898, Federal agencies are responsible for identifying and 

addressing potential disproportionately high and adverse human health and environmental 

impacts on minority and low-income populations. Although the Executive Order is not 

mandatory for independent agencies such as the NRC, the NRC has voluntarily committed to 

undertake environmental justice reviews. In 2004, the Commission issued a Policy Statement 

on the Treatment of Environmental Justice Matters in NRC Regulatory and Licensing Actions

(69 FR 52040), which states “The Commission is committed to the general goals set forth in 

E.O. 12898, and strives to meet those goals as part of its NEPA review process.” 

The Council of Environmental Quality (CEQ) provides the following information in Environmental 

Justice: Guidance Under the National Environmental Policy Act (1997): 

Disproportionately High and Adverse Human Health Effects. Adverse health effects are 

measured in risks and rates that could result in latent cancer fatalities, as well as other fatal 

or nonfatal adverse impacts on human health. Adverse health effects may include bodily 

impairment, infirmity, illness, or death. Disproportionately high and adverse human health 

effects occur when the risk or rate of exposure to an environmental hazard for a minority or 

low-income population is significant (as defined by NEPA [National Environmental Policy 

Act]) and appreciably exceeds the risk or exposure rate for the general population or for 

another appropriate comparison group (CEQ 1997). 

Disproportionately High and Adverse Environmental Effects. A disproportionately high 

environmental impact that is significant (as defined by NEPA) refers to an impact or risk of 

an impact on the natural or physical environment in a low-income or minority community that 

appreciably exceeds the environmental impact on the larger community. Such effects may 

include ecological, cultural, human health, economic, or social impacts. An adverse 

environmental impact is an impact that is determined to be both harmful and significant (as 

defined by NEPA). In assessing cultural and aesthetic environmental impacts, impacts that 

uniquely affect geographically dislocated or dispersed minority or low-income populations or 

American Indian tribes are considered (CEQ 1997). 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-20 December 2010

The environmental justice analysis assesses the potential for disproportionately high and 

adverse human health or environmental effects on minority and low-income populations that 

could result from the operation of PVNGS during the renewal term. In assessing the impacts, 

the following CEQ definitions of minority individuals and populations and low-income population 

were used: 

• Minority individuals. Individuals who identify themselves as members of the following 

population groups: Hispanic or Latino, American Indian or Alaska Native, Asian, Black or 

African American, Native Hawaiian or Other Pacific Islander, or two or more races meaning 

individuals who identified themselves on a Census form as being a member of two or more 

races, for example, Hispanic and Asian. 

• Minority populations. Minority populations are identified when (1) the minority population 

of an affected area exceeds 50 percent or (2) the minority population percentage of the 

affected area is meaningfully greater than the minority population percentage in the general 

population or other appropriate unit of geographic analysis. 

• Low-income population. Low-income populations in an affected area are identified with 

the annual statistical poverty thresholds from the Census Bureau’s Current Population 

Reports, Series PB60, on Income and Poverty. 

4.9.7.1 Minority Population in 2000 

According to 2000 census data, 43.2 percent of the population (689,337 individuals) residing 

within a 50-mile (80-km) radius of PVNGS identified themselves as minority individuals 

(USCB 2009). The largest minority group was Hispanic (532,832 individuals, or 33.4 percent), 

followed by Black or African American (73,281 individuals, or 4.6 percent). Approximately 

48 percent of the Maricopa County population is minority, with Hispanic (24.8 percent) the 

largest minority group, followed by Black or African American (3.7 percent) (USCB 2009). 

The 50-mile radius around PVNGS includes any census block located within the 50-mile radius. 

Of the 1,256 census block groups located wholly or partly within the 50-mile radius of PVNGS, 

841 block groups were determined to have minority population percentages that exceeded the 

state percentages by 20 percentage points or more, while there were 545 block groups where 

minority populations were more than 50 percent of the total (APS 2008a). The largest number 

of minority block groups was Hispanic, with 364 block groups that exceeded the State 

percentage of 20 percent or more, and 322 that were more than 50 percent Hispanic. These 

block groups are concentrated in urban areas with high population densities, primarily in 

Maricopa County, and in the city of Phoenix, Arizona, in particular. Census block groups to the 

south and southwest of PVNGS also have Hispanic populations exceeding threshold levels. 

Based on 2000 census data, Figure 4-1 shows minority block groups within a 50-mile (80-km) 

radius of PVNGS. 

 
Environmental Impacts of Operation

December 2010 4-21 NUREG-1437, Supplement 43

Figure 4.9.7-1. Minority block groups within a 50-mile radius of PVNGS (USCB 2009).
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-22 December 2010

4.9.7.2 Low-Income Population in 2000 

According to 2000 census data, 238,112 individuals (14.9 percent) residing within a 50-mile 

radius of PVNGS were identified as living below the Federal poverty threshold (USCB 2009). 

The 1999 Federal poverty threshold was $17,029 for a family of four. According to Census 

Bureau data, the median household income for Arizona in 2007 was $49,923, while 

14.1 percent of the state population was determined to be living below the 1999 Federal poverty 

threshold. Maricopa County had one of the higher median household incomes ($54,733) and a 

lower percentage (12.9 percent) of individuals living below the poverty level when compared to 

other counties in Arizona (USCB 2009). 

Census block groups were considered low-income block groups if the percentage of households 

below the Federal poverty threshold exceeded the state average by 20 percent or more. Based 

on 2000 Census data, there were 108 block groups within the 50-mile (80-km) radius of PVNGS 

that exceeded the state average for low-income households by 20 percent or more, and 21 

block groups that were more than 50 percent low income (APS 2008a). The majority of census 

block groups with low-income populations were located in Maricopa County, primarily in the city 

of Phoenix, Arizona. Based on 2000 Census data, Figure 4-2 shows low-income block groups 

within a 50-mile radius of PVNGS. 

 
Environmental Impacts of Operation

December 2010 4-23 NUREG-1437, Supplement 43

Figure 4.9.7-2. Low-income block groups within 50-mile radius of PVNGS (APS 2008a).
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-24 December 2010

4.9.7.3 Analysis of Impacts 

Consistent with the impact analysis for the public and occupational health and safety, the 

affected populations are defined as minority and low-income populations who reside within a 

50-mile (80-km) radius of PVNGS. Based on the analysis of environmental health and safety 

impacts presented in this document for other resource areas, there would be no high and 

adverse impacts from the operation of PVNGS during the license renewal period. 

NRC also analyzed the risk of radiological exposure through the consumption patterns of 

special pathway receptors, including subsistence consumption of fish, native vegetation, surface 

waters, sediments, and local produce; absorption of contaminants in sediments through the 

skin; and inhalation of plant materials. The special pathway receptors analysis is important to 

the environmental justice analysis because consumption patterns may reflect the traditional or 

cultural practices of minority and low-income populations in the area. This analysis is presented 

below. 

4.9.7.4 Subsistence Consumption 

Section 4-4 of Executive Order 12898 (1994) directs Federal agencies, whenever practical and 

appropriate, to collect and analyze information on the consumption patterns of populations who 

rely principally on fish and/or wildlife for subsistence and to communicate the risks of these 

consumption patterns to the public. In this document, NRC considered whether there were any 

means for minority or low-income populations to be disproportionately affected by examining 

impacts to American Indian, Hispanic, and other traditional lifestyle special pathway receptors. 

Special pathways that took into account the levels of contaminants in native vegetation, crops, 

soils and sediments, surface water, fish, and game animals on or near PVNGS were 

considered. 

As described in Section 4.8.1 of this document, APS maintains a comprehensive Radiological 

Environmental Monitoring Program (REMP) at PVNGS to assess the impact of site operations 

on the environment. Summarized results of sampling and analyses conducted on air, 

vegetation, milk, water, sludge and sediment are presented in the following paragraphs (APS 

2009f). 

Air particulate filters and charcoal cartridges were analyzed for gross beta activity, gamma 

emitting radionuclides and radioiodine. Gross beta activity is consistent with pre-operational 

baseline and previous operational results. Gamma and radioiodine analysis observed no 

detectable levels of Cesium-134, Cesium-137, or Iodine-131 in any of the samples. 

Vegetation samples (cabbages) were analyzed for gamma emitting radionuclides. No gamma 

emitting radionuclides were observed in any of the samples. 

Goat and cow milk samples were analyzed for gamma emitting radionuclides. No gamma 

emitting radionuclides were observed in any of the samples. 

Drinking water samples were analyzed for gross beta activity, tritium and gamma emitting 

radionuclides. No tritium or gamma emitting radionuclides were observed in any samples. 

Gross beta activity was either less than detectable or low enough to be attributable to natural 

(background) radioactive materials. 

Groundwater samples were analyzed for tritium and gamma emitting radionuclides. No tritium 
Environmental Impacts of Operation

December 2010 4-25 NUREG-1437, Supplement 43

or gamma-emitting radionuclides were observed in any samples. 

Although no tritium or gamma-emitting radionuclides were observed in any offsite groundwater 

samples, tritium was found in subsurface water onsite, within the Radiological Controlled Area 

(RCA). Section 2.1.7.4 of this document discusses the potential sources of tritium and the 

corrective actions taken including the installation of monitoring wells which are routinely 

sampled for radiological analyses. 

Surface water samples were analyzed for tritium and gamma emitting radionuclides. The 

following discussion of surface water sampling and analysis includes the Water Reclamation 

Facility (WRF) influent, the water storage reservoirs, the evaporation ponds and Sedimentation 

Basin #2. 

As described in Sections 2.2.6 of this document, the main source of cooling water for PVNGS is 

wastewater effluent from Phoenix-area wastewater treatment plants. This wastewater is 

pumped to the on-site WRF where it is treated to meet the plant’s water quality requirements. 

Samples of WRF influent were analyzed for tritium and gamma emitting radionuclides. 

Iodine-131 was observed routinely in this influent and is due to radiopharmaceutical Iodine-131 

use by medical patients in the Phoenix area ending up in the Phoenix sewage effluent. No 

tritium was observed in any samples. 

After being treated by the WRF, this water is stored in the water storage reservoirs. Reservoir 

water samples were analyzed for tritium and gamma emitting radionuclides. Iodine-131 was 

observed in the reservoir samples but tritium was not. These results are consistent with the 

WRF influent results. 

Water from the WRF and water storage reservoirs is used for cooling the reactors. The water is 

not a source of drinking water. Cooling water that has gone through several cycles of reactor 

cooling (system blowdown) is discharged to above grade evaporation ponds. Evaporation pond 

samples were analyzed for tritium and gamma emitting radionuclides. Iodine-131 was observed 

in the evaporation ponds consistent with the WRF influent and water storage reservoirs. Tritium 

was also observed in these samples. APS attributes this tritium to permitted gaseous effluent 

releases and secondary plant liquid discharges. 

Sedimentation Basin #2 was sampled and analyzed for tritium and gamma-emitting 

radionuclides. This basin was dry for most of 2009. No tritium or gamma-emitting radionuclides 

were observed in any samples. 

Sludge samples from the WRF centrifuge were analyzed by gamma spectroscopy. Iodine-131 

was present consistent with prior year sample results. Indium-111, a diagnostic 

radiopharmaceutical, was also identified in the sludge. Sludge and sediment samples from the 

cooling towers and/or circulating water canals were analyzed for gamma emitting radionuclides, 

and results are consistent with previous years.

The results of the PVNGS REMP demonstrate that the only measurable radionuclide was the 

tritium discovered in the onsite water storage reservoirs. No elevated radiation levels were 

detected in the offsite environment as a result of plant operations and the storage of radioactive 

waste. The results of the REMP continue to demonstrate that the operation of the plant did not 

result in a significant impact to a member of the general population or adversely impact the 

environment (APS 2009f). 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-26 December 2010

Based on recent monitoring results, concentrations of contaminants in air, vegetation, milk, 

water, sludge and sediment at and near PVNGS have been at or near the threshold of detection 

and seldom above background levels (APS 2009f). Consequently, no disproportionately high 

and adverse human health impacts would be expected in special pathway receptor populations 

in the region as a result of subsistence consumption. 

4.10 EVALUATION OF NEW AND POTENTIALLY SIGNIFICANT INFORMATION 

New and significant information is (1) information that identifies a significant environmental issue 

not covered in the GEIS and codified in Table B-1 of 10 CFR Part 51, Subpart A, Appendix B, or 

(2) information that was not considered in the analyses summarized in the GEIS and that leads 

to an impact finding that is different from the finding presented in the GEIS and codified in 10 

CFR Part 51. 

In preparing to submit its application to renew the PVNGS operating license, APS developed a 

process to ensure that information not addressed in or available during the GEIS evaluation 

regarding the environmental impacts of license renewal for PVNGS would be properly reviewed 

before submitting the ER, and to ensure that such new and potentially significant information 

would be identified, reviewed, and assessed during the NRC review period. APS reviewed the 

Category 1 issues that appear in Table B-1 of 10 CFR Part 51, Subpart A, Appendix B, to verify 

that the conclusions of the GEIS remained valid with respect to PVNGS. This review was 

performed by personnel from PVNGS and its support organization that were familiar with NEPA 

issues and the scientific disciplines involved in the preparation of a license renewal ER. NRC 

also has a process for identifying new and significant information. That process is described in 

detail in NUREG-1555, Supplement 1, Standard Review Plans for Environmental Reviews for 

Nuclear Power Plants: Environmental Standard Review Plan for Operating License Renewal 

(NRC 2000). The search for new information includes (1) review of an applicant’s ER and the 

process for discovering and evaluating the significance of new information; (2) review of records 

of public comments; (3) review of environmental quality standards and regulations; 

(4) coordination with Federal, State, and local environmental protection and resource agencies; 

and (5) review of the technical literature. New information discovered by the NRC staff is 

evaluated for significance using the criteria set forth in the GEIS. For Category 1 issues where 

new and significant information is identified, reconsideration of the conclusions for those issues 

is limited in scope to the assessment of the relevant new and significant information; the scope 

of the assessment does not include other facets of the issue that are not affected by the new 

information. 

The NRC staff has not identified any new and significant information on environmental issues 

listed in Table B-1 of 10 CFR Part 51, Subpart A, Appendix B, related to the operation of 

PVNGS during the period of license extension. The NRC staff also determined that information 

provided during the public comment period did not identify any new issues that require sitespecific assessment. The NRC staff reviewed the discussion of environmental impacts in the 

GEIS (NRC 1996) and conducted its own independent review (including the public scoping 

meetings held in July 2009) to identify new and significant information. 

4.11 CUMULATIVE IMPACTS 

The NRC staff considered potential cumulative impacts in the environmental analysis of 

continued operation of PVNGS. For the purposes of this analysis, past actions are those 

related to the resources at the time of the power plant licensing and construction. Present 
Environmental Impacts of Operation

December 2010 4-27 NUREG-1437, Supplement 43

actions are those related to the resources at the time of current operation of the power plant, 

and future actions are considered to be those that are reasonably foreseeable through the end 

of plant operation including the period of extended operation. Therefore, the analysis considers 

potential impacts through the end of the current license terms as well as the 20-year renewal 

license term. The geographic area over which past, present, and future actions would occur is 

dependent on the type of action considered and is described below for each impact area. 

The impacts of the proposed action, as described in Sections 4.1–4.9, are combined with other 

past, present, and reasonably foreseeable future actions regardless of what agency (Federal or 

non-Federal) or person undertakes such other actions. 

4.11.1 Cumulative Impacts on Water Resources 

4.11.1.1 Groundwater Use 

PVNGS draws water from three onsite wells completed in the regional aquifer at depths ranging 

from 340 feet (104 meters) to 1,413 feet (431 meters) (as listed in Table 2.1.7-1). Based on 

usage from 2001 through 2008, the maximum demand for these wells is about 1,535 gpm 

(6,978 liters per minute) or 2,476 acre-feet (3.1 million cubic meters) per year (reported for 

2006), well below the 3,206 gpm (14,575 liters per minute) authorized by the ADWR as part of 

the plant’s grandfathered nonirrigation groundwater right within the Phoenix AMA. The average 

annual demand for groundwater in the Phoenix AMA is estimated at 883,000 acre-feet 

(1.1 billion cubic meters). In comparison, PVNGS operational uses are considered 

inconsequential, i.e., less than 1 percent of annual demand for groundwater in the Phoenix AMA 

(ADWR 2008). 

Based on the current and planned groundwater pumping rates and the fact that the PVNGS 

pumps groundwater at rates well below its authorized water right, the NRC staff concludes that 

the plant’s contribution to cumulative impacts on groundwater resources through its water usage 

would be SMALL, and no additional mitigation is warranted. 

4.11.1.2 Surface Water Use 

PVNGS annually diverts approximately 53,000 acre-feet (73.1 million cubic meters) of treated 

effluent that would otherwise be discharged to the Gila River (APS 2008a). This constitutes 

about 43 percent of the treated effluent generated by the 91st Avenue Wastewater Treatment 

Plant. Given that the projected annual flow volumes of the treatment plant are expected to 

increase by as much as 90 percent over the next 20 years, almost double its current capacity, 

and PVNGS annual usage is not expected to increase the proportion of the treated effluent from 

the 91st Avenue Wastewater Treatment Plant used by the nuclear plant would be reduced by 

about half (to about 22 percent by 2030). 

Based on its current and planned treated effluent usage rates and the fact that the ADWR’s 

management goal for the Phoenix AMA is to increase the use of renewable (recycled) water 

supplies (even though such increases would reduce the perennial flow and recharge capacity of 

the Gila River), the NRC staff concludes that the plant’s contribution to cumulative impacts on 

surface water resources through its water usage would be SMALL, and no additional mitigation 

is warranted. 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-28 December 2010

4.11.2 Cumulative Impacts of Thermophilic Microbiological Organisms and 

Electromagnetic Fields 

PVNGS does not discharge water to a natural surface water body. Therefore, the NRC staff 

concludes that the cumulative impacts on public health from thermophilic microbiological 

organisms from continued operation of PVNGS during the license renewal period would be 

SMALL. 

The NRC staff determined that the PVNGS transmission lines are operating within original 

design specifications and meet current NESC clearance standards; therefore, the PVNGS 

transmission lines do not detectably affect the overall potential for electric shock from induced 

currents within the analysis area. With respect to the chronic effects of electromagnetic fields, 

although the GEIS finding of “not applicable” is appropriate to PVNGS, the transmission lines 

associated with PVNGS are not likely to detectably contribute to the regional exposure to 

extremely low frequency electromagnetic fields. Therefore, the NRC staff concludes that the 

cumulative impacts of continued operation of the PVNGS transmission lines would be SMALL. 

4.11.3 Cumulative Impacts on Aquatic Resources 

PVNGS does not draw water from any natural surface water body in the area. Instead, it uses 

treated wastewater effluent from the Phoenix area. 

PVNGS does not release water to any natural surface water body. Instead, water is discharged 

to man-made lined evaporation ponds with no outlet and no hydraulic connection to any natural 

water body. The NRC staff concludes that the cumulative impacts of continued operation of 

PVNGS on aquatic resources would be SMALL.

4.11.4 Cumulative Impacts on Terrestrial Resources 

This section addresses past, present, and future actions that could result in adverse cumulative 

impacts to terrestrial resources, including wildlife populations, desert wash habitats, invasive 

species, protected species, and land use. For purposes of this analysis, the geographic area 

considered in the evaluation includes the PVNGS site and in-scope transmission line ROWs. 

Approximately 1330 acres of the 4280 acres of PVNGS are developed and maintained for 

operation of PVNGS (APS 2008a). Developed areas with impervious surfaces have increased 

precipitation runoff and reduced infiltration into the soil, thus reducing groundwater recharge and 

increasing soil erosion. Undeveloped portions of the site are composed predominately of desert 

wash habitat. Before PVNGS was constructed, the site’s land was open desert (NRC 1975). 

Construction of the transmission lines maintained by Salt River Project (SRP), Arizona Public 

Service Company (APS), and Southern California Edison (SCE) for PVNGS resulted in 

subsequent changes to the wildlife and plant species present within the vicinity of PVNGS. 

Some fragmentation may have occurred, though because the transmission lines pass through 

lands that are primarily desert habitat or cultivated farmland, these impacts were likely minimal. 

ROW maintenance, such as spraying of herbicides, has likely had past impacts and is likely to 

continue to impact the terrestrial habitat. These impacts may include bioaccumulation of 

chemicals and prevention of the natural successional stages of the surrounding vegetative 

communities in and around the ROWs. ROW maintenance has also likely resulted in increases 

in invasive species, such as saltcedar (Tamarix spp.), which are typically more aggressive than 

native species in colonizing disturbed areas. Within the ROWs, the Saguaro cactus is 
Environmental Impacts of Operation

December 2010 4-29 NUREG-1437, Supplement 43

transplanted or removed because it is a safety threat due to the species’ ability to conduct 

electricity. Cumulatively, this action over time could limit the local recruitment of this species. 

Protected terrestrial species, which are discussed in Sections 2.2.7.2 and 4.7.2, are not 

expected to be adversely affected due to future actions during the renewal term. Numerous 

wildlife refuges and national parks are located near PVNGS and its associated transmission line 

ROWs, and these will continue to provide habitat to protected species and other wildlife.

There are no known Federal projects and little industrial development near the immediate 

vicinity of PVNGS (APS 2008a). Phoenix, the nearest metropolitan area, is 26 miles (42 km) 

east of the site. Four natural gas-fired power plants are located near PVNGS, which could 

contribute to cumulative effects on terrestrial resources. The four plants are: Red Hawk Power 

Station, located 3 miles (5 km) south of the PVNGS site, Mesquite Power Generating Station, 

also located 3 miles (5 km) south of the site, Arlington Valley Energy Facility just south of the 

site, and New Harquahala Generating Company, located 17 miles (27 km) northwest of the site 

(APS 2008a). ROW maintenance of the transmission lines associated with these facilities will 

have similar cumulative impacts as those discussed above. 

The NRC staff examined the cumulative effects of habitat fragmentation, the spread of invasive 

species, impacts to protected species, and effects of neighboring facilities. The NRC staff 

concludes that the minimal terrestrial impacts from continued PVNGS operations would not 

contribute to the overall decline in the condition of terrestrial resources. Furthermore, the NRC 

staff concludes that the cumulative impacts of other and future actions during the term of license 

renewal on terrestrial habitat and associated species, when added to past, present, and 

reasonably foreseeable future actions, would be SMALL. 

4.11.5 Cumulative Air Quality Impacts 

The analysis below considers potential impacts through the end of the current license term as 

well as the 20-year renewal license term. As described in Section 2.2.2.1 (Air Quality Impacts), 

the Phoenix metropolitan area is designated as a nonattainment area for 8-hour ozone and 

PM10. In support of improved air quality, APS promotes a travel reduction program that includes 

vanpooling, travel reduction incentives, compressed work weeks, telecommuting, and 

videoconferencing at PVNGS (APS 2008a). APS has reduced its contributions to air pollutant 

emissions (including greenhouse gases (GHGs)) and traffic congestion in the area as a result of 

these efforts. 

Operational activities at PVNGS release GHGs (see Table 2.2.2-1), including carbon dioxide 

(CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons 

(PFCs), and sulfur hexafluoride (SF6). Combustion-related GHG emissions (such as CO2, CH4

and N2O) at PVNGS are minor, given the nature of a nuclear facility that is not burning fossil 

fuels to generate electricity. As discussed in Section 2.2.2.1, GHG stationary emission sources 

at PVNGS include primarily emergency diesel generators, diesel fire pumps, auxiliary boilers, 

and miscellaneous portable equipment. These combustion sources are designed for efficiency 

and operated using good combustion practices on a limited basis throughout the year (often 

only for testing). Other combustion-related GHG emission sources at PVNGS include 

commuter, visitor, support, and delivery vehicle traffic within, to, and from PVNGS. In addition, 

a small amount of CH4 emissions would be released from biological treatment at the Water 

Reclamation Facility. The HFCs and PFCs with higher global warming potential (GWP)7

 are 

 

7 Various greenhouse gases have different GWP, defined as the cumulative radiative forcing effects of a 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-30 December 2010

contained in refrigeration systems, while SF6 with the highest GWP is contained in high-voltage 

electric equipment; thus, emissions of HFCs and PFCs would be zero, unless these chemicals 

are mismanaged or mishandled. APS inventories and manages its GHG-containing equipment 

through its Emergency Planning and Community Right-to-Know Act Section 312 Tier II reporting 

program and Pollution Prevention Plan reporting program with the Arizona Department of 

Environmental Quality (ADEQ) (see Section 2.1.3 Nonradioactive Waste Management). In 

particular, APS’s Pollution Prevention Plan (PPP) includes pollution prevention opportunities to 

eliminate, reduce, reuse or recycle each waste, emission or toxic substance and submits an 

annual PPP Progress Report to the ADEQ Pollution Prevention Program (ADEQPPP) that 

tracks the facility operating activities in achieving the Plan goals. Based on the above 

discussions, release of GHGs should be minor, and the potential impacts of continued operation 

of PVNGS on climate change are anticipated to be SMALL. 

Along with other southwestern states, Arizona is experiencing the ramifications of climate 

change, such as prolonged drought, degraded forest health, early snowmelts and the attendant 

severe forest fires, and declining water levels and quality in lakes and reservoirs. In response, 

Arizona has established two primary objectives in coordination with ADEQ: (1) to prepare an 

inventory and forecast of GHG emissions in Arizona (ACCAG 2006a); and (2) to develop a 

Climate Change Action Plan to reduce GHG emissions in Arizona (ACCAG 2006b). In addition, 

Arizona established a primary Statewide goal of reducing GHG emissions in Arizona to 2000 

levels by 2020 and to 50 percent below 2000 levels by 2040. 

Recently, the Southwest8

 has experienced rapid population and economic growth. Associated 

with this growth, it has experienced warming at a rate significantly higher than the global 

average (GCCRP 2009). The prospect of droughts becomes more severe as a result of 

environmental warming. Changes in precipitation patterns and projected temperature increases 

are expected to cause reductions in rain and snowmelt in the spring months, when water is 

most needed to fill reservoirs to meet summer demands. Record wildfires have also been 

observed with rising temperatures and associated reductions in spring snowpack and soil 

moisture. Water, already in great demand, is at the center of many conflicts in the Southwest. 

Continued rapid population and economic growth will likely exacerbate water conflicts. 

Provided below is a brief discussion of the impacts to air quality if fossil-fuel power plant(s) 

replaced the generating capacity of PVNGS to meet the electricity demands in the region. 

A more detailed analysis of alternatives and their associated potential impacts are presented in 

Chapter 8, including a discussion of the power generation technologies and control equipment 

likely to be used at the time the PVNGS licenses expire. 

Nuclear power generation avoids GHG emissions that would otherwise be released from fossilfuel power plants, such as coal- or natural gas-fired power plants. GHG emissions at fossil-fuel 

power plants result primarily from the burning of fossil fuel for power generation. 

To estimate the amount of CO2 releases avoided by continued operation of PVNGS, its 

 

gas over a specified time horizon resulting from the emission of a unit mass of gas relative to a 

reference gas, CO2. As the reference point in this index, CO2 has a GWP of 1. On the basis of 100-

year time horizon, GWPs for other key GHGs are as follows (IPCC 2007): 21 for CH4, 310 for N2O, 

11,700 for HFC-23, and 23,900 for SF6. 

8 The Southwest region includes Arizona, California, Nevada, Utah, and western parts of Colorado, New 

Mexico, and Texas within the Rocky Mountains. 
Environmental Impacts of Operation

December 2010 4-31 NUREG-1437, Supplement 43

electricity generation can be compared to an equivalent amount of electricity generation in 

fossil-fuel power plant(s). For 2005, the composite CO2 emission factor (representing an 

average of all operating fossil-fuel power plants) is approximately 1,700 pounds per megawatt 

hour (lb/MWh) for Arizona (EPA 2009b). PVNGS generates approximately 29,933 gigawatt 

hours (GWh) per year (assuming a power generating capacity of 4,020 MWe and a capacity 

factor of 85 percent). Thus, PVNGS generating capacity avoids the release of 23.1 million 

metric tons of CO2. This is approximately 20 percent of the projected total gross CO2 emissions 

for Arizona in 2010. Considering other GHG emissions, such as N2O or CH4, the total GHG 

emissions being avoided should be slightly higher than those estimated above. 

In summary, the NRC staff concludes that potential impacts from the continued operation of 

PVNGS on GHG emissions and climate change would be SMALL. Replacing PVNGS 

generating capacity with fossil-fuel generating capacity would result in significant emissions of 

GHG. Therefore, continued operation of PVNGS contributes to more positive impacts than 

adverse impacts on environmental warming. 

4.11.6 Cumulative Human Health Impacts 

The NRC and EPA established radiological dose limits for protection of the public and workers 

from both acute and long-term exposure to radiation and radioactive materials. These dose 

limits are codified in 10 CFR Part 20 and 40 CFR Part 190. As discussed in Section 4.8.1, the 

doses resulting from operation of PVNGS are below regulatory limits, and the impacts of these 

exposures are SMALL. For the purposes of this analysis, the geographical area considered is 

the area included within a 50-mile (80-km) radius of the PVNGS site. 

EPA regulations in 40 CFR Part 190 limit the dose to members of the public from all sources in 

the nuclear fuel cycle, including nuclear power plants, fuel fabrication facilities, waste disposal 

facilities, and transportation of fuel and waste. As discussed in Section 4.8.1, PVNGS has 

conducted a radiological environmental monitoring program since 1979, well before commercial 

operation began in 1985. This program measures radiation and radioactive materials in the 

environment from PVNGS and all other sources. The NRC staff reviewed the radiological 

environmental monitoring results for the five-year period from 2005-2009 as part of the 

cumulative impacts assessment. There are no other uranium fuel cycle facilities with a 50-mile 

(80 km) radius of PVNGS. The NRC and the State of Arizona will regulate any future 

development or actions near PVNGS that could contribute to cumulative radiological impacts. 

Based on the NRC staff’s review of PVNGS’s radiological environmental monitoring results, the 

radioactive effluent release data, and the expected continued compliance with Federal radiation 

protection standards, the cumulative radiological impacts to the public from the operation of 

PVNGS during the renewal term would be SMALL. 

4.11.7 Cumulative Socioeconomic Impacts 

As discussed in Section 4.4 of this document, the continued operation of PVNGS during the 

license renewal term would have no impact on socioeconomic conditions in the region beyond 

those already being experienced. Since APS has no plans to hire additional non-outage 

workers during the license renewal term, overall expenditures and employment levels at 

PVNGS would remain relatively constant with no additional demand for permanent housing and 

public services. In addition, since employment levels and tax payments would not change, 

there would be no population and tax revenue-related land use impacts. There would also be 

no disproportionately high or adverse health or environmental impacts on minority and low-
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-32 December 2010

income populations in the region. Based on this and other information presented in Chapter 4 

of this document, there would be no cumulative socioeconomic impacts from the continued 

operation of PVNGS during the license renewal term beyond what is currently being 

experienced. 

It does not appear likely that the proposed license renewal would adversely affect cultural 

resources at PVNGS. APS has indicated that no refurbishment or replacement activities, 

including additional land-disturbing activities, at the plant site (or along existing transmission 

corridors) are planned for the license renewal period (APS 2008a). Absent land-disturbing 

activities, continued operation of PVNGS would likely protect any cultural resources present 

within the PVNGS site boundary by protecting those lands from development and providing 

secured access. Prior to any ground-disturbing activity in an undisturbed area, it is expected 

the applicant would evaluate the potential for impacts on cultural resources according to APS 

procedure (91DP-0EN02) and in consultation with the AZ SHPO and appropriate Native 

American Tribes, as required under Section 106 of the National Historic Preservation Act; 

therefore, the incremental contribution to a cumulative impact on cultural resources by 

continued operation of PVNGS during the license renewal period would be SMALL. 

4.11.8 Summary of Cumulative Impacts 

NRC staff considered the potential impacts resulting from the operation of PVNGS during the 

period of extended operation and other past, present, and future actions in the vicinity of 

PVNGS. The staff determination is that the potential cumulative impacts resulting from PVNGS 

operation during the period of extended operation would be SMALL. 

Table 4-11. Summary of Cumulative Impacts on Resources Areas 

Resource Area Impact Discussion 

Water Resources SMALL PVNGS operational uses of groundwater are considered 

inconsequential, i.e., less than 1 percent of annual demand 

for groundwater in the Phoenix AMA. PVNGS annual use of 

treated wastewater effluent from the Phoenix area is expected 

to decrease as a percentage of available effluent over time, 

therefore, the plant’s contribution to cumulative impacts on 

surface water resources through its water usage would be 

SMALL. 

Electromagnetic Fields and 

Thermophilic Microbiological 

Organisms 

SMALL The NRC staff determined that PVNGS transmission lines are 

operating within original design specifications and meet 

current NESC clearance standards; therefore, PVNGS 

transmission lines do not detectably affect the overall potential 

for electric shock from induced currents within the analysis 

area. With respect to the chronic effects of EMFs, although 

the GEIS finding of “not applicable” is appropriate to PVNGS, 

the transmission lines associated with PVNGS are not likely to 

detectably contribute to the regional exposure of extremely 

low frequency-electromagnetic fields; therefore, the NRC staff 

has determined that the cumulative impacts of the continued 

operation of the PVNGS transmission lines would be SMALL. 

PVNGS does not release cooling water (or cooling water 

blowdown) effluents to any natural surface water body. The 

staff concludes that the cumulative impacts on public health 

from thermophilic microbiological organisms from continued 

operation of PVNGS during the license renewal period would 

be SMALL. 
Environmental Impacts of Operation

December 2010 4-33 NUREG-1437, Supplement 43

Resource Area Impact Discussion 

Aquatic Resources SMALL PVNGS does not draw its cooling (or makeup) water from any 

natural surface water body in the area. It also does not 

release cooling water (or cooling water blowdown) effluents to 

any natural surface water body. Therefore, the cumulative 

impact on aquatic resources would be SMALL. 

Terrestrial Resources SMALL Protected terrestrial species are not expected to be adversely 

affected by future actions during the renewal term. Numerous 

wildlife refuges and national parks are located near PVNGS 

and its associated transmission lines, and these will continue 

to provide habitat for wildlife. Cumulative impacts on 

terrestrial resources resulting from all past, present, and 

reasonably foreseeable future actions would be SMALL. 

Air Quality SMALL No new or significant information was identified during the 

review of PVNGS ER, the site audit, or the scoping process. 

Therefore, there are no impacts related to air quality beyond 

those discussed in the GEIS. NRC staff concludes that the 

minimal air quality impacts expected from the continued 

PVNGS operation would not destabilize the air quality in the 

vicinity of PVNGS; therefore, the NRC staff concludes that the 

cumulative impacts on the air quality from the continued 

operation of PVNGS during the license renewal period would 

be SMALL. 

Human Health SMALL Cumulative radiological impacts from all uranium fuel cycle 

facilities within a 50-mile (80-km) radius of PVNGS are limited 

by the dose limits codified in 

10 CFR Part 20 and 40 CFR Part 190. In Section 4.8 of this 

report, the NRC staff concluded that the impacts of radiation 

exposure to the public from the operation of PVNGS during 

the renewal term would be SMALL. NRC and the State of 

Arizona will regulate any future actions near PVNGS that 

could contribute to cumulative radiological impacts; therefore, 

the NRC concludes that the cumulative impacts from 

continued operations of PVNGS would be SMALL. 

Socioeconomics SMALL Overall expenditures and employment levels at PVNGS are 

expected to remain relatively constant during the license 

renewal period. No refurbishment is planned. APS has no 

plans to alter the PVNGS site for license renewal. Therefore, 

there would be no cumulative impacts to socioeconomics and 

historic and archaeological resources during the license 

renewal period would be SMALL. 

4.12 REFERENCES 

10 CFR 51.53(a)(3)(ii)(A). Code of Federal Regulations, Title 10, Energy, Part 51, 

“Environmental Protection Regulations for Domestic Licensing and Related Regulatory 

Functions.” 

36 CFR Part 800. Code of Federal Regulations, Title 36, Parks, Forests, and Public Property, 

Part 800, “Protection of Historic Properties.” 

69 FR 52040. Federal Register. Volume 69, Number 163, pp. 52040-8. Policy Statement on 

the Treatment of Environmental Justice Matters in NRC Regulatory and Licensing Actions. 

ADAMS No. ML072200594 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-34 December 2010

Arizona Climate Change Advisory Group (ACCAG), 2006a. Final Greenhouse Gas Inventory 

and Reference Case Projections 1990-2020, Formally approved by the Arizona CCAG in March 

2006, March. Available at http://www.epa.gov/statelocalclimate/state/state-examples/ghginventory.html#az. 

Arizona Climate Change Advisory Group (ACCAG), 2006b. Climate Change Action Plan, 

August. Available at: http://www.azclimatechange.gov/download/O40F9347.pdf. 

Advisory Council on Historic Preservation (ACHP), 2008. “National Register Evaluation 

Criteria.” Available at http://www.achp.gov/nrcriteria.html (accessed April 13, 2010). 

Arizona Department of Environmental Quality (ADEQ). 2009a. Palo Verde Aquifer Protection 

Permit (Area-Wide) No. P-100388. May 1. ADAMS No. ML101660749 

Arizona Department of Water Resources (ADWR). 1999. Third Management Plan for the 

Phoenix Active Management Area, 2000-2010. Dec. Available at 

http://www.adwr.state.az.us/azdwr/WaterManagement/AMAs/ThirdManagementPlan3.htm 

Arizona Department of Water Resources (ADWR). 2009. Arizona Water Atlas, Volume 8 – 

Active Management Area Planning Area. Draft. July. Available at: 

http://azwater.gov/azdwr/statewideplanning/wateratlas/activemanagementareas/documents/volu

me_8_final.pdf 

Arizona Game and Fish Department (AGFD). 2009. Letter from G. Ritter, Project Evaluation 

Program Specialist, Arizona Game and Fish Department, to D. Wrona, Branch Chief, Division of 

License Renewal, dated July 16, 2009. Subject: Special Status Species Information for Palo 

Verde Nuclear Facility and Transmission Line License Renewal Review. ADAMS No. 

ML09310018. 

Arizona Public Service Company (APS). 2006c. 2005 Annual Monitoring and Compliance 

Report, APP No. P-100388, May 15, 2006. ADAMS No. ML101540061, Part 2 of 2, Appendix 

A. 

Arizona Public Service Company (APS). 2006X2. 2005 Annual Radiological Environmental 

Operating Report. Phoenix, Arizona. ADAMS No. ML061290293. 

Arizona Public Service Company (APS). 2006Y2. 2005 Annual Radioactive Effluent Release 

Report. Phoenix, Arizona. ADAMS No. ML061230086. 

Arizona Public Service Company (APS). 2007a. 2006 Annual Water Withdrawal and Use 

Report – Groundwater Right 58-114051.0001. Filed with the Arizona Department of Water 

Resources on March 12, 2007. ADAMS No. ML101590175. 

Arizona Public Service Company (APS). 2007c. 2006 Annual Radiological Environmental 

Operating Report. Phoenix, Arizona. ADAMS No. ML071310137. 

Arizona Public Service Company (APS). 2007Y3. 2006 Annual Radioactive Effluent Release 

Report. Phoenix, Arizona. ADAMS No. ML071220298. 

Arizona Public Service Company (APS). 2008a. Palo Verde Nuclear Generating Station, Units 

1, 2, and 3, Applicant’s Environmental Report, License Renewal Operating Stage. ADAMS No. 

ML083510615, Appendix E. 

Arizona Public Service Company (APS). 2008b. Updated Final Safety Analysis Report, Palo 

Verde Nuclear Generating Station Units 1, 2, and 3, Revision 14B. Feb. ADAMS No. 

ML083510615, Appendix A. 
Environmental Impacts of Operation

December 2010 4-35 NUREG-1437, Supplement 43

Arizona Public Service Company (APS). 2008c. 2007 Annual Water Withdrawal and Use 

Report – Groundwater Right 58-114051.0001. Filed with the Arizona Department of Water 

Resources on March 28, 2008. ADAMS No. ML101550146. 

Arizona Public Service Company (APS). 2008h. Annual Radiological Environmental Operating 

Report 2007. ADAMS Accession No. ML081150510. 

Arizona Public Service (APS). 2008Y4. 2007 Annual Radioactive Effluent Release Report. 

Phoenix, Arizona. ADAMS No. ML081140730. 

Arizona Public Service Company (APS). 2009d. 2008 Annual Water Withdrawal and Use 

Report – Groundwater Right 58-114051.0001. Filed with the Arizona Department of Water 

Resources on March 31, 2009. ADAMS No. ML101590117. 

Arizona Public Service Company (APS). 2009e. 2008 Annual Monitoring and Compliance 

Report – Palo Verde Nuclear Generating Station APP Permit No. P-100388. May 13. ADAMS 

No. ML101550341. 

Arizona Public Service Company (APS). 2009f. 2008 Annual Radiological Environmental 

Operating Report. ADAMS Accession No. ML091240287. 

Arizona Public Service Company (APS). 2010a. 2009 Annual Radiological Environmental 

Operating Report. Phoenix, Arizona. ADAMS Accession No. ML101390061. 

Arizona Public Service Company (APS). 2010b. 2009 Annual Radioactive Effluent Release 

Report. Phoenix, Arizona. ADAMS No. ML101320288. 

Arizona Public Service Company (APS). 2009Y5. 2008 Annual Radioactive Effluent Release 

Report. Phoenix, Arizona. ADAMS No. ML091250438. 

City of Phoenix. 2005. Water Resources Plan update 2005. Water Services Department, 

Water Resources and Development Planning Section. Available at 

http://phoenix.rhinonet.com/wrdp/wrplan.shtml. 

Council on Environmental Quality, 1997, Environmental Justice: Guidance Under the National 

Environmental Policy Act, December 10. 

Global Climate Change Research Program (GCCRP). 2009. Global Climate Change Impacts in 

the United States, A State of Knowledge Report from the U.S. Climate Change Research 

Program, T.R. Karl, et al. Editors, Cambridge University Press. Available at 

http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts. 

Gunter, G., 2006, Calculation Package Groundwater and Treated Effluent Use, Tetra Tech, SC. 

91st Avenue Wastewater Treatment Plant 25-Year Facility Master Plan (2005-2030). ADAMS 

No. ML101590643. 

Institute of Electrical and Electronics Safety Code (IEEE). 2007. National Electric Safety Code. 

Intergovernmental Panel on Climate Change (IPCC). 2007. Climate Change 2007: The 

Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of 

the Intergovernmental Panel on Climate Change. S. Solomon, D. Qin, M. Manning, Z. Chen, 

M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.). Cambridge University Press, 

Cambridge, United Kingdom and New York, New York. Available at 

<http://www.ipcc.ch/publications_and_data/publications_ipcc_fourth_assessment_report_wg1_r

eport_the_physical_science_basis.htm> (Accessed November 17, 2009). 

National Institute of Environmental Health Sciences (NEIHS). 1999. “NIEHS Report on Health 

Effects from Exposure to Power Line Frequency and Electric and Magnetic Fields.” Publication 

No. 99-4493, Research Triangle Park, NC. Available at 

http://www.niehs.nih.gov/health/docs/niehs-report.pdf 
Environmental Impacts of Operation 

NUREG-1437, Supplement 43 4-36 December 2010

Southern California Edison (SCE). 2006. Endangered Species Alert Program Manual: Species 

Accounts and Procedures. Winter 2006. Available at 

http://www.sce.com/nrc/bioarc/0812_ESAM.pdf (accessed December 28, 2009). 

Southern California Edison (SCE). 2009. “Environmental Commitment – Biological and 

Archaeological Resource Protection.” Available at 

http://www.sce.com/PowerandEnvironment/EnvironmentalCommitment/BiologicalArchaeological

/Programs/endangered-species-awareness.htm (accessed December 28, 2009). 

Stein, P.H. 1981a. The Palo Verde Archaeological Investigations, Part 1: Aboriginal Resources 

at the Palo Verde Plant Site, Museum of Northern Arizona Research Paper 21, Museum of 

Northern Arizona Press, Flagstaff, Arizona. ADAMS No. ML101590412. 

Stein, P.H. 1981b. The Palo Verde Archaeological Investigations, Part 2: Wintersburg: An 

Archaeological, Archival, and Folk Account of Homesteading in Arizona, Museum of Northern 

Arizona Research Paper 21, Museum of Northern Arizona Press, Flagstaff, Arizona. ADAMS 

No. ML101590412. 

U.S. Bureau of the Census (USCB). 2009. American Fact Finder. Available at 

http://factfinder.census.gov/ 

U.S. Geological Survey (USGS). 2006. Water Resources Data – Arizona, Water Year 2005. 

Water-Data Report AZ-05-1. Available at http://pubs.usgs.gov/wdr/2005/wdr-az-05-1/ 

U.S. Nuclear Regulatory Commission (NRC). 1975. Final Environmental Statement Related to 

Construction of Palo Verde Nuclear Generating Station, Units 1, 2, and 3, Docket Nos. STN 50-

528, STN 50-529, and STN 50-530. NUREG-75/078. Office of Nuclear Reactor Regulation, 

Washington, D.C. September, pages 2-1, 5, 18-20. ADAMS No. ML101590158. 

U.S. Nuclear Regulatory Commission (NRC). 1982. Final Environmental Statement Related to 

the Operation of Palo Verde Nuclear Generating Station, Units 1, 2, and 3, Docket Nos. STN 

50-528, STN 50-529, and STN 50-530. NUREG-0841. Office of Nuclear Reactor Regulation, 

Washington, D.C. February. ADAMS No. ML090160247. 

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants. NUREG-1437, Volumes 1 and 2, Washington, D.C. 

ADAMS Nos. ML040690705 and ML040690738. 

U.S. Nuclear Regulatory Commission (NRC). 2000. Standard Review Plans for Environmental 

Reviews for Nuclear Power Plants: Environmental Standard Review Plan for Operating License 

Renewal. NUREG-1555, Supplement 1. Washington, D.C. ADAMS No. ML0037020191 

World Health Organization (WHO). 2007a. “Extremely Low Frequency Fields Environmental 

Health Criteria Monograph No.238”, World Health Organization, Geneva, Switzerland. 

http://www.who.int/pehemf/publications/elf_ehc/en/index.html Accessed August, 2008. 
 

December 2010 5-1 NUREG-1437, Supplement 43

5.0 ENVIRONMENTAL IMPACTS OF POSTULATED ACCIDENTS 

This chapter describes the environmental impacts from postulated accidents that Palo Verde 

Nuclear Generating Station (PVNGS) might experience during the period of extended operation. 

For a more detailed discussion of this assessment, the reader is referred to Appendix F. The 

term “accident” refers to any unintentional event outside the normal plant operational envelope 

that results in a release or the potential for release of radioactive materials into the environment. 

Two classes of postulated accidents are evaluated in the Generic Environmental Impact 

Statements (GEIS) for License Renewal of Nuclear Power Plants prepared by the U.S. Nuclear 

Regulatory Commission (NRC), as listed in Table 5-1. These two classes include: 

● design-basis accidents (DBAs) 

● severe accidents 

Table 5-1. Issues Related to Postulated Accidents. Two issues related to postulated 

accidents are evaluated under the National Environmental Policy Act (NEPA) in the license 

renewal review: design-basis accidents and severe accidents.

Issues GEIS Section Category 

Design-basis accidents 5.3.2; 5.5.1 1 

Severe accidents 5.3.3; 5.3.3.2; 5.3.3.3; 5.3.3.4; 5.3.3.5; 5.4; 5.5.2 2 

(a) Generic issues (Category 1 issues, see Chapter 1) rely on the analysis provided in the GEIS and are 

discussed briefly (NRC 1996,1999a). 

5.1 DESIGN-BASIS ACCIDENTS 

As part of the process for receiving NRC approval to operate a nuclear power facility, an 

applicant for an initial operating license must submit a safety analysis report (SAR) as part of its 

application. The SAR presents the design criteria and design information for the proposed 

reactor and comprehensive data on the proposed site. The SAR also discusses various 

hypothetical accident situations and the safety features that are provided to prevent and mitigate 

accidents. The NRC staff (staff) reviews the application to determine whether or not the plant 

design meets the NRC’s regulations and requirements and includes, in part, the nuclear plant 

design and its anticipated response to an accident. 

DBAs are those accidents that both the licensee and the staff evaluate to ensure that the plant 

can withstand normal and abnormal transients, and a broad spectrum of postulated accidents, 

without undue hazard to the health and safety of the public. A number of these postulated 

accidents are not expected to occur during the life of the plant, but are evaluated to establish 

the design basis for the preventive and mitigative safety systems of the facility. The acceptance 

criteria for DBAs are described in Title 10 of the Code of Federal Regulations (CFR) Parts 50 

and 100. 

The environmental impacts of DBAs are evaluated during the initial licensing process. Before a 

license renewal is issued, the DBA assessment must demonstrate that the plant can withstand 

these accidents. The results of these evaluations are found in license documentation such as 

the applicant’s final safety analysis report (FSAR), the safety evaluation report (SER), the final 
Environmental Impacts of Postulated Accidents 

NUREG-1437, Supplement 43 5-2 December 2010

environmental statement (FES), and here in Section 5.1 of this document. A licensee is 

required to maintain the acceptable design and performance criteria throughout the life of the 

plant, including any extended-life operation. The consequences for these events are evaluated 

for the hypothetical maximum exposed individual; as such, changes in the plant environment will 

not affect these evaluations. Because of the requirements that continuous acceptability of the 

consequences and aging management programs be in effect for the period of extended 

operation, the environmental impacts, as calculated for DBAs, should not differ significantly from 

initial licensing assessments over the life of the plant, including the period of extended 

operation. Accordingly, the design of the plant relative to DBAs during the period of extended 

operation is considered to remain acceptable and the environmental impacts of those accidents 

were not examined further in the GEIS. 

The Commission has determined that the significance level of the environmental impacts of 

DBAs are SMALL for all plants because the plants were designed to successfully withstand 

these accidents. For the purposes of license renewal, DBAs have been designated as a 

Category 1 issue. The early resolution of the DBAs makes them a part of the current licensing 

basis of the plant; the current licensing basis of the plant is to be maintained by the licensee 

under its current license and, therefore, under the provisions of 10 CFR 54.30, is not subject to 

review under license renewal. 

No new and significant information related to DBAs was identified during the review of Arizona 

Public Service Company’s (APS) environmental report (ER) (APS 2008a), site audit, scoping 

process, or evaluation of other available information. Therefore, there are no impacts related to 

these issues beyond those discussed in the GEIS. 

5.2 SEVERE ACCIDENTS 

Severe nuclear accidents are those that are more severe than DBAs because they could result 

in substantial damage to the reactor core, whether or not there are serious offsite 

consequences. In the GEIS, the staff assessed the impacts of severe accidents during the 

period of extended operation, using the results of existing analyses and site-specific information 

to conservatively predict the environmental impacts of severe accidents for each plant during 

the period of extended operation. 

Severe accidents initiated by external phenomena such as tornadoes, floods, earthquakes, 

fires, and sabotage have not traditionally been discussed in quantitative terms in FESs and 

were not specifically considered for PVNGS in the GEIS. However, the GEIS did evaluate 

existing impact assessments performed by the staff and by the industry at 44 nuclear plants in 

the United States and concluded that the risk from beyond design-basis earthquakes at existing 

nuclear power plants is SMALL. The GEIS for license renewal performed a discretionary 

analysis of sabotage in connection with license renewal, and concluded that the core damage 

and radiological release from such acts would be no worse than the damage and release 

expected from internally-initiated events. In the GEIS, the NRC concludes that the risk from 

sabotage and beyond design-basis earthquakes at existing nuclear power plants is small, and 

additionally, that the risks from other external events are adequately addressed by a generic 

consideration of internally-initiated severe accidents (NRC 1996). A more detailed discussion of 

severe accidents initiated by terrorism associated with license renewal is provided in Section 

5.2.1 of this chapter. 
Environmental Impacts of Postulated Accidents

December 2010 5-3 NUREG-1437, Supplement 43

Based on information in the GEIS, the NRC found that: 

The probability weighted consequences of atmospheric releases, fallout onto 

open bodies of water, releases to ground water, and societal and economic 

impacts from severe accidents are small for all plants. However, alternatives to 

mitigate severe accidents must be considered for all plants that have not 

considered such alternatives. 

The staff identified no new and significant information related to postulated accidents during the 

review of APS’s ER (APS 2008a), the site audit, the scoping process, or evaluation of other 

available information. Therefore, there are no impacts related to these issues beyond those 

discussed in the GEIS. However, in accordance with 10 CFR 51.53(c)(3)(ii)(L), the staff 

reviewed severe accident mitigation alternatives (SAMAs) for PVNGS. The results of the review 

are discussed in Section 5.3. 

5.2.1 Severe Accidents Initiated by Sabotage and Terrorism 

5.2.1.1 Background 

Generic Finding for Sabotage and Terrorism for License Renewal of Nuclear Power Plants 

The 1996 GEIS for License Renewal of Nuclear Plants (NUREG-1437) addresses 

environmental impact of terrorist acts. Section 5.3.3.1 of the GEIS states: 

Although the threat of sabotage events cannot be accurately quantified, the 

Commission believes that acts of sabotage are not reasonably expected. 

Nonetheless, if such events were to occur, the Commission would expect that 

resultant core damage and radiological releases would be no worse than those 

expected from internally initiated events. 

Based on this, the Commission concluded in the GEIS that the risk from sabotage at existing 

nuclear power plants (NPPs) is small. 

Implications of 9/11 

As a result of the terrorist attacks of September 11, 2001 (9/11), the NRC conducted a 

comprehensive review of the agency’s security program and required significant enhancements 

to security at a wide range of NRC-regulated facilities. These enhancements included 

significant reinforcement of the security response capabilities for nuclear facilities, better control 

of sensitive information, and implementation of mitigating strategies to deal with postulated 

events potentially causing loss of large areas of the plant due to explosions or fires, including 

those that an aircraft impact might create. These measures are outlined in greater detail in 

NUREG/BR-0314 (NRC 2004), NUREG-1850 (NRC 2006a), and Sandia National Laboratory’s 

“Mitigation of Spent Fuel Loss-of-Coolant Inventory Accidents and Extension of Reference Plant 

Analyses to Other Spent Fuel Pools” (NRC 2006b). 

The NRC continues to routinely assess threats and other information provided by a variety of 

Federal agencies and sources. The NRC also ensures that licensees meet appropriate 

security-level requirements. The NRC will continue to focus on prevention of terrorist acts for all 

nuclear facilities and will not focus on site-specific evaluations of speculative environmental 

impacts resulting from terrorist acts. While these are legitimate matters of concern, the NRC will 

continue to address them through the ongoing regulatory process as a current and generic 
Environmental Impacts of Postulated Accidents 

NUREG-1437, Supplement 43 5-4 December 2010

regulatory issue that affects all nuclear facilities and many of the activities conducted at nuclear 

facilities. The issue of security and risk from malevolent acts at nuclear power facilities is not 

unique to facilities that have requested a renewal of their licenses (NRC 2006a). 

Implications of NRC Licensing Actions Located in the Jurisdiction of the US Court of Appeals for 

the Ninth Circuit 

The Commission has stated that licensing actions for facilities subject to the jurisdiction of the 

United States Court of Appeals for the Ninth Circuit will include an analysis of the environmental 

impacts of a terrorist attack [San Luis Obispo Mothers for Peace v. NRC, 449 F.3d 1016, 1028 

(9th Cir. 2006)]. The discussion is limited to the impacts on the nuclear power plant reactor and 

spent fuel pool. It does not address spent nuclear fuel in the Palo Verde Independent Spent 

Fuel Storage Installation (ISFSI) since the environmental impacts of the ISFSI have been 

addressed in a separate licensing process and environmental assessment, including a finding of 

no significant environmental impact (55 FR 29181, July 18, 1990). 

5.2.1.2 Security Requirements and Federal/Industry Actions in Response to 9/11 

General Security Considerations 

The NRC has historically considered the potential impacts of sabotage and terrorist acts in the 

development and implementation of its security requirements. NPPs are among the most 

secure commercial facilities in the country. NPP security is achieved in layers as described 

below: 

• NPPs are inherently secure, robust structures, built to withstand hurricanes, tornadoes 

and earthquakes. NPPs have redundant safety systems and multiple barriers to protect 

the reactor and prevent or minimize off-site releases. 

• Security measures are in place, including but not limited to trained and armed security 

officers, physical barriers, intrusion detection and surveillance systems, and access 

control features. These measures are routinely inspected and evaluated via force-onforce exercises. 

• An additional layer of protection involves coordinating threat information and off-site 

response. The NRC works closely with the Department of Homeland Security (DHS), 

FBI, intelligence agencies, the Departments of Defense and Energy, states, and local 

law enforcement. These relationships ensure the NRC can act quickly on any threats 

that might affect its licensed facilities and allows effective emergency response from 

“outside the fence” should a terrorist attack occur (NRC 2004). 

Federal/Industry Actions in Response to 9/11 

Since 9/11, detailed assessments were performed, a spectrum of measures was evaluated to 

reduce the likelihood or consequences of terrorist attacks, and additional requirements were 

promulgated to prevent or mitigate the consequences of acts of sabotage/terrorism. The scope 

of the threats considered, assessments performed, and additional regulatory requirements 

include: (1) ground-based, water-based, cyber-based, and air-based attacks, (2) reactor, 

containment, and spent fuel; and, (3) Generic Communications, orders, license conditions, new 

regulations/rules. A brief discussion of some of the post-9/11 studies conducted, security 

requirements strengthened and enhanced liaison with Federal, State and local agencies follows. 
Environmental Impacts of Postulated Accidents

December 2010 5-5 NUREG-1437, Supplement 43

NRC studies

The NRC conducted detailed site-specific engineering studies of a limited number of NPPs to 

assess potential vulnerabilities to deliberate attacks involving large commercial aircraft. The 

NRC also assessed the potential impacts of other types of terrorist attacks. In conducting these 

studies, the NRC drew on national experts from several Department of Energy laboratories 

using state-of-the-art experiments, structural analyses, and fire analyses. While the details are 

classified, the studies confirmed that the plants are robust, and the likelihood of a radioactive 

release affecting public health and safety is very low (NRC 2006c). 

Specific findings included: 

• With mitigation strategies and measures in place, the probability of damaging the reactor 

core and releasing radioactivity that could affect public health and safety is very low; 

• Significant releases due to a terrorist attack on a spent fuel pool (SFP) are very unlikely; 

• If a radiation release did occur, there would be time to implement mitigating actions and 

offsite emergency plans at power plants, SFPs, and dry-cask storage installations; and, 

• Safety and security studies confirm that NRC's emergency planning bases remain valid 

(NRC 2006c). 

Strengthened Security Requirements

After consideration of terrorist actions, NRC strengthened security requirements at NPPs. NRC 

major actions included: 

• Ordering plant owners to sharply increase physical security programs to defend against 

a more challenging adversarial threat; 

• Requiring more restrictive site access controls for all personnel; 

• Enhancing communication and liaison with the Intelligence Community; 

• Ordering plant owners to improve their capability to respond to events involving 

explosions or fires; 

• Enhancing readiness of security organizations by strengthening training and 

qualifications programs for plant security forces; 

• Requiring vehicle checks at greater stand-off distances; 

• Enhancing force-on-force exercises to provide a more realistic test of plant capabilities to 

defend against an adversary force; and, 

• Improving liaison with Federal, State, and local agencies responsible for protection of the 

national critical infrastructure through integrated response training (NRC 2006c). 

NRC also promulgated additional security-related regulations including: 

• A revision of the Design Basis Threat (DBT) rule in 2007 to impose generic security 

requirements similar to those previously imposed on operating NPPs by the 

Commission’s April 29, 2003 DBT orders (FR 12705, Vol 72, No 52); and, 

• Issuance of a new Power Reactor Security Requirements rule in 2009 to establish and 

update generically applicable security requirements for power reactors similar to those 

previously imposed by several Commission orders issued after 9/11, including security 

requirements for ground-based, water-based, cyber-based, and air-based attacks (FR 

13926, Vol 74, No 58). 
Environmental Impacts of Postulated Accidents 

NUREG-1437, Supplement 43 5-6 December 2010

Enhanced Government-to-Government Coordination

The NRC continues to work with other governmental agencies to assure consistency and 

effectiveness in thwarting a potential attack on a NPP. For example, the NRC has worked with 

the Transportation Security Administration (TSA) and the Federal Aviation Administration (FAA) 

to develop guidance for general aviation pilots flying near NPPs. The TSA has initiated a 

number of other programs to reduce the likelihood an aircraft could attack any type of facility in 

the U.S. Some of these include: 

• Criminal history checks on flight crew members; 

• Reinforced cockpit doors; 

• Checking of passenger lists against "no-fly" lists; 

• Increased control of cargo; 

• Random inspections; 

• Increased number of Federal Air Marshals; 

• Improved screening of passengers and baggage; 

• Controls on foreign airlines operating to and from the U.S.; 

• Additional requirements for charter aircraft; and, 

• Improved coordination and communication between civilian and military authorities (NRC 

2008). 

Plant-Specific Actions in Response to 9/11 

Following the events of 9/11, the NRC issued more robust security requirements as discussed 

above, and the NRC routinely verifies that PVNGS complies with those requirements. Thus, it is 

highly unlikely that an adversary force could successfully overcome these security measures 

and gain entry into the sensitive facilities, and even less likely that they could do this quickly 

enough to prevent operators from placing the plant’s reactors into a safe shutdown mode. 

Multiple plant-specific assessments with respect to potential malevolent acts have been and will 

continue to be completed for PVNGS (APS 2010). An example of an on-going, plant-specific 

evaluation is the periodic NRC security inspections at PVNGS that occur as part of operating 

reactor oversight. In response to these evaluations, numerous enhancements were 

implemented at PVNGS. Examples of resulting enhancements stemming from the various 

assessments completed include plant hardware changes; improved maintenance, testing and 

calibration of security equipment; improved training for both security and non-security 

personnel; and improved procedures in emergency planning and safeguards contingency 

planning. An example of a post-9/11 industry-wide initiative to enhance NPP security and how it 

was addressed at PVNGS is provided below (the “B.5.b” mitigation strategies). 

Mitigation Strategies for Reactor, Containment, and Spent Fuel Pools (B.5.b)

An Interim Compensatory Measures (ICM) Order was issued February 25, 2002, as part of a 

comprehensive effort by the NRC, in coordination with other government agencies, to improve 

the capabilities of commercial nuclear reactor facilities to respond to terrorist threats. 

Section B.5.b. of the ICM Order required licensees to develop specific guidance and strategies 

to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities using 

existing or readily available resources (equipment and personnel) that could be effectively 

implemented under the circumstances associated with loss of large areas of the plant due to 

explosions or fire, including those that a large aircraft impact might create. Although it was 
Environmental Impacts of Postulated Accidents

December 2010 5-7 NUREG-1437, Supplement 43

recognized prior to 9/11 that nuclear reactors already had significant capabilities to withstand a 

broad range of attacks, implementing these mitigation strategies significantly enhances the 

plants’ capabilities to withstand a broad range of threats (NRC 2007c). 

NRC staff conducted inspections of the implementation of the Section B.5.b requirements in 

2002 and 2003. Next, engineering studies were conducted by the NRC providing insights into 

the implementation of mitigation strategies. In 2005, additional guidance was issued by the 

NRC establishing a phased approach for responding to Section B.5.b of the ICM Order. 

Determination of the specific strategies required to satisfy the Order was termed Phase 1. Sitespecific assessments of SFPs were deemed Phase 2, and site-specific assessments of reactor 

core and containment were deemed Phase 3. During 2005 and 2006, the NRC staff performed 

Phase 1 inspections and Phases 2 and 3 assessments (NRC 2007c). 

The NRC staff’s technical evaluation for PVNGS is described in a publicly-available Safety 

Evaluation (SE) report (NRC 2007c) The NRC staff concluded that APS’s responses to the 

February 25, 2005, Phase 1 guidance document and the Phases 2 and 3 SFP and reactor core 

and containment mitigating strategy assessments meet the requirements of Section B.5.b of the 

February 25, 2002, ICM Order. Additionally, the NRC staff concluded that full implementation of 

APS’s enhancements constitutes satisfactory compliance with Section B.5.b and that they 

represent reasonable measures to enhance APS’s effectiveness in maintaining reactor core and 

SFP cooling and containment integrity under circumstances involving the loss of large areas of 

the plant due to fires or explosions. 

The requirements for the B.5.b mitigating strategies were incorporated into the Facility 

Operating Licenses for PVNGS. The effectiveness of APS’s actions to implement the mitigative 

strategies implemented in response to the ICM Order (which were subsequently codified in 

10 CFR 50.54 (hh)(2)) is subject to NRC review and inspection. 

5.2.1.3 Consideration of Environmental Impacts from Sabotage/Terrorist Acts 

In describing the potential for environmental impacts from terrorist activities a description of the 

relevant terminology is necessary and includes three broad topics: threat, vulnerability, and 

consequences, as discussed below. 

Threat 

A threat is considered present when an organization or person has the intent and capability to 

cause damage to a target. 

NRC currently assesses that there is a general, credible threat to NRC-licensed facilities and 

materials, although there is no specific information available that indicates a specific threat to 

NPP facilities.

Vulnerability 

Vulnerability in this context refers to a weakness in physical protection or mitigation capabilities 

which can lead to unacceptable consequences. Vulnerabilities are specific to the type of attack. 

Frequency of Malevolent Acts 

With regard to the frequency of malevolent acts, the NRC has determined that security and 
Environmental Impacts of Postulated Accidents 

NUREG-1437, Supplement 43 5-8 December 2010

mitigation measures the NRC has imposed upon its licensees since 9/11, coupled with national 

anti-terrorist measures and the robust nature of reactor containments and SFPs, make the 

probability of a successful terrorist attack, though numerically indeterminate, very low. 

The security-related measures and other mitigation measures implemented since 9/11 include 

actions that would improve the likelihood of identifying/thwarting the attack before it is initiated, 

mitigating the attack before it results in damage to the plant, and mitigating the impact of the 

plant damage such that reactor core damage or an SFP fire is avoided. Given the 

implementation of additional security enhancements and mitigation strategies, as well as further 

consideration of the factors identified above, the NRC staff concludes that the frequency of large 

radionuclide releases due to malevolent acts is very low. 

Consequences 

Consequences relate to the magnitude and type of effect from terrorist actions. A range of 

consequences can result from sabotage and malevolent acts. NPPs have numerous security 

measures and protective features that help to prevent or mitigate consequences of potential 

terrorist attacks. Physical protection was described previously and generally consists of the 

robust characteristics of the containment and SFP structures; redundant safety systems; and 

additional security measures in place, including trained and armed security officers, physical 

barriers, intrusion detection and surveillance systems. Mitigating strategies have also been 

implemented to deal with postulated events potentially causing loss of large areas of the plant 

due to explosions or fires, including those that an aircraft impact might create. 

Potential consequences are highly dependent on the type of attack or event scenario. Based on 

the plant-specific probabilistic risk assessment for PVNGS (as summarized in Attachment D to 

the Environmental Report), the reactor accidents with the highest offsite consequences at 

PVNGS involve core damage events in which the reactor containment is bypassed or fails to 

isolate at the onset of the event. These events result in release of a significant fraction of the 

reactor core radionuclide inventory to the environment within about one hour of event initiation. 

Accident consequences are described in Table D.3-5 of Attachment D to the Environmental 

Report. 

Although SFP accidents are not specifically addressed in the PVNGS ER, the consequences of 

the most severe SFP accident, culminating in an SFP fire, were assessed in several previous 

NRC studies, among others, NUREG-1353, Regulatory Analysis for the Resolution of Generic 

Issue 82, “Beyond Design Basis Accidents in Spent Fuel Pools,” April 1989, and NUREG-1738, 

Technical Study of Spent Fuel Pool Accident Risk at Decommissioning Nuclear Power Plants, 

January 2001. NUREG-1738 did not specifically address PVNGS, however its analysis 

addressed most power stations. Accident consequence results are provided in Table 4.8.3 of 

NUREG-1353 for site population densities of 340 persons per square mile (reflective of the 

mean population density around all NPPs in year 2000) and 860 persons per square mile 

(reflective of a high population site). Given that the projected 2040 population density within 

50 miles of the PVNGS site is approximately 460 persons per square mile (based on a projected 

population of 3,588,728 reported in Section D.3.1 of Attachment D to the ER), these results are 

considered reasonably representative of PVNGS. 

Potential consequences from malevolent acts against the PVNGS reactor or SFP would not 

exceed those for a reactor or SFP accident, and would likely be much less due to the need for 
Environmental Impacts of Postulated Accidents

December 2010 5-9 NUREG-1437, Supplement 43

the adversaries to rapidly defeat physical protection and access controls, as well as the 

redundant safety system functions. This would be extremely difficult given the significant 

physical protection (robust containment and SFP structures; redundant safety systems; 

additional security measures) and the post-9/11 mitigating strategies to deal with postulated 

events involving loss of large areas of the plant due to explosions or fires. Even if the physical 

protection and mitigating strategies were only partially effective, these features/measures would 

delay the time to core damage and radionuclide release, and reduce the consequences of any 

such release. 

In the unlikely event that a terrorist attack did successfully breach the physical and other 

safeguards at PVNGS resulting in the release of radionuclides, the consequences of such a 

release are discussed in the 1996 GEIS for license renewal. In the GEIS, the Commission 

considered sabotage as the potential initiator of a severe accident. The Commission generically 

determined the risk to be of small significance for all NPPs. The Commission’s evaluation of the 

potential environmental impacts of a terrorist attack, including the GEIS analysis of severe 

accident consequences, considers the potential consequences that might result from a large 

scale radiological release, irrespective of the initiating cause. 

5.2.1.4 SAMAs for Sabotage/Terrorist Initiated Events 

The focus of the Severe Accident Mitigation Alternative (SAMA) evaluation is on plant 

improvements (e.g., hardware, procedures, and training) that would both substantially reduce 

plant risk and be cost-beneficial. Given that risk from terrorist events is already reduced by the 

implementation of post 9/11 existing security enhancements and mitigation strategies, the staff 

considers it unlikely that there are any additional enhancements that would both substantially 

reduce plant risk and be cost-beneficial. 

5.2.1.5 Consideration of SAMAs for Spent Fuel Pools 

GEIS conclusions for Spent Fuel Pool accidents 

The GEIS for license renewal provides a generic evaluation of potential SFP accidents, 

encompassing the potentially most serious accident (a seismically-generated accident causing 

catastrophic failure of the pool) and concludes that there is no further need for a site-specific 

SFP accident or mitigation analysis for license renewal. The GEIS concludes, without exception 

or qualification for any type of SFP accident, that “regulatory requirements already in place 

provide adequate mitigation incentives for on-site storage of spent fuel,” and therefore mitigation 

alternatives for the SFP need not be considered for the license renewal review. See GEIS at 6-

86, 6-91 to 6-92. 

Risk Associated with Spent Fuel Pool Accidents 

Risk is defined as the probability of the occurrence of a given event multiplied by the 

consequences of that event. The risk of beyond-design-basis accidents in SFPs was first 

examined as part of the landmark Reactor Safety Study: An Assessment of Accident Risks in 

U.S. Commercial Nuclear Power Plants (WASH–1400, NUREG–75/014, 1975), and was found 

to be several orders of magnitude below those involving the reactor core. The risk of an SFP 

accident was re-examined in the 1980’s as Generic Issue 82, “Beyond Design Basis Accidents 

in Spent Fuel Pools,” in light of increased use of high-density storage racks and laboratory 

studies that indicated the possibility of zirconium fire propagation between assemblies in an aircooled environment. The risk assessment and cost-benefit analyses developed through this 
Environmental Impacts of Postulated Accidents 

NUREG-1437, Supplement 43 5-10 December 2010

effort, NUREG–1353, Regulatory Analysis for the Resolution of Generic Issue 82, Beyond 

Design Basis Accidents in Spent Fuel Pools, Section 6.2, April 1989, concluded that the risk of a 

severe accident in the SFP was low and ‘‘appear[s] to meet’’ the objectives of the Commission’s 

‘‘Safety Goals for the Operations of Nuclear Power Plants; Policy Statement,’’ (August 4, 1986; 

51 FR 28044), as amended (August 21, 1986; 51 FR 30028), and that no new regulatory 

requirements were warranted. 

SFP accident risk was re-assessed in the late 1990s to support a risk-informed rulemaking for 

permanently shutdown, or decommissioned, NPPs. The study, NUREG–1738, Technical Study 

of Spent Fuel Pool Accident Risk at Decommissioning Nuclear Power Plants, January 2001, 

conservatively assumed that if the water level in the SFP dropped below the top of the spent 

fuel, an SFP zirconium fire involving all of the spent fuel would occur, and thereby bounded 

those conditions associated with air cooling of the fuel (including partial-draindown scenarios) 

and fire propagation. Even when all events leading to the spent fuel assemblies becoming 

partially or completely uncovered were assumed to result in an SFP zirconium fire, the study 

found the risk of an SFP fire to be low and well within the Commission’s Safety Goals. 

Several analyses conducted by Sandia National Laboratories since 9/11, collectively referred to 

herein as the ‘‘Sandia studies,’’ indicate that the risk of a successful terrorist attack (i.e., one 

that results in an SFP zirconium fire) is very low. The Sandia studies include sensitive securityrelated information and are not available to the public. The Sandia studies considered spent 

fuel loading patterns and other aspects of a pressurized-water reactor SFP and a boiling-water 

reactor SFP, including the role that the circulation of air plays in the cooling of spent fuel. The 

Sandia studies indicated that there may be a significant amount of time between the initiating 

event (i.e., the event that causes the SFP water level to drop) and the spent fuel assemblies 

becoming partially or completely uncovered. In addition, the Sandia studies indicated that for 

those hypothetical conditions where air cooling may not be effective in preventing a zirconium 

fire (i.e., the partial drain down scenario), there is a significant amount of time between the 

spent fuel becoming uncovered and the possible onset of such a zirconium fire, thereby 

providing a substantial opportunity for event mitigation. The Sandia studies, which address 

relevant heat transfer and fluid flow mechanisms, also indicated that air-cooling of spent fuel 

would be sufficient to prevent SFP zirconium fires at a point much earlier following fuel offload 

from the reactor than previously considered (e.g., in NUREG–1738). Thus, the fuel would be 

more easily cooled, and the likelihood of an SFP fire would therefore be reduced (FR 46207, 

Vol 73, No. 154). 

Additional mitigation strategies implemented subsequent to 9/11 enhance spent fuel coolability 

and the potential to recover SFP water level and cooling prior to a potential SFP zirconium fire. 

The Sandia studies also confirmed the effectiveness of these additional mitigation strategies to 

maintain spent fuel cooling in the event the pool is drained and its initial water inventory is 

reduced or lost entirely. Based on this more recent information, and the implementation of 

additional strategies following 9/11, the probability and the risk of an SFP zirconium fire initiation 

is expected to be less than reported in NUREG–1738 and previous studies. In view of the 

physical robustness of SFPs, the physical security measures, and SFP mitigation measures, 

and based upon NRC site evaluations of every SFP in the United States, the NRC has 

determined that the risk of an SFP zirconium fire, whether caused by an accident or a terrorist 

attack, is very low and less than that for a reactor accident. 

The NRC and licensees’ efforts to address SFP vulnerabilities through enhancements since 

9/11 have focused on “readily available mitigation strategies” which are typically the most costeffective alternatives. The NRC’s ongoing oversight of plant security and safety will continue to 
Environmental Impacts of Postulated Accidents

December 2010 5-11 NUREG-1437, Supplement 43

include review of SFPs and, in some cases, may require changes associated with SFPs. 

5.2.1.6 Conclusions Regarding Sabotage and Terrorism 

NRC’s efforts to protect against terrorism, including efforts to evaluate potential options or 

alternatives to reduce the likelihood or severity of a terrorist attack, will continue during the 

current licensing period and any potential license renewal periods. The NRC staff’s 

consideration of terrorism is a matter of ongoing regulatory oversight, and one that will continue 

to be dealt with on a daily basis. Based on this and the many actions that have been taken 

since, the NRC staff maintains the Commission’s 1996 finding that although the threat of 

terrorist or sabotage events cannot be accurately quantified, acts of terrorism or sabotage are 

not reasonably expected and that even if such events were to occur, the resultant core damage 

and radiological releases would be no worse than those expected from internally-initiated 

events. 

5.3 SEVERE ACCIDENT MITIGATION ALTERNATIVES 

10 CFR 51.53(c)(3)(ii)(L) requires that license renewal applicants consider alternatives to 

mitigate severe accidents if the staff has not previously evaluated SAMAs for the applicant's 

plant in an environmental impact statement (EIS) or related supplement or in an environmental 

assessment. The purpose of this consideration is to ensure that plant changes (i.e., hardware, 

procedure, and training) with the potential for improving severe accident safety performance are 

identified and evaluated. SAMAs have not been previously considered for PVNGS; therefore, 

this section addresses those alternatives. 

5.3.1 Introduction 

The following is a summary of the SAMA evaluation for PVNGS conducted by APS and the 

NRC staff's review of that evaluation. The NRC staff performed its review with contract 

assistance from Pacific Northwest Laboratory. The NRC staff’s review is available in full in 

Appendix F; the SAMA evaluation is available in full in APS’s ER (APS 2008a). 

The SAMA evaluation for PVNGS was conducted with a four-step approach. In the first step, 

APS quantified the level of risk associated with potential reactor accidents using the 

plant-specific probabilistic risk assessment (PRA) and other risk models. 

In the second step, APS examined the major risk contributors and identified possible ways 

(SAMAs) of reducing that risk. Common ways of reducing risk are changes to components, 

systems, procedures, and training. APS identified 23 potential SAMAs for PVNGS. APS 

performed an initial screening to determine if any SAMAs could be eliminated because they are 

not applicable at PVNGS due to design differences, have already been implemented at PVNGS, 

or have estimated implementation costs that would exceed the dollar value associated with 

completely eliminating all severe accident risk at PVNGS. This screening reduced the list of 

potential SAMAs to 13. 

In the third step, APS estimated the benefits and the costs associated with each of the 

remaining SAMAs. Estimates were made of how much each SAMA could reduce risk. Those 

estimates were developed in terms of dollars in accordance with NRC guidance for performing 

regulatory analyses (NRC 1997). The cost of implementing the proposed SAMAs was also 

estimated. 
Environmental Impacts of Postulated Accidents 

NUREG-1437, Supplement 43 5-12 December 2010

Finally, in the fourth step, the costs and benefits of each of the remaining SAMAs were 

compared to determine whether the SAMA was cost-beneficial, meaning the benefits of the 

SAMA were greater than the cost (a positive cost-benefit). APS concluded in its ER that several 

of the SAMAs evaluated are potentially cost-beneficial (APS 2008a). The potentially costbeneficial SAMAs do not relate to adequately managing the effects of aging during the period of 

extended operation; therefore, they need not be implemented as part of license renewal 

pursuant to 10 CFR Part 54. APS's SAMA analyses and the NRC's review are discussed in 

more detail below. 

5.3.2 Estimate of Risk 

APS submitted an assessment of SAMAs for PVNGS as part of the ER (APS 2008a). This 

assessment was based on the most recent PVNGS PRA available at that time; a plant-specific 

offsite consequence analysis performed using the MELCOR Accident Consequence Code 

System 2 (MACCS2) computer program, and insights from the PVNGS Individual Plant 

Examination (IPE) (APS 1992) and Individual Plant Examination of External Events (IPEEE) 

(APS 1995). 

The PVNGS core damage frequency (CDF) is approximately 5.07 x 10-6 per year for internal 

events (not including internal flooding) and 2.72 x 10-6 per year for fire events, as determined 

from quantification of the Level 1 PRA model. When determined from the sum of the 

containment event tree sequences, or Level 2 PRA model, the release frequency is 

approximately 5.24 x 10-6 per year. The latter value was used in the SAMA evaluations. The 

CDF value is based on the risk assessment for internally-initiated events. APS accounted for 

the potential risk reduction benefits associated with external events by applying a multiplier to 

the estimated benefits for internal events. The breakdown of CDF by initiating event is provided 

in Table 5-3a and 5-3b for internal events and fire events, respectively. 
Environmental Impacts of Postulated Accidents

December 2010 5-13 NUREG-1437, Supplement 43

Table 5-3a. PVNGS Core Damage Frequency for Internal Events 

Initiating Event CDF 

(per year)a

% Contribution 

to CDF 

Station Blackout 1.2 × 10-6 23 

Loss of Engineered Safeguard Feature (ESF) Train A or B Bus 8.9 × 10-7 18 

Uncomplicated (Unplanned) Reactor Trips 5.9 × 10-7 12 

Loss of Condensate Feedwater or Vacuum 5.5 × 10-7 11 

Anticipated Transient Without Scram (ATWS) 4.6 × 10-7 9 

Loss of Off-Site Power (LOOP) 3.5 × 10-7 7 

Turbine Trip 2.9 × 10-7 6 

Small Break Loss of Coolant Accident (LOCA) 2.5 × 10-7 5 

Other 1.7 × 10-7 3 

Medium and Large Break LOCAs 1.5 × 10-7 3 

Steam Generator Tube Rupture (SGTR) 1.0 × 10-7 2 

Loss or DC Power 3.5 × 10-8 1 

Interfacing Systems LOCA 1.5 × 10-8 <1 

Loss of Off-Site Power to Train A or B 1.0 × 10-8 <1 

Loss of Vital 120V AC 5.1 × 10-9 <1 

Total CDF (internal events)b 5.07 × 10-6 100

(a) Based on percent contribution from response to RAI 1.e (APS 2009, APS 2010) and total CDF. 

(b) Column totals may be different due to round off. 

As shown in Table 5-3a, events initiated by station blackout, loss of an ESF train, unplanned 

reactor trips, and loss of condensate feedwater are the dominant contributors to the internal 

event CDF. 
Environmental Impacts of Postulated Accidents 

NUREG-1437, Supplement 43 5-14 December 2010

Table 5-3b. Important PVNGS Fire Compartments and their Contribution to Fire CDF 

Fire 

Compartment Fire Compartment Description CDF 

(per year) 

% Contribution 

to CDFa

FZ 17 Main Control Room 7.2 × 10-7 27 

FZ TB9 Main Turbine Bearings Areas 5.7 × 10-7 21 

FZ 5A Train A Essential Switchgear Room 3.5 × 10-7 13 

FZ COR2A Corridor Building – 120 foot 2.5 × 10-7 9 

FZ TB1 Turbine Building – 100 foot West 2.3 × 10-7 8 

FZ TB5 Turbine Building – 140 foot West 1.8 × 10-7 7 

FZ TB3B Feedwater Pumps Area 1.1 × 10-7 4 

FZ TB4B DC Equipment Room 3.3 × 10-8 1 

FZ 5B Train B Essential Switchgear Room 3.3 × 10-8 1 

FZ 42A Electrical Penetration Room – Train A, 

Channel A 

2.9 × 10-8 1 

 Other Fire Compartmentsb 2.1 × 10-7 8 

Total Fire CDF 2.72 × 10-6 100

(c) Based on Fire CDF contribution in ER (APS 2008a) and total Fire CDF. 

(d) CDF value derived as the difference between the total Fire CDF and the sum of the fire CDFs reported for 

the 10 dominant fire compartments. 

As shown in Table 5-3b, the dominant contributors to fire CDF are fires in the Control Room, the 

main turbine bearings area, and the Train A Essential Switchgear Room. 

APS estimated the dose to the population within 50 miles (80 km) of PVNGS to be 

approximately 13.6 person-rem (0.136 person-sievert [Sv]) per year. The breakdown of the total 

population dose by containment release mode is summarized in Table 5-4. Late containment 

over-pressure failures and SGTR-initiated accidents drive the population dose risk at PVNGS. 

Table 5-4. Breakdown of Population Dose by Containment Release Mode 

Containment Release Mode 

Population Dose 

(Person-Rem(a) Per Year) Percent Contribution 

Containment Over-pressure Failure (Late) 10.5 77 

Basemat Melt-Through (Late) 0.5 4 

Steam Generator Tube Rupture 2.3 17 

Containment Isolation Failure 0.2 1 

Interfacing Systems LOCA 0.1 1 

Intact Containment negligible negligible 

Total 13.6 100

(a) One person-rem = 0.01 person-Sv 

The NRC staff has reviewed APS's data and evaluation methods and concludes that the quality 
Environmental Impacts of Postulated Accidents

December 2010 5-15 NUREG-1437, Supplement 43

of the risk analyses is adequate to support an assessment of the risk reduction potential for 

candidate SAMAs. Accordingly, the staff based its assessment of offsite risk on the CDFs and 

offsite doses reported by APS. 

5.3.3 Potential Plant Improvements 

Once the dominant contributors to plant risk were identified, APS searched for ways to reduce 

that risk. In identifying and evaluating potential SAMAs, APS considered insights from the plantspecific PRA, and SAMA analyses performed for other operating plants that have submitted 

license renewal applications. APS identified 23 potential risk-reducing improvements (SAMAs) 

to plant components, systems, procedures and training. 

APS removed all but 13 of the SAMAs from further consideration because they are not 

applicable at PVNGS due to design differences, have already been implemented at PVNGS, or 

have estimated implementation costs that would exceed the dollar value associated with 

completely eliminating all severe accident risk at PVNGS. A detailed cost-benefit analysis was 

performed for each of the remaining SAMAs. 

The staff concludes that APS used a systematic and comprehensive process for identifying 

potential plant improvements for PVNGS, and that the set of potential plant improvements 

identified by APS is reasonably comprehensive and, therefore, acceptable. 

5.3.4 Evaluation of Risk Reduction and Costs of Improvements 

APS evaluated the risk-reduction potential of the remaining 13 SAMAs. The SAMA evaluations 

were performed using realistic assumptions with some conservatism. 

APS estimated the costs of implementing the candidate SAMAs through the development of 

site-specific cost estimates and use of other licensee’s estimates for similar improvements. The 

cost estimates conservatively did not include the cost of replacement power during extended 

outages required to implement the modifications, nor did they account for inflation. 

The staff reviewed APS’s bases for calculating the risk reduction for the various plant 

improvements and concludes that the rationale and assumptions for estimating risk reduction 

are reasonable and generally conservative (i.e., the estimated risk reduction is higher than what 

would actually be realized). Accordingly, the staff based its estimates of averted risk for the 

various SAMAs on APS’s risk reduction estimates. 

The staff reviewed the bases for the applicant’s cost estimates. For certain improvements, the 

staff also compared the cost estimates to estimates developed elsewhere for similar 

improvements, including estimates developed as part of other licensees’ analyses of SAMAs for 

operating reactors. The staff found the cost estimates to be reasonable, and generally 

consistent with estimates provided in support of other plants’ analyses. 

The staff concludes that the risk reduction and the cost estimates provided by APS are sufficient 

and appropriate for use in the SAMA evaluation. 

5.3.5 Cost-Benefit Comparison 

The cost-benefit analysis performed by APS was based primarily on NUREG/BR-0184 (NRC 

1997) and was executed consistent with this guidance. NUREG/BR-0058 has recently been 

revised to reflect the agency’s revised policy on discount rates. Revision 4 of NUREG/BR-0058 
Environmental Impacts of Postulated Accidents 

NUREG-1437, Supplement 43 5-16 December 2010

states that two sets of estimates should be developed: one at 3 percent and one at 7 percent 

(NRC 2004). APS provided both sets of estimates (APS 2008a). 

The cost-benefit analysis, as revised in response to NRC staff RAIs, showed that one of the 

SAMA candidates was potentially cost-beneficial in the baseline analysis (i.e., SAMA 6). APS 

performed additional analyses to evaluate the impact of parameter choices and uncertainties on 

the results of the SAMA assessment (APS 2009). As a result, two additional SAMAs were 

identified as potentially cost-beneficial (SAMAs 17 and 23). In response to another NRC staff 

RAI regarding the method used to assess the fire-related population dose and offsite economic 

cost reduction for certain SAMAs, APS identified one additional potentially cost-beneficial SAMA 

(SAMA 8). 

The potentially cost-beneficial SAMAs are: 

• SAMA 6 – Develop procedures to guide recovery actions for spurious 

electrical protection faults. 

• SAMA 17 – Modify the procedures to preclude reactor coolant pump 

operations that would clear the water seals in the cold leg after core damage. 

• SAMA 23 – Enhance procedures to direct steam generator flooding for 

release scrubbing. 

• SAMA 8 – Add auto start/load capability to the gas turbine generators. 

APS has committed to implement the first three SAMAs (SAMA 6, 17, and 23) and also 

indicated that they will further consider the last SAMA (SAMA 8) for potential implementation 

(APS 2010). 

The staff concludes, with the exception of the potentially cost-beneficial SAMAs discussed 

above, the costs of the SAMAs evaluated would be higher than the associated benefits. 

5.3.6 Conclusions 

The staff reviewed APS’s analysis and concluded that the methods used and the 

implementation of those methods was sound. The treatment of SAMA benefits and costs 

support the general conclusion that the SAMA evaluations performed by APS are reasonable 

and sufficient for the license renewal submittal. 

Based on its review of the SAMA analysis, the staff concurs with APS’s identification of areas in 

which risk can be further reduced in a cost-beneficial manner through the implementation of all 

or a subset of potentially cost-beneficial SAMAs. Given the potential for cost-beneficial risk 

reduction, the staff considers that further evaluation of these SAMAs by APS is warranted. 

However, none of the potentially cost-beneficial SAMAs relate to adequately managing the 

effects of aging during the period of extended operation. Therefore, they need not be 

implemented as part of the license renewal pursuant to 10 CFR Part 54. 

 
Environmental Impacts of Postulated Accidents

December 2010 5-17 NUREG-1437, Supplement 43

5.4 REFERENCES 

Arizona Public Service Company (APS). 1992. Letter from William F. Conway, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2 

and 3, Docket Nos. STN 50-528, 50-529, and 50-530, Submittal of PVNGS Individual Plant 

Examination for Severe Accident Vulnerabilities (Response to Generic Letter 88-20),” Phoenix, 

Arizona. April 28, 1992. ADAMS No. ML080040089 and ML082940053. 

Arizona Public Service Company (APS). 1995. Letter from William L. Stewart, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2 

and 3, Docket Nos. STN 50-528/529/530, Individual Plant Examination of External Events 

(IPEEE) for Severe Accident Vulnerabilities (Generic Letter No. 88-20, Supplement 4),” 

Phoenix, Arizona. June 30, 1995. ADAMS No. ML080040087. 

Arizona Public Service Company (APS). 2008a. Palo Verde Nuclear Generating Station, Units 

1, 2, and 3, Applicant’s Environmental Report, License Renewal Operating Stage. ADAMS No. 

ML083510615, Appendix E. 

Arizona Public Service Company (APS). 2009. Letter from John H. Hesser, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Stations (PVNGS), Units 1, 

2 and 3, Docket Nos. STN 50-528, 50-529, and 50-530, Response to Severe Accident 

Mitigation Alternatives for the Review of the PVNGS License Renewal Application, and License 

Renewal Application Amendment No. 2,” Phoenix, Arizona. November 10, 2009. ADAMS No. 

ML093230225. 

Arizona Public Service Company (APS). 2010. Letter from Dwight C. Mims, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Stations (PVNGS), Units 1, 

2 and 3, Docket Nos. STN 50-528, 50-529, and 50-530, Follow-up Clarification to the Response 

to September 30, 2009, Request for Additional Information Regarding Severe Accident 

Mitigation Alternatives for the Review of the PVNGS License Renewal Application, and License 

Renewal Application Amendment No. 7,” Phoenix, Arizona. January 13, 2010. ADAMS No. 

ML100270290. 

Arizona Public Service Company (APS). 2010c. Letter from Dwight C. Mims, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Stations (PVNGS), Units 1, 

2 and 3, Docket Nos. STN 50-528, 50-529, and 50-530, Response to April 8, 2010, Request for 

Additional Information Regarding Security Assessments, for the Review of the PVNGS 

License Renewal Application,” Phoenix, Arizona. April 29, 2010. ADAMS No. ML101310227. 

National Academy of Sciences (NAS). 2006. Safety and Security of Commercial Spent Nuclear 

Fuel Storage, NAS Committee on the Safety and Security of Commercial Spent Nuclear Fuel 

Storage, National Academies Press. (2006). 

U.S. Nuclear Regulatory Commission (NRC). 1975. Reactor Safety Study – An Assessment of 

Accident Risks in U.S. Commercial Nuclear Power Plants, WASH-1400, NUREG-75/014. 

(October 1975). 

U.S. Nuclear Regulatory Commission (NRC). 1989. Regulatory Analysis for the Resolution of 

Generic Issue 82, “Beyond Design Basis Accidents in Spent Fuel Pools”, NUREG-1353. (April 

1989). 

U.S. Nuclear Regulatory Commission (NRC). 1997. Regulatory Analysis Technical Evaluation 

Handbook. NUREG/BR-0184, Washington, D.C., January 1997. 
Environmental Impacts of Postulated Accidents 

NUREG-1437, Supplement 43 5-18 December 2010

U.S. Nuclear Regulatory Commission (NRC). 2001. Technical Study of Spent Fuel Pool 

Accident Risk at Decommissioning Nuclear Power Plants, NUREG-1738. (January 2001). 

U.S. Nuclear Regulatory Commission (NRC). 2004. Protecting Our Nation – Since 9-11-01, 

NUREG/BR-0314. (September 2004). 

U.S. Nuclear Regulatory Commission (NRC). 2004a. Regulatory Analysis Guidelines of the 

U.S. Nuclear Regulatory Commission. NUREG/BR-0058, Revision 4, Washington, D.C., 

September 2004. 

U.S. Nuclear Regulatory Commission (NRC). 2005. Safety and Security Improvements at 

Nuclear Plants, Fact Sheet, Office of Public Affairs. (February 2005). Available at: 

http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/safety-security.pdf 

U.S. Nuclear Regulatory Commission (NRC). 2006a. Frequently Asked Questions on License 

Renewal of Nuclear Power Reactors, NUREG-1850. (March 2006). 

U.S. Nuclear Regulatory Commission (NRC). 2006b. Mitigation of Spent Fuel Loss-of-Coolant 

Inventory Accidents and Extension of Reference Plant Analyses to Other Spent Fuel Pools, 

Sandia Letter Report, Revision 2. (November 2006). (Official Use Only; Redacted version 

available). 

U.S. Nuclear Regulatory Commission (NRC). 2006c. Nuclear Security, Backgrounder, Office of 

Public Affairs. (September 2006). Available at: http://www.nrc.gov/reading-rm/doccollections/fact-sheets/security-enhancements.pdf 

U.S. Nuclear Regulatory Commission (NRC). 2007c. Safety Evaluation of PVNGS Mitigation 

Strategies Required by Section B.5.b of Commission Order EA-02-026. August 2007. ADAMS 

No. ML072110440 

U.S. Nuclear Regulatory Commission (NRC). 2007d. Appendices to Safety Evaluation of 

PVNGS Mitigation Strategies Required by Section B.5.b of Commission Order EA-02-026. 

August 2007. ADAMS No. ML072110142 

U.S. Nuclear Regulatory Commission (NRC). 2008. Security Spotlight: Protecting Against 

Aircraft, Fact Sheet, Office of Public Affairs. (January 2008). Available at: 

http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/security-spotlight/aircraft.html
December 2010 6-1 NUREG-1437, Supplement 43

6.0 ENVIRONMENTAL IMPACTS OF THE URANIUM FUEL CYCLE, 

SOLID WASTE MANAGEMENT, AND GREENHOUSE GAS EMISSIONS 

6.1 THE URANIUM FUEL CYCLE AND SOLID WASTE MANAGEMENT 

This section addresses issues related to the uranium fuel cycle and solid waste management 

during the period of extended operation. The uranium cycle includes uranium mining and 

milling, the production of uranium hexafluoride, isotopic enrichment, fuel fabrication, 

reprocessing of irradiated fuel, transportation of radioactive materials, and management of 

low-level wastes and high-level wastes related to uranium fuel cycle activities. The Generic 

Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437 

(NRC 1996), (NRC 1999) details the potential generic impacts of the radiological and 

nonradiological environmental impacts of the uranium fuel cycle and transportation of nuclear 

fuel and wastes, as listed in Table 6-1 below. The GEIS is based, in part, on the generic 

impacts provided in Table S-3, “Table of Uranium Fuel Cycle Environmental Data,” in Title 10 of 

the Code of Federal Regulations (CFR), Section 51.51(b), and in Table S-4, “Environmental 

Impact of Transportation of Fuel and Waste to and from One Light-Water-Cooled Nuclear Power 

Reactor,” in 10 CFR 51.52(c). The GEIS also addresses the impacts from radon-222 and 

technetium-99. 

The staff of the U.S. Nuclear Regulatory Commission (NRC) did not identify any new and 

significant information related to the uranium fuel cycle during the review of the Arizona Public 

Service Company (APS) environmental report (ER) (APS 2008a), the site audit, and the scoping 

process. Therefore, there are no impacts related to these issues beyond those discussed in the 

GEIS. For these Category 1 issues, the GEIS concludes that the impacts are designated as 

SMALL, except for the collective offsite radiological impacts from the fuel cycle and from 

high-level waste and spent fuel disposal, which the Commission concluded are acceptable. 
Environmental Impacts of the Uranium Fuel Cycle 

NUREG-1437, Supplement 43 6-2 December 2010

Table 6-1. Issues Related to the Uranium Fuel Cycle and Solid Waste Management Nine 

generic issues are related to the fuel cycle and solid waste management. There are no 

site-specific issues.

Issues GEIS Section Category 

Offsite radiological impacts (individual effects from other than the 

disposal of spent fuel and high-level waste) 

6.1, 6.2.1, 6.2.2.1, 

6.2.2.3, 6.2.3, 6.2.4, 

6.6 

1 

Offsite radiological impacts (collective effects) 6.1, 6.2.2.1, 6.2.3, 

6.2.4, 6.6 

1 

Offsite radiological impacts (spent fuel and high-level waste 

disposal) 

6.1, 6.2.2.1, 6.2.3, 

6.2.4, 6.6 

1 

Nonradiological impacts of the uranium fuel cycle 6.1, 6.2.2.6, 6.2.2.7, 

6.2.2.8, 6.2.2.9, 

6.2.3, 6.2.4, 6.6 

1 

Low-level waste storage and disposal 6.1, 6.2.2.2, 6.4.2, 

6.4.3, 6.4.3.1, 

6.4.3.2, 6.4.3.3, 

6.4.4, 6.4.4.1, 

6.4.4.2, 6.4.4.3, 

6.4.4.4, 6.4.4.5, 

6.4.4.5.1, 6.4.4.5.2, 

6.4.4.5.3, 6.4.4.5.4, 

6.4.4.6, 6.6 

1 

Mixed waste storage and disposal 6.4.5.1, 6.4.5.2, 

6.4.5.3, 6.4.5.4, 

6.4.5.5, 6.4.5.6, 

6.4.5.6.1, 6.4.5.6.2, 

6.4.5.6.3, 6.4.5.6.4, 

6.6 

1 

Onsite spent fuel 6.1, 6.4.6, 6.4.6.1, 

6.4.6.2, 6.4.6.3, 

6.4.6.4, 6.4.6.5, 

6.4.6.6, 6.4.6.7, 6.6 

1 

Nonradiological waste 6.1, 6.5, 6.5.1, 6.5.2, 

6.5.3, 6.6 

1 

Transportation 6.1, 6.3.1, 6.3.2.3, 

6.3.3, 6.3.4, 6.6, 

Addendum 1 

1 

6.2 GREENHOUSE GAS EMISSIONS 

This section provides a discussion of potential impacts from greenhouse gases (GHGs) emitted 

during the nuclear fuel cycle. The GEIS does not directly address these emissions, and its 

discussion is limited to an inference that substantial carbon dioxide (CO2) emissions may occur 
Environmental Impacts of the Uranium Fuel Cycle

December 2010 6-3 NUREG-1437, Supplement 43

if coal- or oil-fired alternatives to license renewal are implemented. 

6.2.1 Existing Studies 

Since the development of the GEIS, the relative volumes of GHGs emitted by nuclear and other 

electricity generating methods have been widely studied. However, estimates and projections 

of the carbon footprint of the nuclear power life cycle vary depending on the type of study 

conducted. Additionally, considerable debate also exists among researchers regarding the 

relative impacts of nuclear and other forms of electricity generation on GHG emissions. Existing 

studies on GHG emissions from nuclear power plants generally take two different forms: 

(1) Qualitative discussions of the potential to use nuclear power to reduce GHG emissions 

and mitigate global warming; and 

(2) Technical analyses and quantitative estimates of the actual amount of GHGs 

generated by the nuclear fuel cycle or entire nuclear power plant life cycle and 

comparisons to the operational or life cycle emissions from other energy 

generation alternatives. 

6.2.1.1 Qualitative Studies 

The qualitative studies consist primarily of broad, large-scale public policy or investment 

evaluations of whether an expansion of nuclear power is likely to be a technically, economically, 

and/or politically feasible means of achieving global GHG reductions. Examples of the studies 

identified by the staff during the subsequent literature search include: 

• Evaluations to determine whether investments in nuclear power in developing 

countries should be accepted as a flexibility mechanism to assist 

industrialized nations in achieving their GHG reduction goals under the Kyoto 

Protocols (Schneider 2000), (IAEA 2000), (NEA 2002). Ultimately, the parties 

to the Kyoto Protocol did not approve nuclear power as a component under 

the Clean Development Mechanism (CDM) due to safety and waste disposal 

concerns (NEA 2002). 

• Analyses developed to assist governments, including the United States, in 

making long-term investment and public policy decisions in nuclear power 

(Keepin 1988), (Hagen et al. 2001), (MIT 2003). 

Although the qualitative studies sometimes reference and critique the existing quantitative 

estimates of GHGs produced by the nuclear fuel cycle or life cycle, their conclusions generally 

rely heavily on discussions of other aspects of nuclear policy decisions and investment such as 

safety, cost, waste generation, and political acceptability. Therefore, these studies are typically 

not directly applicable to an evaluation of GHG emissions associated with the proposed license 

renewal for a given nuclear power plant. 

6.2.1.2 Quantitative Studies 

A large number of technical studies, including calculations and estimates of the amount of 

GHGs emitted by nuclear and other power generation options, are available in the literature and 

were useful to the staff’s efforts in addressing relative GHG emission levels. Examples of these 

studies include—but are not limited to—Mortimer (1990), Andseta et al. (1998), Spadaro et al. 

(2000), Storm van Leeuwen and Smith (2005), Fritsche (2006), Parliamentary Office of Science 

and Technology (POST) (2006), Atomic Energy Authority Technology (AEA) (2006), Weisser 
Environmental Impacts of the Uranium Fuel Cycle 

NUREG-1437, Supplement 43 6-4 December 2010

(2006), Fthenakis and Kim (2007), and Dones (2007). 

Comparing these studies and others like them is difficult because the assumptions and 

components of the life cycles the authors evaluate vary widely. Examples of areas in which 

differing assumptions make comparing the studies difficult include: 

• energy sources that may be used to mine uranium deposits in the future 

• reprocessing or disposal of spent nuclear fuel 

• current and potential future processes to enrich uranium and the energy 

sources that will power them 

• estimated grades and quantities of recoverable uranium resources 

• estimated grades and quantities of recoverable fossil fuel resources 

• estimated GHG emissions other than CO2, including the conversion to CO2

equivalents per unit of electric energy produced 

• performance of future fossil fuel power systems 

• projected capacity factors for alternative means of generation 

• current and potential future reactor technologies 

In addition, studies may vary with respect to whether all or parts of a power plant’s life cycle are 

analyzed (i.e., a full life cycle analysis will typically address plant construction, operations, 

resource extraction (for fuel and construction materials), and decommissioning, whereas a 

partial life cycle analysis primarily focuses on operational differences). 

In the case of license renewal, a GHG analysis for that portion of the plant’s life cycle (operation 

for an additional 20 years) would not involve GHG emissions associated with construction 

because construction activities have already been completed at the time of relicensing. In 

addition, the proposed action of license renewal would also not involve additional GHG 

emissions associated with facility decommissioning because that decommissioning must occur 

whether the facility is relicensed or not. However, in some of the aforementioned studies, the 

specific contribution of GHG emissions from construction, decommissioning, or other portions of 

a plant’s life cycle cannot be clearly separated from one another. In such cases, an analysis of 

GHG emissions would overestimate the GHG emissions attributed to a specific portion of a 

plant’s life cycle. Nonetheless, these studies provide some meaningful information with respect 

to the relative magnitude of the emissions among nuclear power plants and other forms of 

electric generation, as discussed in the following sections. 

In Tables 6-2, 6-3, and 6-4, the staff presents the results of the aforementioned quantitative 

studies to provide a weight-of-evidence evaluation of the relative GHG emissions that may 

result from the proposed license renewal as compared to the potential alternative use of 

coal-fired, natural gas-fired, and renewable generation. Most studies from Mortimer (1990) 

onward suggest that uranium ore grades and uranium enrichment processes are leading 

determinants in the ultimate GHG emissions attributable to nuclear power generation. 

These studies indicate that at this time when compared to fossil-fueled alternatives, nuclear 

power emits a relatively lower order of magnitude of GHG emissions. A subset of these studies 

indicate that this advantage, especially when compared to natural gas, could potentially 

disappear if available uranium ore grades drop sufficiently while enrichment processes continue 
Environmental Impacts of the Uranium Fuel Cycle

December 2010 6-5 NUREG-1437, Supplement 43

to rely on the same technologies. 

6.2.1.3 Summary of Nuclear Greenhouse Gas Emissions Compared to Coal 

Considering that coal fuels the largest share of electricity generation in the United States and 

that its burning results in the largest emissions of GHGs for any of the likely alternatives to 

nuclear power generation, including Palo Verde Nuclear Generating Station (PVNGS), most of 

the available quantitative studies focused on comparisons of the relative GHG emissions of 

nuclear to coal-fired generation. The quantitative estimates of the GHG emissions associated 

with the nuclear fuel cycle (and, in some cases, the nuclear life cycle), as compared to an 

equivalent coal-fired plant, are presented in Table 6-2. The following chart does not include all 

existing studies but provides an illustrative range of estimates developed by various 

researchers. 

Table 6-2. Nuclear Greenhouse Gas Emissions Compared to Coal 

Source GHG Emission Results

Mortimer (1990) Nuclear—230,000 tons CO2 

Coal—5,912,000 tons CO2

Note: Future GHG emissions from nuclear to increase because of declining ore grade, 

particularly if the ore grade falls to anything less than 0.01% uranium oxide, at which 

point the nuclear power system could release as much carbon dioxide as fossil fuelfired power station. 

Andseta et al. (1998) Nuclear energy produces 1.4 percent of the GHG emissions compared to coal. 

Note: Future reprocessing and use of nuclear-generated electrical power in the mining 

and enrichment steps are likely to change (lower) the projections of earlier authors, 

such as Mortimer (1990). 

Spadaro et al. (2000) Nuclear—2.5 to 5.7 g Ceq/kWh 

Coal—264 to 357 g Ceq/kWh 

Fritsche (2006) (Values 

estimated from graph in 

Figure 4) 

Nuclear—33 g Ceq/kWh 

Coal—950 g Ceq/kWh 

POST (2006) (Nuclear 

calculations from AEA, 

2006) 

Nuclear—5 g Ceq/kWh 

Coal—>1000 g Ceq/kWh 

Note: Decrease of uranium ore grade to 0.03 percent would raise nuclear to 6.8 g Ceq 

/kWh. Future improved technology and carbon capture and storage could reduce 

coal-fired GHG emissions by 90 percent. 

Weisser (2006) 

(Compilation of results 

from other studies) 

Nuclear—2.8 to 24 g Ceq/kWh 

Coal—950 to 1250 g Ceq/kWh 

6.2.1.4 Summary of Nuclear Greenhouse Gas Emissions Compared to Natural Gas 

The quantitative estimates of the GHG emissions associated with the nuclear fuel cycle (and, in 

some cases, the nuclear life cycle), as compared to an equivalent natural gas-fired plant, are 

presented in Table 6-3. The following chart does not include all existing studies but provides an 

illustrative range of estimates developed by various researchers. 
Environmental Impacts of the Uranium Fuel Cycle 

NUREG-1437, Supplement 43 6-6 December 2010

Table 6-3. Nuclear Greenhouse Gas Emissions Compared to Natural Gas 

Source GHG Emission Results

Spadaro et al. (2000) Nuclear—2.5 to 5.7 g Ceq/kWh 

Natural Gas—120 to 188 g Ceq/kWh 

Storm van Leeuwen 

and Smith (2005) 

Nuclear fuel cycle produces 20 to 33 percent of the GHG emissions compared to 

natural gas (at high ore grades). 

Note: Future nuclear GHG emissions to increase because of declining ore grade. 

Fritsche (2006) (Values 

estimated from graph in 

Figure 4) 

Nuclear—33 g Ceq/kWh 

Cogeneration Combined-Cycle Natural Gas—150 g Ceq/kWh 

POST (2006) (Nuclear 

calculations from AEA, 

2006) 

Nuclear—5 g Ceq/kWh 

Natural Gas—500 g Ceq/kWh 

Note: Decrease of uranium ore grade to 0.03 percent would raise nuclear to 

6.8 g Ceq/kWh. Future improved technology and carbon capture and storage could 

reduce natural gas GHG emissions by 90 percent. 

Weisser (2006) 

(Compilation of results 

from other studies) 

Nuclear—2.8 to 24 g Ceq/kWh 

Natural Gas—440 to 780 g Ceq/kWh 

Dones (2007) Author critiqued methods and assumptions of Storm van Leeuwen and Smith (2005) 

and concluded that the nuclear fuel cycle produces 15 to 27 percent of the GHG 

emissions of natural gas. 

6.2.1.5 Summary of Nuclear Greenhouse Gas Emissions Compared to Renewable Energy 

Sources 

The quantitative estimates of the GHG emissions associated with the nuclear fuel cycle, as 

compared to equivalent renewable energy sources, are presented in Table 6-4. Calculation of 

GHG emissions associated with these sources is more difficult than the calculations for nuclear 

energy and fossil fuels because of the large variation in efficiencies due to their different 

sources and locations. For example, the efficiency of solar and wind energy is highly dependent 

on the location in which the power generation facility is installed. Similarly, the range of GHG 

emissions estimates for hydropower varies greatly depending on the type of dam or reservoir 

involved (if used at all). Therefore, the GHG emissions estimates for these energy sources 

have a greater range of variability than the estimates for nuclear and fossil fuel sources. The 

following chart does not include all existing studies but provides an illustrative range of 

estimates developed by various researchers. 
Environmental Impacts of the Uranium Fuel Cycle

December 2010 6-7 NUREG-1437, Supplement 43

Table 6-4. Nuclear Greenhouse Gas Emissions Compared to Renewable Energy Sources 

Source GHG Emission Results

Mortimer (1990) Nuclear—230,000 tons CO2 

Hydroelectric—78,000 tons CO2

Wind power—54,000 tons CO2

Tidal power—52,500 tons CO2

Note: Future GHG emissions from nuclear to increase because of declining ore grade. 

Spadaro et al. (2000) Nuclear—2.5 to 5.7 g Ceq/kWh 

Solar photovoltaic (PV)—27.3 to 76.4 g Ceq/kWh 

Hydroelectric—1.1 to 64.6 g Ceq/kWh 

Biomass—8.4 to 16.6 g Ceq/kWh 

Wind—2.5 to 13.1 g Ceq/kWh 

Fritsche (2006) (Values 

estimated from graph in 

Figure 4) 

Nuclear—33 g Ceq/kWh 

Solar PV—125 g Ceq/kWh 

Hydroelectric—50 g Ceq/kWh 

Wind—20 g Ceq/kWh 

POST (2006) (Nuclear 

calculations from AEA, 

2006) 

Nuclear—5 g Ceq/kWh 

Biomass—25 to 93 g Ceq/kWh 

Solar PV—35 to 58 g Ceq/kWh 

Wave/Tidal—25 to 50 g Ceq/kWh 

Hydroelectric—5 to 30 g Ceq/kWh 

Wind—4.64 to 5.25 g Ceq/kWh 

Note: Decrease of uranium ore grade to 0.03 percent would raise nuclear to 

6.8 g Ceq/kWh. 

Weisser (2006) 

(Compilation of results 

from other studies) 

Nuclear—2.8 to 24 g Ceq/kWh 

Solar PV—43 to 73 g Ceq/kWh 

Hydroelectric—1 to 34 g Ceq/kWh 

Biomass—35 to 99 g Ceq/kWh 

Wind—8 to 30 g Ceq/kWh 

Fthenakis and Kim 

(2007) 

Nuclear—16 to 55 g Ceq/kWh 

Solar PV—17 to 49 g Ceq/kWh 

6.2.2 Conclusions: Relative Greenhouse Gas Emissions 

The sampling of data presented in Tables 6-2, 6-3, and 6-4 above demonstrates the challenges 

of any attempt to determine the specific amount of GHG emission attributable to nuclear energy 

production sources, as different assumptions and calculation methodology will yield differing 

results. The differences and complexities in these assumptions and analyses will further 

increase when they are used to project future GHG emissions. Nevertheless, several 

conclusions can be drawn from the information presented. 

First, the various studies indicate a general consensus that nuclear power currently produces 

fewer GHG emissions than fossil-fuel-based electrical generation, e.g., the GHG emissions from 

a complete nuclear fuel cycle currently range from 2.5 to 55 g Ceq/kWh, as compared to the use 

of coal plants (264 to 1,250 g Ceq/kWh) and natural gas plants (120 to 780 g Ceq/kWh). The 
Environmental Impacts of the Uranium Fuel Cycle 

NUREG-1437, Supplement 43 6-8 December 2010

studies also provide estimates of GHG emissions from five renewable energy sources based on 

current technology. These estimates included solar-photovoltaic (17 to 125 g Ceq/kWh), 

hydroelectric (1 to 64.6 g Ceq/kWh), biomass (8.4 to 99 g Ceq/kWh), wind (2.5 to 30 g Ceq/kWh), 

and tidal (25 to 50 g Ceq/kWh). The range of these estimates is wide, but the general conclusion 

is that current GHG emissions from the nuclear fuel cycle are of the same order of magnitude as 

from these renewable energy sources. 

Second, the studies indicate no consensus on future relative GHG emissions from nuclear 

power and other sources of electricity. There is substantial disagreement among the various 

authors regarding the GHG emissions associated with declining uranium ore concentrations, 

future uranium enrichment methods, and other factors, including changes in technology. Similar 

disagreement exists regarding future GHG emissions associated with coal and natural gas for 

electricity generation. Even the most conservative studies conclude that the nuclear fuel cycle 

currently produces fewer GHG emissions than fossil-fuel-based sources and is expected to 

continue to do so in the near future. The primary difference between the authors is the 

projected cross-over date (the time at which GHG emissions from the nuclear fuel cycle exceed 

those of fossil-fuel-based sources) or whether cross-over will occur at all. 

Considering the current estimates and future uncertainties, it appears that GHG emissions 

associated with the proposed PVNGS relicensing action are likely to be lower than those 

associated with fossil-fuel-based energy sources. The staff based this conclusion on the 

following rationale: 

(1) As shown in Tables 6-2 and 6-3, the current estimates of GHG emissions from the 

nuclear fuel cycle are far below those for fossil-fuel-based energy sources. 

(2) PVNGS license renewal will involve continued GHG emissions due to uranium mining, 

processing, and enrichment but will not result in increased GHG emissions associated 

with plant construction or decommissioning (as the plant will have to be decommissioned 

at some point whether the license is renewed or not). 

(3) Few studies predict that nuclear fuel cycle emissions will exceed those of fossil fuels 

within a timeframe that includes the PVNGS period of extended operation. Several 

studies suggest that future extraction and enrichment methods, the potential for higher 

grade resource discovery, and technology improvements could extend this timeframe. 

In comparing GHG emissions among the proposed PVNGS license renewal action and 

renewable energy sources, it appears likely that there will be future technology improvements 

and changes in mining, processing, and constructing facilities of all types. Currently, the GHG 

emissions associated with the nuclear fuel cycle and renewable energy sources are within the 

same order of magnitude. Because nuclear fuel production is the most significant contributor to 

possible future increases in GHG emissions from nuclear power and because most renewable 

energy sources lack a fuel component, it is likely that GHG emissions from renewable energy 

sources would be lower than those associated with PVNGS at some point during the period of 

extended operation. 

The staff provides an additional discussion about the contribution of GHGs to cumulative air 

quality impacts in Section 4.11.5 of this document. 
Environmental Impacts of the Uranium Fuel Cycle

December 2010 6-9 NUREG-1437, Supplement 43

6.3 REFERENCES 

10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

Protection Regulations for Domestic Licensing and Related Regulatory Functions.” 

AEA Technology (AEA). 2006. “Carbon Footprint of the Nuclear Fuel Cycle, Briefing Note,” 

Prepared for British Energy, March 2006. 

Andseta et al. 1998. “CANDU Reactors and Greenhouse Gas Emissions,” Canadian Nuclear 

Association, 11th Pacific Basin Nuclear Conference, Banff, Alberta, Canada, May 1998. 

Arizona Public Service Company (APS). 2008a. Palo Verde Nuclear Generating Station, Units 

1, 2, and 3, Applicant’s Environmental Report, License Renewal Operating Stage. ADAMS No. 

ML083510615, Appendix E. 

Dones, R. 2007. “Critical Note on the Estimation by Storm Van Leeuwen J.W., and Smith P. of 

the Energy Uses and Corresponding CO2 Emissions for the Complete Nuclear Energy Chain,” 

Paul Sherer Institute, April 2007. 

Fritsche, U.R. 2006. “Comparison of Greenhouse-Gas Emissions and Abatement Cost of 

Nuclear and Alternative Energy Options from a Life-Cycle Perspective,” Oko-Institut, Darmstadt 

Office, January 2006. 

Fthenakis, V.M. and H.C. Kim. 2007. “Greenhouse-gas emissions from solar-electric and 

nuclear power: A life cycle study,” Energy Policy, Volume 35, Number 4. 

Hagen, R.E., J.R. Moens, and Z.D. Nikodem. 2001. “Impact of U.S. Nuclear Generation on 

Greenhouse Gas Emissions.” International Atomic Energy Agency, Vienna, Austria. November 

2001. 

International Atomic Energy Agency (IAEA). 2000. “Nuclear Power for Greenhouse Gas 

Mitigation under the Kyoto Protocol: The Clean Development Mechanism (CDM),” November 

2000. 

Keepin, B. 1988. “Greenhouse Warming: Efficient Solution of Nuclear Nemesis?” Rocky 

Mountain Institute. Joint Hearing on Technologies for Remediating Global Warming, 

Subcommittee on Natural Resources, Agriculture Research and Environment and 

Subcommittee on Science, Research and Technology, United States House of Representatives. 

June 1988. 

Massachusetts Institute of Technology (MIT). 2003. “The Future of Nuclear Power: An 

Interdisciplinary MIT Study.” 

Mortimer, N. 1990. “World Warms to Nuclear Power,” SCRAM Safe Energy Journal, December 

1989 and January 1990. Available URL: 

http://www.no2nuclearpower.org.uk/articles/mortimer_se74.php (accessed July 15, 2010). 

Organization for Economic Co-Operation and Development, Nuclear Energy Agency (NEA). 

2002. Nuclear Energy and the Kyoto Protocol. 

Parliamentary Office of Science and Technology (POST). 2006. “Carbon Footprint of Electricity 

Generation,” Postnote, Number 268, October 2006. 

Schneider, M. 2000. Climate Change and Nuclear Power, World Wildlife Fund for Nature, April 

2000. 

Spadaro, J.V., L. Langlois, and B. Hamilton. 2000. “Greenhouse Gas Emissions of Electricity 

Generation Chains: Assessing the Difference,” IAEA Bulletin 42/2/2000, Vienna, Austria. 
Environmental Impacts of the Uranium Fuel Cycle 

NUREG-1437, Supplement 43 6-10 December 2010

Storm van Leeuwen, J.W. and P. Smith 2005. Nuclear Power—The Energy Balance, August 

2005. 

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants, NUREG-1437, Volumes 1 and 2, Washington, D.C, 

1996. ADAMS Accession Nos. ML040690705 and ML040690738. 

U.S. Nuclear Regulatory Commission (NRC). 1999. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants, Main Report, “Section 6.3 – Transportation, Table 9.1, 

Summary of Findings on NEPA Issues for License Renewal of Nuclear Power Plants, Final 

Report,” NUREG-1437, Volume 1, Addendum 1, Washington, D.C. ADAMS Accession No. 

ML040690720. 

Weisser, D. 2006. “A Guide to Life-Cycle Greenhouse Gas (GHG) Emissions from Electric 

Supply Technologies.” Available URL: 

http://www.iaea.org/OurWork/ST/NE/Pess/assets/GHG_manuscript_preprint_versionDanielWeisser.pdf (accessed May 19, 2009). 
December 2010 7-1 NUREG-1437, Supplement 43

7.0 ENVIRONMENTAL IMPACTS OF DECOMMISSIONING 

Environmental impacts from the activities associated with the decommissioning of any reactor 

before or at the end of an initial or renewed license are evaluated in the Generic Environmental 

Impact Statement on Decommissioning of Nuclear Facilities: Supplement 1, Regarding the 

Decommissioning of Nuclear Power Reactors, NUREG-0586, Supplement 1 (NRC 2002). The 

staff's evaluation of the environmental impacts of decommissioning presented in NUREG-0586, 

Supplement 1, identifies a range of impacts for each environmental issue. 

The incremental environmental impacts associated with decommissioning activities resulting 

from continued plant operation during the renewal term are discussed in the Generic 

Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437, 

Volumes 1 and 2 (NRC 1996; 1999). 

7.1 DECOMMISSIONING 

Category 1 issues in Table B-1 of Title 10 of the Code of Federal Regulations (CFR) Part 51, 

Subpart A, Appendix B that are applicable to Palo Verde Nuclear Generating Station (PVNGS) 

decommissioning following the renewal term are listed in Table 7-1. 

Table 7-1. Category 1 Issues Applicable to the Decommissioning of PVNGS Following 

the Renewal Term

ISSUE GEIS Section

Radiation doses 7.3.1 

Waste management 7.3.2 

Air quality 7.3.3 

Water quality 7.3.4 

Ecological resources 7.3.5 

Socioeconomic impacts 7.3.7 

A brief description of the staff’s generic review and the conclusions, as stated in Table B-1, 10 

CFR Part 51, for each of the issues follows: 

● Radiation doses. The GEIS concludes that: 

Doses to the public will be well below applicable regulatory standards regardless 

of which decommissioning method is used. Occupational doses would increase 

no more than 1 man-rem caused by buildup of long-lived radionuclides during the 

license renewal term. 

● Waste management. The GEIS concludes that: 

Decommissioning at the end of a 20-year license renewal period would generate 

no more solid wastes than at the end of the current license term. No increase in 

the quantities of Class C or greater than Class C wastes would be expected. 

● Air quality. The GEIS concludes that: 
Environmental Impacts of Decommissioning 

NUREG-1437, Supplement 43 7-2 December 2010

Air quality impacts of decommissioning are expected to be negligible either at the 

end of the current operating term or at the end of the license renewal term. 

● Water quality. The GEIS concludes that: 

The potential for significant water quality impacts from erosion or spills is no 

greater whether decommissioning occurs after a 20-year license renewal period 

or after the original 40-year operation period, and measures are readily available 

to avoid such impacts. 

● Ecological resources. The GEIS concludes that: 

Decommissioning after either the initial operating period or after a 20-year 

license renewal period is not expected to have any direct ecological impacts. 

● Socioeconomic Impacts. The GEIS concludes that: 

Decommissioning would have some short-term socioeconomic impacts. The 

impacts would not be increased by delaying decommissioning until the end of a 

20-year relicense period, but they might be decreased by population and 

economic growth. 

The NRC staff has not identified any new and significant information during the review of the 

Arizona Public Service Company (APS) environmental report (ER), the site audit, or the scoping 

process; therefore, there are no impacts related to these issues beyond those discussed in the 

GEIS (NRC 1996, 1999). For the issues listed in Table 7-1 above, the GEIS concluded that the 

impacts are SMALL. 

7.2 REFERENCES 

10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

Protection Regulations for Domestic Licensing and Related Regulatory Functions 

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants, NUREG-1437, Volumes 1 and 2, Washington, D.C. 

ADAMS Accession No. ML040690705 and ML040690738. 

U.S. Nuclear Regulatory Commission (NRC). 1999. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants, Main Report, “Section 6.3, Transportation, Table 9.1, 

Summary of Findings on NEPA Issues for License Renewal of Nuclear Power Plants, Final 

Report.” NUREG-1437, Volume 1, Addendum 1, Washington, D.C. 

U.S. Nuclear Regulatory Commission (NRC). 2002. Generic Environmental Impact Statement 

on Decommissioning of Nuclear Facilities: Supplement 1, “Regarding the Decommissioning of 

Nuclear Power Reactors.” NUREG-0586, Supplement 1, Volumes 1 and 2, Washington, D.C. 
December 2010 8-1 NUREG-1437, Supplement 43

8.0 ENVIRONMENTAL IMPACTS OF ALTERNATIVES 

The National Environmental Policy Act (NEPA) mandates that each environmental impact 

statement (EIS) consider alternatives to any proposed major federal action. NRC regulations 

implementing NEPA for license renewal require that a supplemental EIS “considers and weighs 

the environmental effects of the proposed action [license renewal]; the environmental impacts of 

alternatives to the proposed action; and alternatives available for reducing or avoiding adverse 

environmental effects,” (10 CFR 51.71d). In this case, the proposed Federal action is issuing 

renewed licenses for Palo Verde Nuclear Generating Station (PVNGS), which will allow the 

plant to operate for 20 years beyond the license expiration dates of its three reactors. In this 

chapter, the NRC staff examines the potential environmental impacts of alternatives to license 

renewal for PVNGS, as well as alternatives that may reduce or avoid adverse environmental 

impacts from license renewal, when and where these alternatives are applicable. 

While the Generic Environmental Impact Statement for License Renewal of Nuclear Plants, 

NUREG-1437 (GEIS; NRC 1996, 1999), reached generic conclusions regarding many 

environmental issues associated with license renewal, it did not determine which alternatives 

are reasonable or reach conclusions about site-specific environmental impact levels. As such, 

NRC staff must evaluate environmental impacts of alternatives on a site-specific basis. 

As stated in Chapter 1 of this document, alternatives to the proposed action of license renewal 

for PVNGS must meet the purpose and need for issuing a renewed license; they must 

“provide an option that allows for power generation capability beyond the term 

of a current nuclear power plant operating license to meet future system 

generating needs, as such needs may be determined by State, utility, and, 

where authorized, Federal (other than NRC) decisionmakers.” 

The NRC staff ultimately makes no decision as to which alternative (or the proposed action) to 

implement, since that decision falls to utility, State, or other Federal officials to decide. 

Comparing the environmental effects of these alternatives will assist the NRC in deciding 

whether the environmental impacts of license renewal are so great that preserving the option of 

license renewal for energy-planning decisionmakers would be unreasonable (10 CFR 

51.95(c)(4)). If the NRC acts to issue renewed licenses, all of the alternatives, including the 

proposed action, will be available to energy planning decisionmakers. If NRC decides not to 

renew the licenses (or takes no action at all), then energy planning decisionmakers may no 

longer elect to continue operating PVNGS and will have to resort to another alternative–which 

may or may not be one of the alternatives considered in this section–to meet the energy needs 

now being satisfied by PVNGS. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-2 December 2010

In evaluating alternatives to license renewal, the NRC staff 

first selects energy technologies or options currently in 

commercial operation as well as some technologies not 

currently in commercial operation but likely to be 

commercially available by the time the current PVNGS 

operating license expires. The current operating licenses 

for the three reactors at PVNGS will expire on December 

31, 2024, December 9, 2025, and March 25, 2027 and an 

alternative must be available (constructed, permitted, and 

connected to the grid), by the time those current PVNGS 

licenses expire. 

Secondly, the staff screens the alternatives to remove 

those that cannot meet future system needs by providing 

amounts of baseload power equivalent to PVNGS’s 

current generating capacity, including consideration of 

other options which, if pursued concurrently, might further 

reduce future system demands, and then screens the 

remaining options to remove those whose costs or benefits 

do not justify inclusion in the range of reasonable 

alternatives. Any alternatives remaining, then, constitute 

alternatives to the proposed action that NRC staff 

evaluates in-depth throughout this section. In Section 8.5, 

the NRC staff will briefly address each alternative that was 

removed during screening and provide the basis for its 

removal. 

NRC staff initially considered 19 discrete potential alternatives to the proposed action (see text 

box), and then narrowed the list to the three discrete alternatives and one combination 

alternative considered in Sections 8.1 through 8.4. 

For those technologies undergoing in-depth review, the generic environmental impact 

evaluations in the Generic Environmental Impact Statement (GEIS) published by NRC in 1996 

provides a basic overview of performance and impacts. The NRC staff then augments the 

information provided in the GEIS with additional evaluation incorporating unique site-specific 

factors that can influence the feasibility, performance, and environmental impacts of the 

technologies undergoing review. In addition, since 1996, many energy technologies have 

evolved significantly in capability and cost, while regulatory structures have changed to either 

promote or impede development of particular alternatives. 

As a result, the NRC staff’s analyses start with the GEIS and then include updated information 

from sources like the Energy Information Administration (EIA), other organizations within the 

Department of Energy (DOE), the US Environmental Protection Agency (EPA), industry sources 

and publications, and information submitted in the applicant’s Environmental Report (ER) (APS 

2008a). 

In 2007, electricity generation in Arizona involved the use of nuclear (23.6%), natural gas 

(33.9%), coal (36.4%), and renewable energy (5.8%) technologies (EIA 2009a, SWEEP 2009). 

Of the 113,392,528 MWh produced in 2007, 41,275,362 MWh were derived from coal, 

38,469,221 MWh came from combustion of natural gas, 26,782,391 MWh from nuclear, 

6,597,671 MWh from conventional hydroelectric, 125,411 MWh from other renewables, 49,276 

Alternatives Evaluated In-Depth: 

• Coal-fired (supercritical) 

• Natural Gas-fired 

Combined Cycle (NGCC) 

• New Nuclear 

• Combination 

Other Alternatives Considered: 

• Coal-fired IGCC 

• Wind power 

• Energy Conservation 

• Purchased power 

• Solar power 

- photovoltaic (PV) 

- concentrating solar power 

(CSP) 

• Wood-fired combustion 

• Conventional hydroelectric 

power 

• Wave and ocean energy 

• Geothermal power 

• Municipal solid waste 

• Biofuels 

• Methane 

• Oil-fired power 

• Fuel cells 

• Delayed retirement 
Environmental Impacts of Alternatives

December 2010 8-3 NUREG-1437, Supplement 43

MWh from combustion of petroleum distillate fuels, and 41,639 MWh were derived from pumped 

storage (EIA 2009a). The NRC staff believes that the mix of electricity generating technologies 

currently operating in Arizona is representative of the complexion of future power pools and 

therefore has determined that the technologies represented in the existing mix are examples of 

reasonable alternatives to the PVNGS reactors. 

Consequently, the in-depth alternatives that the staff considered include a supercritical steam 

pulverized coal-fired plant (section 8.1), a natural gas-fired combined-cycle power plant 

(Section 8.2), a new nuclear plant (section 8.3), and a reasonable combination of alternatives 

(Section 8.4), that includes some natural gas-fired capacity, energy conservation, and two 

concentrated solar power (CSP) facilities. In Section 8.5, the staff explains why it dismissed 

many other alternatives from in-depth consideration. Finally, in Section 8.6, the staff considers 

the environmental effects that may occur if NRC takes no action and does not issue a renewed 

license for PVNGS. 

For each in-depth analysis, the staff analyzed environmental impacts across seven impact 

categories: (1) air quality, (2) groundwater use and quality, (3) surface water use and quality, 

(4) ecology, (5) human health, (6) socioeconomics, and (7) waste management. As in earlier 

chapters of this SEIS, the staff used the NRC’s three-level standard of significance – SMALL, 

MODERATE, or LARGE – to indicate the intensity of environmental effects for each alternative 

undergoing in-depth evaluation. 

8.1 SUPERCRITICAL COAL-FIRED GENERATION 

The EIA reported that, in 2007, coal accounted for 48.5% of electricity generated nationwide 

(EIA 2009b). Natural gas, nuclear, and coal remain the three primary electricity generation 

technologies, with coal being the primary source of baseload electricity generation, generating 

2,016 million MWh of the total 4,157 million MWh produced nationwide in 2007. In Arizona, coal 

accounted for 36.4% of the 41,275,362 MWh of electricity generated in 2007 (EIA 2009a, 

SWEEP 2009). Coal-fired electricity generation is therefore a reasonable alternative. Units 

using pulverized coal and producing supercritical steam, known as Super Critical Pulverized 

Coal (SCPC) boilers, are the most likely variant among current-day coal-fired electricity 

generation technologies. 

Myriad sizes of pulverized coal boilers and steam turbine generators are available; however, the 

NRC staff recognizes that no single boiler/steam turbine generator (STG) combination could 

match the 4,020 MWe capacity of PVNGS reactors. Clearly, multiple units would be required. 

To complete this analysis, the NRC staff has elected not to specify the number or discrete sizes 

of the coal-fired units that could collectively serve as an alternative, but instead presumes that 

all units, regardless of size, would have the same features, operate at generally the same 

conditions, impact the environment in a manner proportional to their power capacity, and be 

equipped with the same pollution control devices, such that once all parasitic loads are 

overcome, the net power collectively available will be roughly equal to 4,020 MWe. 

The boilers comprising the supercritical coal-fired alternative are presumed to have the following 

characteristics and be equipped with the following pollution control devices: 

• Dual wall-fired, dry bottom boilers, configured to be NSPS-compliant 

• Overall thermal efficiency of 38% 

• Capacity factor of 85% 

• Collective nameplate rating of 4,020 MWe (net) 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-4 December 2010

• Supercritical steam 

• Powder River Basin Coal; caloric value 8,820 Btu/lb, ash 6.44%, sulfur 0.48%, 

pulverized to >70% passing a 200-mesh sieve 

• Fabric filter for particulate control, operating at 99% efficiency, 

• Wet calcium carbonate sulfur dioxide (SO2) scrubber operating at 95% efficiency 

• Low-NOx burners with overfire air and selective catalytic reduction for nitrogen oxide 

controls capable of attaining nitrogen oxides (NOx) removal of 86% [an emission rate 

≤ 2.5 ppmv (dry basis)] 

Current regulations would require that these coal-fired generating units be fitted with pollution 

control equipment to control particulates, sulfur oxide and nitrogen oxide pollutant emissions; 

future regulations may also require such plants to be outfitted with equipment to control 

hazardous air pollutants (especially mercury) and to capture and sequester carbon dioxide 

(CO2). All such pollution controls will impose parasitic loads such that the net electric power 

available will be reduced from nameplate values. However, because the required performance 

of a given pollution control device is dependent on the nature of the coal being burned (and the 

nature and amounts of pollutants generated and their required levels of control) and because 

some of the regulations that may require pollution controls in the future have not yet been 

promulgated in final form, it is difficult to anticipate and quantify parasitic loads with any 

precision for incorporation into any evaluation of coal-fired alternatives. Despite what is 

expected to be an increased environmental regulatory burden for coal plants built in the future, 

the NRC staff still agrees with the EIA projection that 

coal will continue to be a primary source of baseload 

power through 2030 (EIA 2009b). Further, because 

the NRC staff is not aware of any pending 

developments that would significantly change the 

complexion of electricity generating technologies in 

Arizona over the period of the PVNGS license 

extensions, it is reasonable to conclude that coalfired generation is a likely alternative. 

In the ER, PVNGS suggests that sufficient space 

exists on the current PVNGS plant site to 

accommodate coal-fired alternatives with net 

generating capacity roughly equivalent to the PVNGS 

reactors. Locating an alternative generating 

technology on the existing PVNGS site would 

minimize overall environmental impacts since much 

of the infrastructure now in place to support operation 

of the reactors could be redeployed with minimal 

modification to support a coal-fired alternative. The 

NRC staff concurs in that assessment and therefore 

presumes that to be the case for analysis of the 

impacts of the coal-fired alternative. Cooling 

systems, electrical substations and switchyards, and 

transportation facilities (including rail) are among the 

existing critical infrastructures on the PVNGS site 

that would be utilized to support an on-site, coal-fired 

alternative. 

It is reasonable to assume that a coal-fired 

Supercritical Steam 

 Supercritical refers to the thermodynamic 

properties of the steam being produced. 

Steam whose temperature and pressure 

is below water’s “critical point’ 

(3,200 pounds per square inch absolute 

[psia] and 705 °F) is subcritical. 

Subcritical steam forms as water boils 

and both liquid and gas phases are 

observable in the steam. The majority of 

coal boilers currently operating in the 

U.S. produce subcritical steam with 

pressures around 2,400 psia and 

temperatures as high as 1,050 °F. 

Above the critical point pressure, water 

expands rather than boils and the liquid 

and gaseous phases of water are 

indistinguishable in the supercritical 

steam that results. More than 150 coal 

boilers currently operating in the U.S. 

produce supercritical steam with 

pressure between 3,300 and 3,500 psia 

and temperatures between 1,000 and 

1,100 °F. Ultrasupercritical boilers 

produce steam at pressures above 

3,600 psia and temperatures exeeding 

1,100 °F. There are only a few of these 

boilers in operation worldwide, and none 

in the U.S. 
Environmental Impacts of Alternatives

December 2010 8-5 NUREG-1437, Supplement 43

alternative would utilize supercritical steam (see text box). Supercritical steam technologies are 

increasingly common in new coal-fired plants. Supercritical plants operate at higher 

temperatures and pressures than most older subcritical coal-fired plants and therefore can 

attain higher thermal efficiencies. While supercritical facilities are more expensive to construct, 

they consume less fuel for a given output, reducing environmental impacts throughout the fuel 

life cycle. Based on technology forecasts from EIA, the NRC staff expects that a new, 

supercritical, coal-fired plant beginning operation in 2014 would operate at a heat rate of 

9,069 British thermal units/kilowatt hour (Btu/kWh, or approximately 38-39% thermal efficiency 

(EIA 2009c). However, heat inputs could be less, depending on the coal source and whether 

fuel blending is practiced in order to remain compliant with emission limitations. 

In a supercritical, coal-fired power plant, burning coal heats pressurized water. As the 

supercritical steam/water mixture moves through plant pipes to a turbine generator, the 

pressure drops, and the mixture flashes to steam. The heated steam expands across the 

turbine stages, which then spin and turn the generator to produce electricity. After passing 

through the turbine, any remaining steam is condensed back to water in the plant’s condenser. 

In most modern U.S. facilities, condenser cooling water circulates through cooling towers or a 

cooling pond system (either of which are closed-cycle cooling systems9

). Older power plants 

often withdraw cooling water directly from existing rivers or lakes and discharge heated water 

directly to the same body of water (called open-cycle cooling). However, adequately sized 

surface water bodies are not present in the vicinity of PVNGS and such open-cycle cooling is 

not possible at PVNGS. Instead, redeployment of the current closed-cycle cooling system using 

grey water from local municipalities is the most likely option for cooling. Because nuclear plants 

require more cooling capacity than comparably-sized, coal-fired plants, the existing cooling 

towers are expected to be adequate to support a coal-fired alternative without significant 

amendment or expansion. 

Various coal sources exist in northeast Arizona and in the nearby states of New Mexico and 

Colorado, with over 75% of that total comprised of the sub-bituminous rank. The largest 

western coal deposits exist within the Powder River Basin (PRB) in Wyoming and Montana. For 

the purpose of this analysis, the NRC staff presumes that sub-bituminous Powder River Basin 

coal will be used because of its relatively high BTU content (among sub-bituminous western 

coals) (8,820 Btu/lb), and low ash (6.44%, as received) and sulfur (0.48%, as received) contents 

(Stricker and Ellis 1999). 

Future environmental regulations may also require utility scale coal-fired units capable of 

emitting over 250 tons per year of CO2 to be equipped with various devices capable of removing 

CO2 at efficiency as high as 88% (NETL 2007). While such levels of removal are technically 

feasible, they occur with substantial performance penalties. Because regulations requiring CO2

control are not now in place, specific control strategies cannot be proposed and the 

assessment, therefore, disregards the impacts of CO2 removal requirements on net power 

availability. (However, some projected impacts are nevertheless provided in the discussion 

regarding climate change impacts and greenhouse gas (GHG) emissions.) 

 

9 Although they are known as “closed-cycle cooling systems,” both mechanical and natural draft cooling 

towers and all cooling ponds lose a small amount of water to evaporation during operation. The water 

that evaporates takes heat away from the remaining water in the system, thus lowering its 

temperature. The water lost to evaporation typically represents as much as 10 to 15% of the system 

volume and must be continuously replaced. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-6 December 2010

The overall environmental impacts of a coal-fired alternative as well as the current 

environmental impacts of the PVNGS reactors are shown in Table 8-1. Additional details on the 

impacts on individual resources of the coal-fired alternative are provided in subsequent 

sections. 

Table 8-1. Summary of Environmental Impacts of the Supercritical Coal-Fired Alternative 

Compared to Continued Operation of PVNGS 

Supercritical Coal-Fired 

Generation 

Continued PVNGS Operation 

Air Quality MODERATE SMALL 

Groundwater SMALL SMALL 

Surface Water SMALL SMALL 

Aquatic and Terrestrial 

Resources 

SMALL SMALL 

Human Health SMALL SMALL 

Socioeconomics SMALL to MODERATE SMALL 

Waste Management MODERATE SMALL 

8.1.1 Air Quality 

Air quality impacts from coal-fired generation can be substantial, resulting from the emissions of 

significant quantities of sulfur oxides (SOx), nitrogen oxides (NOx), particulates, carbon 

monoxide (CO), and hazardous air pollutants such as mercury. Coal combustion is also a major 

source of the GHG gas, CO2.

10 However, many of these pollutants can be effectively controlled 

by various technologies, albeit with performance penalties that result in reductions in net power 

generating capacity. 

PVNGS is located in Maricopa County, Arizona. A portion of Maricopa County that includes 

PVNGS is designated as non-attainment for 8-hour ozone.11 Another portion of Maricopa 

County (not including PVNGS), together with the adjacent Pinal County, is designated nonattainment for particulate (PM10) and a portion (not including PVNGS) is designated as CO 

maintenance. A new coal-fired generating plant would qualify as a new major source of criteria 

 

10 Depending on the coal source and boiler firing conditions, many other pollutants can be emitted, 

including acid gases such as hydrogen chloride, various heavy metals besides mercury, a wide array 

of organic compounds, and various greenhouses gases beside CO2. However, because the chemical 

composition of a particular coal source and specific firing conditions cannot be guaranteed with 

certainty, this assessment does not extend to estimating the amounts of those other pollutants. 

Emission estimates of CO2 appearing later are based on average CO2 emission factors of the 

presumed coal source (PRB) and no carbon capture or removal capabilities in place. 

11 Areas considered to have air quality as good as or better than National Ambient Air Quality Standards 

(NAAQS) are designated by EPA as “attainment areas”. Areas where air quality is worse than NAAQS 

are designated by EPA as “nonattainment areas.” Areas that previously were nonattainment areas but 

where air quality has since improved to meet the NAAQS are redesignated “maintenance areas” and 

are subject to an air quality maintenance plan. 
Environmental Impacts of Alternatives

December 2010 8-7 NUREG-1437, Supplement 43

pollutants because of its potential to emit (PTE) more than 100 tons/year. It would be subject to 

Prevention of Significant Deterioration of Air Quality Review under requirements of the Clean Air 

Act (CAA), and Arizona state regulations. It would also need to comply with the New Source 

Performance Standards (NSPS) for coal-fired plants set forth in 40 CFR 60 Subpart D. The 

standards establish limits for particulate matter and opacity (40 CFR 60.42(a)), SO2 (40 CFR 

60.43(a)), and NOx (40 CFR 60.44(a)). Maricopa County Health Department adopts the EPA's 

regulations regarding pollutant emission limits. 

Section 169A of the CAA (42 USC 7401) establishes a national goal of preventing future, and 

remedying existing, impairment of visibility in mandatory Class I Federal areas when impairment 

results from man-made air pollution. The Regional Haze Rule, promulgated by EPA in 1999 

and last amended in October 2006 (71 FR 60631) requires states to demonstrate reasonable 

progress towards the national visibility goal established in 1977. Together with the states of 

Utah, New Mexico and Wyoming, and the City of Albuquerque, NM, Arizona participated in the 

development of a Regional Haze Plan, as required by Section 309 of the rule. The Arizona 

Department of Environmental Quality (ADEQ) published the State’s Regional Haze 

Implementation Plan on December 23, 2003 (ADEQ, 2003). A revision was published in 

December 2004 (ADEQ, 2004) 

The visibility protection regulatory requirements, contained in 40 CFR Part 51, Subpart P, 

include the review of the new sources that would be constructed in the attainment or 

unclassified areas and may affect visibility in any Federal Class I area 

(40 CFR Part 51, Subpart P, §51.307). Under the State’s plan, coal-fired electric generating 

units with the potential to emit more than 250 tons/year of SO2, NOx and particulate matter 

would be evaluated for their potential to affect visibility in Class I areas and, if found to be 

potentially responsible for Class I visibility impacts, would be required to control emissions of 

those pollutants to the extent necessary to prevent visibility deterioration. There are 12 

Mandatory Class I Federal areas in the state of Arizona, four of which—Grand Canyon National 

Park, Sycamore Canyon Wilderness Area, Petrified Forest National Park and the Mount Baldy 

Wilderness Area—are specifically addressed in the Regional Haze State Implementation Plan 

because their location suggests potential visibility impairment from human activities. None of 

the Class I areas in Arizona or in surrounding states is located within 62 miles (100 km) of 

PVNGS, so it is unlikely that additional Regional Haze-specific emission controls would be 

imposed on an alternative coal-fired unit constructed at PVNGS. 

Arizona stationary sources of criteria pollutants are also subject to the Clean Air Interstate Rule 

(CAIR), which has outlined emissions reduction goals for both SO2 and NOx for the year 2015; 

however, the rule was vacated by the D.C. Circuit court on February 8, 2008. In December 

2008, the U.S. Court of Appeals for the D.C. Circuit reinstated the rule, but required EPA to 

revise both the rule and its implementation plan. CAIR would require Arizona major sources to 

reduce SO2 emissions by 7,000 tons (or 5 percent), and NOx emissions by 37,000 tons (or 

49%) (EPA 2008b). 

In response to the Consolidated Appropriations Action of 2008 (Public Law 110-161), EPA 

promulgated final mandatory GHG gas reporting regulations on October 30, 2009, that became 

effective in December 2009 (EPA 2009c) The rules are applicable to major sources of CO2, 

defined as those emitting more than 25,000 tons/year. New utility-scale coal-fired power plants 

would be subject to those regulations. The GHG gases covered by the final rule are CO2, 

methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFC), perfluorocarbons (PFC), sulfur 

hexafluoride (SF6), and other fluorinated gases including nitrogen trifluoride (NF3) and 

hydrofluorinated ethers (HFE). Future regulations may require control of CO2 emissions (i.e., 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-8 December 2010

carbon capture and sequestration (CCS)). 

8.1.1.1 Sulfur Oxides 

The coal-fired alternative at the PVNGS site would likely use wet, limestone-based scrubbers to 

remove SO2. The National Energy Technology Laboratory (NETL) indicates that this technology 

can remove 95 to 98% of SO2 from flue gases (NETL 2007). SO2 emissions from a new coalfired power plant would be subject to the requirements of Title IV of the CAA. Title IV was 

enacted to reduce emissions of SO2 and NOx, the two principal precursors of acid rain, by 

restricting emissions of these pollutants from power plants. Title IV caps aggregate annual 

power plant SO2 emissions and imposes controls on SO2 emissions through a system of 

marketable allowances. EPA issues one allowance for each ton of SO2 that a unit is allowed to 

emit. New units do not receive allowances, but are required to have secured allowances (or 

offsets) from existing sources to cover their SO2 emissions. Owners of new units must therefore 

purchase allowances from owners of other power plants or reduce SO2 emissions at other 

power plants they own. Allowances can be banked for use in future years. Thus, provided a 

new coal-fired power plant is able to purchase sufficient allowances to operate, it would not add 

to net regional SO2 emissions, although it might do so locally. 

8.1.1.2 Nitrogen Oxides 

A coal-fired alternative at the PVNGS site would most likely employ various available NOx

control technologies, which can be grouped into two main categories: combustion modifications 

and post-combustion processes. Combustion modifications include low-NOx burners, over fire 

air, and operational modifications. Post-combustion processes include selective catalytic 

reduction and selective non-catalytic reduction. An effective combination of the combustion 

modifications and post-combustion processes allow the reduction of NOx emissions by up to 95 

percent (EPA 1998). As discussed above, the most likely NOx control would involve a 

combination of low-NOx burners and selective catalytic reduction technologies in order to reduce 

NOx emissions from this alternative. 

Section 407 of the CAA establishes technology-based emission limitations for NOx emissions. 

A new coal-fired power plant would be subject to the new source performance standards for 

such plants as indicated in 40 CFR 60 44a(d)(1). This regulation, issued on September 16, 

1998 (63 FR 49453), limits the discharge of any gases that contain NOx to 200 nanograms (ng) 

of NOx per joule (J) of gross energy output (equivalent to 1.6 lb/MWh), based on a 30-day rolling 

average. 

8.1.1.3 Particulates 

The new coal-fired power plant would use fabric filters to remove particulates from flue gases 

with an expected 99% removal efficiency (NETL 2007). When present, wet SO2 scrubbers 

further reduce particulate matter emissions (EPA 2008a). Coal-handling equipment would 

introduce fugitive dust emissions when fuel is being transferred to on-site storage and then 

reclaimed from storage for use in the plant. During the construction of a coal-fired plant, on-site 

activities would also generate fugitive dust. Vehicles and motorized equipment would create 

exhaust emissions during the construction process. These impacts would be intermittent and 

short-lived, however, and, to minimize dust generation, construction crews would use applicable 

dust-control measures. 
Environmental Impacts of Alternatives

December 2010 8-9 NUREG-1437, Supplement 43

8.1.1.4 Carbon Monoxide 

Based on firing conditions and the boiler’s overall firing efficiency, SCPC boilers will emit carbon 

monoxide (CO) in limited quantities. Emission limits for CO will be based on heat input and 

typically expressed as pounds per million Btu input. 

8.1.1.5 Hazardous Air Pollutants 

Consistent with the D.C. Circuit Court’s February 8, 2008, ruling that vacated its Clean Air 

Mercury Rule (CAMR), EPA is in the process of developing mercury emissions standards for 

power plants under the CAA (Section 112) (EPA 2009a). Before CAMR, EPA determined that 

coal- and oil-fired electric utility steam-generating units are significant emitters of the following 

hazardous air pollutants (HAPs): arsenic, beryllium, cadmium, chromium, dioxins, hydrogen 

chloride, hydrogen fluoride, lead, manganese, and mercury (EPA 2000b). EPA concluded that 

mercury is the HAP of greatest concern and that (1) a link exists between coal combustion and 

mercury emissions, (2) electric utility steam-generating units are the largest domestic source of 

mercury emissions, and (3) certain segments of the U.S. population (e.g., the developing fetus 

and subsistence fish-eating populations) are believed to be at potential risk of adverse health 

effects resulting from mercury exposures caused by the consumption of contaminated fish (EPA 

2000b). On February 6, 2009, the Supreme Court denied the EPA’s request to review the 2008 

Circuit Court’s decision, and also denied a similar request by the Utility Air Regulatory Group 

later that month (EPA 2009a).

8.1.1.6 Carbon Dioxide 

A coal-fired plant would also have currently unregulated carbon dioxide (CO2) emissions during 

operations as well as during mining, processing, and transportation, which the GEIS indicates 

could contribute to global warming and connected climate changes. The amount of CO2

released per unit of power produced would be dependent on the quality of the fuel and the firing 

conditions and overall firing efficiency of the boiler. Sub-bituminous coal from the Powder River 

Basin has an average CO2 emission factor of 212.7 lb/million Btu of heat input (Hong and Slatik 

1994). See Section 8.1.8 below for additional discussions regarding climate-related impacts of 

a coal-fired alternative. 

8.1.1.7 Estimated Quantities of Pollutants Emitted 

Although the NRC staff has identified the primary features and operating parameters of the 

supercritical pulverized coal boiler represented in this coal-fired alternative, many more aspects 

of system design, boiler firing conditions, and operating procedures can influence the amount of 

criteria pollutants ultimately released to the environment. Consequently, the quantifications of 

pollutant emissions appearing below should be considered only as estimates. Algorithms and 

emission coefficients developed by EPA (EPA 1998) were used to estimate the amounts of 

pollutants that would result from operation of the coal-fired alternative. With a collective net 

generating capacity of 4020 MWe, the coal-fired alternative, operating at a capacity factor of 

85% would produce 29,932,920 MWh of electricity per year or nearly 30 million MWh.12 With an 

overall power plant thermal efficiency of 39% and an average caloric value of PRB coal of 

 

12 For comparison, the total amount of electricity sold at retail in Arizona in 2007 was 77,193,206 MWh 

(EIA 2009e). Therefore, operating at an average capacity factor of 85%, PVNGS reactors would have 

accounted for 38.8% of retail electricity sales in the state in 2007. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-10 December 2010

8,820 Btu/lb, the amount of coal consumed annually will be approximately 

29,900 million pounds or (15.0 million T/yr) (13.6 million metric T/yr). 

Applying EPA emission factors and reasonable control equipment efficiencies, the resulting 

estimated annual pollutant releases are shown in Table 8-2. 

Table 8-2. Estimated Emissions of Criteria Pollutants and Carbon Dioxide from the 

Coal-Fired Alternative 

Pollutant Lb/yr (T/yr) 

Uncontrolled 

Tons/yr (MT/yr) 

Emitted 

Notes 

SO2 249.5 million

(124,739) 

6,237 

(5,658) 

Assumes 95% efficient limestone 

scrubber. 

Emission Factor: 35(% sulfur) lb/Ton of 

coal 

NOx 109.9 million

(54,944) 

7,692 

(6,978) 

Assumes 86% efficient pre- and postcombustion NOx controls. 

Emission Factor: 7.4 lb/Ton of coal 

CO 7.43 million

(3,712) 

3,712 

(3,368) 

Assumes typical NSPS-compliant firing 

conditions. 

Emission Factor: 0.5 lb/Ton of coal 

Particulates 

(filterable PM10) 

956.3 million

(478,165) 

4,782 

(4,338) 

Assumes 99% efficient fabric filter 

control device. 

Emission Factor: 

10(% ash) lb/Ton of coal 

CO2 55,700 million

(27.9 million) 

27.85 million Tons/yr 

(25.27 million MT/yr) 

Assumes 95% conversion of carbon in 

coal. 

Emission Factor: 212.7 lb/MMBtu (for 

subbituminous coal from Wyoming) 

(Hong and Slatik, 1994). 

Value represents uncontrolled 

emissions of CO2, i.e., no CCS. 

8.1.1.8 Summary of Air Quality 

While the GElS analysis mentions global warming from unregulated CO2 emissions and acid 

rain from SO2 and NOx emissions as potential impacts, it does not quantify emissions from coalfired power plants. However, the GElS analysis does imply that air impacts would be 

substantial (NRC 1996). The above analysis shows that emissions of air pollutants, including 

SOx, NOx, CO, and particulates, exceed those produced by the existing nuclear power plant 

plant (provided in Table 2.2.2-1 of this document), as well as those of the other alternatives 

considered in this section. Operational emissions of CO2 are also much greater under the coalfired alternative. Adverse human health effects such as cancer and emphysema have also 

been associated with air emissions from coal combustion and are discussed further in Section 

8.1.5. 

The NRC analysis for a coal-fired alternative at the PVNGS site indicates that impacts from the 

coal-fired alternative would have clearly noticeable effects, but given existing regulatory 

regimes, permit requirements, and emissions controls, the coal-fired alternative would not 

destabilize air quality. Therefore, the appropriate characterization of air impacts from a coalfired plant located at PVNGS would be MODERATE. Existing ambient air quality would dictate 
Environmental Impacts of Alternatives

December 2010 8-11 NUREG-1437, Supplement 43

the installation of pollution control equipment to meet applicable local requirements and permit 

conditions and may eventually require participation in emissions trading schemes. 

8.1.2 Groundwater Use and Quality 

Impacts to groundwater from the coal-fired alternative would be minimal. Except for potable 

uses, groundwater resources would not be utilized to support operation of the coal-fired plant. 

Total usage for potable purposes would likely be less under the coal-fired alternative than for 

continued PVNGS operation because of a smaller operating workforce. No effect on 

groundwater quality would be apparent. 

Construction of a coal-fired plant may have a limited and minor impact on groundwater due to 

changes to surface drainage patterns during construction and thereafter. The impact to 

groundwater of the coal-fired alternative would be SMALL. 

8.1.3 Surface Water Use and Quality 

Minor impacts to surface water would occur during construction of the coal-fired alternative due 

to ground disturbances, alteration of natural drainage patterns and potential increases in 

sediment loadings in surface drainage. A site-wide storm water pollution prevention plan would 

be established for the construction period and would include controls and mitigations that would 

limit adverse impact to surface water quality. The elements of that plan would be incorporated 

into a General Stormwater Permit, enforceable under the NPDES program authority. The 

existing cooling infrastructure is expected to be redeployed to meet the heat rejection demands 

of the coal-fired alternative. That system currently relies on grey water obtained from nearby 

municipalities (primarily Phoenix). That arrangement is not expected to change and 

consequently, the impact to surface water quality during operation would be unchanged from 

the current conditions. The NRC staff therefore concludes that impacts to surface water quality 

would be SMALL. 

8.1.4 Aquatic and Terrestrial Ecology 

8.1.4.1 Aquatic Ecology 

Because no surface water bodies are expected to be involved in supporting the operation of the 

coal-fired alternative, no impacts to aquatic resources are expected; therefore the overall 

impacts to aquatic resources would be SMALL. 

8.1.4.2 Terrestrial Ecology 

On-site and offsite land disturbances form the basis for impacts to terrestrial ecology. Because 

the coal-fired alternative would be built on the PVNGS site, most of the land area involved will 

have been previously disturbed and currently exists in industrial uses. Thus, terrestrial ecology 

impacts would have occurred largely during the initial construction of PVNGS. It is possible that 

some fallow lands on PVNGS would be used for the coal-fired alternative, and terrestrial 

ecosystems that have re-established on those lands would be impacted by construction and 

subsequent operation. Construction activities could destroy habitats and affect food supplies, 

especially for migrating birds. During operation, cooling towers could deposit chemically-treated 

water on surrounding land areas as drift. However, such impacts would be generally the same 

as those that are now occurring from the operation of PVNGS. It is further recognized that, 

because availability of water for cooling is limited at PVNGS, the cooling towers are expected to 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-12 December 2010

be operated in a manner that would minimize drift. 

Coal-mining operation will also affect terrestrial ecology in offsite coal mining areas, although 

some of the land is likely already disturbed by mining operations. 

Any on-site or offsite waste disposal by landfilling of coal combustion residues (CCR) will also 

affect terrestrial ecology at least through the period when the disposal area is reclaimed. 

Deposition of acid rain resulting from NOx or SOx emissions, as well as the deposition of other 

pollutants, can also affect terrestrial ecology. Given the emission controls discussed in 

Section 8.1.1, air deposition impacts may be noticeable, but are not likely to be destabilizing. 

Impacts to terrestrial resources from a coal-fired alternative would be SMALL. 

8.1.5 Human Health 

Coal-fired power plants introduce worker risks from coal and limestone mining, from coal and 

limestone transportation, and from disposal of coal combustion residues and scrubber wastes. 

In addition, there are public risks from inhalation of stack emissions (as addressed in 

Section 8.1.1) and the secondary effects of eating foods grown in areas subject to deposition 

from plant stacks. 

Human health risks of coal-fired power plants are described, in general, in Table 8-2 of the 

GEIS (NRC 1996). Cancer and emphysema as a result of the inhalation of toxins and 

particulates are identified as potential health risks to occupational workers and members of the 

public (NRC 1996). The human health risks of coal-fired power plants, both to occupational 

workers and to members of the public, are greater than those of the current PVNGS due to 

exposures to chemicals such as mercury; SOx; NOx; radioactive elements such as uranium and 

thorium contained in coal and coal ash; and polycyclic aromatic hydrocarbon (PAH) compounds, 

including benzo(a)pyrene. 

Regulations restricting emissions enforced by either EPA or delegated State agencies have 

reduced potential health effects but have not entirely eliminated them. These agencies also 

impose site-specific emission limits as needed to protect human health. Even if the coal-fired 

alternative were located in a nonattainment area, emission controls and trading or offset 

mechanisms could prevent further regional degradation; however, local effects could be visible. 

Many of the byproducts of coal combustion responsible for health effects are largely controlled, 

captured, or converted in modern power plants (as described in Section 8.1.1), although some 

level of health effects may remain. 

Aside from emission impacts, the coal-fired alternative introduces the risk of coal pile fires and 

for those plants that use coal combustion residue liquid and sludge waste impoundments, the 

release of the waste due to a failure of the impoundment. Good housekeeping practices to 

control coal dust greatly reduce the potential for coal dust explosions or coal pile fires. Although 

there have been several instances in recent years, sludge impoundment failures are still rare. 

Further, the lack of available space and topography make it unlikely that sludge impoundments 

would be used for long-term on-site storage or disposal of coal combustion residue liquids or 

scrubber sludge at PVNGS. Instead, it is reasonable to assume that free water will be 

recovered from such waste streams and recycled and the solid or semi-solid portions removed 

to permitted off-site disposal facilities. 
Environmental Impacts of Alternatives

December 2010 8-13 NUREG-1437, Supplement 43

Human health issues related to construction would be equivalent to those associated with the 

construction of any major complex industrial facility and would be controlled to acceptable levels 

through the application of best management practices and APS’s compliance with application 

Federal and State worker protection regulations. Both continuous and impulse noise impacts 

can be expected at off-site locations, including at the closest residences. However, confining 

noise-producing activities to core hours of the day (7:00 am to 6:00 pm), suspending the use of 

explosives during certain meteorological conditions, and notifying potentially-affected parties 

beforehand of such events will control noise impacts to acceptable levels. Noise impacts will be 

of short duration and will be SMALL. 

Overall, given extensive health-based regulation and controls likely to be imposed as permit 

conditions, the NRC staff expects human health impacts to be SMALL. 

8.1.6 Socioeconomics 

8.1.6.1 Land Use 

The GEIS generically evaluates the impacts of coal-fired power plant operations on land use 

both on and off a power plant site. The analysis of land use impacts focuses on the amount of 

land area that would be affected by the construction and operation of a new supercritical coalfired power plant on the PVNGS site. 

PVNGS indicated that approximately 628 acres (254 ha) of land would be needed to support a 

coal-fired alternative capable of replacing PVNGS (including 495 acres (200 ha) for on-site 

disposal of CCR and scrubber sludge that is not recycled). However, additional land would be 

required for coal and limestone storage and possibly coal cleaning or blending. Therefore, CCR 

and scrubber sludge disposal would more likely occur at off-site locations. 

Additional offsite land use impacts would occur from coal mining in addition to land use impacts 

from the construction and operation of the new power plant. However, most of the land in 

existing coal-mining areas has already experienced some level of disturbance. This would 

undoubtedly be the case if the primary source of coal were the PRB mines. The elimination of 

the need for uranium mining to supply fuel for the PVNGS would partially offset this offsite land 

use impact. Based on this information and the need for additional land, land use impacts could 

range from SMALL to MODERATE. 

8.1.6.2 Socioeconomics 

Socioeconomic impacts are defined in terms of changes to the demographic and economic 

characteristics and social conditions of a region. For example, the number of jobs created by 

the construction and operation of a new coal-fired power could affect regional employment, 

income, and expenditures. Two types of job creation result from this alternative: 

(1) construction-related jobs, and (2) operation-related jobs in support of power plant operations, 

which have the greater potential for permanent, long-term socioeconomic impacts. Workforce 

requirements for the construction and operation of a new coal-fired power plant were evaluated 

in order to measure their possible effect on current socioeconomic conditions. 

PVNGS projected that a peak construction workforce of 2,580 workers would be required to 

construct the coal-fired alternative at PVNGS. During construction, the communities 

surrounding the plant site would experience increased demand for rental housing and public 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-14 December 2010

services, with most such demands occurring in the Phoenix metropolitan area, approximately 

40 miles east of PVNGS. The relative economic contributions of construction workers to local 

business and tax revenues would vary over time, but would not likely have a noticeable effect in 

a metropolitan area as large as Phoenix. 

After construction, some local communities may be affected by the loss of construction jobs and 

associated loss in demand for business services. In addition, the rental housing market could 

experience increased vacancies and decreased prices. As noted in the GEIS, the 

socioeconomic impacts at a rural construction site could be larger than at an urban site, 

because the workforce would need to relocate closer to the construction site. Although the ER 

indicates that PVNGS is a rural site, it is located near the Phoenix metropolitan area where most 

of the socioeconomic impacts would be expected to occur. Therefore, these effects may be 

somewhat lessened because workers are likely to commute to the site from these areas instead 

of relocating closer to the construction site. Based on the site’s proximity to the Phoenix 

metropolitan area, construction impacts would be SMALL. 

Arizona Public Service Company (APS) estimated an operational workforce of 454 workers for 

the coal-fired alternative. The APS estimate appears reasonable and is consistent with trends 

calling for reduced workforces at power generating facilities. Operational impacts would 

therefore be SMALL. 

8.1.6.3 Transportation 

During construction, up to 2,580 workers would be commuting daily to the site, primarily from 

the Phoenix metropolitan area. In addition to commuting workers, trucks would transport 

construction materials and equipment to the worksite increasing the amount of traffic on local 

roads, while trains would transport some of the largest components to the plant site. The 

increase in vehicular traffic on roads would peak during shift changes resulting in temporary 

levels of service impacts and delays at intersections. Trains would likely be used to deliver 

large components to PVNGS given its existing rail spur. Although much of the commute from 

the Phoenix metropolitan area would be by Interstate highway, transportation impacts would 

likely be MODERATE during construction. 

Transportation traffic-related impacts would be greatly reduced after construction, but would not 

disappear during plant operations. The maximum number of plant operating personnel 

commuting to PVNGS would be approximately 454 workers. Frequent deliveries of coal and 

limestone by rail would add to the overall transportation impact by potentially causing frequent 

and lengthy delays at railroad crossings. Onsite coal storage would make it possible to receive 

several trains per day. Limestone delivered by rail could also add traffic-related impacts (though 

considerably less traffic than that generated by coal deliveries). The coal-fired alternative 

transportation impacts would range from SMALL to MODERATE during plant operations. 

8.1.6.4 Aesthetics 

The aesthetics impact analysis focuses on the degree of contrast between the coal-fired 

alternative and the surrounding landscape as well as the visibility of the coal plant. 

The supercritical coal-fired power plant would be up to 200 ft (61 m) tall with one or more 

exhaust stacks up to 500 ft (152 m). The facility would likely be visible off site during daylight 

hours. The coal-fired power plant would be taller than the current PVNGS reactor building, 

which stands at 140 ft (43 m) with a 328 ft (100 m) offgas stack. The mechanical draft towers 
Environmental Impacts of Alternatives

December 2010 8-15 NUREG-1437, Supplement 43

would also generate a condensate plume, which would be no more noticeable than the existing 

PVNGS plumes. The coal-fired alternative may only require the use of one cooling tower, thus 

minimizing the size of the plume. Noise from plant operations and coal delivery, as well as 

lighting on plant structures, may be detectable off site. 

Overall, aesthetic impacts associated with the supercritical coal-fired alternative would range 

from SMALL to MODERATE. 

8.1.6.5 Historic and Archeological Resources 

Cultural resources are the indications of human occupation and use of the landscape as defined 

and protected by a series of Federal laws, regulations, and guidelines. Prehistoric resources 

are physical remains of human activities that predate written records; they generally consist of 

artifacts that may alone or collectively yield information about the past. Historic resources 

consist of physical remains that postdate the emergence of written records; in the United States, 

they are architectural structures or districts, archaeological objects, and archaeological features 

dating from 1492 and later. Ordinarily, sites less than 50 years old are not considered historic, 

but exceptions can be made for such properties if they are of particular importance. American 

Indian resources are sites, areas, and materials important to American Indians for religious or 

heritage reasons. Such resources may include geographic features, plants, animals, 

cemeteries, battlefields, trails, and environmental features. The cultural resource analysis 

encompassed the power plant site and adjacent areas that could potentially be disturbed by the 

construction and operation of alternative power plants. 

The potential for impacts on historic and archaeological resources can vary greatly depending 

on the location of the proposed site. To consider a project's effects on historic and 

archaeological resources, any proposed areas would need to be surveyed to identify and record 

historic and archaeological resources, identify cultural resources (e.g., traditional cultural 

properties), and develop possible mitigation measures to address any adverse effects from 

ground disturbing activities. Studies would be needed for all areas of potential disturbance at 

the proposed plant site and along associated corridors where construction would occur (e.g., 

roads, transmission corridors, rail lines, or other right of ways (ROWs)). Areas with the greatest 

sensitivity should be avoided. Potential impacts to historic or archeological resources on land 

located off of PVNGS needed to support the construction and operation of an on-site coal-fired 

power plant could range from SMALL to MODERATE. 

For those portions of the coal-fired alternative that would be located on previously-disturbed 

lands within the currently-active industrial portion of PVNGS, the potential for adverse impacts 

to historic and archeological resources is low. Construction of the coal-fired alternative that 

extends to undisturbed portions of the PVNGS site could impact historic and archeological 

resources. However, PVNGS performed the necessary surveys in advance of construction to 

expand the cooling water impoundment infrastructure, and NRC therefore concludes that any 

such surveys required in connection with construction of the coal-fired alternative would also be 

completed in a timely manner. The NRC staff therefore further concludes that impacts to 

historic or archeological resources from pursuit of an on-site coal-fired alternative are likely to be 

SMALL. 

8.1.6.6 Environmental Justice 

The environmental justice impact analysis evaluates the potential for disproportionately high and 

adverse human health and environmental effects on minority and low-income populations that 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-16 December 2010

could result from the construction and operation of a new supercritical coal-fired power plant. 

Adverse health effects are measured in terms of the risk and rate of fatal or nonfatal adverse 

impacts on human health. Disproportionately high and adverse human health effects occur 

when the risk or rate of exposure to an environmental hazard for a minority or low-income 

population is significant and exceed the risk or exposure rate for the general population or for 

another appropriate comparison group. Disproportionately high environmental effects refer to 

impacts or risk of impact on the natural or physical environment in a minority or low-income 

community that are significant and appreciably exceeds the environmental impact on the larger 

community. Such effects may include biological, cultural, economic, or social impacts. Some of 

these potential effects have been identified in resource areas discussed in this document. For 

example, increased demand for rental housing during power plant construction could 

disproportionately affect low-income populations. Minority and low-income populations are 

subsets of the general public residing around PVNGS, and all are exposed to the same hazards 

generated from constructing and operating a new coal-fired power plant. 

Potential impacts to minority and low-income populations from the construction and operation of 

a new supercritical coal-fired power plant at PVNGS would mostly consist of environmental and 

socioeconomic effects (e.g., noise, dust, traffic, employment, and housing impacts). Noise and 

dust impacts from construction would be short-term and primarily limited to onsite activities. 

However, minority and low-income populations residing along site access roads could be 

affected by increased commuter vehicle traffic during shift changes. Increased demand for 

rental housing during construction in the vicinity of PVNGS could affect low-income populations. 

However, these effects would be short-term, limited to certain hours of the day, and therefore, 

not likely to be high and adverse. Given the close proximity to the Phoenix metropolitan area, 

most construction workers would commute to the site thereby reducing the potential demand for 

rental housing. 

Based on this information and the analysis of human health and environmental impacts 

presented in this document, the construction and operation of a new supercritical coal-fired 

power plant would not have disproportionately high and adverse human health and 

environmental effects on minority and low-income populations residing near PVNGS. 

8.1.7 Waste Management 

Coal combustion generates several waste streams including ash (a dry solid recovered from 

both pollution control devices (fly ash) and from the bottom of the boiler (bottom ash)) and 

sludge (a semi-solid by-product of emission control system operation, in this case, primarily 

calcium sulfate from the operation of the wet calcium carbonate SO2 scrubber). Combustion of 

14.85 million T/yr (13.47 million MT/yr) of PRB coal will result in substantial amounts of coal 

combustion residue (CCR, which includes both fly and bottom ash) recovered from the fabric 

filter and from the bottom of the boiler. Although recycling options may exist for some of the 

CCR in such applications as road sub-base, as an admixture in light-weight concrete products, 

or in embankment stabilization, much of the CCR will require disposal. Although EPA has not 

declared CCR as hazardous, it does contain hazardous constituents that may leach from 

improperly designed or operated disposal cells that may threaten surface or groundwater 

resources. Most sludge may be recycled for use in production of gypsum wallboard for the 

construction industry. However, temporary holding facilities as well as drying facilities may need 

to be constructed. Spent catalysts from NOx catalytic reduction would also be produced. 

Scrubber sludge and CCR may have beneficial uses, but, in the worst case, all solid wastes 

resulting from operation would require disposal.
Environmental Impacts of Alternatives

December 2010 8-17 NUREG-1437, Supplement 43

The coal-fired alternative would also include construction impacts such as vegetation removal, 

excavation, and preparing the site surface before other crews begin actual construction of the 

plant, as well as modifying existing infrastructure and constructing any additionally required 

infrastructure. Wastes typical of the construction of large industrial facilities will also be 

generated. Because this alternative would be constructed at the PVNGS site, it is not likely that 

new transmission lines or a new rail spur will be necessary. 

The NRC staff estimates that 956,331 tons of ash will be generated each year, approximately 

473,384 tons/year collected as bottom ash and 478,165 tons/year collected as fly ash in the 

fabric filter.13 PVNGS anticipates that as much as 90% of the captured ash can be recycled and 

be put to beneficial uses14, with the remainder requiring disposal.15 Because the recycle 

potential for CCR relies on both the physical properties of the ash and the leachability of any 

toxic constituents present, the NRC staff assumes a more conservative estimate of 50% 

recycled, with the remaining amount, 475,774 tons/yr, requiring disposal. Disposal of this 

amount of ash annually by landfilling over the expected 40-year lifetime of the coal-fired plants 

could noticeably affect land use and groundwater quality. Landfill locations would require 

proper siting in accordance with state solid waste regulations16 and leachate from the disposal 

cells would need to be monitored and possibly captured for treatment because of leaching of 

toxic components (including heavy metals) in the ash. The NRC staff has not determined the 

location of this ash disposal landfill, but presumes that insufficient area would be available on 

the PVNGS site. After closure of the waste site and revegetation, the land could be available for 

other uses. 

Combustion of 14.95 million T/yr of PRB coal with 0.48% sulfur will result in the generation of 

119,081 T/yr of SO2, 95% of which will be captured in the wet scrubber and converted to an 

equimolar amount of calcium sulfate or 253,030 T/yr (dry basis). The NRC staff presumes that 

as much as 90% of the scrubber sludge can be recycled for such applications as gypsum 

wallboards and that the remaining 25,303 T/yr can be co-disposed with the CCR that is not 

recycled. 

The NRC staff has not made an estimate of the amount of spent catalysts that will be produced, 

but presumes that the entire amount will have no recycling opportunities and will require 

disposal. Depending on the catalysts used, special handling may also be required to address 

the potential hazardous character of these spent catalysts. 

The impacts from waste generated during operation of this coal-fired alternative would be 

MODERATE to LARGE; the impacts would be clearly visible, but if properly managed the 

 

13 Some additional fly ash may also be captured in the SO2 scrubber downstream of the fabric filter. That 

amount has not been quantified, however. 14 Beneficial uses might include an admixture to lightweight concrete, road base, and road embankment 

stabilization. 

15 The American Coal Ash Association reported that 136,073,107 tons of coal combustion residues (fly 

ash, bottom ash, boiler slag, scrubber sludge, etc.) were produced nationwide in 2008. Of that 

amount, 60,593,660 tons were put to beneficial uses, reflecting a recycling (or utilization) rate of 

44.53% (ACAA 2009). 16 In May 2000, the EPA issued a “Notice of Regulatory Determination on Wastes from the Combustion 

of Fossil Fuels” (EPA 2000a) stating that it would issue regulations for disposal of coal combustion 

waste under Subtitle D of the Resource Conservation and Recovery Act. EPA has not yet issued 

these regulations. Until such rules are issued at the Federal level, State regulations concerning solid 

waste disposal are the primary controls. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-18 December 2010

wastes would not destabilize any important resource. The extent of the impacts of disposal will 

be dependent on the percentage of the CCR and scrubber sludge that can be recycled. 

The impacts from waste generated during construction stage would be short-lived. The amount 

of the construction waste is small compared to the amount of waste generated during 

operational stage and most could be recycled. Overall, the impacts from waste generated 

during construction stage would be SMALL. 

Therefore, NRC staff concludes that the overall impacts on wastes from construction and 

operation of this alternative would be MODERATE to LARGE.

8.1.8 Climate Change-Related Impacts of a Coal-Fired Alternative 

The largest anthropogenic source of CO2 emissions is the combustion of fossil fuels, including 

coal. After a thorough examination of the scientific evidence and careful consideration of public 

comments, the U.S. EPA announced on December 7, 2009, that greenhouse gases (GHGs) 

threaten the public health and welfare of the American people and fit the Clean Air Act definition 

of air pollutants. Climate change could have potential direct and indirect impacts on the 

operations of a coal-fired alternative to the PVNGS reactors. The construction and operation of 

the coal-fired alternative would emit greenhouse gases that likely contribute to climate change. 

Impacts to climate change from the construction of a coal-fired alternative would result primarily 

from the consumption of fossil fuels in reciprocating internal combustion engines (RICE) of 

construction vehicles and equipment, workforce vehicles used in commuting to and from the 

work site, and delivery vehicles. All such impacts would be temporary, however. Given the 

relatively small workforce and a relatively short construction period, the overall impact on 

climate change from the releases of GHGs during construction of a coal-fired alternative would 

be SMALL. 

In 2007, all Arizona electricity generation sources produced an estimated 97 million MT of CO2. 

Nationwide, 7,501 million MT were emitted from electricity generating sources (EPA 2009d). 

The NRC staff estimates that uncontrolled emissions of CO2, the primary GHG emitted during 

operation of the coal-fired alternative, would amount to 25.3 MMT/y. This amount represents 

0.34% and 26.1%, respectively of 2007 US and Arizona GHG emissions. Although coal 

combustion would be the primary source, other miscellaneous ancillary sources–as well as truck 

and rail deliveries of coal, limestone and other materials to the site and removals of CCR and 

other operational wastes to off-site disposal and/or recycling facilities–would also release 

GHGs. Precise quantification of GHG releases from these activities is difficult since neither the 

location of the coal source nor the locations of off-site disposal or recycling facilities is known at 

this time. Nevertheless, these activities are considered to be relatively minor sources of GHGs. 

The National Energy Technology Laboratory (NETL) estimates that technologies currently being 

perfected will capture and remove as much as 90% of the CO2 from the exhausts of supercritical 

pulverized coal-fired boilers. However, NETL anticipates that such equipment will impose a 

significant parasitic load that will result in a power production capacity decrease of 

approximately 0.8%, a reduction in overall thermal efficiency from 39.1% to 27.2% and a 

potential increase in the levelized cost of electricity produced in SCPC units so equipped by as 

much as 54.9% (NETL 2007). Further, permanent sequestering of the CO2 would involve 

removing impurities (including water) and pressurizing it to meet pipeline specifications and 

transferring the gas by pipeline to acceptable geologic formations. Even when opportunities 

exist to utilize the CO2 for enhanced oil recovery (rather than simply dispose of the CO2 in 
Environmental Impacts of Alternatives

December 2010 8-19 NUREG-1437, Supplement 43

geologic formations), permanent disposal costs could be substantial, especially if the SCPC 

units are far removed from acceptable geologic formations. With carbon capture and 

sequestration in place, the coal-fired alternative would release 2.53 MMT/yr. 

8.2 NATURAL GAS COMBINED-CYCLE GENERATION 

In this section, NRC evaluates the environmental impacts of natural gas-fired combined-cycle 

(NGCC) generation at the PVNGS site.

In 2007, natural gas was responsible for 33.9% of all electricity generation in Arizona, 

38,469,221 MWh of the statewide total of 113,392,528 MWh (EIA 2009a, SWEEP 2009). Like 

coal-fired power plants, natural gas-fired plants may be affected by future regulations that may 

limit greenhouse gas emissions. A gas-fired power plant, however, produces markedly fewer 

greenhouse gases per unit of electrical output than a coal-fired plant of the same electrical 

output. Natural gas-fired power plants are feasible, commercially-available options for providing 

electrical-generating capacity beyond PVNGS’s current license expiration. 

Combined-cycle power plants differ significantly from coal-fired and existing nuclear power 

plants. They derive the majority of their electrical output from a gas-turbine (a Brayton cycle 

combustion turbine/generator), without the production of steam and then generate additional 

power by recovering latent heat from gases exiting the combustion turbine (CT) and delivering it 

to a Heat Recovery Steam Generator (HRSG). The resulting steam subsequently drives a 

conventional Rankine cycle STG. Power resulting from this secondary cycle is completely 

pollution-free since it involves no fuel combustion. This “combined-cycle” approach provides 

significantly greater thermal efficiency than any single-cycle system, with efficiencies routinely 

attaining 60 percent (as compared to typical thermal efficiencies of coal-fired plants utilizing only 

Rankine cycle STGs of 39%) (Siemens 2007, NETL 2007). Since the natural-gas-fired 

alternative derives much of its power from a gas turbine cycle, and because it wastes less heat 

than either the coal-fired alternative or the existing PVNGS, it requires significantly less cooling. 

Typical power trains for large scale combined cycle power generation would involve one, two or 

three CTs operating simultaneously with the heat extracted from each directed to one HRSG 

(commonly known as a “1x1”, a “2x1” or a “3x1” configuration, respectively). CTs, HRSGs and 

STGs are all available in a variety of standard sizes. To complete the assessment of a NGCC 

alternative, the NRC staff presumes that appropriately sized CTs, HRSGs, and STGs could be 

assembled in appropriate multiple power train configurations to produce net electrical power 

virtually equivalent to the 4,020 MWe of the PVNGS reactors. The NRC staff further assumes 

that 75% of the net power produced (3015 MWe) comes from the operation of the CTs with the 

remainder (1,005 MWe) coming from operation of the HRSG-STG power trains. The CTs are 

presumed to each be of Advanced F-Class design, equipped with water or steam injection as a 

pre-combustion control to suppress NOx formation and selective catalytic reduction (SCR) of the 

CT exhaust with ammonia for post-combustion control of NOx emissions. The facility would 

burn natural gas meeting pipeline specifications, including: chemical composition (volume %): 

methane-93.9, ethane-3.2, propane-0.7, n-butane-0.4, CO2-1.0, and nitrogen-0.8; and a higher 

heating value (HHV) of 22,792 Btu/lb (1,040 Btu/standard cubic foot), a lower heating value 

(LHV) of 20,552 Btu/lb (939 Btu/scf), and an average HV of 1,020 Btu/scf. (Although EIA 

estimates average heating value of pipeline natural gas to be 1,049 Btu/scf (EIA 2009d), EPA 

emission factors used in estimating air impacts are based on an average HV of 1,020 Btu/scf). 

With the entire facility operating at a capacity factor of 85%, CT load factors greater than 80%, a 

thermal efficiency of 42% for the CTs, and an overall facility thermal efficiency of 60%, the 

NGCC facility will consume 178.9 Billion ft3

 (4.47 Billion m3) of natural gas to produce 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-20 December 2010

29,953,422 MWh of power annually. 

This gas-fired alternative would produce relatively little solid waste, primarily in the form of spent 

catalysts used for control of NOx emissions. The NRC staff presumes that the SCR technology 

employed would involve introducing ammonia into the exhaust ducts of the CTs where it 

combines with NOx in a nickel catalyst bed to form zero-valent nitrogen and water. Referring to 

data provided by the Institute of Clean Air Companies, EPA acknowledges that typical SCR 

devices can demonstrate removal efficiencies of between 70 and 90% (EPA 2000c). Because 

the NRC staff presumes that the NGCC alternative would use the existing PVNGS cooling 

system, cooling tower blowdown would still occur and waste resulting from the subsequent 

treatment of that blowdown and of incoming grey water would continue, but at diminished rates 

of generation. 

Environmental impacts from the gas-fired alternative will be greatest during construction. Site 

crews will clear vegetation from the site, prepare the site surface, and begin excavation before 

other crews begin actual construction on the plant and any associated infrastructure. A 

substantial natural gas pipeline infrastructure already exists within what is known as the Palo 

Verde Hub to support various power plants, including incidental activities at PVNGS, the 

1,100 MWe NGCC Harquahala Generating Station 17 miles northwest of PVNGS, the 

1,060 MWe NGCC Red Hawk Facility three miles south of PVNGS, the 1,250 MWe Mesquite 

Power Generating Station immediately west of the Red Hawk plant, and the 550 MWe Arlington 

Valley Energy Facility directly west of the Mesquite plant. The NGCC alternative would likely 

require modifications to the natural gas supply line to PVNGS, as well as major changes or 

capacity upgrades to the pipeline infrastructure serving the Palo Verde Hub, including the 

installation of one or more additional compressor stations to maintain adequate line pressures. 

Modifications to existing electricity transmission infrastructure and on-site cooling systems are 

not expected to be required. 

Environmental impacts from the NGCC alternative are summarized in Table 8-3. 

Table 8-3. Summary of Environmental Impacts of the Natural Gas Combined-Cycle 

Generation Alternative Compared to Continued Operation of PVNGS 

Natural Gas Combined-Cycle 

Generation 

Continued PVNGS Operation 

Air Quality SMALL SMALL 

Groundwater SMALL SMALL 

Surface Water SMALL SMALL 

Aquatic and Terrestrial 

Resources 

SMALL SMALL 

Human Health SMALL SMALL 

Socioeconomics SMALL SMALL 

Waste Management SMALL SMALL 

8.2.1 Air Quality 

Maricopa County, Arizona is currently a non-attainment area for 8-hour ozone. Portions of the 

county not including PVNGS are in non-attainment for particulate matter (PM10) and carbon 

monoxide. A new gas-fired 3,900 MWe (net) generating plant developed at the PVNGS site 

would qualify as a new major-emitting industrial facility and require a New Source Review 
Environmental Impacts of Alternatives

December 2010 8-21 NUREG-1437, Supplement 43

(NSR)/Prevention of Significant Deterioration of Air Quality review under CAA requirements, 

adopted by ADEQ and the Maricopa County Health Department. The natural gas-fired plant 

would need to comply with the standards of performance for stationary gas turbines set forth in 

40 CFR Part 60, Subpart GG. 

40 CFR Part 51, Subpart P contains the visibility protection regulatory requirements, including 

the review of the new sources that would be constructed in the attainment or unclassified areas 

and may affect visibility in any Federal Class I area (40 CFR Part 51, Subpart P, §51.307). If a 

gas-fired alternative were located close to a mandatory Class I area, additional air pollution 

control requirements would potentially apply. There are 12 Mandatory Class I Federal areas in 

the state of Arizona, but none within 50 miles of PVNGS, the closest being the Superstition 

Wilderness Area east of Phoenix. 

The NRC staff projects the following emissions for a gas-fired alternative based on data 

published by the EIA, EPA, and on performance guarantees by the manufacturer of the SCR for 

this alternative and its emissions controls: 

• Sulfur oxides (SOx) – 310 tons (281 MT) per year;17

• Nitrogen oxides (NOx) – 1,186 tons (1,076 MT) per year; 

• Carbon monoxide (CO) – 2,736 tons (2,483 MT) per year; 

• Particulate matter (PM) (PM10) – 602 tons (546 MT) per year; 

• Carbon dioxide (CO2) – 10,033,675 tons (9,102,550 MT) per year18. 

A new natural gas-fired plant would have to comply with Title IV of the CAA reduction 

requirements for SO2 and NOx, which are the main precursors of acid rain and the major cause 

of reduced visibility. Title IV establishes maximum SO2 and NOx emission rate from the existing 

plants and a system of the SO2 emission allowances that can be used, sold or saved for future 

use by new plants. 

8.2.1.1 Sulfur and Nitrogen Oxides 

As stated above, the new natural gas-fired alternative would produce 310 tons (281 MT) per 

year of SOx and 1,186 tons (1,076 MT) per year of NOx based on the use of the dry low NOx

combustion technology and use of the selective catalytic reduction (SCR) in order to 

significantly reduce NOx emissions. 

The new plant would be subjected to the continuous monitoring requirements of SO2, NOx and 

CO2 specified in 40 CFR Part 75. The natural gas-fired plant would emit approximately 

10.03 million tons (approximately 9.10 million MT) per year of (currently) unregulated CO2

emissions. In response to the Consolidated Appropriations Action of 2008 (Public Law 110-

161), EPA recently promulgated final mandatory greenhouse gas reporting regulations for major 

 

17 Approximately 99% of this total will be SO2, with the remainder being SO3. 18 Values represent uncontrolled CO2 emissions. Emission factor for CO2 released from the combustion 

of natural gas is 110 lb/MMBtu (EPA 1998), assuming a conversion of 95% of the carbon in the fuel. 

Note that in its calculations, EIA uses a value of 120.593 lb/1,000 ft3

 or 117.08 lb/MMBtu. (EIA 2009g). 

Combustion of natural gas also releases other greenhouse gases such as methane (CH4) and nitrous 

oxide (N2O) so that the total GHG emission is typically represented as CO2-equivalents (CO2-e). 

However, CO2 predominates and, for simplicity, contributions of CH4 and N2O were ignored in the 

above calculations. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-22 December 2010

sources (emitting > 25,000 tons/year of all GHGs) in October 2009, effective in December 2009 

(EPA 2009c). Regulations appearing in 40 CFR Parts 86, 87 and 89 apply to emissions of 

carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFC), 

perfluorocarbons (PFC), sulfur hexafluoride (SF6), and other fluorinated gases including nitrogen 

trifluoride (NF3) and hydrofluorinated ethers (HFE). This new NGCC plant would be subject to 

those regulations. Future regulations may require control of CO2 emissions (i.e., CCS). 

8.2.1.2 Particulates 

The new natural gas-fired alternative would produce 602 tons (546 MT) per year of particulates, 

all of which would be emitted as PM10. Particulate control would likely not be required. 

8.2.1.3 Carbon Monoxide 

Based on EPA emission factors (EPA 1998), NRC staff estimates that the total CO emissions 

would be approximately 2,736 tons (3,483 MT) per year. 

8.2.1.4 Hazardous Air Pollutants 

The EPA issued in December 2000 regulatory findings (EPA 2000b) on emissions of hazardous 

air pollutants (HAPs) from electric utility steam-generating units, which identified that natural 

gas-fired plants emit hazardous air pollutants such as arsenic, formaldehyde and nickel and 

stated that 

“. . . the impacts due to HAP emissions from natural gas-fired electric utility 

steam generating units were negligible based on the results of the study. The 

Administrator finds that regulation of HAP emissions from natural gas-fired 

electric utility steam generating units is not appropriate or necessary.” 

8.2.1.5 Construction Impacts 

Activities associated with the construction of the new natural gas-fired plant at the PVNGS site 

would cause some additional air impacts as a result of emissions from construction equipment 

and fugitive dust from operation of the earth-moving and material handling equipment. Workers’ 

vehicles and motorized construction equipment would generate temporary criteria pollutant 

emissions. Dust-control practices would reduce fugitive dust, which would be temporary in 

nature. The NRC staff concludes that the impact of vehicle exhaust emissions and fugitive dust 

from operation of earth-moving and material handling equipment would be SMALL. 

The overall air quality impacts of a new natural gas-fired plant located at the PVNGS site would 

be SMALL. 

8.2.2 Groundwater Use and Quality 

No groundwater is expected to be used in the construction or operation of the NGCC 

alternative. 

Some foundation excavations may intrude on the groundwater zone and require dewatering. 

Otherwise, no impacts on groundwater quality are expected. The impact of the natural gas-fired 

alternative on groundwater would be SMALL. 
Environmental Impacts of Alternatives

December 2010 8-23 NUREG-1437, Supplement 43

8.2.3 Surface Water Use and Quality 

The NGCC alternative is expected to utilize the existing cooling system which uses grey water 

obtained from nearby municipalities. No surface water is expected to be used in the 

construction or operation of the NGCC. Some impacts to surface water quality may result in 

increased sediment loading to storm water run-off from active construction zones, however, the 

NRC staff expects that a stormwater pollution prevention general permit would require best 

management practices that would prevent or significantly mitigate such impacts. The NRC staff 

concludes the impact on surface water would be SMALL. 

8.2.4 Aquatic and Terrestrial Ecology 

8.2.4.1 Aquatic Ecology 

No surface water bodies would be used to support the construction or operation of the NGCC 

alternative. Treated grey water in lined impoundments would provide feedwater for cooling 

towers. The NRC staff concludes that impacts to aquatic ecology would be SMALL. 

8.2.4.2 Terrestrial Ecology 

As indicated in previous sections, the NRC staff presumes that an NGCC alternative could be 

constructed on the existing PVNGS property. While much of the plant is likely to be located on 

previously-disturbed industrialized portions of the site, some fallow areas may also be involved. 

Terrestrial ecology in these fallow areas will be affected, primarily resulting in habitat 

fragmentation and loss of food sources. Off-site impacts will occur at the locations where the 

existing natural gas pipleine infrastructure needs to be modified or expanded and at the 

locations where natural gas is extracted to supply the Palo Verde Hub; however, modifications 

to the existing infrastructure would occur on previously-disturbed areas within existing ROWs, 

and existing natural gas fields are expected to be used to provide the necessary amount of gas 

for this facility. 

Operation of the cooling towers would produce a visible plume and cause some deposition of 

dissolved solids on surrounding vegetation and soil from cooling tower drift, however, these 

impacts will be equal to or less severe than currently-occurring impacts. Based on this 

information, impacts to terrestrial resources would be SMALL. 

8.2.5 Human Health 

Like the coal-fired alternative discussed above, a gas-fired plant would emit criteria air 

pollutants, but in smaller quantities per MW of power produced. None of the criteria pollutants 

except for NOx is expected to require control. Human health effects of gas-fired generation are 

generally low, although in Table 8-2 of the GEIS (NRC 1996), the NRC staff identified cancer 

and emphysema as potential health risks from gas-fired plants. NOx emissions contribute to 

ozone formation, which in turn contributes to human health risks. Emission controls on this gasfired alternative can be expected to maintain NOx emissions well below air quality standards 

established for the purposes of protecting human health, and emissions trading or offset 

requirements mean that overall NOx releases in the region will not increase. Health risks to 

workers may also result from handling spent catalysts that may contain heavy metals. 

Human health issues related to construction would be equivalent to those associated with the 

construction of any major complex industrial facility and would be controlled to acceptable levels 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-24 December 2010

through the application of best management practices and APS’s compliance with application 

Federal and State worker protection regulations. Both continuous and impulse noise impacts 

can be expected at off-site locations, including at the closest residences. However, confining 

noise-producing activities to core hours of the day (7:00 am to 6:00 pm), suspending the use of 

explosives during certain meteorological conditions, and notifying potentially-affected parties 

beforehand of such events will control noise impacts to acceptable levels. Noise impacts will be 

of short duration and will be SMALL. 

Overall, human health risks to occupational workers and to members of the public from gas-fired 

power plant emissions sited at PVNGS would be less than the risks described for coal-fired 

alternative and therefore, would likely be SMALL. 

8.2.6 Socioeconomics 

8.2.6.1 Land Use 

The GEIS generically evaluates the impacts of natural gas power plant operations on land use 

both on and off a power plant site. The analysis of land use impacts focuses on the amount of 

land area that would be affected by the construction and operation of a natural gas-fired 

combined-cycle power plant at the PVNGS site. 

Approximately 154 acres (62.4 ha) of land would be needed to support a natural gas-fired 

alternative to replace PVNGS. An area of sufficient size in previously-disturbed industrial 

footprint of the site is expected to be available for the NGCC plant, thus minimizing the amount 

of disturbance in undeveloped portions of the site. Onsite land use impacts from construction 

would be SMALL. 

In addition to onsite land requirements, land would be required offsite for natural gas wells and 

collection stations. Land may also be affected by natural gas pipeline modifications. Most of 

this land requirement would occur on land where gas extraction already occurs. 

The elimination of uranium fuel for PVNGS could partially offset off site land requirements. 

Based on this information and the need for additional land, overall land use impacts from a gasfired power plant would be SMALL. 

8.2.6.2 Socioeconomics 

Socioeconomic impacts are defined in terms of changes to the demographic and economic 

characteristics and social conditions of a region. For example, the number of jobs created by 

the construction and operation of a new natural gas-fired power plant could affect regional 

employment, income, and expenditures. Two types of job creation would result: 

(1) construction-related jobs, which are transient, short in duration, and less likely to have a 

long-term socioeconomic impact; and (2) operation-related jobs in support of power plant 

operations, which have the greater potential for permanent, long-term socioeconomic impacts. 

Workforce requirements for the construction and operation of the natural gas-fired power plant 

alternative were evaluated in order to measure their possible effect on current socioeconomic 

conditions. 

APS estimated a construction workforce of 946 workers. During construction, the communities 

surrounding the power plant site would experience increased demand for rental housing and 
Environmental Impacts of Alternatives

December 2010 8-25 NUREG-1437, Supplement 43

public services. The relative economic effect of construction workers on local economy and tax 

base would vary over time. 

After construction, some local communities may be temporarily affected by the loss of 

construction jobs and associated loss in demand for business services, and the rental housing 

market could experience increased vacancies and decreased prices. As noted in the GEIS, the 

socioeconomic impacts at a rural construction site could be larger than at an urban site, 

because workers may relocate to rural communities to be closer to the construction site. 

Although the ER identifies PVNGS as a rural site, it is near the Phoenix metropolitan area. 

Therefore, workers would likely commute instead of relocating closer to the construction site. 

Because of PVNGS’s proximity to Phoenix, the impact of construction on socioeconomic 

conditions would be SMALL. 

APS estimated an operations workforce of 131 workers. The APS estimate appears reasonable 

and is consistent with trends toward lowering labor costs by reducing the size of power plant 

operations workforces. The small number of operations workers is not likely to have a 

noticeable effect on socioeconomic conditions in the Phoenix metropolitan area. 

Socioeconomic impacts associated with the operation of a gas-fired power plant at PVNGS 

would be SMALL. 

8.2.6.3 Transportation 

Transportation impacts associated with construction and operation of the gas-fired power plant 

would consist of commuting workers and truck deliveries of construction materials to the 

PVNGS site. During construction, APS estimates that as many as 946 workers would be 

commuting daily to the site, most likely from the Phoenix metropolitan area. In addition to 

commuting workers, trucks would transport construction materials and equipment to the 

worksite increasing the amount of traffic on local roads. The increase in vehicular traffic would 

peak during shift changes resulting in temporary levels of service impacts and delays at 

intersections. However, since most of the commute from the Phoenix metropolitan area would 

occur on interstate highways, increases in vehicular traffic would be easily absorbed without 

significant adverse impacts. Some plant components are likely to be delivered by train via the 

existing onsite rail spur. Pipeline construction and modification to existing natural gas pipeline 

systems could also have a temporary impact on local transportation. Traffic-related 

transportation impacts during construction would be SMALL. 

During plant operations, traffic-related transportation impacts would almost disappear. 

According to APS, approximately 131 workers would be needed to operate the gas-fired power 

plant. Because fuel for the plant is transported by pipeline, a new gas-fired plant would have to 

be supported by the current gas pipeline system. If the required capacity is not available, any 

upgrades to the current pipeline system could result in additional transportation impacts. 

The transportation infrastructure would experience little to no increased traffic from plant 

operations. Overall, the gas-fired alternative transportation impacts would be SMALL during 

plant operations. 

8.2.6.4 Aesthetics 

The aesthetics impact analysis focuses on the degree of contrast between the natural gas-fired 

alternative and the surrounding landscape and the visibility of the natural gas-fired plant. 

The power block of the gas-fired units would be approximately 100 foot (30 m) tall, with an 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-26 December 2010

exhaust stack up to 500 feet (152 m). The facility would be visible offsite during daylight hours. 

The gas-fired power plant would be shorter than the current PVNGS reactor buildings, but the 

exhaust stack would be taller. The mechanical draft towers would also generate a condensate 

plume, which would be no more noticeable than the existing PVNGS plume. The gas-fired 

alternative may only require the use of one cooling tower, thus minimizing the size of the plume. 

Noise from plant operations, as well as lighting on plant structures, may be detectable offsite. 

Pipelines delivering natural gas fuel could be audible offsite near gas compressors. 

In general, aesthetic changes would be limited to the immediate vicinity of the PVNGS and 

would be SMALL. 

8.2.6.5 Historic and Archaeological Resources 

Cultural resources are the indications of human occupation and use of the landscape as defined 

and protected by a series of Federal laws, regulations, and guidelines. Prehistoric resources 

are physical remains of human activities that predate written records; they generally consist of 

artifacts that may alone or collectively yield information about the past. Historic resources 

consist of physical remains that postdate the emergence of written records; in the United States, 

they are architectural structures or districts, archaeological objects, and archaeological features 

dating from 1492 and later. Ordinarily, sites less than 50 years old are not considered historic, 

but exceptions can be made for such properties if they are of particular importance. American 

Indian resources are sites, areas, and materials important to American Indians for religious or 

heritage reasons. Such resources may include geographic features, plants, animals, 

cemeteries, battlefields, trails, and environmental features. The cultural resource analysis 

encompassed the power plant site and adjacent areas that could potentially be disturbed by the 

construction and operation of alternative power plants. 

The potential for impacts on historic and archaeological resources can vary greatly depending 

on the location of the proposed site. To consider a project's effects on historic and 

archaeological resources, any proposed areas would need to be surveyed to identify and record 

historic and archaeological resources, identify cultural resources (e.g., traditional cultural 

properties), and develop possible mitigation measures to address any adverse effects from 

ground-disturbing activities. Studies would be needed for all areas of potential disturbance at 

the proposed plant site and along associated corridors where construction would occur (e.g., 

roads, transmission corridors, rail lines, or other ROWs). Areas with the greatest sensitivity 

should be avoided. Potential impacts to historic or archeological resources on land located off 

of PVNGS needed to support the construction and operation of an on-site gas-fired power plant 

could range from SMALL to MODERATE. 

For those portions of the gas-fired alternative that would be located on previously-disturbed 

lands within the currently active industrial portion of the PVNGS site, the potential for adverse 

impacts to historic and archeological resources is low. Construction of the gas-fired power plant 

that extends to undisturbed portions of the PVNGS site could impact historic and archeological 

resources. However, PVNGS performed the necessary surveys in advance of construction to 

expand the cooling water impoundment infrastructure, and NRC therefore concludes that any 

such surveys required in connection with construction of the gas-fired alternative would also be 

completed in a timely manner. Further, NRC expects that the majority of the gas-fired power 

plant could be constructed on previously-disturbed lands in the active industrial portion of the 

site. Therefore, impacts to historic and archeological resources from the construction and 

operation of an on-site gas-fired power plant are likely to be SMALL. 
Environmental Impacts of Alternatives

December 2010 8-27 NUREG-1437, Supplement 43

8.2.6.6 Environmental Justice 

The environmental justice impact analysis evaluates the potential for disproportionately high and 

adverse human health and environmental effects on minority and low-income populations that 

could result from the construction and operation of a new gas-fired power plant. Adverse health 

effects are measured in terms of the risk and rate of fatal or nonfatal adverse impacts on human 

health. Disproportionately high and adverse human health effects occur when the risk or rate of 

exposure to an environmental hazard for a minority or low-income population is significant and 

exceeds the risk or exposure rate for the general population or for another appropriate 

comparison group. Disproportionately high environmental effects refer to impacts or risk of 

impact on the natural or physical environment in a minority or low-income community that are 

significant and appreciably exceeds the environmental impact on the larger community. Such 

effects may include biological, cultural, economic, or social impacts. Some of these potential 

effects have been identified in resource areas discussed in this document. For example, 

increased demand for rental housing during power plant construction could disproportionately 

affect low-income populations. Minority and low-income populations are subsets of the general 

public residing around PVNGS, and all are exposed to the same hazards generated from 

constructing and operating a new gas-fired power plant. 

Potential impacts to minority and low-income populations from the construction and operation of 

a new gas-fired power plant at PVNGS would mostly consist of environmental and 

socioeconomic effects (e.g., noise, dust, traffic, employment, and housing impacts). Noise and 

dust impacts from construction would be short-term and primarily limited to onsite activities. 

However, minority and low-income populations residing along site access roads could be 

affected by increased commuter vehicle traffic during shift changes. Increased demand for 

rental housing during construction in the vicinity of PVNGS could affect low-income populations. 

However, these effects would be short-term, limited to certain hours of the day, and therefore, 

not likely to be high and adverse. Given the close proximity to the Phoenix metropolitan area, 

most construction workers would commute to the site thereby reducing the potential demand for 

rental housing. 

Based on this information and the analysis of human health and environmental impacts 

presented in this document, the construction and operation of a new gas-fired power plant 

would not have disproportionately high and adverse human health and environmental effects on 

minority and low-income populations residing in the vicinity of PVNGS. 

8.2.7 Waste Management 

During the construction stage of this alternative, land clearing and other construction activities 

would generate waste that can be recycled, disposed onsite or shipped to an offsite waste 

disposal facility. Because the alternative would be constructed on the previously-disturbed 

PVNGS site, the amounts of wastes produced during land clearing would be minimal. 

During the operational stage, spent selective catalytic reduction catalysts used to control NOx

emissions from the natural gas-fired plants would make up the majority of the waste generated 

by this alternative. PVNGS estimates that approximately 2,440 ft3

 of spent catalysts would be 

generated during each year of operation of the NGCC alternative. NRC staff concluded in the 

GEIS (NRC 1996) that a natural gas-fired plant would generate minimal solidwaste and further 

concludes that the waste impacts would be SMALL for an NGCC alternative located at the 

PVNGS site. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-28 December 2010

8.2.8 Climate Change-Related Impacts of a Natural Gas Combined Cycle Alternative 

Combustion of fossil fuels, including natural gas, is thought to be the greatest anthropogenic 

source of GHG emissions. This section presents an assessment of the potential impacts the 

construction and operation of an NGCC alternative will have on climate change. 

Impacts to climate change from the construction of an NGCC alternative would result primarily 

from the consumption of fossil fuels in reciprocating internal combustion engines (RICE) of 

construction vehicles and equipment, workforce vehicles used in commuting to and from the 

work site, and delivery vehicles. Such impacts would be temporary, however. Given the 

relatively small workforce and a relatively short construction period, the overall impact on 

climate change from the releases of GHGs during construction of a NGCC alternative would 

be SMALL.

As noted in Section 8.1.8 of this document, the total amounts of GHGs released in the US and 

in Arizona in 2007 related to electricity production were 7,501 MMT and 97 MMT of 

CO2-equivalents (CO2-e are explained in a footnote on page 8-11), respectively (EPA 2009d). 

The NRC staff estimates that uncontrolled emissions of CO2-e from operation of the NGCC 

alternative would amount to 9.10 MMT/y. This amount represents 0.12% and 9.38%, 

respectively of 2007 US and Arizona CO2-e emissions. Although natural gas combustion in the 

combustion turbines would be the primary source, other miscellaneous ancillary sources such 

as truck and rail deliveries of materials to the site and commuting of the workforce would make 

minor contributions. 

NETL estimates that carbon capture and storage technologies (CCS) will capture and remove 

as much as 90% of the CO2 from the exhausts of combustion turbines (CTs). However, NETL 

estimates that such equipment imposes a significant parasitic load that will result in a power 

production capacity decrease of approximately 14%, a reduction in net overall thermal efficiency 

of the CTs studied from 50.8% to 43.7% and a potential increase in the levelized cost of 

electricity produced in NGCC units so equipped by as much as 30% (NETL 2007). Further, 

permanent sequestering of the CO2 would involve removing impurities (including water) and 

pressurizing it to meet pipeline specifications and transferring the gas by pipeline to acceptable 

geologic formations. Even when opportunities exist to utilize the CO2 for enhanced oil recovery 

(rather than simply dispose of the CO2 in geologic formations), permanent disposal costs could 

be substantial, especially if the NGCC units are far removed from acceptable geologic 

formations. With carbon capture and sequestration in place, the NGCC alternative would 

release 0.91 MMT/yr of CO2. 

If future regulations require the capture and sequestration of CO2 from NGCC facilities, the 

impact on climate change from this alternative would be further reduced. 

8.3 NEW NUCLEAR GENERATION 

In this section, NRC evaluates the environmental impacts of new nuclear generation at the 

PVNGS site.

In evaluating the new nuclear alternative in its ER, APS presumed that replacement reactors 

would be installed on the PVNGS site, allowing for the maximum use of existing ancillary 

facilities such as the cooling system (including the grey water treatment facility that supports it). 

APS further presumed that the replacement reactors would be light-water reactors such as the 

Advanced Passive 1000 model Pressurized Water Reactors (PWRs), a reactor design for which 
Environmental Impacts of Alternatives

December 2010 8-29 NUREG-1437, Supplement 43

NRC has already issued a certification, and that four such reactors would be required to 

approximate the power-generating capacity of the existing reactors. To estimate the impacts of 

these replacement reactors, APS reviewed the NRC’s assessment of construction and 

operating impacts of 2,258 MWe of new electric-generating capacity at the McGuire Nuclear 

Generating Station through the use of similar reactors and scaled those impacts to the PVNGS 

rated capacity of 4,020 MWe, amending some parameters as necessary to reflect extant 

conditions at the PVNGS site. The NRC staff considers the approach taken by APS in 

evaluating the new nuclear alternative to be appropriate and therefore bases its own 

assessment on similar assumptions and parameters. APS did not provide estimates of the 

construction schedule for a new nuclear alternative. However, estimates provided by Southern 

Nuclear Corporation for the construction of two AP 1000 reactors at the Vogtle Electric 

Generating Plant (VEGP) in Georgia included 18 months for site preparation, 48 months for 

construction, and 6 months from fuel loading to initial power generation (SNC 2009). The NRC 

staff considers these time frames to be reasonable and, although site conditions between VEGP 

and PVNGS are not the same, and the VEGP construction included construction of a new 

cooling system dedicated to the two new reactors, the NRC staff presumes that construction of 

new nuclear alternative at PVNGS would follow generally the same time frames, including 

simultaneous construction of the multiple reactors required, as was the case in the VEGP 

example. 

Regarding construction impacts, APS estimated that the power block and ancillary facilities 

(excluding the cooling water system) for the replacement reactors would require approximately 

500 acres and that sufficient contiguous fallow acreage was available on the PVNGS site. APS 

further estimated that the existing cooling system would meet the heat rejection demands of the 

replacement reactors with only minor modifications. 

Environmental impacts from the new nuclear power alternative are summarized in Table 8-4. 

Table 8-4. Summary of Environmental Impacts of the New Nuclear Alternative Compared 

to Continued Operation of PVNGS 

New Nuclear Power 

Generation

Continued PVNGS Operation

Air Quality SMALL SMALL 

Groundwater SMALL SMALL 

Surface Water SMALL SMALL 

Aquatic and Terrestrial 

Resources 

SMALL SMALL 

Human Health SMALL SMALL 

Socioeconomics SMALL SMALL 

Waste Management SMALL SMALL 

8.3.1 Air Quality 

Air quality would be affected by the release of criteria pollutants from the gasoline- and dieselfueled RICE of construction vehicles and equipment, workforce commuting vehicles, and 

material delivery vehicles. Releases of volatile organic compounds can be expected from onsite vehicle and equipment fueling activities and from the use of cleaning agents and corrosion 

control coatings. Finally, ground disturbances such as ground clearing and cut and fill activities, 

movement of construction vehicles on unpaved and disturbed land surfaces, and delivery and 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-30 December 2010

stockpiling of natural materials used in construction (e.g., sand and gravel) would increase 

fugitive dust releases. APS would be expected to apply best management practices to control 

such air quality impacts to acceptable levels. Overall, air impacts during construction would be 

of relatively short duration and would be SMALL. 

8.3.2 Groundwater Use and Quality 

Although some groundwater may be used for construction purposes, the amounts are expected 

to be minimal and would likely be obtained from existing on-site wells. Impacts to groundwater 

would be SMALL.

8.3.3 Surface Water Use and Quality 

Construction would result in minor impacts to surface water due to altered drainage patterns 

and the potential for increased sediment and construction-related pollutants in run-off from the 

active construction site. Best management practices, as would be addressed in a General 

Storm Water Permit for construction, would control such releases so that impacts to surface 

water from construction would be SMALL. 

8.3.4 Aquatic and Terrestrial Ecology 

Aquatic Ecology

No surface water bodies would be used to support the construction or operation of the new 

nuclear alternative. Treated grey water in lined impoundments would provide feedwater for 

cooling towers. The NRC staff concludes that impacts to aquatic ecology would be SMALL. 

Terrestrial Ecology

As indicated in previous sections, the NRC staff presumes that a new nuclear alternative could 

be constructed on the existing PVNGS property. While much of the plant is likely to be located 

on previously-disturbed industrialized portions of the site, some fallow areas may also be 

involved. Terrestrial ecology in these fallow areas will be affected, primarily resulting in habitat 

fragmentation and loss of food sources. 

Operation of the cooling towers would continue to produce a visible plume and cause some 

deposition of dissolved solids on surrounding vegetation and soil from cooling tower drift, 

however, these impacts will be equal to or less severe than currently-occurring impacts. Based 

on this information, impacts to terrestrial resources would be SMALL. 

8.3.5 Human Health 

Human health effects of a new nuclear power plant would be similar to those of the existing 

PVNGS. NRC staff expects that operational human health effects would be SMALL. Human 

health issues related to construction would be equivalent to those associated with the 

construction of any major complex industrial facility and would be controlled to acceptable levels 

through the application of best management practices and APS’s compliance with application 

Federal and State worker protection regulations. Human health impacts from operation of the 

nuclear alternative would be equivalent to those associated with continued operation of the 

existing reactors under license renewal. Both continuous and impulse noise impacts can be 

expected at off-site locations, including at the closest residences. However, confining noiseproducing activities to core hours of the day (7:00 am to 6:00 pm), suspending the use of 
Environmental Impacts of Alternatives

December 2010 8-31 NUREG-1437, Supplement 43

explosives during certain meteorological conditions, and notifying potentially-affected parties 

beforehand of such events will control noise impacts to acceptable levels. Noise impacts will be 

of short duration and will be SMALL. Overall, human health impacts would be SMALL. 

8.3.6 Socioeconomics 

8.3.6.5 Land Use 

The GIES generically evaluates the impacts that an advanced light-water nuclear reactor would 

have on land use both on and off a power plant site. The analysis of land use impacts here 

focuses on the amount of land area that would be affected by the construction and operation of 

a new nuclear power plant on the PVNGS site. 

NRC staff estimates that approximately 154 acres (62.4 ha) of land would be needed to support 

the construction and operation of a new nuclear power plant at PVNGS. An area of sufficient 

size in previously-disturbed industrial footprint of the site is expected to be available for the 

nuclear plant, thus minimizing the amount of disturbance in undeveloped portions of the site. 

Onsite land use impacts from construction would be SMALL. 

Additional off-site land use impacts would occur from uranium mining and fuel fabrication in 

addition to land use impacts from the construction and operation of the new nuclear power 

plant. However, most of the land in existing mining areas has already experienced some level 

of disturbance. Off-site land use impacts would be the same as those currently being 

experienced for the existing PVNGS reactors and during the license renewal term. Therefore, 

overall land use impacts from a new nuclear power plant would be SMALL. 

8.3.6.6 Socioeconomics 

Socioeconomic impacts are defined in terms of changes to the demographic and economic 

characteristics and social conditions of a region. For example, the number of jobs created by 

the construction and operation of a new nuclear power plant could affect regional employment, 

income, and expenditures. Two types of job creation would result: (1) construction-related jobs, 

which are transient, short in duration, and less likely to have a long-term socioeconomic impact; 

and (2) operation-related jobs in support of power plant operations, which have the greater 

potential for permanent, long-term socioeconomic impacts. Workforce requirements for the 

construction and operation of the new nuclear power plant alternative were evaluated in order to 

measure their possible effect on current socioeconomic conditions. 

APS estimates a peak construction workforce of 3,000, most likely from the Phoenix 

metropolitan area. During construction, the communities surrounding the power plant site would 

experience increased demand for rental housing and public services. The relative economic 

effect of construction workers on local economy and tax base would vary over time. 

After construction, some local communities may be temporarily affected by the loss of 

construction jobs and associated loss in demand for business services, and the rental housing 

market could experience increased vacancies and decreased prices. As noted in the GEIS, the 

socioeconomic impacts at a rural construction site could be larger than at an urban site, 

because workers may relocate to rural communities to be closer to the construction site. 

Although the ER identifies the PVNGS as a rural site, it is near the Phoenix metropolitan area. 

Therefore, workers would likely commute instead of relocating closer to the construction site. 

Because of the PVNGS’s proximity to Phoenix, the impact of construction on socioeconomic 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-32 December 2010

conditions would be SMALL. 

The operations workforce for the new nuclear power plant would be the same size as the 

current operating workforce at PVNGS. Socioeconomic impacts would therefore be the same 

as those currently being experienced from the operation of the existing reactors. 

Socioeconomic impacts associated with the operation of a new nuclear power plant at the 

PVNGS would therefore be SMALL. 

8.3.6.7 Transportation 

Transportation impacts associated with construction and operation of the new nuclear power 

plant would consist of commuting workers and truck and rail deliveries of construction materials 

to the PVNGS site. During construction, APS estimates that at its peak as many as 3,000 

workers would be commuting daily to the construction site, most likely from the Phoenix 

metropolitan area. In addition to commuting workers, trucks would transport construction 

materials and equipment to the worksite increasing the amount of traffic on local roads. The 

increase in vehicular traffic would peak during shift changes resulting in temporary levels of 

service impacts and delays at intersections. However, since most of the commute from the 

Phoenix metropolitan area would occur on interstate highways, increases in vehicular traffic 

would be easily absorbed without significant adverse impacts. Major plant components would 

be delivered by train via the existing onsite rail spur. Traffic-related transportation impacts 

during construction would be SMALL. 

During plant operations, traffic-related transportation impacts would include commuting by 

operations workers as well as truck deliveries of equipment and materials including the removal 

of industrial wastes to offsite disposal and/or recycling facilities. 

Since the operations workforce for the new nuclear power plant would be the same size as the 

current operating workforce at PVNGS, transportation impacts would be the same as those 

currently being experienced during the operation of the existing reactors. Overall, the new 

nuclear alternative transportation impacts would be SMALL during plant operations. 

8.3.6.8 Aesthetics 

The aesthetics impact analysis focuses on the degree of contrast between the new nuclear 

alternative and the surrounding landscape and the visibility of the new nuclear plant. 

Construction of the new nuclear power plant at PVNGS would not contrast greatly from the 

visual appearance of the existing industrial site. Once completed, the new nuclear power block 

would be similar to the existing PVNGS power block, including the use of the existing 

mechanical draft cooling towers . The new nuclear power plant would not change the overall 

visual impact of PVNGS. Visual impacts during plant operations would therefore be SMALL. 

8.3.6.9 Historic and Archaeological Resources 

Cultural resources are the indications of human occupation and use of the landscape as defined 

and protected by a series of Federal laws, regulations, and guidelines. Prehistoric resources 

are physical remains of human activities that predate written records; they generally consist of 

artifacts that may alone or collectively yield information about the past. Historic resources 

consist of physical remains that postdate the emergence of written records; in the United States, 

they are architectural structures or districts, archaeological objects, and archaeological features 
Environmental Impacts of Alternatives

December 2010 8-33 NUREG-1437, Supplement 43

dating from 1492 and later. Ordinarily, sites less than 50 years old are not considered historic, 

but exceptions can be made for such properties if they are of particular importance. American 

Indian resources are sites, areas, and materials important to American Indians for religious or 

heritage reasons. Such resources may include geographic features, plants, animals, 

cemeteries, battlefields, trails, and environmental features. The cultural resource analysis 

encompassed the power plant site and adjacent areas that could potentially be disturbed by the 

construction and operation of alternative power plants. 

The potential for impacts on historic and archaeological resources can vary greatly depending 

on the location of the proposed site. To consider a project's effects on historic and 

archaeological resources, any proposed areas would need to be surveyed to identify and record 

historic and archaeological resources, identify cultural resources (e.g., traditional cultural 

properties), and develop possible mitigation measures to address any adverse effects from 

ground disturbing activities. Studies would be needed for all areas of potential disturbance at 

the proposed plant site and along associated corridors where construction would occur (e.g., 

roads, transmission corridors, rail lines, or other ROWs). Areas with the greatest sensitivity 

should be avoided. Potential impacts to historic or archeological resources on land located off 

of PVNGS needed to support the construction and operation of a new nuclear power plant could 

range from SMALL to MODERATE. 

For those portions of the new nuclear alternative that would be located on previously-disturbed 

lands within the currently active industrial portion of the PVNGS site, the potential for adverse 

impacts to historic and archeological resources is low. Construction of the new nuclear power 

plant that extends to undisturbed portions of the PVNGS site could impact historic and 

archeological resources. However, PVNGS performed the necessary surveys in advance of 

construction to expand the cooling water impoundment infrastructure, and NRC staff therefore 

concludes that any such surveys required in connection with construction of the new nuclear 

alternative would also be completed in a timely manner. Further, NRC staff expects that the 

majority of the new nuclear power plant could be constructed on previously-disturbed lands in 

the active industrial portion of the site. Therefore, impacts to historic and archeological 

resources from the construction and operation of an on-site new nuclear power plant are likely 

to be SMALL. 

8.3.6.10 Environmental Justice 

The environmental justice impact analysis evaluates the potential for disproportionately high and 

adverse human health and environmental effects on minority and low-income populations that 

could result from the construction and operation of a new nuclear power plant. Adverse health 

effects are measured in terms of the risk and rate of fatal or nonfatal adverse impacts on human 

health. Disproportionately high and adverse human health effects occur when the risk or rate of 

exposure to an environmental hazard for a minority or low-income population is significant and 

exceeds the risk or exposure rate for the general population or for another appropriate 

comparison group. Disproportionately high environmental effects refer to impacts or risk of 

impact on the natural or physical environment in a minority or low-income community that are 

significant and appreciably exceeds the environmental impact on the larger community. Such 

effects may include biological, cultural, economic, or social impacts. For example, increased 

demand for rental housing during power plant construction could disproportionately affect lowincome populations. Minority and low-income populations are subsets of the general public 

residing around PVNGS, and all are exposed to the same hazards generated from constructing 

and operating a new nuclear power plant. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-34 December 2010

Potential impacts to minority and low-income populations from the construction and operation of 

a new nuclear power plant at PVNGS would mostly consist of environmental and socioeconomic 

effects (e.g., noise, dust, traffic, employment, and housing impacts). Noise and dust impacts 

from construction would be short-term and primarily limited to onsite activities. However, 

minority and low-income populations residing along site access roads could be affected by 

increased commuter vehicle traffic during shift changes. Increased demand for rental housing 

during construction in the vicinity of PVNGS could affect low-income populations. However, 

these effects would be short-term, limited to certain hours of the day, and therefore, not likely to 

be high and adverse. Given the close proximity to the Phoenix metropolitan area, most 

construction workers would commute to the site thereby reducing the potential demand for 

rental housing. 

Based on this information and the analysis of human health and environmental impacts 

presented in this document, the construction and operation of a new nuclear power plant would 

not have disproportionately high and adverse human health and environmental effects on 

minority and low-income populations residing in the vicinity of PVNGS. 

8.3.7 Waste Management 

During the construction stage of this alternative, land clearing and other construction activities 

would generate waste that can be recycled, disposed onsite or shipped to an offsite waste 

disposal facility. Because the alternative would be constructed on the previously-disturbed 

PVNGS site, the amounts of wastes produced during land clearing would be minimal. 

Wastes associated with construction will be similar in nature and amount to wastes from similar 

industrial construction endeavors and should be easily managed in area landfills and waste 

treatment facilities. Operating impacts of the replacement reactors with respect to waste 

generation can also be expected to be virtually equivalent to impacts from the continued 

operation of the existing reactors. Overall, waste impacts of new reactors at the PVNGS would 

be SMALL. 

8.3.8 Climate Change-Related Impacts of a New Nuclear Alternative 

Operation of a new nuclear alternative would have essentially identical effects on climate 

change as operating the current PVNGS. These effects are discussed in Chapter 6 of this 

document. Construction activities would increase these impacts from RICE and commuting 

workers, though these effects would be short-lived. 

8.4 COMBINATION ALTERNATIVE 

In this section, the NRC staff evaluates the environmental impacts of a combination of 

alternatives. Myriad combinations are possible. However, the combination the staff selected for 

evaluation represents what NRC believes to be both a technically feasible and practicable 

technology combination alternative to continuing the operation of the PVNGS reactors. This 

combination will include an NGCC power plant located on the PVNGS site with 3,120 MWe 

capacity, a demand side management (DSM) equivalent to a peak load reduction of 100 MWe, 

annually, and two Concentrated Solar Power (CSP) facilities constructed somewhere in 

southwest Arizona within the APS service area each with a 400 MWe nameplate capacity and 

each equipped with thermal storage capabilities. Table 8-5 contains a summary of 

environmental impacts of the combination alternative compared to continued operation of 

PVNGS. 
Environmental Impacts of Alternatives

December 2010 8-35 NUREG-1437, Supplement 43

Table 8-5. Summary of Environmental Impacts of the Combination Alternative Compared 

to Continued Operation of PVNGS 

Combination Alternative

(NGCC, 2 CSPs, DSM)

Continued PVNGS Operation

Air Quality SMALL SMALL 

Groundwater SMALL SMALL 

Surface Water MODERATE to LARGE a

 SMALL 

Aquatic and Terrestrial 

Resources 

SMALL (for Aquatic) 

SMALL to LARGE (for terrestrial) 

SMALL 

Human Health SMALL SMALL 

Socioeconomics SMALL to MODERATE SMALL 

Waste Management SMALL SMALL 

(a) Treats the water in the existing PVNGS cooling system as surface water. MODERATE impact if only NGCC 

is supported by the cooling system, LARGE if NGCC and both CSPs are supported by the cooling system. 

8.4.1 Impacts of the Natural Gas Combined Cycle Facility Portion of the Combination 

Alternative 

The environmental resource demands and environmental footprint of a 3,120 MWe NGCC plant 

are generally proportional to the requirements and impacts of the 4,020 MWe facility evaluated 

in Section 8.2 above. The hypothetical facility would consist of appropriately sized CTs, 

HRSGs, and STGs arranged in multiple power trains and capable of producing 3,120 MWe (net) 

amounts of power. The NRC staff further assumes that 75% of the power generated, 

2,340 MW, comes from the operation of the CTs, with the remainder resulting from operation of 

the HRSG-STG power trains. As with the alternative described in Section 8.2, this alternative 

would be built on PVNGS site and utilize existing infrastructures. It would consume pipeline 

specification natural gas and operate at a thermal efficiency of 60% and a capacity factor of 

85%. The NGCC portion of this combination alternative would consume 138.8 billion ft3

(3.89 billion m3

) of natural gas each year to generate 23,231,520 MWh of electricity annually. 

Its impacts would be proportional to the impacts of the alternative assessed in Section 8.2. The 

NRC staff projects the air quality impacts as follows: 

• Sulfur oxides (SOx) – 241 tons (218 MT) per year;19

• Nitrogen oxides (NOx) – 920.3 tons (834.9 MT) per year; 

• Carbon monoxide (CO) – 2,124 tons (1,927 MT) per year; 

• Particulate matter (PM) (PM10) – 467 tons (424 MT) per year; 

• Carbon dioxide (CO2) – 7,787,330 tons (7,064,666 MT) per year. 

Most other impacts of the 4,020 MWe NGCC facility identified in Section 8.2 would similarly be 

reduced by roughly 20%. The footprint of this reduced-capacity facility would be only 

incrementally smaller than the NGCC alternative assessed above so most site-specific impacts 

would undergo only incremental reductions in severity or extent. However, some impacts may 

experience a greater reduction or be eliminated entirely. For example, the lesser amount of 

natural gas required to support this NGCC facility may obviate the need to modify or upgrade 

the existing natural gas pipeline (or, especially, to add another compressor station). The GHG 

emissions from the construction of the 3,120 MW NGCC portion of this combination alternative 

 

19 Approximately 99% of this total will be SO2, with the remainder being SO3. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-36 December 2010

would be virtually the same as for construction of the NGCC alternative discussed in 

Section 8.2. Finally, because the 3,120 MW NGCC portion of this combination alternative would 

consume less natural gas than the NGCC alternative (138.8 billion ft3

 vs. 178.9 billion ft3), GHG 

emissions from its operation would be proportionally reduced from that of the NGCC alternative 

(7.06 MMT/y of CO2, as compared to 9.10 MMT/yr of CO2). 

8.4.2 Impacts of the Conservation Portion of the Combination Alternative 

The combination alternative would include activities aimed at reducing the load that is now 

being satisfied by the PVNGS reactors. For the purpose of this assessment, “conservation” 

would include a variety of programs and initiatives generally described as “Demand Side 

Management” (DSM). DSM programs fall into two broad categories: improving the energy 

efficiency of facilities and equipment comprising the electrical load supplied by PVNGS reactors, 

and demand response programs. Energy conservation programs will result in a reduction in the 

overall quantity of electricity consumed over the year, but may not result in reduction in 

electricity demand during peak periods.20 Demand response programs are actions and 

initiatives aimed at encouraging customers to reduce usage during peak times, or to shift that 

usage to off-peak times. Unlike energy generation initiatives discussed in this chapter, DSM 

programs focus on the behavior of the energy end user. DSM can include measures that shift 

energy consumption to different times of the day to reduce peak loads, measures that can 

interrupt certain large customers during periods of high demand or measures that interrupt 

certain appliances during high demand periods, and measures like replacing older, less efficient 

appliances, lighting, or control systems. While DSM can also include measures that utilities use 

to boost sales, such as encouraging customers to switch from gas to electricity for water 

heating, the staff is not evaluating such load-building activities as part of this alternative, as it 

would result in the need for more energy generation capacity. 

In a 2008 staff report, the Federal Energy Regulatory Commission (FERC) outlined the results 

of the 2008 FERC Demand Response and Advanced Metering Survey (FERC, 2008). 

Nationwide, approximately 8% of retail electricity customers are enrolled in some type of 

demand response program. The potential demand response resource contribution from all US 

demand response programs is estimated to be close to 41,000 MW, or about 5.8% of US peak 

demand. A national assessment of Demand Response Potential required of FERC by 

Section 529 of the Energy Independence and Security Act of 2007 was published by FERC in 

June 2009 (FERC 2009). The survey evaluated potential energy savings in five- and ten-year 

horizons for four development scenarios: Business As Usual, Expanded Business As Usual, 

Achievable Participation, and Full Participation, each representing successively greater demand 

response program opportunities and successively increasing levels of customer participation. 

The greatest savings would be realized under the Full Participation scenario with peak demand 

reductions of 188 GW by the year 2019, a 20% reduction of the anticipated peak load without 

any demand response programs in place. Under the Achievable Participation scenario, 

reflecting a more realizable voluntary customer participation level of 60%, peak demand would 

be reduced by 138 GW by 2019, a 14% reduction. 

In Arizona, the retail electricity customer profile is made up of relatively large percentages of 

residential customers and small commercial and industrial customers (54% and 26%, 

respectively). Much of their demand is spent on central air conditioning. Under the Achievable 

 

20 In Arizona, peak loads are generally experienced during the hottest part of the day and are 

dispropoortionally the result of air conditioner usage by residential and commercial customers. 
Environmental Impacts of Alternatives

December 2010 8-37 NUREG-1437, Supplement 43

Participation and Full Participation scenarios, residential customer participation could reduce 

peak loads by 3,082 MW and 4,755 MW, respectively by 2019, whereas small commercial and 

industrial participation could reduce peak loads by 273 and 606 MW, respectively, by 2019. 

With all retail electricity customers enrolled in the Full Participation scenario, Arizona has the 

potential to reduce the projected 2019 statewide peak demand of 22.4 GW by 6,200 MW, or 

27.7% of the peak demand. 

APS already offers a number of demand response program opportunities to its retail customers, 

including rebates for installing distributed solar energy systems and high efficiency air 

conditioning equipment, election of the percentage of power to be generated by renewable 

energy technologies, voluntary load interruptions during peak times, time-differentiated rates to 

encourage off-peak energy usage, and a variety of cash incentives, training, and energy 

information services offered to business customers. Overviews of these programs are available 

on the APS website: http://www.aps.com/main/services/default.html. 

In 2008 testimony before the Arizona Corporation Commission, David Pickles, speaking on 

behalf of APS, outlined the APS demand response programs and provided an estimation of 

potential expansion (Pickles 2008). The collective impact of all of APS’s currently approved 

DSM Programs through December 2007 has resulted in a peak load reduction of 64.2 MW. 

Given a reasonable set of assumptions regarding incentive levels and customer acceptance, 

APS concluded that cost-effective demand response programs could be responsible for peak 

demand reductions of between 2,600 and 3,900 GWh by 2020. Thus, APS would need to 

increase the reach of its DSM programs by slightly more than 50% to meet the capacity 

demands of this hypothetical technology combination alternative to continued operation of the 

PVNGS reactors. 

Although it is impossible to predict with precision which specific DSM programs would be 

expanded (or started) to meet the 100 MW capacity requirement of this Combination Alternative, 

it is safe to suggest that conservation programs, by their very nature, represent little to no 

adverse environmental impacts relative to the conventional electricity generation technology 

they would replace. The NRC staff concludes, therefore, that the impacts of the conservation 

portion of the combination alternative will by SMALL for all categories. 

Land use impacts of an energy efficiency alternative would be SMALL. Rapid replacement and 

disposal of old energy inefficient appliances and other equipment would generate waste 

material and could potentially increase the size of landfills. However, given time for program 

development and implementation, the cost of replacements, and the average life of appliances 

and other equipment, the replacement process would probably be gradual. Older energy 

inefficient appliances and equipment would likely be replaced by more efficient appliances and 

equipment as they fail (especially frequently-replaced items, like light bulbs). In addition, many 

items (like home appliances or industrial equipment) have substantial recycling value and would 

likely not be disposed of in landfills. 

Low-income families could benefit from weatherization and insulation programs. This effect 

would be greater than the effect for the general population because (according to the Office of 

Management and Budget [OMB]) low-income households experience home energy burdens 

more than four times larger than the average household (OMB 2007). Weatherization programs 

could target low-income residents as a cost-effective energy efficiency option since low-income 

populations tend to spend a larger proportion of their incomes paying utility bills (OMB 2007). 

Overall impacts to minority and low-income populations from energy efficiency programs would 

be nominal, depending on program design and enrollment. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-38 December 2010

8.4.3 Impacts of the Concentrated Solar Power (CSP) Portion of the Combination 

Alternative 

In recent years, solar power has enjoyed explosive growth, especially in portions of six 

southwestern states (California, Nevada, Utah, Colorado, New Mexico, and Arizona). Although 

both photovoltaic (PV) solar power and concentrated solar power (CSP) technologies have 

enjoyed growth, the NRC staff considers CSP to have a greater potential to serve as baseload 

power, primarily because of currently-existing opportunities to store thermal energy for delayed 

production of electricity over time periods coincident with peak loads.21 

EIA reports that total statewide electricity capacity in 2007 was 25,579 MW, 2,736 MW of which 

was from all renewable energy sources, and 9 MW of which was from grid-connected solar, with 

all solar energy facilities in the state producing 9,000 MWh of electricity in 2007 (EIA 2009e). 

Three CSP technologies have been developed for utility-scale power production: parabolic 

trough, power tower, and Stirling heat engine. The parabolic trough and power tower both 

concentrate the sun’s heat by reflecting it onto a container of heat transfer fluids that is 

circulated to a conventional tube-type heat exchanger to make steam to drive a conventional 

STG. The Stirling heat engine concentrates the sun’s heat on a closed container of hydrogen 

gas which expands to drive a piston whose motion is converted to angular momentum to drive a 

generator. Both parabolic trough and power tower facilities are operational at utility scale. The 

first utility-scale Stirling heat engine facility is expected to become operational in California in the 

near future. 

Although having substantially less impact on air quality than any conventional fossil fuel power 

generating technology, CSP is not entirely without impact. Substantial amounts of land are 

required for utility-scale CSP facilities. CSP facilities are thermoelectric technologies whose 

steam cycles must be supported by heat rejection capabilities at least equivalent in capacity to 

similarly-sized fossil fuel plants. Most utility-scale CSP facilities have nameplate ratings of no 

more than 400 MW. At the current stage of CSP development, both parabolic trough and power 

tower CSP facilities require approximately 5 acres for every MW of capacity, without accounting 

for the increased capacity necessary for thermal storage capabilities. CSP facilities can use 

molten salt to store heat for steam production when the sun is not shining, but to do so and to 

still maintain their nameplate capacities, such CSP facilities must increase the size of their solar 

field. A CSP facility with 6 hours of thermal storage (considered at this stage of development to 

be the practical limit) and operating at a capacity factor of approximately 48% would require a 

solar field over 3.5 times as large as the field size required to generate power at the facility’s 

nameplate rating, or a “solar multiple” of 3.5 (SDRREG 2005). Thus, a 400 MWe CSP plant 

with 6 hours of thermal storage operating at a capacity factor of 48% would have a solar field of 

roughly 7,000 acres. 

Both parabolic trough and power tower facilities utilize conventional steam cycles and thus have 

cooling demands similar to equivalently-sized fossil fuel power plants with the same overall 

 

21 Work is proceeding to equip PV systems with battery storage or fuel cell storage capabilities, thus 

improving the dispatchability of power, however, these technologies are in their infancy and not 

currently being deployed at utility scale in the United States. PV technologies continue to improve and 

are excellent options for distributed systems as well as for low-power-demand activities such as water 

heating and structure heating and cooling and a variety of remote, off-grid applications, where their 

widespread use could substantially reduce peak loads. 
Environmental Impacts of Alternatives

December 2010 8-39 NUREG-1437, Supplement 43

thermal efficiency. CSP facilities using closed loop cooling (e.g., a mechanical or natural draft 

cooling tower) can consume as much as 15 acre-ft/yr/MW, or approximately 4.89 million 

gallons/yr for every MW of capacity (DOE 2009). Because water is a scarce commodity in the 

desert southwest where solar resources are greatest, dry cooling alternatives that simply pass 

ambient air across a tube heat exchanger containing the steam condensate or a secondary heat 

transfer fluid have been explored. Such dry cooling can be feasible, albeit with some 

performance penalties (a reduction in net power production of 10% or more). Further, such dry 

cooling alternatives exhibit their worst performance during the hottest part of the day, typically 

the time when APS experiences load peaks due primarily to air conditioning demands of its 

residential and small commercial/industrial customers. Hybrid wet/dry cooling introduces a 

small stream of water into the ambient air stream which flash evaporates (due to low relative 

humidity in the southwest) by extracting heat from the air stream. Such hybrid systems result in 

significant reductions in water demands over wet recirculating closed loop cooling systems with 

less severe losses in performance than the dry cooling alternative. The NRC staff concludes 

that two 400 MWe CSP facilities utilizing either parabolic trough or power tower technologies 

and with adequate thermal storage to meet baseload demands would have a SMALL impact on 

air quality, and a SMALL to MODERATE impact on land use. The NRC staff presumes that the 

cooling system currently in place for the reactors would be more than adequate to provide 

cooling support to the two 400 MWe CSP plants. However, because the extant cooling system 

is also expected to provide heat rejection for the 3,120 MWe NGCC portion of this combination 

alternative,22 the available amount of water may not be sufficient to support all three power plant 

units simultaneously and such a configuration could result in a MODERATE to LARGE impact 

on water. 

An area of sufficient size in previously-disturbed industrial footprint of the site is expected to be 

available for the CSP facility, thus minimizing the amount of disturbance to undeveloped land. 

The elimination of uranium fuel for PVNGS could partially offset land requirements. Based on 

this information and the need for additional land, overall land use impacts from a concentrated 

solar power plant would be SMALL. 

During construction, the communities surrounding the power plant site would experience 

increased demand for rental housing and public services. Using modified cost data extracted 

from a model developed by NREL (NREL 2010) and incorporating relevant parametric data from 

economic impact analyses of representative CSP facilities (Stoddard 2008, Schwer 2004), the 

NRC staff estimates that construction of trough technologies would produce between 1,218 and 

1,744 jobs. The relative economic effect of construction workers on local economy and tax 

base would vary over time. 

After construction, some local communities may be temporarily affected by the loss of 

construction jobs and associated loss in demand for business services, and the rental housing 

market could experience increased vacancies and decreased prices. Employment impacts 

during a single year of operation would vary from 91 to 252 jobs. As noted in the GEIS, the 

socioeconomic impacts at a rural construction site could be larger than at an urban site, 

 

22 In a 2009 Report to Congress, DOE estimated that a typical NGCC facility would consume 

approximately 200 gallons of water per MWh of power produced while a water-cooled parabolic trough 

plant would consume 800 gal/MWh and a Power Tower facility would consume 600 gal/MWh, as 

compared to 500 gal/MWh consumed by a typical nuclear reactor. Dish engine facilities utilize a closed 

cycle cooling system comparable to an automobile’s radiator cooling system and therefore consume 

only approximately 20 gal/MWh (DOE 2009). 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-40 December 2010

because workers may relocate to rural communities to be closer to the construction site. 

Workers would likely commute instead of relocating closer to the construction site if the CSP 

facility is located near a metropolitan area. Depending on the size of the workforce, the impact 

of construction on socioeconomic conditions would be SMALL to MODERATE. 

The small number of operations workers is not likely to have a noticeable effect on 

socioeconomic conditions in most areas. Socioeconomic impacts associated with the operation 

of a concentrated solar power plant would be SMALL. 

Transportation impacts associated with construction and operation of the concentrated solar 

power plant would consist of commuting workers and truck deliveries of construction materials. 

The increase in vehicular traffic would peak during shift changes resulting in temporary levels of 

service impacts and delays at intersections. Some plant components could be delivered by 

train. Traffic-related transportation impacts during construction would be SMALL to 

MODERATE. 

During plant operations, traffic-related transportation impacts would be reduced. Overall, the 

transportation impacts would likely be SMALL during plant operations. 

The power block of the concentrated solar power plant would be visible offsite during daylight 

hours. Mechanical draft towers would generate a condensate plume, which would be no more 

noticeable than the existing PVNGS plume. Noise from plant operations, as well as lighting on 

plant structures, may be detectable offsite. In general, if located at an existing industrial site, 

aesthetic impacts would be SMALL. 

The potential for impacts on historic and archaeological resources can vary greatly depending 

on the location of the proposed site. To consider a project's effects on historic and 

archaeological resources, any proposed areas would need to be surveyed to identify and record 

historic and archaeological resources, identify cultural resources (e.g., traditional cultural 

properties), and develop possible mitigation measures to address any adverse effects from 

ground disturbing activities. Studies would be needed for all areas of potential disturbance at 

the proposed plant site and along associated corridors where construction would occur (e.g., 

roads, transmission corridors, rail lines, or other ROWs). Potential impacts to historic or 

archeological resources on land needed to support the construction and operation of a 

concentrated solar power plant would range from SMALL to MODERATE. 

Potential impacts to minority and low-income populations from the construction and operation of 

a concentrated solar power plant would mostly consist of environmental and socioeconomic 

effects (e.g., noise, dust, traffic, employment, and housing impacts). Noise and dust impacts 

would be short-term and primarily limited to onsite activities during construction. Minority and 

low-income populations residing along site access roads would be affected by increased 

commuter vehicle traffic during shift changes. Increased demand for rental housing during 

construction could also affect low-income populations. These effects would occur during the 

construction of the power plant and during certain hours of the day. However, if the construction 

site is located near a metropolitan area, most construction workers would commute to the site 

from their homes thereby reducing the potential demand for rental housing. 

Based on this information, the construction and operation of a concentrated solar power plant 

could have a disproportionate effect on minority and low-income populations residing in the 

vicinity of the concentrated solar power plant. 
Environmental Impacts of Alternatives

December 2010 8-41 NUREG-1437, Supplement 43

8.4.4 Summary of Impacts of the Combination Alternative 

Despite the intrinsic limitations of CSP for production of baseload power, the NRC staff believes 

that it is nevertheless feasible to identify an area of adequate size within the APS service area in 

which to construct two 400 MWe facilities to serve in combination with an NGCC facility and 

DSM programs to constitute a combination alternative in replacement of the PVNGS reactors. 

The impacts of the combination alternative are shown in Table 8-5. 

Although the majority of power in the combination alternative is expected to come from the 

operation of an NGCC plant (3,120 MWe of a total 4,020 MWe), many of the impacts of the 

three thermoelectric portions of the combination are additive. The NRC staff concludes that air 

quality, groundwater, aquatic resources, human health and waste impacts are largely the 

consequence only of the operation of the NGCC portion of this combination alternative and 

generally the same as for the NGCC alternative discussed in Section 8.2, i.e., SMALL. 

However, overall impacts from the combination alternative would result in a MODERATE to 

LARGE impact for surface water and SMALL to MODERATE for other resource areas. 

8.5 ALTERNATIVES CONSIDERED BUT DISMISSED 

In this section, the NRC staff presents the alternatives it initially considered for analysis as 

alternatives to license renewal of PVNGS, but later dismissed due to technical, resource 

availability, or commercial limitations that currently exist and that the NRC staff believes are 

likely to continue to exist when the existing PVNGS license expires. Under each of the following 

technology headings, the NRC staff indicates why it dismissed each alternative from further 

consideration. 

8.5.1 Offsite Coal-Fired, Gas-Fired, and Nuclear Capacity 

While it is possible that coal-fired, gas-fired, and nuclear alternatives like those considered in 

Sections 8.1, 8.2, and 8.3, respectively, could be constructed at sites other than PVNGS, the 

NRC staff determined that they would result in greater impacts than alternatives constructed at 

the PVNGS site. Greater impacts would occur primarily as a result of the need to construct 

necessary supporting infrastructure, like transmission lines, roads, and railway spurs, all of 

which are already present on the PVNGS site. Further, the community around PVNGS is 

already familiar with the appearance of a power facility, and it is an established part of the 

region’s aesthetic character. The next most feasible alternatives to the PVNGS site would be 

formerly used industrial sites where some of the required infrastructure may also exist; however, 

remediation of past contamination may be necessary in order to make the site ready for 

redevelopment. The greatest impacts would occur if the alternative were to be constructed at a 

“greenfield” site. In short, an existing power plant site with supporting transmission and cooling 

infrastructures sufficient to support the production of 4,020 MWe would present the best location 

for a new power facility. 

8.5.2 Coal-Fired Integrated Gasification Combined-Cycle (IGCC) 

IGCC is an emerging technology for generating electricity with coal that combines modern coal 

gasification technology with both gas turbine and steam turbine power generation. In general, 

gasifiers use heat pressure and steam to change solid fuels such as petroleum residuals, 

petroleum coke, coal and other solid carbonaceous fuels to produce synthesis gases 

(generically referred to as Syngas) typically composed of carbon monoxide, hydrogen, and 

other flammable constituents. At the same time, the inorganic fractions of the fuels are vitrified 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-42 December 2010

into a glassy, chemically inert slag that can be disposed, typically without adverse 

environmental consequence. Reactions of the Syngas with water (the Water-Gas Shift 

Reaction) convert the carbon monoxide to CO2 and H2. The Syngas is then further processed 

to remove contaminants and produce various liquid chemicals and subsequently combusted in a 

combustion turbine to produce electric power. Separating the CO2 from the Syngas prior to 

combustion is also possible. Latent heat is recovered both from the Syngas as it exits the 

gasifier and from the combustion gases exiting the combustion turbine and directed to a Heat 

Recovery Steam Generator (HRSG) feeding a conventional Rankine cycle STG to produce 

additional amounts of electricity. Only a few IGCC plants are operating at utility scale. 

IGCC systems operate at high thermal efficiencies and are capable of producing electrical 

power that is cleaner and cheaper than the older, conventional fossil fuel power producing 

technologies such as pulverized coal boilers. The technology is cleaner than conventional 

pulverized coal plants because major pollutants can be removed from the gas stream before 

combustion. The IGCC alternative also generates less solid waste than the pulverized coalfired alternative. The largest solid waste stream produced by IGCC installations is slag, a black, 

glassy, sand-like material that is also potentially a marketable by-product as inert, noncompressible fill material. The other large-volume by-product produced by IGCC plants is 

sulfur, which is extracted during the gasification process and can be marketed rather than 

placed in a landfill. IGCC units do not produce ash or scrubber wastes. 

To date, however, IGCC technologies have had limited application and have been plagued with 

operational problems such that their effective, long-term capacity factors are often not high 

enough for them to reliably serve as baseload units. Emissions of criteria pollutants would likely 

be slightly less than those from the NGCC alternative, but significantly lower than those from the 

coal-fired alternative. In addition, an IGCC alternative, especially one equipped with an air 

separation unit for production of a pure oxygen feedstream to the gasifier and with carbon 

capture and sequestration capabilities, would require slightly more onsite space than the coalfired alternative in Section 8.1 and operate at a higher thermal efficiency. Depending on 

gasification technology employed, IGCC would use less water than PC units but slightly more 

than NGCC.23 Long-term maintenance costs of this relatively complex technology would likely 

be greater than that for a similarly-sized coal-fired plant of NGCC plant. 

EIA indicates that IGCC and other advanced coal plants may become increasingly common in 

coming years (EIA 2009f), though uncertainties about construction time periods and commercial 

viability in the near future leads NRC staff to believe that IGCC is an unlikely alternative to 

PVNGS license renewal at this time. 

 

23 In a study completed in 2007, DOE’s National Energy Technology Laboratory (NETL) compared 

various hypothetical IGCC, PC, and NGCC technologies, each equipped to meet current and expected 

pollution limits, and operating with capacity factors of 0.80, 0.85, and 0.85, respectively, on the basis 

of resource demands, environmental footprints, and reliability. The study found that overall efficiencies 

of IGCC facilities using three different gasifier designs ranged from 38.2 to 41% without CCS and from 

31.7 to 32% when CCS was included. Without CCS, the relative normalized raw water use ratios for 

PC:IGCC:NGCC technologies was 2.4:1.4:1.0. The normalized environmental performance with 

respect to criteria pollutant emissions for PC:IGCC:NGCC included: for SO2 (lb/MMBtu) 

0.085:0.0128:negligible, for NOx 0.070 lb/MMBtu:15 ppmv (dry @ 15% O2):2.5 ppmv (dry@ 15% O2), 

and for PM (lb/MMBtu) 0.013:0.0071:negligible. 
Environmental Impacts of Alternatives

December 2010 8-43 NUREG-1437, Supplement 43

8.5.3 Energy Conservation/Energy Efficiency 

As discussed above in Section 8.3.2, conservation programs and initiatives can play an 

important role in meeting future energy needs. However, testimony provided to the Arizona 

Corporation Commission by Pickles suggests that opportunities to further expand conservation 

programs beyond their current levels would not yield a demand savings equivalent to the 

baseload power currently represented by PVNGS’s nuclear reactors, regardless of how 

aggressively such conservation programs are pursued (Pickles 2008). As shown in the 

assessment in Section 8.3 above, however, the NRC nevertheless believes that, when 

combined with other more conventional baseload technologies, including with certain renewable 

technologies, conservation programs can help define a technically feasible and practicable 

alternative to the PVNGS reactors. 

8.5.4 Purchased Power 

Purchased electrical power is not likely to be an alternative to PVNGS license renewal. The 

NRC staff recognizes the potential for purchased power to offset a portion of the electricity 

generated by PVNGS, however, for the timeframe of PVNGS renewal, there are no guaranteed 

available power sources to replace the 4,020 MWe that PVNGS provides. Because of the lack 

of assured available purchased electrical power, NRC staff has not evaluated purchased power 

as an alternative to license renewal. 

8.5.5 Solar Power 

Solar technologies use the sun’s energy to produce electricity. Solar power technologies 

include photovoltaic (PV) and concentrated solar power (CSP). In PV systems, sunlight incident 

on special photovoltaic materials results in the direct production of direct current electricity. Two 

types of CSP technology that have enjoyed the greatest development are the parabolic trough 

and the power tower. Both involve capturing the sun’s heat and converting it to steam which 

powers a conventional Rankine cycle STG. 

Currently, the PVNGS site receives more than 6.8 kWh of solar insolation per square meter per 

day (kWh/m2

/day), for PV solar collectors oriented at an angle equal to the installation’s latitude 

and more than 8.3 kWh/m2/day Direct Normal Insolation (DNI) for CSP (NREL 2008). This is a 

relatively high-value solar resource, sufficient for cost-effective generation of power given the 

current state of PV technology development. Since flat-plate photovoltaics tend to be roughly 

25% efficient (although that is expected to rapidly improve with the development of inexpensive, 

more efficient photocells), a PV alternative will require at least 20,000 acres (8,134 ha) of 

collectors to provide an amount of electricity equivalent to that generated by PVNGS. Space 

between collectors for maintenance purposes and associated infrastructure and areas allowed 

to remain fallow to avoid drainage swales, sensitive habitats, and unacceptable topography 

grades further increase this land requirement. This amount of land, while large, is consistent 

with the land required for coal and natural gas-fired plants when the entire fuel cycles are 

considered. In the GEIS, the NRC staff noted that, by its nature, PV solar power is intermittent 

(i.e., it does not work at night and cannot satisfy baseload power demands when the sun is not 

shining), and the efficiency of collectors varies greatly with weather conditions. The PV 

alternative will require energy storage or backup power supply to provide electric power at night. 

While development of battery storage options is ongoing, none are currently available that 

would provide baseload amounts of power. Given the challenges in meeting baseload 

requirements, the NRC staff does not believe that PV solar power can serve as an alternative to 

license renewal of PVNGS. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-44 December 2010

Concentrated solar power (CSP) which has the potential to store the sun’s energy as heat for 

delayed production of electricity has the potential to overcome PV’s inherent intermittency, and 

therefore, is better suited to offer the reliability and availability of baseload power. At its current 

state of technology development, CSP requires approximately 5 acres of land for every MW of 

power produced and, if wet closed loop cooling is used, an amount of water equal to or greater 

than the amount now required to support PVNGS reactors (as much as 15 acre-ft/yr/MW, or 

approximately 4.89 million gallons/yr/MW). Although CSP alone cannot match the power or 

capacity factor of the PVNGS reactors, the NRC has determined that CSP, in combination with 

other conventional thermoelectric technologies, may provide a technically feasible and practical 

alternative. One such combination of alternatives involving CSP is discussed in detail in 

Section 8.4. 

8.5.6 Wind 

The American Wind Energy Association (AWEA) reports that a total of 25,369 MW of wind 

energy capacity was installed at the end of 2008, with 8,545 MW installed just in 2008 (AWEA 

2009). Texas is by far the leader in installed capacity with 2,671.3 MW, followed by Iowa 

(1,599.8 MW), Minnesota (455.65 MW), Kansas (450.3 MW), and New York (407 MW). There 

are no utility-scale wind farms in Arizona. As with solar, the feasibility of wind resources serving 

as alternative baseload power in the APS service area is dependent on the location, value, 

accessibility, and constancy of the resource. Wind energy must be converted to electricity at or 

near the point where it is extracted, and there are limited energy storage opportunities available 

to overcome the intermittency and variability of wind resource availability. 

At the current stage of wind energy technology development, wind resources of Category 3 or 

better24 are required to produce utility-scale amounts of electricity. Notwithstanding mountain 

ridges where installation of a wind farm would present significant logistical constraints, there are 

very few locations within Arizona where wind resources meet or exceed that value (NREL 

2002). Land-based wind turbines have individual capacities as high as 3 MW, with the 1.67 MW 

turbine being the most popular size to have been installed in 2008 (offshore wind turbines have 

capacities as high as 5 MW). The capacity factors of wind farms are primarily dependent on the 

constancy of the wind resource and while off-shore wind farms can have relatively high capacity 

factors due to high-quality winds throughout much of the day (resulting primarily from differential 

heating of land and sea areas), land-based wind farms typically have capacity factors less than 

40%. Notwithstanding capacity factors much lower than desirable for baseload power, many 

hundreds of turbines would be required to meet the baseload capacity of PVNGS reactors. 

Further, to avoid inter-turbine interferences to wind flow through the wind farm, turbines must be 

located well separated from each other, resulting in utility-scale wind farms requiring substantial 

amounts of land.25 The limited availability of adequately-sized and constantly-available wind 

 

24 By industry convention, wind resource values are categorized on the basis of the power density and 

speed of the prevailing wind at an elevation of 50 meters, from Category 1 with wind power densities 

of 200-300 W/m2

 (typically existing with constant wind speeds between 12.5-14.3 mph (5.8-6.4 m/s) 

through Category 7 with power densities of 800-1800 W/m2

 (wind speeds of 19.7-24.8 mph (8.8-

11.1 m/s)). Category 3 wind has a power density of 300-400 W/m2

 with wind speeds of 15.7-16.8 mph 

(7.0-7.5 m/s). 

25 However, the permanent components of wind farms, the individual turbines, electrical substations and 

maintenance/control/storage buildings occupy roughly 5% of the area of a typical wind farm with the 

remaining land areas available for most other non-intrusive land uses once construction is completed. 
Environmental Impacts of Alternatives

December 2010 8-45 NUREG-1437, Supplement 43

resources in Arizona, low-capacity factors, and the substantial land requirements combine to 

allow the NRC staff to conclude that utility-scale wind farms in the APS service area would not 

be reasonable alternatives to PVNGS reactors. 

8.5.7 Wood Waste 

As noted in the GEIS (NRC 1996), the use of wood waste to generate utility scale baseload 

power is limited to those locations where wood waste is plentiful. Wastes from pulp, paper, and 

paperboard industries and for forest management activities in those areas can be expected to 

provide sufficient, reliable supplies that are feedstocks for energy generation. Beside the fuel 

source, the technological aspects of a wood-fired generation facility are virtually identical to 

those of a coal-fired alternative and, given constancy of fuel source, can be expected to operate 

at equivalent efficiencies and reliabilities. Walsh, et. al. (2000) have determined that forest 

waste, urban wood waste, and primary mill waste are all produced in Arizona, all in relatively 

modest quantities. The availability of each was determined for delivery prices ranging from < 

$30/dry ton to < $50/dry ton. Facilities to convert wood waste to electricity are typically less 

than 50 MW in size, although co-firing biomass with coal can take place in boilers as large as 

300 MW (EPA 2010). Processing the wood waste into pellets can improve the overall efficiency 

of such co-fired units. Although co-fired units can have capacity factors similar to coal-fired 

units, such levels of performance are dependent on the continued availability of the wood waste 

fuel. Given the typically small size of biomass facilities for electricity production and the limited 

availability of wood resources in Arizona at economical delivery prices, the NRC staff has 

determined that production of electricity from biomass at levels equivalent to PVNGS would not 

be a reasonable alternative to the PVNGS reactors. 

8.5.8 Hydroelectric Power 

Three technology variants of hydroelectric power exist: dam and release, run-of-the-river, and 

pumped storage. Dam and release facilities affect large amounts of land behind the dam to 

create reservoirs, but can provide substantial amounts of power at capacity factors greater than 

90%. Power generating capacities of run-of-the-river dams fluctuate with the flow of water in the 

river and the operation of such dams is typically constrained so as not to create undue stress on 

the aquatic ecosystems present. Pumped storage facilities pump water from flowing water 

courses to higher elevations during off-peak load periods, in order to release the water during 

peak load periods through turbines to generate electricity. A comprehensive survey of 

hydropower resources in Arizona was completed in 1997 by DOE’s Idaho National 

Environmental Engineering Laboratory (INEEL 1997)26. At that time, statewide hydroelectric 

potential was approximately 1,809 MW, distributed across 21 dams. More recently, as much as 

37,000 MW of potential installed capacity has been identified for the state, including 22 sites 

where pumped storage hydroelectric facilities could be built (Arizona Solar Center 2009). 

Although Arizona appears to have substantial untapped hydroelectric potential, competing 

demands for water, together with the potential substantial environmental impacts of constructing 

and operating a utility-scale hydroelectric facility have resulted in no large-scale dams being 

approved in recent years. The NRC staff concludes that relying on new hydroelectric power 

facilities as an alternative to PVNGS reactors is not a reasonable alternative to license renewal. 

 

26 Located outside of Idaho Falls, ID, this DOE laboratory is now known as Idaho National Laboratory. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-46 December 2010

8.5.9 Wave and Ocean Energy 

Wave and ocean energy has generated considerable interest in recent years. Ocean waves, 

currents, and tides are often predictable and reliable. Ocean currents flow consistently, while 

tides can be predicted months and years in advance with well-known behavior in most coastal 

areas. Most of these technologies are in relatively early stages of development, and while some 

results have been promising, they are not likely to be able to replace the capacity of PVNGS by 

the time its license expires. Even if a suitably-large facility is built, the PVNGS site is not 

located near an ocean, though a portion of its generating capacity is sold to consumers in 

California. Given the state of technology, scale of likely projects, and distance from an ocean, 

the NRC staff did not consider wave and ocean energy as an alternative to PVNGS license 

renewal. 

8.5.10 Geothermal Power 

As with most renewable energy sources, value, accessibility, and availability within a geographic 

area determines the feasibility of geothermal energy’s use for baseload power generation. Two 

technology variants for geothermal energy have been developed. “Hydrothermal technology” 

involves extracting heat from hot, pressurized groundwater located in readily accessible 

formations readily close to the surface. The heated water is either pumped to the surface where 

the sharp reduction in pressure allows it to flash into steam that is directed to an STG, or a heat 

transfer fluid is pumped into the formation in a closed loop system where it is heated by the 

groundwater before being returned to the surface and its latent heat used to produce steam. 

The water must be at least 150 °C (302 °F) for such systems to run efficiently. A second 

technology variant, hot dry rock (HDR), also known as enhanced geothermal systems (EGS), 

extracts heat from dry, hot formations, first by fracturing those formations and then by circulating 

water in open loop systems in formations where it passes through the just created fractures and 

extracts heat (Duchane 2005). 

Geothermal energy has an average capacity factor of 90% and can be used for baseload power 

where available. However, geothermal electric generation is limited by the geographical 

availability of geothermal resources (NRC 1996). Three areas of the state have low-grade 

geothermal resources: Buckthorn Baths in Apache Junction, Castle Hot Springs in the 

Bradshaw Mountains, and Childs on the Verde River (ASC 2009). No geothermal energy 

generation is currently occurring in Arizona.27 Given the low quality of these resources and their 

relative distances from the APS service area and the primary load center of the Phoenix 

metropolitan area, the NRC staff has concluded that none of these locations can support utility 

scale electricity development using hydrothermal technology. 

Investigations into HDR technology began in 1974 and focused on fracturing the bedrock in a 

HDR formation in order to inject, and later recover water that had been heated. Areas in the 

White Mountains east of Phoenix have also been recently explored for their ability to support 

HDR technologies, but remoteness of the area and lack of a convenient water source make 

such areas infeasible for development. The NRC staff has therefore concluded that utility scale 

electricity generation from geothermal resources in Arizona is not a reasonable alternative to 

PVNGS license renewal. 

 

27 However, geothermal resources of adequate quality and accessibility exist in areas west of Yuma, 

Arizona, in the Imperial Valley of California. 
Environmental Impacts of Alternatives

December 2010 8-47 NUREG-1437, Supplement 43

8.5.11 Municipal Solid Waste 

Municipal solid waste (MSW) combustors use three types of technologies—mass burn, modular, 

and refuse-derived fuel. Mass burning is currently the method used most frequently in the 

United States and involves no (or little) sorting, shredding, or separation. Consequently, toxic or 

hazardous components present in the waste stream are combusted, and toxic constituents are 

exhausted to the air or become part of the resulting solid wastes. Currently, approximately 

87 waste-to-energy plants operate in 25 states (none in Arizona), processing 28.7 million tons of 

trash annually and operate at capacity factors greater than 90% to generate approximately 

2,720 MWe, or an average of 31.3 MWe per plant (Integrated Waste Services Association 

2007). More than 128 average-sized plants would be necessary to provide the same level of 

output as the PVNGS reactors. EPA estimates that, on average, air impacts from MSW-toEnergy plants are: 3,685 lb/MWh of CO2, 1.2 lb/MWh of SO2, and 6.7 lb/MWh of NOx.

28 

Depending on the composition of the municipal waste stream, air emissions can vary greatly, 

and the ash produced may exhibit hazardous character and require special treatment and 

handling (EPA 2009e). 

Estimates in the GEIS suggest that the overall level of construction impact from a waste-fired 

plant would be approximately the same as that for a coal-fired power plant. Additionally, wastefired plants have the same or greater operational impacts than coal-fired technologies (including 

impacts on the aquatic environment, air, and waste disposal). The initial capital costs for 

municipal solid-waste plants are greater than for comparable steam-turbine technology at coalfired facilities or at wood-waste facilities because of the need for specialized waste separation 

and handling equipment (NRC 1996). 

The decision to burn municipal waste to generate energy is usually driven by the need for an 

alternative to landfills rather than energy considerations. The use of landfills as a waste 

disposal option is likely to increase in the near term as energy prices increase (and especially 

since such landfills, of sufficient size and maturity, can be sources of easily recoverable 

methane fuel); however, it is possible that municipal waste combustion facilities may become 

attractive again. 

Regulatory structures that once supported municipal solid waste incineration no longer exist. 

For example, the Tax Reform Act of 1986 made capital-intensive projects such as municipal 

waste combustion facilities more expensive relative to less capital-intensive waste disposal 

alternatives such as landfills. Also, the Supreme Court’s 1994 decision in C&A Carbone, Inc. v. 

Town of Clarkstown, 511 U.S. 383 (1994), limits the ability of local governments to mandate that 

waste be delivered to specific waste combustion facilities, thus adding uncertainty to fuel and 

revenue streams and casting doubt on the financial feasibility of such projects. In addition, 

environmental regulations have increased the capital cost necessary to construct and maintain 

municipal waste combustion facilities. 

Given the small average installed size of municipal solid waste plants and the unfavorable 

regulatory environment, the NRC staff does not consider municipal solid waste combustion to 

be a reasonable alternative to PVNGS license renewal. 

 

28 These estimates assume 0.535 MWh/ton of MSW feed combusted, based on EPA emission factors 

contained in “Compilation of Air Pollutant Emission Factors (AP-42) (EPA 1998). 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-48 December 2010

8.5.12 Biofuels 

In addition to wood and municipal solid waste fuels, there are other concepts for biomass-fired 

electric generators, including direct burning of energy crops, conversion to liquid biofuels, and 

biomass gasification. In the GEIS, the NRC staff indicated that none of these technologies had 

progressed to the point of being competitive on a large scale or of being reliable enough to 

replace a baseload plant such as PVNGS. No electricity was generated in Arizona in 2007 

using biomass technology (EIA 2009e). After reevaluating current technologies, the NRC staff 

finds other biomass-fired alternatives are still unable to reliably replace the PVNGS capacity. 

For this reason, the NRC staff does not consider other biomass-derived fuels to be feasible 

alternatives to PVNGS license renewal. 

8.5.13 Oil-Fired Power 

In Arizona in 2007, oil-fired electricity generation accounted for only 46,137 MWh of the 

statewide total of 88,825,573 MWh produced by all electric utilities (EIA 2009a). EIA projects 

that oil-fired plants will account for very little of the new generation capacity constructed in the 

United States during the 2008 to 2030 time period. Further, EIA does not project that oil-fired 

power will account for any significant additions to capacity (EIA 2009f). 

The variable costs of oil-fired generation tend to be greater than those of the nuclear or coalfired operations, and oil-fired generation tends to have greater environmental impacts than 

natural gas-fired generation. In addition, future increases in oil prices are expected to make oilfired generation increasingly more expensive (EIA 2009f). The high cost of oil has prompted a 

steady decline in its use for electricity generation. Thus, the NRC staff does not consider oilfired generation as a reasonable alternative to PVNGS license renewal. 

8.5.14 Fuel Cells 

Fuel cells oxidize fuels without combustion and its environmental side effects. Power is 

produced electrochemically by passing a hydrogen-rich fuel over an anode and air (or oxygen) 

over a cathode and separating the two by an electrolyte. The only byproducts (depending on 

fuel characteristics) are heat, water, and CO2. Hydrogen fuel can come from a variety of 

hydrocarbon resources by subjecting them to steam under pressure. Natural gas is typically 

used as the source of hydrogen. 

At the present time, fuel cells are not economically or technologically competitive with other 

alternatives for electricity generation. EIA projects that fuel cells may cost $5,374 per installed 

kW (total overnight costs) (EIA 2009f), or 3.5 times the construction cost of new coal-fired 

capacity and 7.5 times the cost of new, advanced gas-fired, combined-cycle capacity. In 

addition, fuel cell units are likely to be small in size (the EIA reference plant is 10 MWe). While 

it may be possible to use a distributed array of fuel cells to provide an alternative to PVNGS, it 

would be extremely costly to do so and would require many units and wholesale modifications to 

the existing transmission system. Accordingly, the NRC staff does not consider fuel cells to be 

a reasonable alternative to PVNGS license renewal. 

8.5.15 Delayed Retirement 

APS indicated in the ER that it has no knowledge of any plans to retire any Arizona coal-fired 

plants with capacities equivalent to PVNGS prior to expiration of PVNGS licenses. As a result, 

delayed retirement is not a viable alternative to license renewal. Other generation capacity may 

be retired prior to the expiration of the PVNGS license, but this capacity is likely to be older, less 
Environmental Impacts of Alternatives

December 2010 8-49 NUREG-1437, Supplement 43

efficient, and without modern emissions controls. 

8.6 NO-ACTION ALTERNATIVE 

This section will examine the environmental effects that occur if NRC takes no action. No action 

in this case means that NRC does not issue renewed operating licenses for any of the three 

reactors at PVNGS and the licenses expire at the end of the current license terms 

(December 31, 2024, December 9, 2025, and March 25, 2027). If NRC takes no action to 

renew the licenses, each reactor will shut down at or before the expiration of its current license. 

After shutdown, plant operators will initiate decommissioning according to 10 CFR 50.82. 

Table 8-6 provides a summary of environmental impacts of no action compared to continued 

operation of the PVNGS reactors.

The NRC staff notes that no action is the only alternative that is considered in-depth that does 

not satisfy the purpose and need for this Supplemental Environmental Impact Statement (SEIS), 

since it does not provide power generation capacity to meet the needs currently satisfied by 

PVNGS reactors. Assuming that a need currently exists for the power generated by PVNGS, 

the no-action alternative would require that the appropriate energy planning decisionmakers rely 

on an alternative to replace the capacity of PVNGS or otherwise reduce the need for power by 

an amount equivalent to PVNGS’s current contribution to the grid. Overall impacts as a result of 

taking no action could therefore ultimately vary widely and may, in some cases, be much larger 

than the immediate impacts of plant shutdown considered in this section. 

This section addresses only those impacts that arise directly as a result of plant shutdown. The 

environmental impacts from decommissioning and related activities have already been 

addressed in several other documents, including the Final Generic Environmental Impact 

Statement on Decommissioning of Nuclear Facilities, NUREG-0586, Supplement 1 (NRC 2002); 

the license renewal GEIS (chapter 7; NRC 1996); and Chapter 7 of this SEIS. These analyses 

either directly address or bound the environmental impacts of decommissioning whenever APS 

ceases operation of PVNGS. 

The NRC staff notes that, even with renewed operating licenses, PVNGS will eventually shut 

down, and the environmental effects addressed in this section will occur at that time. Those 

impacts will be addressed in this section. As with decommissioning effects, shutdown effects 

are expected to be similar whether they occur at the end of the current license or at the end of a 

renewed license period.

Table 8-6. Summary of Environmental Impacts of No Action Compared to Continued 

Operation of PVNGS 

No Action Continued PVNGS Operation

Air Quality SMALL SMALL 

Groundwater SMALL SMALL 

Surface Water SMALL SMALL 

Aquatic and Terrestrial 

Resources 

SMALL SMALL 

Human Health SMALL SMALL 

Socioeconomics SMALL SMALL 

Waste Management SMALL SMALL 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-50 December 2010

8.6.1 Air Quality 

When the plant stops operating, there would be a reduction in emissions from activities related 

to plant operation such as use of diesel generators and employees’ vehicles. In Chapter 4, 

NRC staff determined that these emissions would have a SMALL impact on air quality during 

the renewal term. Therefore, if the emissions decrease, the impact to air quality would also 

decrease and would be SMALL. 

8.6.2 Groundwater Use and Quality 

The current use of groundwater to support facility operation is limited and impacts have been 

evaluated as SMALL. Plant closure would further reduce groundwater usage so the impacts 

would still be SMALL. 

8.6.3 Surface Water Use and Quality 

PVNGS cooling requirements as well as most industrial demands are satisfied by treated grey 

water. No surface water is used, and, consequently, the impacts of operation on surface water 

are SMALL. Likewise, the impact of plant shutdown on surface water would also be SMALL. 

However, it should be noted that PVNGS currently supplies cooling water to the Red Hawk 

Plant. If that support continues, stoppage of the operation of the PVNGS reactors will not result 

in a complete shutdown of the cooling water management system. 

8.6.4 Aquatic and Terrestrial Resources 

8.6.4.1 Aquatic Ecology 

The impacts to aquatic ecology from plant operation are SMALL. Consequently, the impact of 

plant shutdown will also be SMALL. 

8.6.4.2 Terrestrial Ecology 

Terrestrial ecology impacts would be SMALL. No additional land disturbances on or offsite 

would occur. 

8.6.5 Human Health 

Human health risks would be smaller following plant shutdown. The plant, which is currently 

operating within regulatory limits, would emit less gaseous and liquid radioactive material to the 

environment. In addition, following shutdown, the variety of potential accidents at the plant 

(radiological or industrial) would be reduced to a limited set associated with shutdown events 

and fuel handling and storage. In Chapter 4 of this SEIS, the NRC staff concluded that the 

impacts of continued plant operation on human health would be SMALL. In Chapter 5, the NRC 

staff concluded that the impacts of accidents during operation were SMALL. Therefore, as 

radioactive emissions to the environment decrease, and as the likelihood and variety of 

accidents decrease following shutdown, the NRC staff concludes that the risks to human health 

following plant shutdown would be SMALL. 
Environmental Impacts of Alternatives

December 2010 8-51 NUREG-1437, Supplement 43

8.6.6 Socioeconomics 

8.6.6.1 Land Use 

Plant shutdown would not affect onsite land use. Plant structures and other facilities would 

remain in place until decommissioning, and the cooling water management system would 

remain operational, albeit at a reduced level of activity. Most transmission lines connected to 

PVNGS would remain in service after the plant stops operating (and portions of the electricity 

generation and management infrastructure may remain operational to provide amounts of 

reactive power necessary to maintain grid stability). Maintenance of most existing transmission 

lines would continue as before. Impacts on land use from plant shutdown would be SMALL. 

8.6.6.2 Socioeconomics 

Plant shutdown would have an impact on socioeconomic conditions in the region around 

PVNGS. The PVNGS workforce includes 2,200 permanent employees and 620 long-term 

contract employees, with 98% of the workforce living in Maricopa County. Plant shutdown 

would eliminate the great majority of these jobs and would reduce tax revenue in the region. 

Given the size of the workforce pool in Maricopa County, the loss of these contributions, which 

may not entirely cease until after decommissioning, would have a SMALL impact. See 

Appendix J to NUREG-0586, Supplement 1 (NRC 2002), for additional discussion of the 

potential socioeconomic impacts of plant decommissioning. 

8.6.6.3 Transportation 

Traffic volumes on the roads in the vicinity of PVNGS would be reduced after plant shutdown. 

Most of the reduction in traffic volume would be associated with the loss of jobs at the plant. 

Deliveries of materials to the plant would be reduced, as would removals of waste materials 

related to plant operation until decommissioning commences. Transportation impacts would be 

SMALL as a result of plant shutdown. 

8.6.6.4 Aesthetics 

Plant structures and other facilities would remain in place until decommissioning. Noise caused 

by plant operation would cease. Aesthetic impacts of plant closure would be SMALL. 

8.6.6.5 Historic and Archaeological Resources 

Impacts from the no-action alternative would be SMALL, since PVNGS would ultimately be 

decommissioned. A separate environmental review would be conducted for decommissioning. 

That assessment will address the protection of historic and archaeological resources. 

8.6.6.6 Environmental Justice 

Termination of power plant operations would not disproportionately affect minority and lowincome populations outside of the immediate vicinity of PVNGS. Impacts to all other resource 

areas would be SMALL. Therefore, because there are no high or adverse impacts, by 

definition, there is also no disproportionate impact upon low income or minority populations. 

See Appendix J of NUREG-0586, Supplement 1 (NRC 2002), for additional discussion of these 

impacts. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-52 December 2010

8.6.7 Waste Management 

If the no-action alternative were implemented the generation of high-level waste would stop and 

generation of low-level and mixed waste would decrease. There may be a temporary increase 

in wastes resulting from the purging and cleaning of various systems as they are placed into 

stable long-term storage modes. Impacts from implementation of no-action alternative are 

expected to be SMALL. 

8.7 ALTERNATIVES SUMMARY 

In this chapter, the NRC staff considered the following alternatives to PVNGS license renewal: 

supercritical coal-fired generation; natural gas combined-cycle (NGCC) generation; new nuclear 

generation; and a combination alternative involving NGCC, concentrated solar power (CSP) and 

demand side management (DSM). No action by the NRC and the effects it would have were 

also considered. The impacts for all alternatives are summarized in Table 8-7 on the following 

page. 

The environmental impacts of the proposed action (issuing renewed PVNGS operating licenses) 

would be SMALL for all impact categories, except for the Category 1 issue of collective offsite 

radiological impacts from the fuel cycle, high level waste (HLW), and spent fuel disposal. The 

NRC staff did not determine a single significant level for these impacts, but the Commission 

determined them to be Category 1 issues nonetheless. 

The NRC staff concludes that the coal-fired alternative would have the greatest overall adverse 

environmental impact. This alternative would result in MODERATE waste management and air 

quality from nitrogen oxides, sulfur oxides, particulate matter, polycyclic aromatic hydrocarbons, 

carbon monoxide, carbon dioxide, and mercury (and the corresponding human health impacts). 

Its impacts upon socioeconomic and biological resources would result in SMALL impacts. 

The NGCC alternative would result in SMALL impacts in all areas. This alternative would result 

in substantially lower air emissions, and lesser amounts of operational wastes than the coalfired alternative. However, the NGCC alternative could result in off-site local, short-term 

impacts if major modifications and expansions of the natural gas pipeline infrastructure were 

required. Further, although the overall impact to air quality from NGCC operation would be 

SMALL, NGCC operation would release greenhouse gases, albeit in lesser quantities per unit of 

power produced than the coal-fired alternative, but in significantly greater quantities than would 

result from continued operation of the PVNGS reactors. 

Although impacts of installing and operating new nuclear-generating capacity on the PVNGS 

would be SMALL for all impact categories, there would be impacts during construction that 

would not occur if operation of the existing reactors were to continue under license renewal. 

The combination alternative would have lower air emissions and waste management impacts 

than both the NGCC and coal-fired alternatives, however it would have relatively higher 

construction impacts in terms of land use and terrestrial resources, and potential disruption to 

historic and archaeological resources, mainly as a result of construction of the solar portions of 

the combination alternative which is likely to occur in areas off the PVNGS site. 

Under the No Action Alternative, plant shutdown would eliminate approximately 2200 jobs and 

would reduce tax revenue in the region. The loss of these contributions, which may not entirely 

cease until after decommissioning, would have a SMALL impact. However, the no-action 
Environmental Impacts of Alternatives

December 2010 8-53 NUREG-1437, Supplement 43

alternative does not meet the purpose and need stated in this SEIS. 

Of the alternatives that meet the purpose and need for this SEIS, the natural gas-fired 

alternative, the new nuclear alternative, and the continued operation of PVNGS all have SMALL 

environmental impacts. Given the need to construct new facilities for gas-fired and new nuclear 

alternatives, however, NRC staff concludes that continued operation of the existing PVNGS is 

the environmentally-preferred alternative. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-54 December 2010

Table 8-7. Summary of Environmental Impacts of Proposed Action and Alternatives

Alternative 

Impact Area 

Air Quality 

Groundwater 

Surface Water 

Aquatic and 

Terrestrial 

Resources 

Human Health 

Socioeconomics 

Waste Management 

License 

Renewal SMALL SMALL SMALL SMALL SMALL SMALL SMALL(a)

Supercritical 

Coal-fired 

Alternative 

MODERATE SMALL SMALL SMALL SMALL SMALL to 

MODERATE MODERATE

NGCC 

Alternative SMALL SMALL SMALL SMALL SMALL SMALL SMALL 

New Nuclear SMALL SMALL SMALL SMALL SMALL SMALL SMALL 

Combination 

Alternative SMALL SMALL MODERATE 

to LARGE SMALL SMALL SMALL to MODERATE SMALL 

No Action 

Alternative SMALL SMALL SMALL SMALL SMALL SMALL SMALL 

(a) For the PVNGS license renewal alternative, waste management was evaluated in Chapter 6. Consistent 

with the findings in the generic environmental impact statement (GEIS), these impacts were determined to 

be SMALL with the exception of collective offsite radiological impacts from the fuel cycle and from highlevel waste and spent fuel disposal. 

 
Environmental Impacts of Alternatives

December 2010 8-55 NUREG-1437, Supplement 43

8.8 REFERENCES 

10 CFR 51. U.S. Code of Federal Regulations, Title 10 “Environmental Protection Regulations 

for Domestic Licensing and Related Regulatory Functions,” Part 51, “Energy.”

American Coal Ash Association (ACAA). 2007. “ACAA Releases 2006 CCP Production and 

Use Survey.” August 24, 2007. Available at 

http://www.acaausa.org/associations/8003/files/2006_CCP_Survey_(Final-8-24-07).pdf. 

Accessed April 15, 2008. 

American Coal Ash Association (ACAA). 2009. 2008 Coal Combustion Product (CCP) 

Production and use Survey Report. Aurora, Colorado, October 5. Available at http://www.acaausa.org/displaycommon.cfm?an=1&subarticlenbr=3. Accessed February 16, 2010. 

American Wind Energy Association (AWEA). 2009. Windpower Outlook 2009. Available at 

http://www.awea.org/. Accessed December 21, 2009. 

Arizona Department of Environmental Quality (ADEQ). 2004. State Implementation Plan for 

Regional Haze, December 31. Available at http://www.azdeq.gov/environ/air/haze/index.html. 

Accessed December 15, 2009. 

Arizona Department of Environmental Quality (ADEQ). 2003. Regional Haze State 

Implementation Plan for the State of Arizona, December 23. Available at 

http://www.azdeq.gov/environ/air/haze/index.html. Accessed December 15, 2009. 

Arizona Public Service Company (APS). 2008a. Palo Verde Nuclear Generating Station, Units 

1, 2, and 3, Applicant’s Environmental Report, License Renewal Operating Stage. ADAMS No. 

ML083510615, Appendix E. 

Arizona Solar Center (ASC). 2009. Geothermal Potential for Arizona. Available at 

http://www.azsolarcenter.org/azsc/tech-science/other-renewables/geothermal-energy.html. 

Accessed December 16, 2009. 

Duchane, D. and D. Brown. 2005. Hot Dry Rock Geothermal Energy Development in the USA, 

Los Alamos National Laboratory, Los Alamos, NM, September 19. Available at 

www.lanl.gov/orgs/ees/ees11/geophysics/staff/brown/HDRintheUS.pdf - 2005-09-19. Accessed 

December 17, 2009. 

Duke Energy. 2008. Edwardsport Integrated Gasification Combined Cycle (IGCC) Station. 

Available at http://www.duke-energy.com/pdfs/igcc-fact-sheet.pdf. Accessed August 2009. 

Energy Information Administration (EIA). 2009a. Arizona Electricity Profile for 2007, Table 5. 

Electric Power Industry Generation by Primary Source, 1990 through 2007 (Megawatthours), 

DOE/EIA 0348(01)/2, Washington, D.C., Report released April. Available at 

http://www.eia.doe.gov/cneaf/electricity/st_profiles/sept05az.xls. Accessed December 9, 2009. 

Energy Information Administration (EIA). 2009b. Electric Power Annual with Data for 2007, 

“Overview” and “Summary Statistics for the United States, Table ES1”. Washington, D.C. 

January 21. Available at http://www.eia.doe.gov/cneaf/electricity/epa/epates.html. Accessed

December 8, 2009. 

Energy Information Administration (EIA). 2009c. Annual Energy Outlook 2009 with Projections 

to 2030, DOE/EIA 0383(2009), Washington, D.C., March. Available at 

http://www.eia.doe.gov/oiaf/aeo/. Accessed December 2009. 

Energy Information Administration (EIA). 2009d. Table A4. Approximate Heat Content of Natural 

Gas, 1949-2008 (Btu per Cubic Foot). Available at 

http://www.eia.doe.gov/emeu/aer/txt/ptb1304.html. Accessed July 2009. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-56 December 2010

Energy Information Administration (EIA). 2009e. Arizona Renewable energy Electricity Profile, 

2007 Edition, Table 1, June. Available at 

http://www.eia.doe.gov/cneaf/solar.renewables/page/state_profiles/arizona.html. Accessed 

December 17, 2009. 

Energy Information Administration (EIA). 2009f. Assumptions to the Annual Energy Outlook 

2009 with Projections to 2030. DOE/EIA 0554(2009). Washington, D.C., March. Available at 

http://www.eia.doe.gov/oiaf/aeo/assumption/index.html. Accessed December 2009. 

Energy Information Administration (EIA). 2009g. Voluntary Reporting of Greenhouse Gases 

Program (Fuel and Energy Source Codes and Emission Coefficients Glossary. Available at 

http://www.eia.doe.gov/oiaf/1605/coefficients.html. Accessed December 21, 2009. 

Federal Energy Regulatory Commission (FERC). 2008, 2008 Assessment of Demand 

Response and Advanced Metering, Staff Report, December. Available at 

www.ferc.gov/legal/staff-reports/12-08-demand-response.pdf. Accessed December 16, 2009 

Federal Energy Regulatory Commission (FERC). 2009, A National Assessment of Demand 

Response Potential, Staff Report, Prpared by The Brattle Group, Freeman, Sullivan, & Co. and 

Global Energy Partners, LLC, June. Available at http://www.ferc.gov/industries/electric/indusact/demand-response/dr-potential.asp. Accessed December 16, 2009. 

Global Climate Change Research Program (GCCRP) 2009, Global Climate Change Impacts in 

the United States, A State of knowledge Report from the U.S. Global Change Research 

Program, Cambridge University Press, New York, NY. June. Available at: 

http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts. Accessed 

November 18, 2009. 

Hong, B. D., and E. R. Slatik, 1994, Carbon Dioxide Emission Factors for Coal, Originally 

published in Energy Information Admininstration Quarterly Coal Ereports, January-April 1994, 

DOE/EIA-0121(94Q1) Washington DC, August 1994, pp. 1-8. Available at: 

http://www.eia.doe.gov/cneaf/coal/quarterly/co2_article/co2.html. Accessed December 21, 2009. 

Idaho National Engineering and Environmental Laboratory (INEEL). 1997. “U.S. Hydropower 

Resource Assessment for Iowa.” DOE/ID-10430(NE). Available at 

http://hydropower.inl.gov/resourceassessment/pdfs/states/ia.pdf. Accessed July 2009. 

National Energy Technology Laboratory (NETL). 2007. Cost and Performance Baseline for 

Fossil Energy Plants, Vol. 1, Bituminous Coal and Natural Gas to Electricity. DOE/NETL 

2007/1281, Final Report, U.S. Department of Energy, Pittsburgh, Pennsylvania. (Original Issue 

May), Revision 1, August. Available at http://www.fossil.energy.gov/news/techlines/2007/07057-

DOE_Issues_Plant_Performance_Repor.html 

National Renewable Energy Laboratory (NREL). 2009. Dynamic Maps, Gis Data, and Analysis 

Tools: Solar Maps, Golden, Colorado. Available at http://www.nrel.gov/gis/solar.html. Accessed

February 16, 2010. 

National Renewable Energy Laboratory (NREL). 2002, Arizona Wind Resource Map, Golden, 

Colorado. April 2. Available through the Arizona Solar Center Website. Available at 

http://www.azsolarcenter.com/images/az-50mwind.gif. Accessed December 21, 2009. 

National Renewable Energy Laboratory (NREL). 2010. Jobs and Economic Development 

Impact (JEDI) Model, CSP Trough Model rel. CSP1.09.01. Available at 

http://www.nrel.gov/analysis/jedi/download.html. Accessed June 3, 2010. 

Nucleonics Week. 2008. “US new reactors more likely online in 2016 and beyond, NEI official 

says.” Vol. 49, No. 15. April 10, 2008. 
Environmental Impacts of Alternatives

December 2010 8-57 NUREG-1437, Supplement 43

Pickles. 2008. Direct Testimony of David K. Pckles On Behalf of Arizona Public Service 

company, Docket No. E-001345A-08-0172. Available at 

http://www.aps.com/general_info/search_results.html?search=docket. Accessed December 16, 

2009. 

San Diego Regional Renewable Energy Group (SDRREG). 2005. Potential for Renewable 

Energy in the San Diego Region, August. Available at http://www.renewablesg.org/. Accessed 

July 28, 2008. 

Schwer, R. K. and M. Riddel, 2004. The Potential Economic Impact of Constructing and 

Operating Solar Power Generation Facilities in Nevada, NREL/SR-550-35037, Center for 

Business and Economic Research, University of Nevada, Las Vegas, NV, February. Available at 

http://www.nrel.gov/csp/pdfs/35037.pdf. 

Siemens Power Generation. 2007. “Technical Data: Combined Cycle Power Plant Performance 

Data.” Available at http://www.powergeneration.siemens.com/products-solutionsservices/power-plant-soln/combined-cycle-power-plants/technical-data. Accessed July 2009. 

Southern Nuclear Corporation Vogtle Electric Generating Plant (SNC). 2009. Units 3 and 4 

Combined Operating License Application (COLA) (Environmental Report, Rev. 0 – Applicant’s 

Combined License Report, Combined License Stage), March 28. ADAMS No. ML081050181. 

Southwest Energy Efficiency Project (SWEEP). 2009. Arizona Fact Sheet: Energy Efficiency 

and Energy consumption July. Available at http://www.swenergy.org/states/arizona.htm. 

Accessed December 8, 2009. 

Stoddard, L., J. Abiecunas, and R. O’Connel. 2006. Economic, Energy, and Environmental 

Benefits of Concentrating Solar Power in California, NREL/SR-550-39291, Black and Veatch, 

Overland Park, KS, April. Available at: http://www.nrel.gov/docs/fy06osti/39291.pdf. Accessed 

June 3, 2010 

Stricker, G.D. and M.S. Ellis. 1999. Coal Quality and Geochemistry, Power River Basin, 

Wyoming and Montana, in U.S. Geological Professional Paper 1625-A, 1999 Resource 

Assessment of Tertiary Coal Beds and Zones in the Northern Rocky Mountains and Great 

Plains Regions, Chapter PQ. Available at http://pubs.usgs.gov/pp/p1625a/ Accessed December 

11, 2009. 

U.S. Department of Energy (DOE). 2007. GeoPowering the West: Nebraska State Profile. 

Available at http://www1.eere.energy.gov/geothermal/gpw/profile_nebraska.html. Accessed 

July 2009. 

U.S. Department of Energy (DOE). 2009. Concentrating Solar Power Commercial Application 

Study: Reducing Water Consumption of Concentrating Solar Power Electricity Generation, 

Report to Congress, Jan. 13. Available at http://www.nrel.gov/csp/publications.html. Accessed

December 18, 2009. 

U.S. Environmental Protection Agency (EPA). 1998. Compilation of Air Pollutant Emission 

Factors, Volume 1: Stationary Point and Area Sources: AP 42, Fifth Edition. “Section 1.1: 

Bituminous and Subbituminous Coal Combustion: Final Section Supplement E.” Washington, 

D.C. 

U.S. Environmental Protection Agency (EPA). 2000a. “Notice of Regulatory Determination on 

Wastes from the Combustion of Fossil Fuels.” Federal Register, Vol. 65, pp.32214-32237. 

Washington, D.C. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 8-58 December 2010

U.S. Environmental Protection Agency (EPA). 2000b. “Regulatory Finding on the Emissions of 

Hazardous Air Pollutants from Electric Utility Steam Generating Units.” Federal Register, Vol. 

65, No. 245, pp. 79825–79831. Washington, DC. December 20, 2000. 

U.S. Environmental Protection Agency (EPA). 2000c, Air Pollution Control Technology Fact 

Sheet, Selective Catalytic Reduction (SCR) EPA-452/F-03-032. Available at 

www.epa.gov/ttn/catc/dir1/fscr.pdf. Accessed January 18, 2010.

U.S. Environmental Protection Agency (EPA). 2008a. “Basic Concepts of Environmental 

Science. Module 6: Fabric filters”. Available at 

http://www.epa.gov/apti/bces/module6/matter/control/control.htm#fabric. Accessed June 2009. 

ADAMS No. ML091760654 

U.S. Environmental Protection Agency (EPA). 2008b. Clean Air Interstate Rule: Arizona. 

Available at http://www.epa.gov/CAIR/az.html. Accessed August 2009. 

U.S. Environmental Protection Agency (EPA). 2008c. New Resource Review. Available at 

http://www.epa.gov/nsr/. Accessed June 2009. ADAMS No. ML083450073 

U.S. Environmental Protection Agency (EPA). 2009a. Emissions Factors & AP 42. Available at 

http://www.epa.gov/ttn/chief/ap42/index.html. Accessed December 23 2009. 

U.S. Environmental Protection Agency (EPA). 2009c. Final Mandatory Greenhouse Gas 

Reporting Rule. Available at http://www.epa.gov/climatechange/emissions/ghgrulemaking.html. 

Accessed December 15, 2009. 

U.S. Environmental Protection Agency (EPA). 2009d. Clean Air Mercury Rule. Available at 

http://www.epa.gov/camr/. Accessed December 23, 2009. 

U.S. Environmental Protection Agency (EPA). 2009e. Clean Energy: Municipal Solid Waste; 

Electricity From Municipal Solid Waste. Available at http://www.epa.gov/RDEE/energy-andyou/affect/municipal-sw.html. Accessed December 23, 2009. 

U.S. Environmental Protection Agency (EPA). 2010, Combined Heat and Power Partnership, 

Catalog of CHP Technologies, Chapter 5, Biomass conversion Technologies. Available at 

http://www.epa.gov/CHP/basic/catalog.html. Accessed February 17, 2010. 

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants. NUREG-1437, Volumes 1 and 2. Washington, DC. 

U.S. Nuclear Regulatory Commission (NRC). 1999. Generic Environmental Impact Statement 

for License Renewal of Nuclear Plants, Main Report, “Section 6.3 – Transportation, Table 9.1, 

Summary of Findings on NEPA Issues for License Renewal of Nuclear Power Plants, Final 

Report.” NUREG-1437, Volume 1, Addendum 1. Washington, DC. 

U.S. Nuclear Regulatory Commission (NRC). 2002. Generic Environmental Impact Statement 

on Decommissioning of Nuclear Facilities: Supplement 1, Regarding the Decommissioning of 

Nuclear Power Reactors. NUREG-0586, Supplement 1, Volumes 1 and 2. Washington, DC. 

U.S. Office of Management and Budget (OMB). 2007. ExpectMore.gov. “Detailed Information on 

the Low Income Home Energy Assistance Program Assessment.” Available at 

http://www.whitehouse.gov/omb/expectmore/detail/10001059.2003.html. Accessed July 10, 

2007. 

Walsh, et. al. 2000. Biomass Feedstock Availability in the United States: 1999 State Level 

Analysis, Oak Ridge National Laboratory, Oak, Ridge, Tenn., April 30, 1999, Updated January. 

Available at http://www.epa.gov/CHP/basic/catalog.html. Accessed February 17, 2010. 
December 2010 9-1 NUREG-1437, Supplement 43

9.0 CONCLUSION 

This supplemental environmental impact statement (SEIS) contains the environmental review of 

the Arizona Public Service Company (APS) application for a renewed operating license for Palo 

Verde Nuclear Generating Station (PVNGS), as required by the Code of Federal Regulations

(CFR), Part 51 of Title 10 (10 CFR Part 51) and the U.S. Nuclear Regulatory Commission’s 

(NRC) regulations that implement the National Environmental Policy Act (NEPA). This chapter 

presents conclusions and recommendations from the site-specific environmental review of 

PVNGS and summarizes site-specific environmental issues of license renewal that were 

identified during the review. The environmental impacts of license renewal are summarized in 

Section 9.1; a comparison of the environmental impacts of license renewal and energy 

alternatives is presented in Section 9.2; unavoidable impacts of license renewal, energy 

alternatives, and resource commitments are discussed in Section 9.3; and conclusions and 

NRC staff recommendations are presented in Section 9.4. 

9.1 ENVIRONMENTAL IMPACTS OF LICENSE RENEWAL 

The NRC staff’s (staff) review of site-specific environmental issues in this SEIS leads to the 

conclusion that issuing a renewed license would have SMALL impacts for the Category 2 issues 

applicable to license renewal at PVNGS, as well as environmental justice and chronic effects of 

electromagnetic fields (EMF). No impacts beyond those discussed in the GEIS were identified 

for the site-specific environmental issue applicable at PVNGS. 

Mitigation measures were considered for each Category 2 issue, as applicable. The staff 

identified several measures that could mitigate potential acute EMF impacts resulting from 

continued operation of the PVNGS transmission lines, including erecting barriers along the 

length of the transmission line to prevent unauthorized access to the ground beneath the 

conductors and installing road signs at road crossings. These mitigation measures could 

reduce human health impacts by minimizing public exposures to electric shock hazard. 

Additionally, one measure the staff identified that could mitigate potential impacts to threatened 

or endangered species would be for APS to report existence of any Federally- or State-listed 

endangered or threatened species within or near the transmission line rights-of-way to the 

Arizona Game and Fish Department (AGFD), California Department of Fish and Game (CDFG) 

and/or U. S. Fish and Wildlife Service (USFWS) if any such species are identified during the 

renewal term. In particular, if any evidence of injury or mortality of migratory birds, State-listed 

species, or Federally-listed threatened or endangered species is observed within the corridor 

during the renewal period, coordination with the appropriate State or Federal agency would 

minimize impacts to the species and, in the case of Federally-listed species, ensure compliance 

with the Endangered Species Act. 

The NRC staff also considered cumulative impacts of past, present, and reasonably foreseeable 

future actions, regardless of what agency (Federal or non-Federal) or person undertakes them. 

The staff concluded that cumulative impacts of PVNGS’s license renewal would be SMALL for 

potentially-affected resources. 

9.2 COMPARISON OF ENVIRONMENTAL IMPACTS OF LICENSE RENEWAL 

AND ALTERNATIVES 

In the conclusion to Chapter 8, the NRC staff considered the following alternatives to PVNGS 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 9-2 December 2010

license renewal: supercritical coal-fired generation; natural gas combined-cycle (NGCC) 

generation; new nuclear generation; and a combination alternative involving NGCC, 

concentrated solar power (CSP) and demand side management (DSM). The NRC staff 

concluded that the coal-fired alternative and the combination alternative would have a greater 

overall adverse environmental impact than NGCC or new nuclear generation. The NGCC 

alternative, the new nuclear alternative, and the continued operation of PVNGS all have SMALL 

environmental impacts. Given the need to construct new facilities for NGCC and new nuclear 

alternatives, however, NRC staff concluded that continued operation of the existing PVNGS is 

the environmentally preferred alternative. 

9.3 RESOURCE COMMITMENTS 

9.3.1 Unavoidable Adverse Environmental Impacts 

Unavoidable adverse environmental impacts are impacts that would occur after implementation 

of all feasible mitigation measures. Implementing any of the energy alternatives considered in 

this SEIS, including the proposed action, would result in some unavoidable adverse 

environmental impacts. 

Minor unavoidable adverse impacts on air quality would occur due to emission and release of 

various chemical and radiological constituents from power plant operations. Nonradiological 

emissions resulting from power plant operations are expected to comply with Environmental 

Protection Agency (EPA) emissions standards, though the alternative of operating a 

fossil-fueled power plant in some areas may worsen existing attainment issues. Chemical and 

radiological emissions would not exceed the National Emission Standards for Hazardous Air 

Pollutants. 

During nuclear power plant operations, workers and members of the public would face 

unavoidable exposure to radiation and hazardous and toxic chemicals. Workers would be 

exposed to radiation and chemicals associated with routine plant operations and the handling of 

nuclear fuel and waste material. Workers would have higher levels of exposure than members 

of the public, but doses would be administratively controlled and would not exceed standards or 

administrative control limits. In comparison, the alternatives involving the construction and 

operation of a non-nuclear power generating facility would also result in unavoidable exposure 

to hazardous and toxic chemicals to workers and the general public. 

The generation of spent nuclear fuel and waste material, including low-level radioactive waste, 

hazardous waste, and nonhazardous waste would also be unavoidable. In comparison, 

hazardous and nonhazardous wastes would also be generated at non-nuclear power generating 

facilities. Wastes generated during plant operations would be collected, stored, and shipped for 

suitable treatment, recycling, or disposal in accordance with applicable Federal and State 

regulations. Due to the costs of handling these materials, power plant operators would be 

expected to conduct all activities and optimize all operations in a way that generates the 

smallest amount of waste possible. 

9.3.2 The Relationship between Local Short-Term Uses of the Environment and the 

Maintenance and Enhancement of Long-Term Productivity 

The operation of power generating facilities would result in short-term uses of the environment 

as described in Chapters 4, 5, 6, 7, and 8. “Short-term” is the period of time that continued 

power generating activities take place. 
Conclusion

December 2010 9-3 NUREG-1437, Supplement 43

Power plant operations require short-term use of the environment and commitment of 

resources, and also commit certain resources (e.g., land and energy) indefinitely or 

permanently. Certain short-term resource commitments are substantially greater under most 

energy alternatives, including license renewal, than under the no-action alternative because of 

the continued generation of electrical power and the continued use of generating sites and 

associated infrastructure. During operations, all energy alternatives require similar relationships 

between local short-term uses of the environment and the maintenance and enhancement of 

long-term productivity. 

Air emissions from power plant operations introduce small amounts of radiological and 

nonradiological constituents to the region around the plant site. Over time, these emissions 

would result in increased concentrations and exposure, but are not expected to impact air 

quality or radiation exposure to the extent that public health and long-term productivity of the 

environment would be impaired. 

Continued employment, expenditures, and tax revenues generated during power plant 

operations directly benefit local, regional, and State economies over the short term. Local 

governments investing project-generated tax revenues into infrastructure and other required 

services could enhance economic productivity over the long term. 

The management and disposal of spent nuclear fuel, low-level radioactive waste, hazardous 

waste, and nonhazardous waste requires an increase in energy and consumes space at 

treatment, storage, or disposal facilities. Regardless of the location, the use of land to meet 

waste disposal needs would reduce the long-term productivity of the land. 

Power plant facilities are committed to electricity production over the short term. After 

decommissioning these facilities and restoring the area, the land could be available for other 

future productive uses. 

9.3.3 Irreversible and Irretrievable Commitments of Resources 

This section describes the irreversible and irretrievable commitment of resources that have 

been identified in this SEIS. Resources are irreversible when primary or secondary impacts 

limit the future options for a resource. An irretrievable commitment refers to the use or 

consumption of resources that are neither renewable nor recoverable for future use. Irreversible 

and irretrievable commitment of resources for electrical power generation include the 

commitment of land, water, energy, raw materials, and other natural and man-made resources 

required for power plant operations. In general, the commitment of capital, energy, labor, and 

material resources are also irreversible. 

The implementation of any of the energy alternatives considered in this SEIS would entail the 

irreversible and irretrievable commitment of energy, water, chemicals, and in some cases, fossil 

fuels. These resources would be committed during the license renewal term and over the entire 

life cycle of the power plant and would be unrecoverable. 

Energy expended would be in the form of fuel for equipment, vehicles, and power plant 

operations and electricity for equipment and facility operations. Electricity and fuel would be 

purchased from offsite commercial sources. Water would be obtained from existing water 

supply systems. These resources are readily available, and the amounts required are not 

expected to deplete available supplies or exceed available system capacities. 
Environmental Impacts of Alternatives 

NUREG-1437, Supplement 43 9-4 December 2010

The irreversible and irretrievable commitment of material resources includes materials that 

cannot be recovered or recycled, materials that are rendered radioactive and cannot be 

decontaminated, and materials consumed or reduced to unrecoverable forms of waste. None of 

the resources used by these power generating facilities, however, are in short supply, and for 

the most part are readily available. 

Various materials and chemicals derived from chemical vendors, including acids and caustics, 

are required to support the operation’s activities. Their consumption is not expected to affect 

local, regional, or national supplies. 

The treatment, storage, and disposal of spent nuclear fuel, low-level radioactive waste, 

hazardous waste, and nonhazardous waste require the irretrievable commitment of energy and 

fuel and will result in the irreversible commitment of space in disposal facilities. 

9.4 RECOMMENDATION 

The Nuclear Regulatory Commission’s recommendation is that the adverse environmental 

impacts of license renewal for PVNGS are not great enough to deny the option of license 

renewal for energy-planning decision makers. This determination is based on (1) the analysis 

and findings in the Generic Environmental Impact Statement for License Renewal of Nuclear 

Plants (GEIS), NUREG-1437; (2) the Environmental Report submitted by APS; (3) consultation 

with Federal, State, and local agencies; (4) the NRC staff’s own independent review; and (5) the 

NRC staff’s consideration of public comments received during the scoping process and draft 

SEIS comment period.
December 2010 10-1 NUREG-1437, Supplement 43

10.0 LIST OF PREPARERS 

This supplemental environmental impact statement (SEIS) was prepared by members of the 

Office of Nuclear Reactor Regulation, with assistance from other U.S. Nuclear Regulatory 

Commission (NRC) organizations and with contract support from Argonne National Laboratory 

and Pacific Northwest National Laboratory. 

Table 10-1 provides a list of NRC staff that participated in the development of the SEIS. 

Argonne National Laboratory provided contract support for air quality, hydrology, historic and 

archaeological resources, and alternatives, presented primarily in Chapters 2, 4, and 8. Pacific 

Northwest National Laboratory provided contract support for the severe accident mitigation 

alternatives (SAMAs) analysis, presented in Chapter 5 and Appendix F. 

Table 10-1. List of Preparers 

Name Affiliation Function or Expertise 

Jay Robinson Nuclear Reactor Regulation Branch Chief 

Andrew Imboden Nuclear Reactor Regulation Branch Chief 

Lisa Regner Nuclear Reactor Regulation Project Manager 

David Drucker Nuclear Reactor Regulation Project Manager 

Dennis Beissel Nuclear Reactor Regulation Hydrology 

Dennis Logan Nuclear Reactor Regulation Aquatic Ecology; Terrestrial 

Ecology 

Stephen Klementowicz Nuclear Reactor Regulation Radiation Protection; Human 

Health 

Allison Travers Nuclear Reactor Regulation Historic and Archaeological 

Resources 

Briana Balsam Nuclear Reactor Regulation Terrestrial Ecology 

George Bacuta Nuclear Reactor Regulation Air Quality 

Ekaterina Lenning Nuclear Reactor Regulation Electromagnetic Fields 

Robert Palla Nuclear Reactor Regulation Severe Accident Mitigation 

Alternatives 

Jeffrey Rikhoff Nuclear Reactor Regulation Socioeconomics; Land Use; 

Environmental Justice; 

Historic and Archaeological 

Resources 

Andrew Stuyvenburg Nuclear Reactor Regulation Alternatives 
List of Preparers 

NUREG-1437, Supplement 43 10-2 December 2010

Name Affiliation Function or Expertise 

Ron Kolpa Argonne National Laboratory(a) Alternatives 

Konnie Wescott Argonne National Laboratory Historic and Archaeological 

Resources 

Young-Soo Chang Argonne National Laboratory Air Quality 

Terri L. Patton Argonne National Laboratory Hydrology 

Steve Short Pacific Northwest National 

Laboratory(b) Severe Accident Mitigation 

Alternatives 

Bruce Schmitt Pacific Northwest National Laboratory Severe Accident Mitigation 

Alternatives 

Jon Young Pacific Northwest National Laboratory Severe Accident Mitigation 

Alternatives 

(a) Argonne National Laboratory is operated by UChicago Argonne, LLC for the U.S. Department of Energy. 

(b) Pacific Northwest National Laboratory is operated by Batelle for the U.S. Department of Energy. 
December 2010 11-1 NUREG-1437, Supplement 43 

11.0 INDEX 

accidents ............................................................................................................. xxix, 5-1, 5-2, 5-3 

aesthetic ........................................................ xxviii, 2-52, 2-56, 4-20, 8-15, 8-26, 8-33, 8-42, 8-52 

alternatives ........ v, xxix, 1-5, 4-31, 5-3, 5-10, 6-3, 8-1, 8-42, 8-53, 9-1, 10-1, A-13, E-4, F-1, F-32 

archaeological resources ................. xxviii, 1-6, 2-62, 4-19, 8-16, 8-27, 8-41, 8-52, 9-4, 10-1, D-1 

Barnwell ..................................................................................................................................... 2-6 

burnup .............................................................................................................................. 2-1, B-11 

chronic effects ........................................................................ 1-3, 4-11, 4-15, 4-29, 4-33, 9-1, B-1 

closed-cycle cooling .................................................................................................... 4-3, 8-5, B-4 

cultural resources ............................................................... 4-19, 4-33, 8-16, 8-27, 8-33, 8-41, C-1 

decommissioning ...................................................................... xxx, 6-4, 7-1, 8-50, 9-3, A-4, A-30 

design-basis accidents ............................................................................................. xxxiv, 5-1, 5-2 

discharges ............................................................ xxvii, 2-5, 2-19, 2-27, 2-40, 4-2, 4-26, A-6, F-20 

dose ........................................ xxviii, xxxvii, 2-5, 4-12, 4-13, 4-32, 5-13, 9-2, A-8, A-11, F-4, F-15 

education ............................................................................................................. 2-53, A-14, A-20 

electromagnetic fields ............................................ xxxiv, 1-3, 4-9, 4-15, 4-29, 4-33, 9-1, B-1, B-5 

environmental justice ............................................ xxviii, 1-3, 4-20, 8-16, 8-27, 8-34, 9-1, A-4, B-1 

EPA ........................................................... xxxiv, 2-7, 2-34, 2-56, 4-13, 4-32, 8-2, 8-19, A-7, A-13 

GEIS ................................. xxv, xxxv, 1-3,, 1-6, 1-8, 4-1, 4-9, 4-11, 4-27, 4-29, 4-33, 5-1, 6-1, 7-2 

ground water .................................................................................................................... 4-12, C-1 

hazardous waste ......................................................................................................... 2-7, 9-2, C-2 

high level waste ......................................................................................................... 8-53, A-5, 23 

low level waste ........................................................................................................................ xxxvi 

mitigation ......................... xxvi, 1-3, 1-4, 1-5, 2-64, 3-1, 4-1, 4-11, 4-15, 5-3, 8-12, 9-2, 10-1, A-24 

mixed waste ................................................................................................................... 8-52, B-10 

NEPA .............................................................................. xxvi, xxxvii, 1-1, 1-10, 4-27, 5-1, 7-2, 9-1 

no-action alternative ............................................................................................. v, xxix, 8-50, 9-3 

nonattainment ....................................................................................................... 2-34, 4-30, 8-13 

NPDES .................................................................................................................................. xxxviii 

postulated accidents .......................................................................................................... 5-1, 5-3 

pressurized water reactor ............................................................................................ xxxviii, F-29 

radon-222 ........................................................................................................................... 6-1, B-8 

reactor ............................................................................................................... xxv, xxxiv, 5-1, 5-2 

refurbishment .......................................................................... 2-6, 3-1, 4-14, A-28, B-1, B-4, F-29 

replacement power .............................................................................................................. v, F-26 

scoping ................................................ xxv, xxvi, xxvii, 1-2, 1-5, 1-6, 4-11, 4-27, 5-2, 5-3, 6-1, 7-2 

severe accidents (SAMA) ....................................................................... xxix, xxxix, 5-9, 10-1, F-1 

solid waste ............................................................................... 2-6, 2-21, 6-1, 6-2, 8-18, 8-43, C-1 

spent fuel ................................................................... xxvi, xxxvi, 1-4, 5-4, 5-9, 5-10, 6-1, 6-2, A-5 

stormwater ..................................................................................................................... 2-22, 4-12 

surface water ............................................. xxviii, 2-27, 2-40, 4-5, 4-12, 4-25, 8-5, 8-12, 8-23, B-1 

threatened and endangered species ........................................ 1-6, 2-43, 2-44, 4-9, 9-1, C-1, D-1 

transmission lines ....................................................... xxviii, 2-9, 2-43, 2-65, 4-10, 4-29, 4-33, 9-1 

tritium .......................................................................................... 2-22, 2-23, 2-26, 4-12, 4-25, A-7 

uranium ............................................................................................ xxxix, 2-1, 6-1, 6-2, 8-32, A-7 

December 2010 12-1 NUREG-1437, Supplement 43 

12.0 LIST OF AGENCIES, ORGANIZATIONS, AND PERSONS TO 

WHOM COPIES OF THE SUPPLEMENTAL ENVIRONMENTAL IMPACT 

STATEMENT ARE SENT 

Name and Title Company and Address 

Mr. Randall K. Edington 

Executive Vice President 

Nuclear CNO 

Arizona Public Service Company 

P.O. Box 52034, Mail Station 7602 

Phoenix, AZ 85072-2034 

Mr. Steve Olea Arizona Corporation Commission 

1200 W. Washington Street 

Phoenix, AZ 85007 

Mr. Douglas Kent Porter 

Senior Counsel 

Southern California Edison Company 

Law Department, Generation Resources 

P.O. Box 800 

Rosemead, CA 91770 

Mr. Geoffrey M. Cook Southern California Edison Company 

5000 Pacific Coast Highway, Bldg. D21 

San Clemente, CA 92672 

Senior Resident Inspector U.S. Nuclear Regulatory Commission 

P.O. Box 40 

Buckeye, AZ 85326 

Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 

612 E. Lamar Blvd., Suite 400 

Arlington, TX 76011-4125 

Chairman Maricopa County Board of Supervisors 

301 W. Jefferson, 10th Floor 

Phoenix, AZ 85003 

Mr. Aubrey V. Godwin 

Director 

Arizona Radiation Regulatory Agency 

4814 S. 40th Street 

Phoenix, AZ 85040 

Mr. Ron Barnes 

Director, Regulatory Affairs 

Palo Verde Nuclear Generating Station 

Mail Station 7636 

P.O. Box 52034 

Phoenix, AZ 85072-2034 

Mr. Dwight C. Mims 

Vice President, Regulatory Affairs and Plant 

Improvement 

Palo Verde Nuclear Generating Station 

Mail Station 7605 

P.O. Box 52034 

Phoenix, AZ 85072-2034 

Mr. John C. Taylor 

Director, Nuclear Generation 

El Paso Electric Company 

340 E. Palm Lane, Suite 310 

Phoenix, AZ 85004 
List of Agencies, Organizations, and Persons 

NUREG-1437, Supplement 43 12-2 December 2010

Name and Title Company and Address 

Mr. Jeffrey T. Weikert 

Assistant General Counsel 

El Paso Electric Company 

Mail Location 167 

123 W. Mills 

El Paso, TX 79901 

Mr. James Ray Public Service Company of New Mexico 

2401 Aztec NE, MS Z110 

Albuquerque, NM 87107-4224 

Mr. Robert Henry Salt River Project 

6504 E. Thomas Road 

Scottsdale, AZ 85251 

Mr. Eric Tharp Los Angeles Department of Water & Power 

Southern California Public Power Authority 

P.O. Box 51111, Room 1255-C 

Los Angeles, CA 90051-0100 

Mr. Brian Almon Public Utility Commission 

William B. Travis Building 

P.O. Box 13326 

1701 N. Congress Avenue 

Austin, TX 78701-3326 

Mr. Philip McNeely 

Environmental Program Manager 

City of Phoenix 

Office of Environmental Programs 

200 W. Washington Street 

Phoenix, AZ 85003 

Mr. Tom Kelly U.S. Environmental Protection Agency, Region IX 

Environmental Review Office 

Communities and Ecosystems Division 

Mail code: CED-2 

75 Hawthorne Street 

San Francisco, CA 94105 

Mr. Louis J. Manuel Jr. 

Chairman 

Ak-Chin Indian Community 

2507 W. Peters & Nall Road 

Maricopa, AZ 85238 

Mr. John Arminger 708 North 371st Ave. 

Tonopah, AZ 85254-0127 

Barb Painter 36023 W. Buckeye Rd. 

Tonopah, AZ 85354 

Mr. Stephen Brittle 6205 South 12th St. 

Phoenix, AZ 85042 

Mr. William R. Rhodes 

Governor 

Gila River Indian Community Council 

P.O. Box 97 

Sacaton, AZ 85247 
List of Agencies, Organizations, and Persons

December 2010 12-3 NUREG-1437, Supplement 43

Name and Title Company and Address 

Mr. Joseph Manual 

Lt. Governor 

Gila River Indian Community Council 

P.O. Box 97 

Sacaton, AZ 85247 

Ms. Margaret Cook 

Director 

Gila River Indian Community Council 

P.O. Box 97 

Sacaton, AZ 85247 

APPENDIX A. 

COMMENTS RECEIVED ON THE PALO VERDE NUCLEAR 

GENERATING STATION, ENVIRONMENTAL REVIEW 

Appendix A 

December 2010 A-1 NUREG-1437, Supplement 43

A. COMMENTS RECEIVED ON THE PALO VERDE NUCLEAR 

GENERATING STATION, ENVIRONMENTAL REVIEW 

A.1 COMMENTS RECEIVED DURING SCOPING 

The scoping process began on May 26, 2009 with the publication of the U.S. Nuclear 

Regulatory Commission’s (NRC’s) Notice of Intent to conduct scoping in the Federal Register

(74 FR 24884). The scoping process included two public scoping meetings held in Tonopah 

and Avondale, Arizona on June 25, 2009. Approximately 60 people attended the meetings. 

After the NRC’s prepared statements pertaining to the license renewal process, the meetings 

were open for public comments. Twelve (12) attendees provided oral comments that were 

recorded and transcribed by a certified court reporter, written statements or both. Transcripts 

for the afternoon and evening meetings were made publicly available at the NRC Public 

Document Room (PDR) and from the NRC's Agencywide Documents Access and Management 

System (ADAMS) listed under Accession Nos. ML092040121 and ML092040125, respectively. 

A summary of the meeting, which was issued on August 4, 2009, is listed under Accession No. 

ML091900138. 

At the conclusion of the scoping period, the NRC staff reviewed the transcripts and all written 

material received, and identified individual comments. Twenty-two (22) letters, emails, or 

documents containing comments were also received during the scoping period. All comments 

and suggestions received orally during the scoping meetings or in writing were considered. 

Each set of comments from a given commenter was given a unique alpha identifier (Commenter 

ID letter), allowing each set of comments to be traced back to the transcript, letter, or email in 

which the comments were submitted. The Commenter ID letter is preceded by PV (short for 

Palo Verde Nuclear Generating Station). The Commenter ID letter is followed by a number for 

submissions that contained multiple comments. Table A-1 identifies the individuals providing 

comments and the Commenter ID letter associated with each person's set(s) of comments. For 

oral comments, the individuals are listed in the order in which they spoke at the public meeting. 

Accession numbers indicate the location of the written comments in ADAMS. 

The comments received are grouped by category. The categories are as follows: 

1. Comments Regarding License Renewal and Its Processes 

2. Comments Concerning Water Quality and Use 

3. Comments Concerning Air Quality 

4. Comments Concerning Human Health 

5. Comments Concerning Alternatives 

6. Comments Concerning Issues Outside the Scope of License Renewal: Support for 

License Renewal, Security and Terrorism, Emergency Response and Preparedness, 

Plant Performance, Energy Costs, and Other Out of Scope Issues 

 
Appendix A 

NUREG-1437, Supplement 43 A-2 December 2010

TABLE A-1. Individuals Providing Comments During Scoping Comment Period 

Commenter 

ID Commenter Affiliation (If Stated) ADAMS Accession Number (a)

Afternoon Public Meeting 

PV-A Mary Widner Local resident ML092040121 

PV-B Mr. Armiger Local resident ML092040121 

PV-C Mr. Herring Local resident ML092040121 

Evening Public Meeting 

PV-D Steve Brittle President, Don’t Waste Arizona ML092040125 

PV-E Darah Mann Director of Marketing, Western Maricopa 

Coalition ML092040125 

PV-F Ms. Hohmu Southwest Valley Chamber of Commerce ML092040125 

PV-G Adolfo Gamez Mayor of Tolleson, AZ ML092040125 

PV-H John Findley Local resident ML092040125 

PV-I Glenn Hamer Pres., & CEO, AZ Chamber of Commerce 

and Industry ML092040125 

PV-J Felipe Zubia DMB Associates, developer of Verrado, a 

community 30 miles east ML092040125 

PV-K Armando Contreras Pres., & CEO, AZ Hispanic Chamber of 

Commerce ML092040125 

PV-L Jackie Meck Mayor, Buckeye, AZ ML092040125 

Written Comments 

PV-M James Cavanaugh Mayor, Goodyear, AZ ML092110634 

PV-N Bas Aja Executive Vice President, Arizona Cattle 

Feeders’ Association ML092110635 

PV-O Jack Harper Senator, AZ Legislative District 4 ML092110636 

PV-P Connie Wilhelm Pres., & Exec Dir, Home Builders 

Association of Central Arizona ML092110637 

PV-Q Mary Peters Former U.S. Secretary of Transportation 

2006-2009 ML092180409 

PV-R Louis J. Manuel Jr. Chairman, Ak-Chin Indian Community ML092180427 

PV-S Phil Gordon Mayor, Phoenix, AZ ML092180666 

PV-T Tom Boone Representative, AZ Legislative District 4 ML092180428 
Appendix A

December 2010 A-3 NUREG-1437, Supplement 43

Commenter 

ID Commenter Affiliation (If Stated) ADAMS Accession Number (a)

PV-U Tom Kelly U.S. EPA, Region IX, Envr Review Office, 

Communities and Ecosystems Division ML092180429 

PV-V Deanna K. Kupcik President/CEO, Buckeye Valley, Chamber 

of Commerce ML092180430 

PV-W Patricia Fleming AZ State Representative, District 25 ML092180431 

PV-X Judy Burges Representative, AZ Legislative District 4 ML092220044 

PV-Y Todd Sanders Pres., & CEO Greater Phoenix Chamber of 

Commerce ML092370065 

PV-Z Chris Horyza 

Planning and Environmental Coordinator, 

Bureau of Land Management, Arizona State 

Office 

ML091730377 

PV-AA Steve Brittle President, Don’t Waste Arizona ML092720530 

PV-AB Steve Brittle President, Don’t Waste Arizona ML092720533 

PV-AC Steve Brittle President, Don’t Waste Arizona ML092160241 

PV-AD Steve Brittle President, Don’t Waste Arizona ML092160239 

PV-AE Steve Brittle President, Don’t Waste Arizona ML092160232 

(a) The accession number for the afternoon transcript is ML0920401210. 

The accession number for the evening transcript is ML092041250. 

The comments and suggestions received as part of the scoping process are discussed below. 

Comments can be tracked to the commenter and the source document through the ID letter and 

comment listed in Table A-1. 

A.1.1. Comments Regarding License Renewal and Its Processes 

Comment PV-H: My name is John Findley. I'm here tonight representing myself as a member 

of the public. I want to thank the NRC for coming to Arizona from their home in Rockville, which 

we know is next to paradise. And I just wish at this point to express my concern about some of 

the issues that have been brought up tonight and express my hopes that the NRC will examine 

this in a thorough and extensive process that you have set out in the table that you laid out. 

Concerns involve the uneven performance of Palo Verde in the past, along with the uncertain 

future of long-term storage for nuclear waste; I think that's a really important issue that has to be 

taken into consideration. And probably most of all and as has been pointed out, the aging 

infrastructure that we're dealing with. 

The implications of this are basically unknown. We've had incidents in the past in other 

locations where corrosion and the effects of radiation on the physical infrastructure have gone 

unnoticed in spite of continued surveillance and this has to be something that is taken into 

consideration. 
Appendix A 

NUREG-1437, Supplement 43 A-4 December 2010

Comment PV-U-2: With regard to the existing Palo Verde facility, we recommend the DEIS 

include: an evaluation of environmental justice concerns, based on CEQ guidance1

; a summary 

of routine releases and a description of any non-routine releases; a discussion of the capacity 

and adequacy of nuclear waste storage for an additional twenty years or more; an updated 

estimate to decommission the facility; and financial assurance mechanisms in place to ensure 

proper decommissioning in the event of bankruptcy on the part of the owner. 

1

Environmental Justice Guidance under 'the National Environmental Policy Act; Appendix A 

(Guidance for Federal Agencies on Key Term is in Executive Order 12898), CEQ, December 

10, 1997. 

Response: The comments, in general, express concern with the thoroughness of the license 

renewal process. Overall, NRC has developed a comprehensive license renewal process to 

evaluate applications for extended periods of operation. 

In 1982, the NRC established a comprehensive program for Nuclear Plant Aging Research as 

the result of a widely attended workshop on nuclear power plant aging. Based on the results of 

that research, a technical review group concluded that many aging phenomena were readily 

manageable and did not pose technical issues that would preclude life extension for nuclear 

power plants. 

The NRC also concluded that the existing regulatory requirements governing a nuclear reactor 

facility would offer reasonable assurance of adequate protection if the license were renewed, 

provided that the current licensing basis was modified to account for age-related safety issues. 

In 1991, the Commission approved a rule on the technical requirements for license renewal and 

published the rule in the Code of Federal Regulations, 10 CFR Part 54. The NRC then 

undertook a demonstration program to apply the rule to pilot plants and to develop experience 

to establish implementation guidance. The rule defined the scope as age-related degradation 

unique to license renewal. However, during the demonstration program, the NRC found that 

many aging effects are managed adequately during the initial license period. In addition, the 

NRC found that the review did not allow sufficient credit for existing programs, particularly the 

maintenance rule, which also helps manage plant-aging phenomena. 

As a result, in 1995, following the rulemaking process, the NRC amended the license renewal 

rule. The amended rule in 10 CFR Part 54 established a regulatory process that is more 

effective, stable and predictable than the previous license renewal rule. In particular, Part 54 

was clarified to focus on managing the adverse effects of aging. The rule changes were 

intended to ensure that important systems, structures, and components would continue to 

perform their intended function during the 20-year period of extended operation. 

The comments, in specific, express concern with the following topics: 

History of plant performance - The NRC will ensure that the safety of a currently operating power 

plant will continue to be maintained before renewing the license by ensuring that aging effects 

will be adequately managed and that the licensing basis related to the present plant design and 

operation will be maintained. Before a new license is issued, the NRC will ensure that there is a 

technically credible and legally sufficient basis for granting a new license for an extended 20 

years as reflected in the NRC’s safety evaluation report (SER), final SEIS, and the proposed new 

license. 

Nuclear waste storage - The staff notes that on March 3, 2010, DOE submitted a motion to the 
Appendix A

December 2010 A-5 NUREG-1437, Supplement 43

Atomic Safety and Licensing Board to withdraw with prejudice its application for a permanent 

geologic repository at Yucca Mountain, Nevada. Nevertheless, the safety and environmental 

effects of spent fuel storage have been evaluated by the NRC and, as set forth in the Waste 

Confidence Rule (10 CFR 51.23), the NRC generically determined that such storage could be 

accomplished without significant environmental impacts. In the Waste Confidence Rule, the 

Commission determined that spent fuel can be safely stored onsite for at least 30 years beyond 

the plant’s life, including license renewal. In 10 CFR Part 51, on-site spent fuel storage is 

classified as a Category 1 issue that is applicable to all nuclear power plant sites. While the 

Commission did not assign a single level of significance (i.e., Small, Moderate, or Large) in Table 

B-1 of Appendix B to Subpart A to Part 51 for the impacts associated with spent fuel and high 

level waste disposal, it did conclude that the impacts are acceptable in that these impacts would 

not be sufficiently large to require the NEPA conclusion, for any plant, that the option of extended 

operation under 10 CFR Part 54 should be eliminated. 

The GEIS for license renewal (NUREG-1437) evaluated a variety of spent fuel and waste 

storage scenarios, including on-site storage of these materials for up to 30 years following 

expiration of the operating license, transfer of these materials to a different plant, and transfer of 

these materials to an Independent Spent Fuel Storage Installation (ISFSI). During dry cask 

storage and transportation, spent nuclear fuel must be "encased" in NRC-approved casks. An 

NRC-approved cask is one that has undergone a technical review of its safety aspects and 

been found to meet all of the NRC's requirements. These requirements are specified in 10 CFR 

Part 72 for storage casks and 10 CFR Part 71 for transportation casks. For each potential 

scenario involving spent fuel, the GEIS determined that existing regulatory requirements, 

operating practices, and radiological monitoring programs were sufficient to ensure that impacts 

resulting from spent fuel and waste storage practices during the term of a renewed operating 

license would be small, and is a Category 1 issue. 

Aging Infrastructure – The principle safety concerns associated with license renewal are related 

to the aging of structures, systems and components important to the continued safe operation of 

the facility. When the plants were designed, certain assumptions were made about the length of 

time each plant would be operated. During the safety review for license renewal, the NRC must 

determine whether aging effects will be adequately managed so that the original design 

assumptions will continue to be valid throughout the period of extended operation or verify that 

any aging effects will be adequately managed. For all aspects of operation, other than the 

aging management during the period of extended operation, there are existing regulatory 

requirements governing a plant that offer reasonable assurance of adequate protection if its 

license were renewed. The NRC's environmental review is confined to environmental matters 

relevant to the extended period of operation requested by the applicant. Safety matters related 

to aging are outside of the scope of this review. An NRC safety review for the license renewal 

period is conducted separately. The comment provides no new information and will not be 

evaluated further in the context of the environmental review. 

Environmental Justice - Environmental Justice will be addressed in Chapters 2 and 4 of the 

PVNGS SEIS. 

Routine and non-routine releases - The comment regarding a summary of routine releases and 

a description of any non-routine releases is noted. The NRC staff will evaluate the applicant’s 

routine and non-routine releases in Chapters 2 and 4 of the PVNGS SEIS. 

Financial assurance of decommissioning - The comment regarding financial assurance of 

decommissioning is noted. Decommissioning funding assurance is outside the scope of license 
Appendix A 

NUREG-1437, Supplement 43 A-6 December 2010

renewal. Decommissioning funding assurance is addressed pursuant to the requirements of 10 

CFR 50.75(f)(1). Arizona Public Service Company (APS) submitted the 2008 Decommissioning 

Funding Status Report for Palo Verde Nuclear Generating Station, Units 1, 2, and 3 

(ML091030418, dated March 31, 2009). NRC staff reviewed this document and found APS to 

be providing decommissioning funding assurance. 

A.1.2. Comments Concerning Water Quality and Use 

Comment PV-D-8: Another issue I call "Water." With global warming projections indicating a 

hotter, drier southwest, we must be reminded that the vast majority of wastewater from the 

Phoenix metro area, mainly the discharge from the 91st Avenue Wastewater Treatment Plant in 

west Phoenix, goes to cool Palo Verde. 

With hotter temperatures expected, even more water will be needed and nuclear power already 

uses more power per megawatt of power generated than any other form of electrical power 

generation. 

Is this sustainable? Is this water supply for Palo Verde really reliable and sufficient? Is this 

projected Palo Verde water usage a severe economic disincentive to overall economic growth 

and even population growth in this part of Arizona? Are the water needs of Palo Verde a type of 

opportunity cost and opportunity loss brought about by a lack of affordable water for industrial 

and residential uses?

Comment PV-AB-1: The Maricopa Association of Governments (MAG) is the regional planning 

organization of local government in Maricopa County. MAG's Transportation Policy Committee 

has "Interstates 8 and 10-Hidden Valley Transportation Framework Study" as one of its 

upcoming agenda items. This is an early attempt at planning for the transportation needs of a 

projected population of 2.5 million people in the western part of Maricopa County. That 

population is almost the size of the Phoenix metro area now. 

The NRC needs to fully examine the planned population growth in that area near Palo Verde, 

and especially in the context of planned or needed groundwater pumping and the potential land 

subsidence and fissuring, again especially in the area near and including Palo Verde. Some 

areas of Arizona are especially prone to subsidence and fissuring.

Response: The comments, in general, pertain to the plant’s consumptive use of waste water 

from the Phoenix metro area, groundwater resources in the vicinity of PVNGS, and the plant’s 

potential impact on subsidence and fissuring. Groundwater use and water quality issues are 

Category 2 issues and will be addressed in Chapters 2 and 4 of the PVNGS SEIS.

A.1.3. Comments Concerning Air Quality 

Comment PV-D-9: Next topic, carbon impacts. If uranium demand rises as projected, the 

carbon cost of developing less rich ores nullifies any presumed carbon savings from keeping 

their reactors online. Isn't it likely that the true lifecycle carbon emissions of nuclear power 

generation will be officially recognized by the EPA and the U.S. Congress, and carbon cap and 

trade or carbon tax strategies will make nuclear power even more unprofitable? 

Nuclear power is not at all free from carbon emissions. A number of recent studies have found 

out that when mining, processing, and extensive transportation of uranium in order to make 

nuclear fuel is considered, the release of carbon dioxide as a result of making electricity from 

uranium is comparable to converting natural gas into electric power. 
Appendix A

December 2010 A-7 NUREG-1437, Supplement 43

Additional energy required for decommissioning and disposition of the wastes generated 

increases this carbon dioxide output substantially.

Comment PV-AB-7: In addition to radiological pollution, nuclear power also contributes 

massive thermal pollution to both our air and water. It has been estimated that every nuclear 

reactor daily releases thermal energy –heat-- that is in excess of the heat released by the 

detonation of a 15 kiloton nuclear bomb blast. Nuclear power contributes significantly to the 

thermal energy inside Earth’s atmosphere, making it contraindicated at this time of rapid global 

warming. 

Nuclear power is not at all free from carbon emissions. A number of recent studies have found 

that when mining, processing, and extensive transportation of uranium in order to make nuclear 

fuel is considered, the release of carbon dioxide (CO2) as the result of making electricity from 

uranium is comparable to burning natural gas to make electric power. Additional energy 

required for decommissioning and disposition of the wastes generated increases this CO2 

output substantially. What if the national and worldwide economic downturn causes a 

downgrade of the economic viability of funds set aside for decommissioning of Palo Verde? 

Putting decommissioning off even further increases uncertainty, in light of massive resource 

depletion and environmental deterioration aspects like global warming. All of these issues need 

to be analyzed and mitigated. 

Response: The comments are noted, and pertain to impacts to air quality from carbon 

emissions. Impacts to air quality from carbon emissions associated with the uranium fuel cycle 

will be evaluated in Chapter 6 of the PVNGS SEIS.

A.1.4. Comments Concerning Human Health 

Comment PV-D-1: My name is Stephen Brittle, I'm the president of Don't Waste Arizona, a 

nonprofit environmental organization, 501(c)(3)(7) here in Arizona. On behalf of the 

organization and its effect of their concerns are these comments on the record: 

Thank you for the opportunity to submit concerns and questions about the wisdom of renewing 

the license of an aging, severely-troubled, nuclear power plant complex that has caused 

significant economic hardship for a financially troubled company that just asked for a rate 

increase to forestall an even worse credit rating. 

The first concern I have is that in April, there was a meeting and you let them off the hook for 

their closer scrutiny. I was frankly disappointed that NRC representatives seemed unaware of 

the plume of tritium under the nuclear plant; something I found out about by looking through the 

facility's file at the Arizona Department of Environmental Quality. And the fact that they didn’t 

seem to know about it raised real questions about NRC's oversight. 

I understand that the plume was caused by the monsoon rains knocking the normal radioactive 

air emissions from Palo Verde onto the roof of the facility that then drained into an unpaved area 

where it soaked into the ground. Levels of tritium in the ground seemed likely to increase. 

I remind everyone that the National Academy of Sciences agrees there is no safe dose. 

According to the National Academy of Sciences in 2005, there is no threshold dose below which 

ionizing radiation is safe. 

And years before that, it stated there is no safer level of exposure, there is no dose of ionizing 
Appendix A 

NUREG-1437, Supplement 43 A-8 December 2010

radiation so low that the risk of a malignancy is zero; that's from Dr. Karl Morgan, the father of 

health physics. 

Historically, the significance of internal dosage from fission products has not been appreciated. 

There is something that is called "Reference Man" and these standards ignore those most at 

risk. 

Women are 52 percent more likely to get cancer from the same amount of radiation dose 

compared to men. Children are at greater risk, of course, than adults. 

A female infant has about a seven times greater chance of getting cancer than a 30—year old 

male with the same radiation exposure. Pregnant women and the developing fetus are 

particularly vulnerable to radiation exposure; however, non-cancer reproductive effects are not 

part of the U.S. Regulatory framework for radiation protection. 

U.S. radiation exposure regulations and compliance methods often fail women, children, and 

other more radiosensitive groups because they are based on the reference man; a hypothetical 

20 to 30 year old Caucasian male. 

At least three federal agencies, the Environmental Protection Agency, the NRC, and the 

Department of Energy, still use reference man in radiation dose regulations and compliance 

assessment including the Clean Air Act and safe drinking water rules despite evidence that the 

standard is not adequate to protect many groups. 

In both France and the U.S., for nearly 30 years after the first reactors went on line, no studies 

of cancer near reactors were done. Neither utilities nor the NRC conducts health studies; 

neither monitor local cancer rates near reactors, yet both strongly criticize any studies that 

suggest harm. One is left wondering who to trust. 

Look at the French. Official French statistics, among 39 European nations the 2006 cancer 

incidence rate is the third highest for men and 13th highest for women. The incidence rates 

rose 39 percent from 1980 to 2005 compared to 10 percent in the United States. 

Perhaps most telling, the thyroid cancer rate in France rose a staggering 433 percent for males 

and 186 percent for females, far more than in the U.S. A clue and indicator, if not a smoking 

gun. Doctors know of no other clear cut cause of thyroid cancer other than radiation exposure. 

The thyroid cancer rates in the four counties closest to Indian Point, for example, are nearly 

double the U.S. average, and that childhood cancer in these counties is also above the national 

rate. 

Something called the Mother's Milk Project, also this year; of 30 milk samples from 

breastfeeding mothers and goats within 50 miles of Indian Point, nearly all revealed levels of 

strontium-90 with the highest results occurring closest to the Indian Point reactors. 

Of great concern, the presence of both strontium-90 and a related fission product strontium-89, 

which has a short half life. Its presence provides strong evidence radioactivity was recently 

produced from a nearby source. 

Comment PV-AE: While analyzing and determining the additional risks posed by relicensure of 

aging nuclear power plants like Palo Verde’s, please consider the attached article, “Push For 

New Nuclear Power Sputters, But Old Reactors Still Pose Cancer Risks”.
Appendix A

December 2010 A-9 NUREG-1437, Supplement 43

A recent energy bill sponsored by Congressional Republicans proposed building 100 new 

nuclear reactors across the United States in the next 20 years. 

The proposal, which would double the current U.S. total of 104 operating nuclear reactors, 

would amount to a nuclear renaissance, as no new reactors have been ordered since 1978. 

Concerns about global warming gave utilities the idea for this revival since reactors don’t emit 

greenhouse gases while generating power, and utilities have stopped closing old reactors while 

proposing 33 new ones to be sited in New England, throughout the South and Southeast, and in 

Texas, Utah and Idaho. 

(For a list of applications to the Nuclear Regulatory Commission for approval of new reactors 

click here. http://www.nrc.gov/reactors/new-reactors/new-licensingfiles/expected-new-rxapplications.pdf) 

But this month, two Swedish scientists published an article concluding that a large increase in 

nuclear reactors will not solve global warming. 

The utilities, of course, fail to report that greenhouse gases are emitted throughout the entire 

nuclear fuel cycle, and operating the reactor itself is the only exception. Both the nuclear 

reactor industry and its support industries spew radioactive materials into local air and water, 

posing a serious health hazard, warns Dr. Samuel S. Epstein, chairman of the Cancer 

Prevention Coalition and Professor emeritus Environmental & Occupational Medicine at the 

University of Illinois at Chicago School of Public Health. 

In the 1970s, Wall Street investors stopped funding new reactor projects due to cost and safety 

concerns. Today, these issues are unchanged, and private investors again gave a thumbsdown to nuclear power. A 2005 law authorizing $18.5 billion in federal loan guarantees would 

only cover two reactors. 

The Bush administration was a willing partner in the nuclear revival. George W. Bush became 

the first sitting U.S. president to visit a nuclear plant since a grim-faced President James Carter 

toured the damaged Three Mile Island reactor on April 1, 1979. 

President Barack Obama has poured cold water on the renaissance. He rejected a request for 

$50 billion in loan guarantees in the stimulus package. Additionally, he rejected further funding 

for developing the nuclear waste dump at Yucca Mountain Nevada, leaving utilities with no 

place to permanently store their highly radioactive nuclear waste. It is now being held 

temporarily at 55 storage sites licensed by the Nuclear Regulatory Commission and at 

Department of Defense sites and national laboratories across the country. 

The major threat posed by nuclear reactors is not the addition of new reactors, but continuing to 

operate old and corroding ones, says Dr. Epstein. U.S. reactors are granted licenses for 40 

years, and many are approaching that mark. Many utilities have asked regulators to extend 

their licenses for an additional 20 years. 

"Each of the first 52 requests has been given a rubber-stamp approval, even though operating a 

60 year old reactor would be a huge risk to human health," says Joseph Mangano, MPH, MBA, 

executive director of the Radiation and Public Health Project. Notable exceptions are state 

government officials in New York and New Jersey, who are opposing the attempts to extend 

licenses for reactors in their states. 
Appendix A 

NUREG-1437, Supplement 43 A-10 December 2010

About 80 million Americans in 37 states live within 40 miles of a nuclear reactor, including 

residents of New York City, Chicago, Philadelphia, Detroit, Miami, Phoenix, Cleveland, and 

Boston. "If a meltdown were to occur, safe evacuation would be impossible and many 

thousands would suffer from radiation poisoning or cancer," warns Dr. Epstein. "The horrifying 

specter of Chernobyl, or of terrorists attacking a nuclear plant, is not lost on concerned 

Americans." 

Reactors are a real health threat, not just a potential one, a fact largely ignored by mainstream 

media, he declares. 

To generate electricity, over 100 radioactive chemicals are created – among the most 

dangerous chemicals on Earth, and the same toxic mix in atomic bomb test fallout. These 

gases and particles, including Strontium-90, Cesium-137, and Plutonium-239, are mostly stored 

as waste. But some must be routinely released into air and water. Humans breathe, eat, and 

drink them - just as they did bomb fallout - raising the cancer risk, especially to children. 

Industry and government officials argue that reactor emissions are too small to cause harm. But 

for years, scientists have produced study after study documenting high cancer rates near 

reactors. For example, a 2007 review of the scientific literature by researchers from the 

University of South Carolina found elevated rates of childhood cancers, particularly leukemia 

and brain cancers, in nearly all 17 studies examined. A 2008 study of German reactors was 

one of the largest ever done, and it also found high local rates of child cancer. 

Mangano and colleagues published a January 2002 article in the journal "Archives of 

Environmental Health," showing that local infant deaths and child cancer cases plunged 

dramatically right after shut down whenever a U.S. reactor closed. Because the very young 

suffer most from radiation exposures, they benefit most when exposures are removed. This 

research indicated that there would be approximately 18,000 fewer infant deaths and 6,000 

fewer child cancer cases over the next 20 years if all nuclear reactors were closed. 

Over half the states in the United States, 31, currently host nuclear power plants. 

Illinois has the most with 11, Pennsylvania has nine, New Jersey has four. While waiting for the 

federal government to phase out nuclear power in favor of safer alternatives, state governments 

should act to warn and protect their citizens, urges the Cancer Prevention Coalition. 

Governors have responsibilities to take whatever political action they can to phase-out nuclear 

plants. In the first instance, governors should tell their citizens of the danger. 

In 1954, Atomic Energy Chairman Lewis Strauss declared nuclear power “too cheap to meter.” 

President Richard Nixon envisioned that the nation would have 1,000 reactors by this time. But 

the dreams of people like Strauss and Nixon were dashed by staggering costs and built-in 

dangers. 

The attempt to revive this Cold War-era dream has been, and still is, largely talk. While the talk 

goes on, the nation is fast developing technologies like solar and wind power, which never run 

out and don’t pollute. Putting millions of Americans at risk of cancer by hanging on to old 

reactors – that produce only 19% of America's electricity and 8% of the country's total energy – 

is a reckless gamble. Nuclear reactors in the U.S. should be phased out, and replaced by 

options that don’t threaten public health. 
Appendix A

December 2010 A-11 NUREG-1437, Supplement 43

Response: The NRC staff will address the radiological impacts to human health during its 

evaluation of the Palo Verde license renewal application. However, the radiological impact to 

human health is a Category 1 issue. This means that technical issues classified as Category 1 

in Table B-1 of 10 CFR Part 51 have been generically evaluated in the Generic Environmental 

Impact Statement (GEIS) for license renewal and are not specifically reevaluated in the sitespecific supplemental environmental impact statement (SEIS) unless new and significant 

information is identified. During the environmental review, the NRC staff will make a concerted 

effort to determine whether any new and significant information exists at Palo Verde that would 

change the generic conclusion for a Category 1 issue into a Category 2 issue. Category 2 

issues are site specific issues which must be thoroughly analyzed by the applicant as part of its 

submittal and included in detail in its environmental report. The NRC staff would then 

independently evaluate the issue as part of its SEIS. 

The NRC’s primary mission is to protect the public health and safety and the environment from 

the effects of radiation from nuclear reactors, materials, and waste facilities. The NRC’s 

regulatory limits for radiological protection are set to protect workers and the public from the 

harmful health effects (i.e., cancer and other biological impacts) of radiation on humans. The 

limits are based on the recommendations of standards-setting organizations. Radiation 

standards reflect extensive scientific study by national and international organizations. The 

NRC actively participates and monitors the work of these organizations to keep current on the 

latest trends in radiation protection. If the NRC determines that there is a need to revise its 

radiation protection regulations, it will initiate a rulemaking. The models recognized by the NRC 

for use by nuclear power reactors to calculate dose incorporate conservative assumptions and 

do account for differences in gender and age to ensure that workers and members of the public 

are adequately protected from radiation. 

Although radiation may cause cancers at high doses, currently there are no reputable 

scientifically conclusive data that unequivocally establish the occurrence of cancer following 

exposure to low doses, below about 10 rem (0.1 Sv). However, radiation protection experts 

conservatively assume that any amount of radiation may pose some risk of causing cancer or a 

severe hereditary effect and that the risk is higher for higher radiation exposures. Therefore, a 

linear, no-threshold dose response relationship is used to describe the relationship between 

radiation dose and detriments such as cancer induction. Simply stated, any increase in dose, 

no matter how small, results in an incremental increase in health risk. This theory is accepted 

by the NRC as a conservative model for estimating health risks from radiation exposure, 

recognizing that the model probably over-estimates those risks. Based on this theory, the NRC 

conservatively establishes limits for radioactive effluents and radiation exposures for workers 

and members of the public. While the public dose limit in 10 CFR Part 20 is 100 mrem (1 mSv) 

for all facilities licensed by the NRC, the NRC has imposed additional constraints on nuclear 

power reactors. Each nuclear power reactor, including Palo Verde, has enforceable license 

conditions that limit the total annual whole body dose to a member of the public outside the 

facility to 25 mrem (0.25 mSv). In addition, there are license conditions to limit the dose to a 

member of the public from radioactive material in gaseous effluents to an annual dose of 15 

mrem (0.15 mSv) to any organ and for radioactive liquid effluents, a dose of 3 mrem (0.03 mSv) 

to the whole body and 10 mrem (0.1 mSv) to any organ. 

The amount of radioactive material released from nuclear power facilities is well measured, well 

monitored, and known to be very small. The doses of radiation that are received by members of 

the public as a result of exposure to nuclear power facilities are so low (i.e., less than a few 

millirem) that resulting cancers attributed to the radiation have not been observed and would not 

be expected. To put this in perspective, each person in this country receives a total annual 
Appendix A 

NUREG-1437, Supplement 43 A-12 December 2010

dose of about 300 millirems (3 mSv) from natural sources of radiation (i.e., radon, 200 mrem; 

cosmic rays, 27 mrem; terrestrial (soil and rocks), 28 mrem; and radiation within our body, 39 

mrem) and about 63 mrem (0.63 mSv) from man-made sources (i.e., medical x-rays, 39 mrem; 

nuclear medicine, 14 mrem; consumer products, 10 mrem; occupational, 0.9 mrem; nuclear fuel 

cycle, <1 mrem; and fallout, <1 mrem). 

Although a number of studies of cancer incidence in the vicinity of nuclear power facilities have 

been conducted, there are no studies to date that are accepted by the scientific community that 

show a correlation between radiation dose from nuclear power facilities and cancer incidence in 

the general public. 

• In 1990, at the request of Congress, the National Cancer Institute conducted a study of 

cancer mortality rates around 52 nuclear power plants and 10 other nuclear facilities. 

The study covered the period from 1950 to 1984, and evaluated the change in mortality 

rates before and during facility operations. The study concluded there was no evidence 

that nuclear facilities may be linked causally with excess deaths from leukemia or from 

other cancers in populations living nearby. 

• In June 2000, investigators from the University of Pittsburgh found no link between 

radiation released during the 1979 accident at Three Mile Island power plant and cancer 

deaths among nearby residents. Their study followed 32,000 people who lived within 

five miles of the plant at the time of the accident. 

• The Connecticut Academy of Sciences and Engineering, in January 2001, issued a 

report on a study around the Haddam Neck nuclear power plant in Connecticut and 

concluded radiation emissions were so low as to be negligible and found no meaningful 

associations to the cancers studied. 

• The American Cancer Society in 2000 concluded that although reports about cancer 

clusters in some communities have raised public concern, studies show that clusters do 

not occur more often near nuclear plants than they do by chance elsewhere in the 

population. Likewise, there is no evidence that links strontium-90 with increases in 

breast cancer, prostate cancer, or childhood cancer rates. Radiation emissions from 

nuclear power plants are closely controlled and involve negligible levels of exposure for 

nearby communities. 

• Also in 2001, the Florida Bureau of Environmental Epidemiology reviewed claims that 

there are striking increases in cancer rates in southeastern Florida counties caused by 

increased radiation exposures from nuclear power plants. However, using the same 

data to reconstruct the calculations, on which the claims were based, Florida officials 

were not able to identify unusually high rates of cancers in these counties compared with 

the rest of the state of Florida and the nation. 

• In 2000, the Illinois Public Health Department compared childhood cancer statistics for 

counties with nuclear power plants to similar counties without nuclear plants and found 

no statistically significant difference. 

The NRC, in 2010, asked the National Academy of Sciences (NAS) to update the 1990 U.S. 

National Institutes of Health - National Cancer Institute (NCI) report, “Cancer in Populations 

Living Near Nuclear Facilities.” The NAS will perform a state-of-the-art study on cancer risk for 
Appendix A

December 2010 A-13 NUREG-1437, Supplement 43

populations surrounding nuclear power facilities. The NAS has a broad range of medical and 

scientific experts that can provide the best available analysis of the complex issues involved in 

discussing cancer risk and commercial nuclear power plants. The NAS is a non-governmental 

organization chartered by the U.S. Congress to advise the nation on issues of science, 

technology, and medicine. Through the National Research Council and Institute of Medicine, it 

carries out studies independently of the government using processes designed to promote 

transparency, objectivity, and technical rigor. 

There are three sources of strontium-90 in the environment: fallout from nuclear weapons 

testing, releases from the Chernobyl accident in the Ukraine, and releases from nuclear power 

reactors. The largest source of strontium-90 is from weapons testing fallout as a result of 

above-ground explosions of nuclear weapons (approximately 16.9 million curies of strontium90). The Chernobyl accident released 216,000 curies of strontium-90. The total annual release 

of strontium-90 into the atmosphere from all U.S. nuclear power plants is typically 1/1,000th of 1 

curie, which is so low that the only chance of detecting strontium-90 is sampling the nuclear 

power plant effluents themselves. Radioactive effluent releases are monitored at all nuclear 

power plants, and the results of the monitoring are reported annually to the NRC and are 

publicly available on the NRC’s website. 

To ensure that U.S. nuclear power plants are operated safely, the NRC licenses the nuclear 

power plants to operate, licenses the plant operators, and establishes license conditions for the 

safe operation of each plant. The NRC provides continuous oversight of plants through its 

Reactor Oversight Process (ROP) to verify that they are being operated in accordance with 

NRC regulations. The NRC has full authority to take whatever action is necessary to protect 

public health and safety, and the environment and may demand immediate licensee actions, up 

to and including a plant shutdown. 

In conclusion, the NRC staff will address the radiological impacts to human health during its 

evaluation of the Palo Verde license renewal application. The information will be contained in 

Chapter 4 of the Palo Verde draft SEIS. The public will be offered the opportunity to comment 

on the NRC staff’s findings in the SEIS. 

A.1.5. Comments Concerning Alternatives 

Comment PV-U-1: The U.S. Environmental Protection Agency (EPA) has reviewed the Federal 

Register Notice published on May 26, 2009, requesting comments on the Nuclear Regulatory 

Commission's (NRC's) Notice of Intent to Prepare an Environmental Impact Statement and 

Conduct Scoping Process for Palo Verde Nuclear Generating Station, Units 1, 2. and 3 (Palo 

Verde). Our comments are provided pursuant to the National Environmental Policy Act (NEPA), 

Council on Environmental Quality regulations (40 CFR Parts 1500-1508) and our NEPA review 

authority under Section 309 of the Clean Air Act. 

EPA recognizes the difficulty of finding a viable alternative to an existing facility, such as Palo 

Verde, but we encourage you to consider a full range of alternatives. We recommend that NRC 

examine the most recent information available on renewable energy generation. The Bureau of 

Land Management and Department of Energy have prepared many documents that may be 

helpful, and are currently working on a Solar Energy Programmatic Environmental Impact 

Statement (http://solareis.anl.gov/). This effort is intended to facilitate utility scale solar energy 

development in selected solar energy zones in six western states, including Arizona. We also 

recommend the Draft Environmental Impact Statement (DEIS) discuss the feasibility of using 

residential and wholesale distributed renewable energy generation, in conjunction with 
Appendix A 

NUREG-1437, Supplement 43 A-14 December 2010

increased energy efficiency, as a viable alternative in your analysis. 

Comment PV-AB-8: Another aspect to renewable energy is that it lends itself to something that 

nuclear power cannot: decentralized power production. Therefore, the NRC needs to fully 

examine and analyze the economic impacts and reliability aspects of decentralized power vs. 

nuclear power when examining the relicensure of Palo Verde. 

Response: NRC Staff will consider a wide variety of potential energy alternatives in Chapter 8 

of the PVNGS SEIS. 

A.1.6. Comments Concerning Issues Outside the Scope of License Renewal: Support for 

License Renewal, Security and Terrorism, Emergency Response and Preparedness, Plant 

Performance, Energy Costs, and Other Out of Scope Issues 

Comment PV-B: Not much other than that I appreciate that Palo Verde is here and I want to 

keep it here. But then you said we won't get into a situation like they did out on Avondale where 

they built the plant and then they couldn't license it because of the evaluation maps were -- had 

the population blown at them and then the traffic passed the plant to get out. So we don't have 

that. And just that Palo Verde has had problems in the past, you know with safety compliance, 

but they've come up again with the help of the NRC and they changed management and they're 

doing great. So we'd just like to keep it that way. Thank you, very much. 

Comment PV-C: I'm Jack Herring and I've been in the area since the 1940s. I've seen a lot of 

changes here. And as far as the plant goes, they've been a good neighbor. And anytime there 

was ever anything going on out there that we needed to know, they always called us or let us 

know in some way. So with that I think it should remain here. 

Comment PV-E: Good evening. My name is Darah Mann and I'm the director of marketing 

and communications for WESTMARC. WESTMARC is an acronym for Western Maricopa 

Coalition, which is a broad-based coalition of the 15 communities in western Maricopa County 

which represent more than 35 percent of the county’s population. Our membership consists of 

business, industry, government, education, human services, arts, and cultural organizations, 

chambers of commerce, and community leaders. Thank you for the opportunity to participate 

this evening. 

WESTMARC would like to publicly recognize the multiple significant areas of impact that Palo 

Verde has on our State. On our economy, by providing thousands of well paying jobs, by 

generating low-cost electricity, and by their status of being Arizona's largest taxpayer. On our 

environment, by generating clean energy for a metropolitan area that struggles to meet air 

quality standards. On our quality of life, by powering an unprecedented period of growth, by 

committing to safe and efficient operations. 

Arizonans and others throughout the southwest would not enjoy such a high quality of life 

without the reliable electricity Palo Verde provides to power our businesses, our homes, and 

especially our air conditioners. 

On behalf of WESTMARC, thank you for allowing me to express our continued appreciation for 

the valued contributions Palo Verde continues to provide our community. 

Comment PV-F: It's my new toy [referring to wheel chair]. Thank you for letting me speak 

tonight. I find Palo Verde especially poignant for me. I came to Goodyear in 1980, when we 
Appendix A

December 2010 A-15 NUREG-1437, Supplement 43

were in the throes of building Palo Verde and saw the economic contribution that just the 

building of the plant created. I've subsequently moved to a position with the Southwest Valley 

Chamber of Commerce. The Southwest Valley Chamber of Commerce is an organization that 

focuses on the business communities of Avondale, Goodyear, Litchfield Park, and Tolleson. 

We're a family proximately invested in the organization representing about 15 thousand 

employees. 

I've been with the Chamber since 1984, so I indeed have had the opportunity to see the results 

of the operation of the plant. 

And for those of you who have not been here, did not see the tremendous growth, you have to 

realize, I too, since 1984 did not expect to have the thousands of buildings and people living not 

in just this area, which of course Palo Verde supplies the perfect stage, but we need the energy, 

obviously (indiscernible). It is only when operations such as the power plant that we can supply 

our needs, especially in our peak season which you have the pleasure of joining us in. 

I want to also recognize the Arizona Public Services for their responsible agent managing with 

this particular plant. Their 25 hundred employees do make a significant impact economically. 

But I think more importantly is the contribution that the energy makes to the economic growth of 

our area. Without energy we could not continue our growth. 

So I thank you very much for allowing me to address the issues and I thank you for being in our 

community tonight so that we can. 

Comment PV-G: Good evening. Welcome to the west valley. My name is Adolfo Gamez, I'm 

the Mayor of the city of Tolleson. And for the record, the city of Tolleson supports the license 

renewal of Palo Verde and we're a member of WESTMARC, and so the statements that they 

made on behalf of WESTMARC we echo. 

Comment PV-I: Good evening. My name is Glenn Hamer, I'm the president and CEO of the 

Arizona Chamber of Commerce and Industry. We're a statewide advocacy organization 

representing hundreds of companies across Arizona who employ about 250 thousand 

Arizonans. We're also served as the home to the Arizona Manufacturer's Council, which is -- 

we are the statewide affiliate for manufacturers for the National Association of Manufacturers. 

I just wanted to say that we strongly support this application. Nuclear power, in fact, in our 2009 

business agenda we've identified nuclear power generation as a key goal. In fact, we've talked 

about the importance of removing obstacles to expanding nuclear power generation. 

We strongly believe, for the State’s economic health, that nuclear power must continue to play a 

major role in Arizona's energy net. That becomes all the more important given a number of the 

proposals closer to your home in Washington, DC concerning climate change. It's unimaginable 

for us to think of a world where we didn't have a -- the very important State asset of Palo Verde. 

Again, the Arizona Chamber of Commerce and Industry, we strongly support continuation and 

this application and it's absolutely vital to the state's economic health. 

Thank you for the chance to speak this evening. 

Comment PV-J: Good evening, Felipe Zubia. For the record, I'm here representing DMB 

Associates, developer and master plan developer for a community called Verrado, which is 
Appendix A 

NUREG-1437, Supplement 43 A-16 December 2010

about 30 miles east of the facility. 

And a little bit of history here. About ten years ago we embarked on the investment of this 

community, which is about 10 thousand acres, over 3000 homes. 

And at the time, the property was being used as a Caterpillar proving ground, of course an 

appropriate use for the area at the time. However, we saw the area as much more than that, in 

fact partnered with Caterpillar to bring a master planned community that really is unrivaled in the 

west valley and frankly I'd put it up against any other community here in the State. 

With that in mind, as we went through that process we reached out to all of our constituents in 

the area. Not only the Town of Buckeye and the surrounding communities but Luke Air force 

Base as well as Palo Verde. 

At the time, we certainly wanted to assure all of our partners and constituents that we would be 

good neighbors; and in doing so, we received recommendations of support. We believe that 

we've upheld our commitment to be good neighbors. And in that same regard, we're here today 

to support APS, Pinnacle West, and the extension of the Palo Verde licensing process. 

They have been tremendously good neighbors. They have been a foundation of support and 

economic support for the area. And most importantly, they've been very responsive and reliable 

managers of the facility. 

In fact, as the master plan developer of the community, we have a substantial investment not 

only in the built environment but in the cultural environment, and the natural environment that 

we have built up out there. 

And we too hope that you look at the application very closely. We have a lot of people out there 

that certainly want to make sure that the process is done right. 

But with that in mind we think that you'll find up and down the line from Palo Verde managers to 

APS to Pinnacle West; that you'll have responsive, reliable, and responsible management of the 

facility. So we look forward to the renewal process and the successful completion. 

Thank you, very much. 

Comment PV-K: Good evening. Thank you for the opportunity to say a few words. Armando 

Contreras, the new president and CEO of the Arizona Hispanic Chamber of Commerce. The 

Chamber of Commerce certainly encourage and supports the relicensing process. 

We -- here in the State, there are approximately 35 thousand Hispanic-owned businesses just in 

Phoenix. We're encouraged with the continued development and safety that Palo Verde has 

offered to the community. 

And we're also encouraged at the participation and embracement of the Hispanic minority 

women business and economic development that's been going on here. That has been really 

supported by Palo Verde and we want to continue that partnership and we hope that you 

continue towards these procuring opportunities that are out there for Hispanic businesses and 

all minority businesses in the State of Arizona. 

Thank you, very much. 
Appendix A

December 2010 A-17 NUREG-1437, Supplement 43

Comment PV-L: Thank you. I apologize for being late, but I had another meeting that ended 

just now. My name is Jackie Meck and I reside at 225012 West Walcott, Buckeye, Arizona. 

Nuclear Regulatory Commission Members, thank you for allowing me to speak on behalf of the 

Palo Verde Nuclear Power Plant. 

I am the Mayor of the Town of Buckeye with a population of around 45 thousand. We are 

located approximately 20 miles east of the power plant. In the 1970's I was on the Town 

Council for a period of nine years. The final three years, as Mayor, the Arizona Public Service 

managing partner of Palo Verde asked me, among others, to be on a community advisory 

committee. The committee functioned for approximately 10 to 12 years as I recall. 

During that time, we as committee members, were updated regularly as to the ongoing 

construction and any problems that would arise from traffic, dust, or equipment. We were 

always kept up to date and made aware of any and all situations. 

Since the beginning, they have provided funding for various community clubs, charities, and 

activities. Currently, as a member of the large area fund committee, which was funded by 

Arizona Public Service Palo Verde, the committee meets annually and it supports funding 

various groups such as schools and other opportunities to better our community. They have 

been partners and excellent neighbors to the Town of Buckeye for the past 30 years. 

In closing, they are committed to the community, not only with contributions in real dollars, but in 

employee volunteer service. They operate the plan efficiently, faithfully and continue to help 

Arizonans in inexpensive power. Palo Verde is Arizona's largest tax payer and a major 

employer. I would support them anywhere, anytime, especially at this point in time to continue 

their development of the next phase of the Palo Verde Nuclear Power Plant. 

Thank you for allowing me to speak. And again I apologize for being late to my appointment. 

Thank you. 

Comment PV-M: I am writing to request your board to uphold the standings of the Palo Verde 

Nuclear Generating Station in the review of all its units. Palo Verde matters greatly to the 

citizens of Goodyear. The plant provides the energy that fuels many homes in my city. Further, 

it provides clean, reliable energy to over four million people in the Southwest region. Arizona 

Public Service has worked diligently, along with NRC supervision, to ensure Palo Verde is a 

safe and efficient plant, and a model of America's nuclear energy team as the nation's largest 

energy provider. The plant employs over 2,500 people, many of those from Goodyear, and is 

Arizona's largest taxpayer. It makes economic sense to efficiently continue to run Palo Verde. 

As the Mayor of Goodyear, I strongly encourage you to renew the license for Palo Verde, to 

keep clean and reliable power coming to our homes, and to allow this fine example of America's 

nuclear power to function for years to come. 

Comment PV-N: I am writing to your board to support the renewal application for the Palo 

Verde Nuclear Generating Station. As the largest nuclear power plant in America, Palo Verde is 

a symbol of Arizona's energy leadership and a welcome contributor to our energy infrastructure. 

Palo Verde supplies the clean and efficient power that keeps so many of our state's businesses 

in operation and homes well lit. With recent improvement made to the safety and management 

of the plant, I am confident in APS's ability to continue running Palo Verde reliably for many 
Appendix A 

NUREG-1437, Supplement 43 A-18 December 2010

years more. As a major contributor to Phoenix and Southern California's power structure, Palo 

Verde holds a firm place in our two region's economies. Palo Verde is the baseline standard for 

pricing of energy here and helps keep costs low so that business owners can concentrate more 

on expanding and growing and less on the costs of operation like an expensive utility bill. 

I can recall few times where the power has been out that it has not been swiftly restored. 

Thanks to the reliability of APS and Palo Verde, I have rarely had to worry about such a 

concern. As Arizona is facing one of the toughest economic climates in decades, losing the 

lower costs Palo Verde provides would be yet one more blow to business owners all over the 

region. I hope you will take my letter into consideration and find that renewing the license 

application for Palo Verde is a smart decision for businessmen, homeowners and our entire 

state's economy. 

Comment PV-O: I am writing this letter to express my support for the renewal application of the 

Palo Verde Nuclear Generating Station. Palo Verde creates the clean, reliable and cost 

effective energy that my constituents in Legislative District 4 can rely on. The continued future 

of this generating station is important to all of us. 

Benefits of the energy produced by Palo Verde directly impact the citizens I represent. An 

unwavering and low cost for energy can ease the strain experienced due to the current 

economic climate. Beyond the cost of energy consumption, my constituents expect the power 

coming to their homes to stay on throughout summer heat waves and desert monsoons. Palo 

Verde has been a part of that dependable service provided by APS. 

APS has shown a long-term commitment to the development of the Palo Verde's location and 

wide range of service areas. The generating station is a major employer with more than 2,500 

jobs and is one of Arizona's largest taxpayers. Support of Palo Verde makes strong economic 

sense, especially as it is the nation's largest power provider. 

APS has shown its ability to safely and efficiently operate the generating station. With Palo 

Verde, the utility company has kept power bills low while ensuring environmental benefits such 

as clean air. I ask that you take my letter of support into consideration when reviewing the 

renewal of Palo Verde. I have confidence in APS and the plant to continue delivering clean, 

reliable and cost effective energy to my constituents’ homes, for a very long time. 

Comment PV-P: I am writing in support of the renewal application for the Palo Verde Nuclear 

Generating Station. Palo Verde's contribution to the State of Arizona with clean, reliable, and 

cost effective energy is of great importance to members of the Home Builders Association of 

Central Arizona (HBACA). 

As President and Executive Director of the HBACA, I am intimately familiar with the need for a 

steady and low cost energy supply to support Arizona's economic growth, which has been 

largely spurred by housing. Our homeowners expect reliable power that can be swiftly repaired 

when storms knock down lines, blow transformers or otherwise cause an interruption in service. 

APS and the power it provides with Palo Verde have always ensured this. 

As the state's largest power provider, APS's ability to continue to operate the existing Units at 

Palo Verde makes strong economic sense. It makes sense for homeowners and for 

homebuilders. Losing the low-cost reliable energy provided by Palo Verde, in addition to the 

number of jobs it creates, would be a damaging blow to an already weak housing market in 

Arizona. 
Appendix A

December 2010 A-19 NUREG-1437, Supplement 43

APS's strong management team has led the state in efforts to keep energy efficiency a major 

goal for customers, while continuing to provide energy that balances environmental and 

development concerns. The Palo Verde Station is an important part of the Arizona economy 

and a symbol of Arizona's commitment to delivering clean, reliable, and cost effective energy to 

Arizona homeowners for decades to come. I urge your strong consideration in renewing Palo 

Verde's application.

Comment PV-Q: Palo Verde Nuclear Generating Station provides the power that keeps 

Arizona homes, businesses, our transportation system and our economy moving. When I 

learned of Palo Verde's renewal application, I wanted to take the opportunity to write in support 

of that application to the Nuclear Regulatory Commission. Arizona would simply not run as 

efficiently without this important power plant. 

Palo Verde provides the clean, inexpensive and reliable energy that ensures not only homes 

around Arizona are powered, but the street lights and signs of their neighborhoods as well. As 

the former U.S. Secretary of Transportation and Director of the Arizona Department of 

Transportation, I know how crucial it is for our transportation systems to be efficient and 

dependable. Whether it is a school street sign or the Valley's newest light rail, power provided 

by Palo Verde ensures Arizona's transportation continues to operate smoothly. 

Within recent years APS has renewed their efforts to make Palo Verde the safe and reliable 

plant it is today. One of the most important factors in powering any transportation system is 

reliability. Our transportation systems must be working at all times. I have confidence in APS to 

maintain that reliability with Palo Verde for decades to come and continue providing the low 

cost, efficient and reliable power that runs our systems. 

It is both a strong economic and infrastructure decision to renew the license for Palo Verde 

Nuclear Generating Station. Losing the power provided by Palo Verde would be devastating for 

the state's infrastructure and cost a great deal of money in building additional plants to supplant 

the need. If you would like to speak with me further on why I believe Palo Verde is right for 

Arizona, please do not hesitate to contact me. 

Comment PV-S: I am very pleased to highly recommend the renewal of the license for the 

Palo Verde Nuclear Power Facility which is situated just west of Phoenix. I am even more 

pleased to provide comments in support, of Arizona Public Service (APS) and its parent and 

affiliates who are the primary operators of this incredible facility, the largest nuclear power plant 

in the United States. 

The facility itself appears to meet or exceed standards of safety, environmental regulations, 

security, operations, communications, and community integration. It has a history of operational 

excellence by a company and partnership that truly cares about: its employees and the 

community in which it serves. As with any community near a nuclear facility, we want to ensure 

that such an operation is the safest and most efficient of its kind. As the 5th largest city in the 

nation, that concern is manifold. That is why the most crucial element of the facility is the open 

and frequent communications that exists between its main operator, APS, and our city. APS is 

quick, meticulous, and thorough in responding to any questions or concerns which ever arise. 

They initiate contact with our authorities whenever any incident occurs or if there is even the 

appearance of any incident. That outstanding two-way communications is responsible for 

ensuring that facts are distinguished quickly from rumors and that -all pertinent parties are kept 

regularly informed of any situation occurring at or near the plant. 
Appendix A 

NUREG-1437, Supplement 43 A-20 December 2010

In addition, Palo Verde was an active member of our statewide Domestic Preparedness Task 

Force which was in place years before the tragedy of 9-11. APS had the foresight, since its 

inception, to form public-private partnerships with our city's and state's leaders and managers 

including our vital public safety entities. That partnership has ensured that communications 

flows to all stakeholders and potentially affected persons/organizations on a regular basis and 

during any times of crisis. That joint effort includes training drills with police, fire, and other first 

responders, and there is a cooperative spirit that is second to none. 

That partnership exists with the other productive operations of APS. As a geographic area 

which has peak energy demands in our summer months, APS has been responsive and 

aggressive in ensuring that power is preserved and available for the homes and businesses of 

our residents which is crucial for our economic, educational, public safety, and business climate. 

APS is a company of which you can be very proud. We certainly are. I have known the top 

leaders of this company over the past 20 years. Each one has understood the tremendous 

responsibilities of the company and the nuclear power facility and have lived up to the 

obligations for producing a safe environment for both employees and residents. 

APS is very involved in our community in more ways than providing power and energy. The 

company's contributions have been essential to our social and economic well-being. It is hard 

to find a cause or an element of quality of life in our Valley in which APS has not been involved. 

Its personnel have been leaders in improving elements of transportation, education, the 

environment, health care, and public safety. Its employees serve on numerous non-profit and 

civic organizations and serve as valuable appointees on various public boards and commissions 

which affect public policy. The awards received by the company and its employees are too 

numerous to mention. They are true community partners, and this Mayor is very grateful for 

their endless contributions to our city, our Valley, our state, and our nation. If there is any 

additional information you need or if you have any questions, please do not hesitate to contact 

me.

Comment PV-T: I am writing to express my support for Palo Verde Nuclear Generating Station 

during its upcoming review by the U.S. Nuclear Regulatory Commission (NRC). For roughly 20 

years Palo Verde has been operating safely and efficiently as the largest station of its kind. 

Many of my constituents in Arizona, Legislative District 4 have always relied on the trustworthy 

service provided by APS. Palo Verde has secured its reputation as an area point of pride, in 

part because of the effort by APS and yourselves, the NRC, to ensure Palo Verde runs safely 

under national rules and regulations. The safety and efficiency of the plant stands out and has 

created a model which nuclear energy can be judged. 

Electricity costs are certainly a consideration for many businesses and homeowners relocating 

all over Arizona, including LD4. Palo Verde has been an important generator of low and steady 

energy costs in Arizona. My constituents and their potential new neighbors care about the clean 

efforts of APS with plants such as Palo Verde, which keep the bottom lines on their electric bills 

low. 

Palo Verde provides energy around the southwest and can continue to support Arizona 

economically and safely. I strongly believe APS will continue to run Palo Verde to the highest 

standards and provide Arizona with clean, reliable energy for years more to come.

Comment PV-V: I would like to advise you about how important the Palo Verde Nuclear 
Appendix A

December 2010 A-21 NUREG-1437, Supplement 43

Generating Station is to Buckeye and to Arizona. Palo Verde's contribution to the state of 

Arizona, with clean, reliable and cost effective energy is well appreciated by everyone at the 

Buckeye Valley Chamber of Commerce. It is a vital resource not only for its energy supply, but 

on a broader scale. Palo Verde affects Arizona's entire economy. 

As the President/CEO of the Buckeye Valley Chamber of Commerce, I understand the benefits 

of a steady and lower cost energy supply. It is always a chief concern economically and, often 

times affects how businesses and families in Buckeye spend their money, especially in the hot 

summers. In accordance, APS and the power it provides with Palo Verde have always striven 

to create clean, cost- sensitive energy, while continuing to provide important environmental 

benefits. 

Continuing the operation of Palo Verde makes strong economic sense for Buckeye, for Arizona 

and for other locations across the Southwest. Losing the low-cost reliable energy provided to 

over four million people by Palo Verde, in addition to the over 2,500 jobs it creates would be 

another damaging blow to Arizona's economic standing. 

Palo Verde is a local point of pride for all of us in Buckeye and our neighbors. My request is 

simple, that you take my letter of support into consideration when reviewing the re-licensing of 

Palo Verde and its current units. I hope you will come to the same conclusion I have.

Comment PV-W: I write to you in full support of the renewal application of the Palo Verde 

Nuclear Generating Station. Arizona Public Service (APS) has safely and efficiently operated 

the plant for years, allowing PV to make long-term contributions to local area development. My 

constituents in Arizona Legislative District, 25 are some of those persons directly benefitting 

from Palo Verde's presence. The generating station is a major area business, employing more 

than 2,500 individuals. 

Clean, reliable and cost effective energy is important now more than ever. The electricity 

generated by Palo Verde is something which my constituents in Legislative District 25 and our 

fellow citizens nationwide can rely on. Benefits of the energy produced by Palo Verde directly 

impact more than four million people throughout the Southwest. More than half of those live in 

the state of Arizona. 

Not only does Palo Verde provide for millions, it ensures the light will turn on when our fellow 

citizens flip the switch. APS stands for dependable service, while at the same time keeping 

power bills low and taking important environmental considerations. I believe APS and Palo 

Verde will continue to deliver, clean, reliable and cost effective, energy to Arizona homes for 

decades, and I ask you to keep Palo Verde in operation. 

Comment PV-X: I am contacting you to lend my support to the Palo Verde Nuclear Generating 

Station and the review for continued operation. Palo Verde has a tremendous positive impact 

for my constituents in Arizona Legislative District 4 by providing clean, reliable and low-cost 

energy. 

In these troubling economic times, that low-cost energy is especially important for my 

constituents. Families around the Valley are pinching pennies wherever they can and simply 

struggling to get by. Where they might once have been wondering what expenditures they 

could afford, now they are troubled simply trying to keep the lights on. Palo Verde keeps their 

energy costs lower than alternative measures, and helps ensure they are able to light their 

homes. 
Appendix A 

NUREG-1437, Supplement 43 A-22 December 2010

That reliable and low cost energy is just as important to businesses as it is to homeowners. 

With larger utility expense costs, the difference Palo Verde makes for many businesses can be 

great. In addition, the reliability of the power supplied by APS ensures that businesses are 

never closed due to a failing energy infrastructure. This is extremely attractive for new 

businesses looking to locate to Arizona. 

I am proud to have Palo Verde, the largest nuclear generating station in America, right here in 

Arizona. It is a symbol of Arizona's growing potential within the U.S. market and a welcome 

addition to our family. It is my sincere wish that you approve Palo Verde's request for continued 

operation.

Comment PV-Y: The Greater Phoenix Chamber of Commerce has been following with great 

interest the Nuclear Regulatory Commission's license renewal process for the Palo Verde 

Nuclear Generating Station. Palo Verde plays an important role in meeting the tremendous 

energy requirements of a fast growing state. For decades, it has done so in a safe and efficient 

manner, while also reducing our dependence on foreign oil and the production of green house 

gasses. 

In my role as President and CEO of the Greater Phoenix Chamber of Commerce, I understand 

how much our economy depends on the reliable delivery of power to keep Arizona working. As 

you most certainly are aware, losing power, even for a short period of time, can result in the loss 

of millions of dollars for our businesses large and small. APS and Palo Verde have a strong 

track record of delivering the consistent, reliable and cost effective energy that Arizona 

businesses need to succeed. 

Palo Verde is also Arizona's biggest single tax payer. At a time when our state faces the largest 

budget deficit in the country (as a percentage of the total budget) losing such a major contributor 

will result in the loss of millions to the state's General Fund, local communities and our schools. 

From an economic development perspective, a significant number of businesses in the Phoenix 

metropolitan area operate around the direct or indirect needs of the plant, and would suffer 

greatly in the event of a non-renewal. 

The Greater Phoenix Chamber of Commerce stands squarely behind APS in its license renewal 

bid. I hope you will consider my letter in your review and strongly take into account the 

contributions Palo Verde makes to our economy and our state.

Response: The comments are noted. The comments are supportive of APS and license 

renewal at PVNGS, and are general in nature. The comments provide no new information and 

will not be evaluated further.

Comment PV-D-2: The second large issue, Arizona's nuclear dump. With Yucca Mountain 

apparently out of the picture, Palo Verde is really a huge defacto nuclear waste dump. 

And in 20 more years increases its waste on site by 50 percent even if they're in dry casks, 

while continuing the added risk of cooling pools for a total of 60 years. The question is, can this 

facility handle this securely and reliably? 

Comment PV-D-10: And wasn't it unrealistic, if not the height of arrogance, for a species that 

has only a few thousand years of recorded history to plan on safely managing radioactive waste 

for a minimum of 100 thousand years? 
Appendix A

December 2010 A-23 NUREG-1437, Supplement 43

Thank you. 

Response: The staff notes that on March 3, 2010, DOE submitted a motion to the Atomic 

Safety and Licensing Board to withdraw with prejudice its application for a permanent geologic 

repository at Yucca Mountain, Nevada. Nevertheless, the safety and environmental effects of 

spent fuel storage have been evaluated by the NRC and, as set forth in the Waste Confidence 

Rule (10 CFR 51.23), the NRC generically determined that such storage could be accomplished 

without significant environmental impacts. In the Waste Confidence Rule, the Commission 

originally determined that spent fuel can be safely stored onsite for at least 30 years beyond the 

plants life, including license renewal. In 10 CFR Part 51, on site spent fuel storage is classified 

as a Category 1 issue that is applicable to all nuclear power plant sites. While the Commission 

did not assign a single level of significance (i.e., Small, Moderate, or Large) in Table B-1 of 

Appendix B to Subpart A to Part 51 for the impacts associated with spent fuel and high level 

waste disposal, it did conclude that the impacts are acceptable in that these impacts would not 

be sufficiently large to require the NEPA conclusion, for any plant, that the option of extended 

operation under 10 CFR Part 54 should be eliminated. 

The GEIS for license renewal (NUREG-1437) evaluated a variety of spent fuel and waste 

storage scenarios, including on site storage of these materials for up to 30 years following 

expiration of the operating license, transfer of these materials to a different plant, and transfer of 

these materials to an Independent Spent Fuel Storage Installation (ISFSI). During dry cask 

storage and transportation, spent nuclear fuel must be "encased" in NRC-approved casks. An 

NRC-approved cask is one that has undergone a technical review of its safety aspects and 

been found to meet all of the NRC's requirements. These requirements are specified in 10 CFR 

Part 72 for storage casks and 10 CFR Part 71 for transportation casks. For each potential 

scenario involving spent fuel, the GEIS determined that existing regulatory requirements, 

operating practices, and radiological monitoring programs were sufficient to ensure that impacts 

resulting from spent fuel and waste storage practices during the term of a renewed operating 

license would be small, and is a Category 1 issue. 

In addition, on September 15, 2010, the Commission approved a final revision to the agency’s 

“Waste Confidence” findings and regulation, expressing the Commission’s confidence that the 

nation’s spent nuclear fuel can be safely stored for at least 60 years beyond the licensed life of 

any reactor and that sufficient repository capacity will be available when necessary. In addition, 

the Commission directed the NRC staff to conduct additional analysis for longer-term storage to 

ensure that the NRC remains fully informed by current circumstances and scientific knowledge 

relating to spent fuel storage and disposal. 

Accordingly, as discussed above and as specified by 10 CFR 51.23(b), no site-specific 

discussion of any environmental impact of spent fuel storage in reactor facility storage pools or 

ISFSIs is required in an environmental impact statement associated with license renewal. 

These comments do not provide new and significant information and will not be evaluated 

further in development of the SEIS.Comment PV-D-3: If we want a dump at this site, off-site 

from Palo Verde for the dump, it raises other questions. If a waste disposal site actually 

becomes available, will that put shipments of highly radioactive wastes on the Interstate 10 near 

the facility? And what are the potential impacts to transportation and other economic costs 

associated with such a contingency? 

As a person with over a decade of emergency planning experience, I'm aware of the many 

disaster drills at Palo Verde, but I don't believe there has ever been an exercise or plan 
Appendix A 

NUREG-1437, Supplement 43 A-24 December 2010

involving a worst case scenario of a spill of nuclear waste from Palo Verde or a terror attack on 

a shipment that causes the release of nuclear waste into the environment. 

I did see information about a worst case scenario of a nuclear waste spill along Interstate 40. I 

attended that State Emergency Response Initiative where we discussed it. 

According to their estimates it would take about 15 months to decontaminate to safe levels. 

Further, if the roads to or from Palo Verde are closed for an extended period of time due to a 

radioactive spill; would that give terrorists an advantage? Would such a scenario impede 

response and/or defense? 

Comment PV-AB-2: The number one concern of American citizens about nuclear power plants 

is the threat of a terrorist attack on a nuclear power plant, whether by foreign or domestic 

terrorists. All possible terrorist scenarios regarding Palo Verde need to be examined, along with 

potential impacts and mitigation, including scenarios where there is a significant population 

residing near Palo Verde (within ten miles), per NEPA requirements. There have been train 

derailments caused by someone unknown tampering with the rail lines, a form of domestic 

terrorism, in western Maricopa County, that still have never been solved. So there is already a 

history of suspicious actions and concerns about the ability of authorities to prevent these 

incidents, monitor for them, or prevent them. These incidents indicate a continuing vulnerability 

to terrorist acts, and should be reviewed as part of the terrorism analysis performed under 

NEPA. 

Response: A discussion of the environmental impacts of a terrorist attack is provided in 

Chapter 5 of the SEIS. 

Comment PV-AB-4: Please consider and address the following questions: What would the 

torque be for a full Boeing 747 hitting the generator building at different points of the building, 

such as the middle point of the generator building, at the point that is connected to the reactor 

containment building RCB, at the point 25% of the way from the RCB toward the end of the 

generator building, at the 75% point, all assuming a maximum speed for the aircraft and at a 

perpendicular strike directly against the generator building? 

Is the generator building and the heat transfer area around the primary coolant loops and 

secondary generator loops strong enough to withstand this impact without a coolant breach? 

We know that the RCB is not strong enough for the most powerful strike, as this has been 

admitted in NRC proceedings. What is the likelihood of a full impact strike causing a meltdown? 

Please consider the attached Greenpeace study, New Nukes and Old Radioactive Waste in 

these deliberations and analysis. (P_@_SEJ_2006_Final_Draft). 

Response: A discussion of the environmental impacts of a terrorist attack, including attacks 

involving large commercial aircraft, is provided in Chapter 5 of the SEIS. 

Comment PV-D-4: Next issue, population growth and contingency issues. There are plans for 

a large development near Palo Verde bringing in at this point about 140 thousand people. The 

current contingency plan is to evacuate within a ten mile radius and then wait for federal 

assistance. A footnote, we might want to ask the people of New Orleans what they think about 

the folly of that plan. 

To move such a large population away from the ten mile radius in a timely manner, when time 
Appendix A

December 2010 A-25 NUREG-1437, Supplement 43

would be so much of the essence in a situation like that, would require enormous resources 

including legions of buses that would in themselves become contaminated during the 

evacuation and would need, of course, much more detailed decontamination afterwards if they 

were ever going to be put back into service. It's doubtful that anyone would ever want to ride 

them nonetheless. 

It's also doubtful that buses pulled from normal service for such an evaluation would be able to 

arrive here in a timely manner. I don't think there are enough buses in the Phoenix metro area 

that could move those -- that could move that number of people and of course it's easily more 

than an hour away. Again, time is of the essence. 

It would seem to me that in order to be properly prepared the requisite number of buses would 

have to be ready and in the immediate vicinity of Palo Verde. Where will they be stored? Who 

will maintain them? Who will be ready to drive them in the case of something happening?

Comment PV-AB-3: The current contingency plan is to evacuate people within a ten mile 

radius and then wait for federal assistance. The strategy for moving hundreds of thousands of 

people away quickly and perhaps permanently needs to be examined and laid out, as well as 

any mitigation that could be implemented. 

Response: The Commission considered the need for a review of emergency planning issues in 

the context of license renewal during its rulemaking proceedings on 10 CFR Part 54, which 

included public notice and comment. As discussed in the Statement of Considerations of a 

1991 rulemaking (56 FR 64943 at 64966-7) and reaffirmed in a 1995 rulemaking (60 FR 22461 

at 22468), the programs for emergency preparedness at nuclear plants apply to all nuclear 

power plant licensees and require the specified levels of protection for each licensee regardless 

of plant design, construction, or license date. Requirements related to emergency planning are 

in the regulations at 10 CFR 50.47 and Appendix E to 10 CFR Part 50. These requirements 

apply to all operating licenses and will continue to apply to plants with renewed licenses. 

Through its standards and required exercises, the Commission reviews existing emergency 

preparedness plans throughout the life of any plant, keeping up with changing demographics 

and other site-related factors. Therefore, the Commission has determined that there is no need 

for a special review of emergency planning issues in the context of an environmental review for 

license renewal. 

Comment PV-D-5: The next issue I call "Trust Us." The Palo Verde reactors are only now, 

after an unprecedented length of time, being moved off of the multiple repetitive degraded 

corner stone column, an extreme level of NRC oversight. Can these people really be trusted? 

The NRC decided for years that the culture of management at Palo Verde was such a huge 

problem that it closely scrutinized the plant and was on the brink of closing the facility. 

Suddenly, after five years the NRC decided everything is suddenly okay. That sounds much 

more like a political decision than something that's reality based. And we are left wondering if 

Palo Verde operators might have just straightened up their act just long enough to get their 

license reviewed with plans to backslide or did they really, finally get their act together? 

What assurances do we have that future violations and noncompliance will be detected and 

dealt with early enough? The nuclear industry is admittedly only one big accident away from a 

total collapse. So this makes us wonder, is it time to double down at this facility? 

Comment PV-D-6: The next issue is what they call the "Bathtub Curve." Complex engineering 

projects have most problems at the beginning and the ends of their lifecycle. 
Appendix A 

NUREG-1437, Supplement 43 A-26 December 2010

The bathtub curve is widely used in reliability engineering, although the general concept is also 

applicable to humans, it describes a particular form of the hazard function, which comprises 

three parts: The first part is a decreasing failure rate, known as early failures. The second part 

is a constant failure rate, known as random failures. And the third part is an increasing failure 

rate, known as wear-out failures. The name is derived from the cross-sectional shape of the 

eponymous device. 

The bathtub curve is generated by mapping the rate of early infant mortality failures. When first 

introduced the rate of random failures with constant failure rate during its useful life, and finally 

the rate of wear-out failures as the product exceeds its design. 

It is especially concerning as there are plant aging and radiation embrittlement issues for 

reactors and their associated equipment. My bet is that nobody really knows a lot of what will 

be happening to the metals after 30 to 40 to 60 years of radioactive bombardment. 

Considering the previous and serious problems at Palo Verde already with leaking pipes and all 

the other issues there, will NRC require and monitor the requisite inspections to prevent another 

problem and outage? 

Comment PV-D-7: The next issue I call "New Crew." As reactors get older the crews that run 

them didn't build them and likely haven't looked at the original plans even once in their lives. 

How good is the institutional memory of Palo Verde, given that they've had such significant 

problems in the past? We'll have a new generation of employees. What training programs will 

be in place to assure that this doesn't cause problems? There is already a critical shortage of 

trained workers for the nuclear technology. 

Response: Plant performance is part of the current operating license. To ensure that U.S. 

nuclear power plants are operated safely, the NRC licenses the nuclear power plants to 

operate, licenses the plant operators, and establishes license conditions for the safe operation 

of each plant. The NRC provides continuous oversight of plants through its Reactor Oversight 

Process (ROP) to verify that they are being operated in accordance with NRC regulations. 

The NRC has full authority to take whatever action is necessary to protect public health and 

safety, and the environment and may demand immediate licensee actions, up to and including a 

plant shutdown. 

The NRC's environmental review is confined to environmental matters relevant to the extended 

period of operation requested by the applicant. The NRC will ensure that the safety of a 

currently operating power plant will continue to be maintained before renewing the license by 

ensuring that aging effects will be adequately managed and that the licensing basis related to 

the present plant design and operation will be maintained. Before a new license is issued, the 

NRC will ensure that there is a technically credible and legally sufficient basis for granting a new 

license for an extended 20 years as reflected in the NRC’s safety evaluation report (SER), final 

SEIS, and the proposed new license. The comment provides no new information, and does not 

pertain to the scope of license renewal under 10 CFR Part 51 and Part 54. Therefore, it will not 

be evaluated further. 

Comment PV-AD: Below are DWAZ's questions, with an article of Moody's downgrading SC 

Electric and Gas due to their participation in a nuke. Moody's has said that it would be 

downgrading utilities participating in nuclear energy projects. Moody's study and a recent 

follow-up are attached for inclusion and reference. Fitch also downgraded this utility a while 
Appendix A

December 2010 A-27 NUREG-1437, Supplement 43

back, and the article is below the first one. 

DWAZ includes the attached by reference: "Special Comment, Moody's Corporate Finance--

New Nuclear Generating Capacity: Potential Credit Implications for U. S. Investor Owned 

Utilities," May 2008, at http://massimobray. italianieuropei. it/080527MoodysNewNukeGen

Capacit y.pdf

DWAZ's questions include: 

In relation to the "Special Comment, Moody's Global Infrastructure Finance--New Nuclear 

Generation: Ratings Pressure Increasing," June 2009. 

Q: This report says, "History gives us reason to be concerned about possible balance-sheet 

challenges, the lack of tangible efforts today to defend the existing ratings, and the substantial 

execution risk involved in building new nuclear power facilities." 

While this report largely deals with new reactors, it is true that older reactors are having major 

components replaced, like heat exchangers, plumbing and electrical infrastructure, generators, 

and condensers, etc. Some of these are beyond "variable operating cost" and are capital 

investments, capitalized on the balance sheet. Similar to when an old company truck gets too 

old and the repairs and capital improvements outweigh the cost of payments on a new one, 

when reactors get older, this at some point will happen. When that does happen, what are the 

risks that could down-grade APS/PVNGS ratings with firms like Moody's Standard and Poor's 

and Fitch ratings companies? 

Q: What are the major component and infrastructure replacements that PVNGS has had so far 

that have been capitalized? 

Q: Are is the NRC learning from the collective experience of other reactors in the U.S. and their 

major component and infrastructure replacements? 

Q: What are the costs of capitalized major component and infrastructure replacements for other 

reactors in the U.S., and how does PVNGS compare? 

Q: One of the Browns Ferry reactors had a fire many years ago, and this fire knocked out the 

reactor from producing electricity for decades. When the reactor was refurbished, the total cost 

was about $1.5 billion. Does APS see how this kind of repair/renovation could have a 

significant impact on corporate risk levels and on ratings by credit ratings agencies like 

Moody's? Could APS financially handle such a contingency and survive without bankruptcy, or 

would APS just stick ratepayers with the bill again? 

Q: In another case, at the Davis-Besse in Ohio, the reactor came a few months away from a 

corrosion-caused breach of containment. Does APS or ANPP realize that there are possible 

major repairs that may make an old plant a large previously un-booked liability? 

Q: What are the costs of increased variable operation and maintenance of U.S. reactors as 

reactors have aged, for reactors, per reactor, over 15 years old, over 20 years old, over 25 

years old, over 30 years old and over 35 years old? 

Q: What are the costs of capitalized major component and infrastructure replacements of all 

U.S. reactors, per reactor, as reactors have aged, for reactors over 15 years old, over 20 years 
Appendix A 

NUREG-1437, Supplement 43 A-28 December 2010

old, over 25 years old, over 30 years old and over 35 years old? 

Q: What depreciation duration was used for these capitalization schedules for income tax 

purposes for each U.S. reactor per incident of capitalization? 

Q: This reports says, "We also believe companies will ultimately revise their corporate-finance 

policies to begin materially strengthening balance sheets and bolstering available liquidity 

capacity at the start of the construction cycle.” To the degree that there can be breakdowns and 

capitalized major component and infrastructure replacements with significant economic value at 

any time, what are Arizona Public Service and other members of the Arizona Nuclear Power 

Project doing in terms of "strengthening their balance sheets and bolstering available liquidity 

capacity"? 

Q: What are APS and ANPP target reserve margins, by year, for 2009 and for future years 

through the proposed extended lifespan of PVNGS? 

Q: What have the target reserve margins been for the years since PVNGS Unit 1 has been in 

operation? 

Q: What have the actual reserve margins been for APS and ANPP for the low point of each year 

since PVNGS Unit 1 has been in operation? 

Q: To what degree are APS and the other partners of ANPP counting on PVNGS in its total 

relied- upon capacity and as part of the calculate reserve capacity? 

Q: As PVNGS reactors go down because of increased interruptions in service due to age, is 

APS and ANPP increasing its reserve margin to cover this decrease in reliability? 

Q: If so, by what megawattage and percentage of total power design electrical rating plant 

capacity, for APS and ANPP? 

Q: The report says, "Historical rating actions have been unfavorable for issuers seeing to build 

new nuclear generation. Of the 48 issuers that we evaluated during the last nuclear building 

cycle (roughly 1965-1995), two received ratings upgrades, six went unchanged, and 40 had 

downgrades. Moreover, the average downgraded issuer fell four notches. All these ratings 

were evaluated on the senior secured or first mortgage bond ratings.” While these are for new 

builds, major capitalization may be required numerous times for aging reactors during their last 

2-3 decades of operation. Have APS and ANPP members prepared for the possibility of 

downgrades by the ratings agencies due to large capital outlays? 

Q: The report says, "We view new nuclear generation plans as a 'bet the farm' endeavor for 

most companies. . .” While they are referring to long construction timelines, there may be 

lengthy repair timelines at PVNGS. What are APS and ANPP doing to brace for possible 

extended capital repairs of PVNGS Units 1-3, in terms of bolstering financial health and in terms 

of increasing reserve margins? 

Q: Please provide a list of all capitalized component and infrastructure investments for PVNGS 

year by year and component by component and infrastructure investment by investment, since 

the initial power-up at each reactor. 

Q: Please give projections for what the cost of similar investments will be, item by item, in the 
Appendix A

December 2010 A-29 NUREG-1437, Supplement 43

future. For example, for a generator replacement done in the past, what is the projection on 

cost to do replace a generator in the future, year by year through the proposed license 

extension period? 

Q: The report says that APS moved down 4 notches from 1981-1993, with a beginning rating of 

A2 FMB with the lowest rating at Baa3. If there is to be an extended period of 

repair/construction in the future for any of the Units 1-3, say for 1, 2, 3, or 4 years, what ratings 

downgrade might happen? 

Q: If there is a Moody's rating downgrade of 1, 2, 3 or 4 levels, what impact on interest rates for 

new plant construction and major capitalized repair debt will occur, in percentage increases? 

Q: What are APS and ANPP doing to improve their respective credit ratios in anticipation of 

such component replacements or capitalized infrastructure repair possibilities? 

Q: The reports says, "The likelihood that Moody's will take a more negative rating position for 

most issuers actively seeking to build new nuclear generation is increasing. With only about 24 

months remaining before the NRC begins issuing licenses for new projects and major 

investment begins, few of the issuers we currently rate have taken any meaningful steps to 

strengthen their balance sheets. Considering these new projects tend to raise an issuer's 

business and operating risk profiles, the utility's overall credit profile appears weaker.” Again, 

with increases in major repairs as reactors get older, and with increasing dollar amounts for 

repairs, what are APS and ANPP doing to minimize their risks and to keep from getting downgraded by the ratings agencies? 

SCANA feels rating bite on nuclear plant 

Wednesday, July 15, 2009 

Moody's Investor Services lowered SCANA Corp.’s bond rating this week and listed the outlook 

as negative because of the S.C. utility’s joint ownership of a $12 billion nuclear project under 

construction. Moody’s warned investors two weeks ago that it was likely to take a negative view 

on nuclear development by power companies. Some in the nuclear industry have taken issue 

with that policy. But Moody’s stood by it when explaining its decision on SCANA. 

“We remain concerned with the ... risks associated with a project of this magnitude for a 

company of this size,” said Moody’s Senior Vice President Jim Hempstead. 

SCANA subsidiary S.C. Electric & Gas is expanding the V.C. Summer Nuclear Station with 

Santee Cooper. The power companies are adding two AP100 nuclear reactors at the existing 

nuclear plant. 

Comment PV-AB-6: The life cycle of nuclear power is not only dependent upon fossil fuels for 

the production of uranium fuel, decommissioning, and the disposition of wastes generated: it is 

also dependent upon a grid that is powered by other sources of energy, typically coal. This is 

due to the simple fact that nuclear reactors cannot “black start”– in other words, they depend on 

electric power from the external power grid to be able to come on-line. Transition away from the 

combustion of fossil fuels cannot be accomplished solely by the expansion of nuclear power 

since it depends on the grid being powered up before reactors can come on-line. 

Other studies on the economics of nuclear power generation that should be reviewed and 
Appendix A 

NUREG-1437, Supplement 43 A-30 December 2010

considered in the NEPA analysis are at: http://www.greenpeace.org/raw/ content/usa/ presscenter/ reports4/ the-economics- of-nuclear- power.pdf

http://www.earth- policy.org/ Updates/2008/ Update78_ printable. htm

Amory Lovins: 

http://www.rmi. org/sitepages/ pid467.php

http://www.arizonap irg.org/uploads/ ee/qD/eeqDk_ cKZXyH5yuhZduZTA /The-High- Cost-ofNuclear- Power.pdf

http://www.stanford.edu/group/efmh/jacobson/EnergyEnvRev0908.pdf

Also see the attached file, the copy of SEA Energy Costs. 

Comment PV-AC: The attached study says on page 296, that a 2000 study says every $1.4 

million yields 11.3 to 13.5 full-time equivalent jobs. This study should be used in the economic 

analysis comparing the economic benefits of the relicensure of Palo Verde vs. expending 

resources to get an equivalent amount of generating power from solar, wind, and other 

renewables. The total number of jobs (FTE) at Palo Verde Nuclear Generating Station 

(PVNGS) and the total revenue is for PVNGS' electricity should be determined, and dividing the 

latter by the former will yield dollars/job at PVNGS. The attached study will provide much useful 

information re the dollars/job of renewable energy options. 

Comment PV-AB-5: A recent study by an economic analyst at the University of Vermont finds 

that building 100 new reactors would cost from $1.9 to $4.1 trillion more than getting our 

electricity from clean renewable energy sources. (See

http://www.nirs.org/neconomics/cooperreport_neconomics062009.pdf)

All costs and impacts of energy efficiency programs, alternative and renewable energy sources 

should be examined against the costs and impacts of relicensing Palo Verde. This analysis 

should also include water usage, air pollution impacts (Palo Verde has been fined significantly 

by the Maricopa County Air Quality Department for exceedances of its particulate matter (PM) 

emissions limits, specifically for excess PM emissions from its cooling towers.), wastes, 

radioactive emissions, mining impacts and groundwater impacts of uranium mining, 

sustainability, and the costs in terms of money and of carbon of developing less rich ores for 

reactor fuel, including the rising costs of the electricity used in the process of making fuel rods, 

which includes enrichment and fuel processing. The uranium enrichment plant at Paducah, 

Kentucky is the largest U.S. emitter of CFCs, which destroy the ozone layer. 

The average energy efficiency cost for State programs across the U.S. is 3-4 cents per KWH. 

The average cost of just nuclear fuel, O&M (fixed and variable) is at least 3.7 cents and at most 

4.9 cents per KWH, according to the Keystone report. (See page 42 of referenced Keystone 

report http://www.ne.doe.gov/pdfFiles /rpt_KeystoneReportNuclearPowerJointFact

Finding_2007.pdf.) The Keystone report was hailed by Nuclear Engineering International and it 

was a multidisciplinary report. This averages higher than the average efficiency cost. 

A fundamental element in finding that nuclear power is a false solution to climate change is that 

the economics of nuclear power are not sound – in open markets nuclear cannot compete. 

Since splitting atoms is not a cost-effective source of electric power, it is even less cost-effective 

in preventing greenhouse gas emissions. Life cycle costs for nuclear power generation (in the 
Appendix A

December 2010 A-31 NUREG-1437, Supplement 43

USA) have been estimated at 12 cents a kilowatt hour; whereas life cycle costs for wind power 

in the same analysis is estimated at 4 cents a kilowatt hour. Others find that expanding nuclear 

generating capacity is about twice as expensive as expanding generating capacity through 

investment in wind power. Since the same money will buy 2 – 3 times more electric power 

when used to purchase wind generated electric power, it is clear that prevention of greenhouse 

emissions will also be 2 – 3 times greater when buying wind generated electricity than nuclear 

generated electricity (as opposed to nuclear generating capacity). CO2 production per dollar is 

not constant. According to the Sovacool study, the average study which passed the test for 

quality projects that nuclear power will produce 66 grams of CO2/kilowatt- hour, and that wind's 

life cycle will produce 10 grams. CO2 output is related to KWH, not cost per kilowatt- hour, 

partly because cost is a fluctuating value, but a KWH is a fixed scientific measurement. 

Therefore, nuclear power will produce 66 grams CO2/KWH and wind 10 grams, which is 6.6 

times the pollution output of CO2. If we can assume that wind is half the price per KWH, then 

the output becomes 13.2 times the CO2 output per nuclear power compared to wind. However, 

it is important to note that all the studies reviewed by Sovacool only assume the current ore 

grade of uranium to continue into the future. We know that ore grades will decline, as they have 

already halved over the last 30 years from 3000 ppm to 1500 ppm. The Sovacool report also 

does not assume any CO2 for long-term waste management and remediation, including 

unintentional and intentional terrorist environmental breaches. 

The average cost should include all costs, including transmission & distribution. DWAZ 

estimates that the cost of new nuke energy will be about 24 cents/KWH (18 cents for generation 

plus 7 cents for T&D), wind with T&D is 15 cents on average, and energy efficiency is 3.5. The 

Cooper and other reports are in the same ballpark on nuclear power. 

Comment PV-AA: The following was provided as an attachment to an email. 

Solar Photovoltaic Costs for Life of System 

Spreadsheet by Russell Lowes, www.SafeEnergyAnalyst.org, 3/5/09 DRAFT 

 

Energy Production Assumptions Utility 

Residential Residential Residential Industrial 

Based on Based on 

Construction Lower Cost 

Cost Given Based on Based on Industrial w/ 

By Solon Typical 50% rebate Higher 12% 

at 2/12 Construction from Gov't Charge 

Tour Cost Locally & Utilities Rate 

1 1 1 1 Kilowatt 

8766 8766 8766 8766 hours per year 

30.0% 30.0% 30.0% 30.0% capacity factor (percentage of maximum 

nameplate rating realized in kilowatt-hours) 

25 25 25 25 Lifespan; years of production of electricity 

65745 65745 65745 65745 Subtotal 

10.0% 10.0% 10.0% 10.0% average degradation over 25 year lifespan, 

based on Solon guarantee of 

59170.5 59170.5 59170.5 59170.5 kilowatt-hours production for lifespan 

 

Cost Assumptions 
Appendix A 

NUREG-1437, Supplement 43 A-32 December 2010

$4,000.00 $12,000.00 $6,000.00 $4,000.00 Dollars per kilowatt of e capacity, A/C 

$1,000.00 $1,000.00 $1,000.00 $1,000.00 Repairs and Maintenance over 25 year 

lifespan (GENERAL ESTIMATE) 

$5,000.00 $13,000.00 $7,000.00 $5,000.00 Total investment over lifespan 

 

Simple cost per Kilowatt-hour, without finance charges 

$0.085 $0.220 $0.118 $0.085 dollars per kilowatt-hour 

 

To calculate the finance charges: 

$4,000.00 $12,000.00 $6,000.00 $4,000.00 Capital investment, construction cost 

25 25 25 25 Years of loan 

8.25% 8.25% 8.25% 12.00% Interest rate of loan / FIXED CHARGE RATE 

FOR INDUSTRIAL OPTION 

$386.52 $1,159.56 $579.78 $480.00 

Mortgage payment for loan per year (handentered from loan amortization program for 

Residential, Calc'd for Industrial) 

$9,663.00 $28,989.00 $14,494.50 $12,000.00 Total repayment for loan over lifespan (line 

above times lifespan years) 

 

Total lifespan costs with mortgage payments 

 

$9,663.00 $28,989.00 $14,494.50 $12,000.00 Capital costs (mortgage) over lifespan 

$5,000.00 $5,000.00 $5,000.00 $5,000.00 Repairs and maintenance over lifespan 

$14,663.00 $33,989.00 $19,494.50 $17,000.00 Total cost over lifespan 

 

$0.25 $0.57 $0.33 $0.29 Final cost per kilowatt-hour with interest 

 $0.06 For Utilities, add 6 cents for Transmission and 

Distribution 

 $0.35 End cost for average retail price. 

 

Note that profit for investors, insurance & property taxes are included in the 12% levelized 

fixed charge rate, in the Industrial example. 12% is used by Standard and Poor's for 

utilities (non-nuclear). 

 

Other factors: 

For residential non-utility examples, insurance and property costs are not included. 

The maintenance costs need to be better grounded in experience, for all examples. 

 
Appendix A

December 2010 A-33 NUREG-1437, Supplement 43

Deterioration Rate of Solar PV at 0.5% per year 

 

1 1 Initial kilowatt of capacity 

2 0.995 

3 0.990025 

4 0.985075 

5 0.98015 

6 0.975249 

7 0.970373 

8 0.965521 

9 0.960693 

10 0.95589 

11 0.95111 

12 0.946355 

13 0.941623 

14 0.936915 

15 0.93223 

16 0.927569 

17 0.922931 

18 0.918316 

19 0.913725 

20 0.909156 

21 0.90461 

22 0.900087 

23 0.895587 

24 0.891109 

25 0.886654 

 0.942238 Average delivery of electricity per initial kilowatt of capacity 

 
Appendix A 

NUREG-1437, Supplement 43 A-34 December 2010

Electricity Costs for Pima County Residents 

Now and in the Future 

 

Spreadsheet by Russell Lowes, www.SafeEnergyAnalyst.org, 3/17/09 DRAFT 

 

 Reduction In 

Typical Electricity With 

Residential Different Mix 

of 

Prior 

Column 

 

 

Consumption Consumption over CO2 . . .See

KWH/Mo KWH/Mo 25 years Output. . . Below 

750 750 225000 Current consumption 

for a typical residence 

 $ 0.105 $ 0.105 Cost per kilowatt-hour 

of electricity 

 $ 78.75 $ 78.75 TOTAL ROUGH 

CURRENT COST 

0.00% 25.00% Assumed % reduction 

in consumption of 

KWH 

750 563 168,750 New consumption 

level after energy 

efficiency program 

0 188 56,250 Energy saved per 

month in KWH 

 

Projected Blend of Energy in % 

0.00% 10.00% New Solar PV 

70.00% 50.00% Old Coal 

30.00% 25.00% Old natural gas plants 

0.00% 5.00% New natural gas plants 

0.00% 0.00% New Nuclear 

0.00% 10.00% Wind 

0.00% 0.00% Hydro 

100.00% 100.00% 

 Initial New Mix

CO2 CO2 

Energy efficiency with new mix of solar/coal/natural gas Output Output

 Cost for Electricity 

for Each Source 

grams/KWH Output

 $ - $ 13.50 $ 4,050.00 New Solar PV 0 1,800 

 $ 52.50 $ 28.13 $ 8,437.50 Old Coal 504,000 270,000 

 $ 26.25 $ 16.41 $ 4,922.44 Old natural gas plants 112,500 70,313 

 $ - $ 4.22 $ 1,265.63 New natural gas plants 0 12,459 

 $ - $ - $ - New Nuclear 0 0 

 $ - $ 8.44 $ 2,531.25 Wind 0 506 

 $ - $ - $ - Hydro 0 0 

 $ 0.03 $ 0.03 $ 0.03 Energy efficiency 

cost per KWH 

616,500 354,572 

 $ - $ 5.63 $ 1,687.50 Energy efficiency cost 

per month 
Appendix A

December 2010 A-35 NUREG-1437, Supplement 43

 $ 78.75 $ 67.88 $20,363.06 Total new cost of 

electricity 

 $ (0.00) $ 10.87 $ 3,261.94 Savings/total bill 

0.0% 1.4% 1.4% Savings as % of 

original bill Savings 

in Total CO2: 42% 

 Average CO2 per 

Kilowatt-Hour 822 630 

 

Savings per KWH 

CO2: 23% 

 

Initial New Mix

CO2 CO2 

Output Output

Cost per Kilowatt-Hour Resulting KWH Used grams/KWH Output

$0.240 $0.240 New Solar PV 32 32 

$0.100 $0.100 Old Coal 960 960 

$0.117 $0.117 Old natural gas plants 500 500 

$0.150 $0.150 New natural gas plants 443 443 

$0.240 $0.240 New Nuclear 400 400 

$0.150 $0.150 Wind 9 9 

$0.100 $0.100 Old Hydro 10 10 

$0.035 $0.035 Energy Efficiency 5 5 

 

 KWH Consumption breakdown by source 

0 56 16,875 New Solar PV 

525 281 84,375 Old Coal 

225 141 42,188 Old natural gas plants 

0 28 8,438 New natural gas plants 

0 0 New Nuclear 

0 56 Wind 

0 0 Hydro 

750 563 168,750 Total KWH/Mo 

 $ 0.105 $ 0.121 Total Cost Per KWH 

 

Cost for a Nuclear Reactor and Cost Per Person for 

Nuclear Energy, Capital Portion Only 

A Worksheet by Russell J. Lowes, updated 3/5/09

 

 I have seen nuclear industry estimates have run from $1,000-2,000 per kilowatt of installed electrical 

capacity to $4,000, over the 2000-2006 period. When 2006 arrived, cost estimates increased 

dramatically. 

 Recently, some spokespersons for the industry have begun to face reality and have increased

their projections dramatically, two estimates as high as $8,200 and $10,000 per kilowatt.

 However, reactors in the late 1980s were finishing at just over $3000, in 1980s dollars.
Appendix A 

NUREG-1437, Supplement 43 A-36 December 2010

(See Brice Smith, Insurmountable Risks: The Dangers of Using Nuclear Power

to Combat Global Climate Change at www.ieer.org/)

 This $3000 does not count all the reactors that were canceled due to cost overruns, so this 

figure is low. Running a $3000 price out from 1988 to 2008 with simple inflation yields 

(at the http://data.bls.gov/cgi-bin/cpicalc.pl) $5500, rounded to the nearest $100. 

This $5500 figure is low due to construction costs outpacing general inflation, particularly with the 

price of copper, steel and cement going up with increased world demand. 

On top of the $5500 in 2008, projecting out to 2020 as a completion year for a reactor at

a 4% annual cost escalation rate yields $8500.

 However, more robust reactor designs with two decades worth of lessons of safety improvements

has its costs. The industry is going to be required to build structures capable of withstanding large

jet impacts, per post-911 rules. This will substantially increase the cost of building nukes. 

Additionally, "passive" cooling systems will require substantial cost increases, as massive 

reservoirs will be built to hold water for ECCS backup. 

 What will the nuclear program cost per person in the U.S. if the industry builds 1000 reactors,

each averaging 1000 megawatts, in this nation?

 The following table assumes that the 100 reactors are built the same year, and run for 30 or 40 years.

However, no reactor has run for this long of a period at an average 85% capacity factor, so this 40-year

estimate is giving the nuclear industry the benefit of the doubt. 

1,350 average size reactor, megawatts

$9,000 average cost per kilowatt of electrical capacity installed (for 2020 completion)

$12,150,000,000 cost per plant

100 number of plants under the Bush and McCain plans

$1,215,000,000,000 total construction cost

14.0%

levelized fixed charge rate for 30 year payback 

schedule

$170,100,000,000 annual rate paid per year

$5,103,000,000,000 total capital payback over 30 years

350,000,000

people in the U.S. on average over the 30-year payback 

period 

Keystone 

Report/Nuclear

486 costs per person per year for loan payback

Power Joint FactFinding 

Low Cost 

High 

Cost

 If the above scenario is realized, what will the cost of nuclear power be per 

kilowatt-hour,

for just the capital 

portion? 40Yr90% 30Yr75%

$9,000 Cost per kWe installed $2,950 $2,950 

14.0% Capital payback per year/Fixed Charge Rate 12.3% 13.8%

$1,260 Annual payback per KW, first 30 years $363 $408 
Appendix A

December 2010 A-37 NUREG-1437, Supplement 43

30 Reactor Life in years 40 30

30 Capital Payback Period 30 30

10,887 12,229

$37,800 

Capital payback over 30 years Capital Payback per kW 

installed $14,516 $12,229 

85.0% Capacity factor 90.0% 75.0%

223,533

kWhe generated per kWe installed, for years in Reactor 

Life 315,576

 

197,235

 $ 

0.1691 $/kWhe 0.046

 

0.062

compared with the calculations on the left: 0.127

 

0.169

40 Extended 40-year reactor life in years

298,044 kWhe generated per kWe installed

 $ 

0.1268 Capital cost/kWhe 

If the reactors ran at the fantasy industry figure of $2000 per kWhe, lasted 40 years and had 

a 85% capacity factor:

280 Annual Payback per KW, first 30 years

$8,400 Capital payback over Reactor Life per kilowatt installed

 $ 0.0376 Capital cost/kWhe 

Fuel, and Operation and Maintenance Costs are Projected Differently by the Following Sources

From the Keystone Report/"Nuclear Power Joint Fact-Finding," page 42. 

0.015 Fuel

0.023 Fixed Operating and Maintenance Cost

0.005 Variable O&M

 $ 0.0430 Total Fuel and O&M

 $ 0.1698 Total All Costs/kWhe

From IEER January 2008 Science for Democratic Action newsletter:

 $ 0.0430 per kilowatt-hour, average projection by the Keystone Report, 2007 $

 $ 0.0230 PacifiCorp, a Western states utility company 2007 $
Appendix A 

NUREG-1437, Supplement 43 A-38 December 2010

From Report submitted to the California Public Utilities Commission, 

Energy & Environmental Economics, Inc. 

www.ethree.com/cpuc_ghg_model.html

Fixed O&M is estimated at $83/kW-yr, this would be

 $ 0.0111 Fixed O&M

 $ 0.0012 Variable O&M

Fuel is listed as $.78/MMBtu, with Heat Rate @10,400 btu/kwh

 $ 0.7800 /MMBtu (million btu)

293 kilowatts = 1 MMBtu At 3413 btu/kWh 1MMBtu

 $ 0.0027 Cost of fuel

 $ 0.0150 Cost of Fuel and O&M

From Standard & Poor's "Which Power Generation Technologies Will

Take the Lead In Response to Carbon Controls," May 11, 2007

 $ 0.0134 per kW/yr

$/kWhe @ 85% Capacity factor

*The Keystone report is considered the most accurate and up-to-date for future reactors, and 

will be used in the cost of calculating nuclear energy. It should be noted that there is a 

predicted shortage of uranium for fueling reactors, starting around 2018, with resource 

depletion problems getting worse over the subsequent years. Keystone does not take into 

account the more dire projections. 

Keystone was an interdisciplinary process involving teams of researchers and writers from the 

nuclear industry, NGOs, etc. 

Nuclear and Other Energy Options 

 Cost Recap 

Projected Nuclear Costs per Kilowatt-Hour of Electricity Delivered

 $ 0.1268 Capital costs

 $ 0.0150 Fuel Costs

 $ 0.0230 Fixed Operation and Maintenance

 $ 0.0050 Variable Operation and Maintenance

 $ 0.1698 Total Generating Cost for Nuclear Electricity Per Kilowatt-Hour

 $ 0.0700 Transmission and Distribution

 $ 0.2398 Total Cost of Electricity for Delivered Nuclear Electricity

 $ 0.1000 Current Coal Technology Electricity Generation Cost

 $ 0.0700 Transmission and Distribution

 $ 0.1700 Total Cost of Electricity for Delivered Coal Electricity
Appendix A

December 2010 A-39 NUREG-1437, Supplement 43

 $ 0.0800 Current Natural Gas Technology Electricity Generation Cost

 $ 0.0700 Transmission and Distribution

 $ 0.1500 Total Cost of Electricity for Delivered Gas Electricity

 $ 0.1200 Solar Thermal Electricity Generation Cost

 $ 0.0700 Transmission and Distribution

 $ 0.1900 Total Cost of Electricity for Delivered Solar Thermal Electricity

$ 0.15-0.40 Solar Photovoltaic Electricity Generation, including On-Site T&D

 $ 0.0800 Wind Generation Cost of Electricity

 $ 0.0700 Transmission and Distribution

 $ 0.1500 Total Cost of Electricity for Delivered Wind Electricity

 $ 0.0350 Cost of Energy Efficiency Per Kilowatt-

 Hour Saved, if Implemented On Large Scale

KWH/Household for nukes and coal 2 2

capacity factor for nukes and coal 75 75

capacity factor for wind and PV 35 30

Renewable CF fraction of Nuke/Coal 

CF 

0.466667 0.4

 

KWH/Household for wind and PV 

solar 

4.285714 5

 

Households per kilowatt of nukes & 

coal 

0.5 0.5

Households per kilowatt of wind & 

solar 

0.233333 0.2

Decommissioning and Waste Cost of Surveillance System Over One Million and Ten Thousand 

Years 

 

 The total number of megawatt-hours put out by a 1000 1000-MW nuclear 

 plants over 40 years at 85% capacity factor 

1000 number of reactors 

1000 Megawatts of electricity per reactor, Design Electrical Rating 

40 Number of years 

8766 Hours per year 

85.0% Capacity Factor/Load Factor 
Appendix A 

NUREG-1437, Supplement 43 A-40 December 2010

298,044,000,000 Megawatt-hours of electricity for reactors 

298,044,000,000,000 Kilowatt-hours of electricity for reactors 

 

The federal court system has ruled that the Environmental Protection Agency can no longer use 

10,000 years as a guideline for nuclear waste planning – they must now use 1 million years. 

See: U.S. News & World Report, "Mired in Yucca Muck, Nuclear power is trendy again, but what 

about the waste?" by Bret Schulte, at 

http://www.usnews.com/usnews/news/articles/061022/30nukes.htm 

Under the old 10,000 year guideline, the amount of kilowatt-hours the plants produce divided by 

10,000 would 

equal what? 

298,044,000,000,000 Kilowatt-hours of electricity for reactors 

10,000 years of waste management 

29,804,400,000 Kilowatt-hours of electricity for waste management. 

30.0% Reduced by the 30%, for example of energy input at the front end: 

 mining, milling, conversion, enrichment, re-conversion, fabrication, 

 building the plant, running the plant, short-term waste storage 

30.0% Reduced by say another 30%, with the goal of having a 40% net energy 

 gain. 

11,921,760,000 Hours per year to devote to waste management. 

 

If the new 1,000,000 year guideline is used, the amount of kilowatt-hours for waste storage per 

year: 

298,044,000,000,000 Kilowatt-hours of electricity for waste management. 

1,000,000 years of waste management 

298,044,000 Kilowatt-hours of electricity for waste management. 

30.0% Reduced by the 30%, for example of energy input at the front end: 

 mining, milling, conversion, enrichment, re-conversion, fabrication, 

 building the plant, running the plant, short-term waste storage 

30.0% Reduced by say another 30%, with the goal of having a 40% net energy 

 gain. 

119,217,600 Kilowatt-hours per year to devote to waste management. 

 

How does this waste cost compare to other industrial management processes? 

If the waste is kept at the reactor sites, as may be the case in the future, then there will be 104 

reactor sites (if you count each reactor as a site – many reactors are at multiple-reactor sites). 

10,000-Year Plan: 

11,921,760,000 Kilowatt-hours per year to devote to waste management. 

1,000 reactors 

11,921,760 Kilowatt-hours per year to devote to waste management. 

 

Million-Year Plan: 

119,217,600 Kilowatt-hours per year to devote to waste management. 

1,000 reactors 

119,218 Kilowatt-hours per year to devote to waste management. 

 

What would this value be in today's dollars at, for example, 10 cents per kWhe? 

10,000-Year Plan: 
Appendix A

December 2010 A-41 NUREG-1437, Supplement 43

11,921,760 Kilowatt-hours per year to devote to waste management. 

$0.10 

$1,192,176 Electricity cost per year in today's dollars. 

 

Million-Year Plan: 

119,218 Kilowatt-hours per year to devote to waste management. 

$0.10 

$11,922 Electricity cost per year in today's dollars. 

Response: The need for power and the economic costs and benefits of the proposed action 

are inquires that are, generally, outside of the scope of the environmental review. 10 CFR 

51.95(c)(2). While the comment is noted, it provides no new information and, therefore, will not 

be evaluated further. 

Comment PV-R: The Ak-Chin Indian Community did receive your letter regarding the scoping 

comments for the Palo Verde Nuclear Generating Station license renewal application review. 

Based on the location of this project, the Ak-Chin Indian Community will defer comments to the 

Lead Tribe for Land Management area - the Gila River Indian Community. 

We are still interested in being informed on the SEIS when it is completed and further 

development on the progress of the License Renewal Application. 

Thank you for informing the Ak-Chin Indian Community about this project. If you should have 

any questions, please contact Mrs. Caroline Antone, Cultural Resources Manager at (520) 568-

1372 or Mr. Gary Gilbert, Technician II at (520) 568-1369. 

Response: The comments are noted. The Ak-Chin Indian Community and the Gila River 

Indian Community were added to the expanded service list (those that receive the draft SEIS 

and the final SEIS). 

Comment PV-Z: The Bureau of Land Management appreciates the opportunity to review and 

provide comment regarding the subject ER 09/549. However, the BLM has no jurisdiction or 

authority with respect to the project, the agency does not have expertise or information relevant 

to the project, nor does the agency intend to submit comments regarding the project. 

Response: The comment is noted. 

Comment PV-A: My name is Mary Widner, I live in the community. I was wondering, on the 

impact study, does the future growth the developers have planned for this area affect this in any 

way or can the NRC back them off some? 

What affect does the amount of people that they are planning on putting out here how does that 

affect this? 

Is there any type of system set up that they have to be so far away from Palo Verde in their 

building? You know, like two miles, five miles. 

Because, you know, Luke here they built right up to almost the boundaries. And they've caused 

so much problems trying to shut Luke down. We don't want that to happen out here. 

Well, you know, I would like to be sure that Palo Verde is going to be here. And that this is not – 
Appendix A 

NUREG-1437, Supplement 43 A-42 December 2010

just because we have development that's been brought in and planning development of people 

out there in this local valley doesn't affect Palo Verde. No. Palo Verde has not encroached on 

anybody. I'm just concerned that like Luke where the developers have come out, planted 

homes and subdivisions and developments and now they're complaining. Well, they knew that 

air base was there, they know Palo Verde's here. But they -- that doesn't slow them down. I 

mean, they plan on planting close to a little over a million people in this Valley inside a ten mile 

radius. We would like to know, can NRC slow that down and keep them to some type of bay so 

that Palo Verde does exist and continue to operate without their interference? 

Response: The NRC has no role in land development planning in the area near PVNGS. 

Comment PV-AB-9: The startling revelation that the NRC is proposing to allow an exemption 

to the regulation requiring the written and operations test for the SRO at Palo Verde by a FONSI 

brings forward the question of NRC honesty and integrity. There is a question now whether the 

NRC is acting in a criminal manner in these regards. This must be examined fully and openly. 

The NRC should examine fully in the EIS the probability and likelihood that the NRC has 

exhibited now that it has “unclean hands” and that it is evidently a corrupt agency and not 

capable of regulating Palo Verde. In the course of this investigation and analysis, the NRC 

should examine whether the decision to lift the scrutiny of Palo Verde in spring 2009 was merely 

a cynical move to assist with the relicensure process and if it was the agency yielding to political 

pressure, or if the NRC really did determine, after four to five years of extra scrutiny and 

concern, that suddenly the operators of Palo Verde had indeed changed their corporate culture 

and were worthy of less scrutiny. Included with this analysis is the likelihood or increased 

probability that the NRC’s actions will help cause a serious problem at Palo Verde leading to 

extra charges for ratepayers, at a minimum, or the worst, an incident releasing radiation in 

unpermitted amounts. 

Response: The NRC mission is to enable the nation to safely use radioactive materials for 

beneficial civilian purposes while ensuring that people and the environment are protected. We 

take our responsibilities very seriously and are committed to performing our duties with honesty 

and integrity. The NRC staff followed its regulatory process in addressing the subject 

exemption request. That discussion can be found in NRC Exemption number NRC-2009-0316 

at ML091540950. The concern described in this comment was referred to the NRC’s 

independent Office of the Inspector General (OIG) for evaluation, and OIG concluded there was 

no wrongdoing by the NRC. 
Appendix A

December 2010 A-43 NUREG-1437, Supplement 43

A.2 COMMENTS RECEIVED ON THE DRAFT SUPPLEMENTAL 

ENVIRONMENTAL IMPACT STATEMENT 

The staff transmitted the Generic Environmental Impact Statement for License Renewal of 

Nuclear Plants, Supplement 43, Regarding Palo Verde Nuclear Generating Station, Draft Report 

for Comment [NUREG-1437, Supplement 43, referred to as the draft supplemental 

environmental impact statement (SEIS)] to Federal, State, and local government agencies and 

interested members of the public. As part of the process to solicit public comments on the draft 

SEIS, the staff: 

● placed a copy of the draft SEIS into the NRC’s Public Electronic Reading Room, 

on its license renewal website, at the Litchfield Park Branch Library in Litchfield 

Park, AZ and at the Sam Garcia Western Avenue Library in Avondale, AZ

● sent copies of the draft SEIS to the applicant, members of the public who 

requested copies, and certain Federal, State, and local agencies 

● published a notice of availability of the draft SEIS in the Federal Register

● placed newspaper ads and issued press releases announcing the issuance of 

the draft SEIS, the public meetings, and instructions on how to comment on the 

draft SEIS 

● established an e-mail address to receive comments on the draft SEIS 

electronically 

● announced and held two public meetings on September 15, 2010, at the Saddle 

Mountain Unified School District Board Room in Tonopah, AZ and Estrella 

County Community College in Avondale, AZ to present the results of the 

environmental review and answer questions on the license renewal process 

Approximately 30 people attended each of the public meetings. After the NRC’s prepared 

statements pertaining to the contents of the DSEIS and the license renewal process, the 

meetings were open for public comments. Seven (7) attendees provided oral comments 

that were recorded and transcribed by a certified court reporter, written statements or both. 

Transcripts for the afternoon and evening meetings were made publicly available at the 

NRC Public Document Room (PDR) and from the NRC's Agencywide Documents Access 

and Management System (ADAMS) listed under Accession Nos. ML102730611 and 

ML102730640, respectively. A summary of the meeting, which was issued on 

October 13, 2010, is listed under Accession No. ML102780162. 

During the draft SEIS comment period, the staff received one e-mail from a member of the 

public. Comments were also received from the U.S. Environmental Protection Agency and 

Arizona Public Service Company. A cross-reference of the Commenter ID, author of the 

comment, their affiliation, the comment source, and the ADAMS accession number are 

provided in Table A-2. 
Appendix A 

NUREG-1437, Supplement 43 A-44 December 2010

Table A-2. Comments on the Draft SEIS

Commenter ID Commenter Affiliation Comment Source ADAMS Accession 

Number 

PV-AF Gary Yaquinto Arizona Investment 

Council, President Afternoon transcript ML102730611 

PV-AG Jack Arend Member of the public Afternoon transcript ML102730611 

PV –AH Gordon James 

Greater Phoenix 

Chamber of 

Commerce 

Afternoon transcript 

ML102730611 

PV –AI Clay Goodman Estrella Mountain 

Community College 

Evening transcript ML102730640 

PV –AJ Anna Kupcik 

Buckeye Valley 

Chamber of 

Commerce 

Evening transcript ML102730640 

PV –AK Jeff Muecke Universal Technical 

Institute 

Evening transcript ML102730640 

PV –AL Sharon Hohman 

Southwest Valley 

Chamber of 

Commerce 

Evening transcript ML102730640 

PV –AM Lloyd Rogers Member of the public Email ML102650275 

PV –AN John H. Hesse APS, Vice President Letter ML103130044 

PV –AO-1 J. Doershuk EPA Letter ML102560484 

PV –AO-2 J. Doershuk EPA Letter ML102560484 

PV –AO-3 J. Doershuk EPA Letter ML102560484 

PV –AO-4 J. Doershuk EPA Letter ML102560484 

There was no new and significant information provided on Category 1 issues, and no 

information that required further evaluation of Category 2 issues. Therefore, the conclusions in 

the GEIS and draft SEIS remained valid and bounding, and no further evaluation was 

performed. Where the comment or question resulted in a change in the text of the draft SEIS, 

the corresponding response refers the reader to the appropriate section of this SEIS where the 

change was made. Revisions to text in the draft SEIS are designated by vertical lines beside 

the text in this final SEIS. 

A.2.1 Individual Comments and Responses 

Comments PV-AF through PV-AM: The first 8 comments in Table A-2 are found in the 

afternoon and evening transcripts from the September 15, 2010, DSEIS Public Meetings found 

at ML102730611 and ML102730640, respectively. 

Response: These comments are supportive of APS and license renewal at PVNGS and are 

general in nature. The comments provide no new information and will not be evaluated further. 

Comment PV-AN: This comment is a letter providing editorial comments from the applicant. 

Response: The comments and the NRC staff responses are provided in the following table. 
Appendix A

December 2010 A-45 NUREG-1437, Supplement 43

Table A-3. APS Comments on the Draft SEIS and NRC Staff Responses 

Comment 

No. 

Page No. and 

SER Section Comment NRC Response 

1 

Executive 

Summary, 

Page xiii, Line 

7, and Page 4-

2, Section 

4.3.2, Line 22 

and 23, and 

Table 4-11 on 

Page 4-33 

All of these sections discuss PVNGS use of 

groundwater compared to apparently different 

numbers associated with the Phoenix Active 

Management Area (AMA). In the first two cases, 

the Draft Report states that PVNGS use of 

Groundwater is less than 10% of the water that 

flows through the Phoenix AMA, but Table 4-11 

states that PVNGS use of groundwater is 

“inconsequential,” i.e., less than 1% of annual 

demand. It appears that both of these 

comparisons are correct, but they could be 

confusing when viewed together. It is assumed 

that the less than 10% number is comparing 

PVNGS usage to “natural recharge” of the Phoenix 

AMA, and the less than 1% number is comparing 

PVNGS usage to the total Phoenix AMA cultural 

groundwater usage data. 

Executive 

Summary 

and Section 

4.3.2 text 

changed to 

reflect that 

PVNGS 

groundwater 

use is less 

than 1% of 

annual 

Phoenix 

AMA 

demand. 

The 

assumption 

mentioned in 

the comment 

is correct. 

2 

Page 1-2, 

Section 1.3, 

Line 10 

Draft states that the Scoping Process Summary 

Report was issued in April, 2009 – the actual date 

had to have been after the Public Scoping 

Meetings took place on June 25, 2009. 

Date of the 

Scoping 

Process 

Summary 

Report 

changed to 

April 2010. 

3 

Page 1-3 

Section 1.4, 

Line 16 

The “1” after (NRC 1996, 1999) should be in 

superscript since it refers to a footnote. 

Text 

changed. 

4 

Pages 1-8 and 

1-9, Section 

1.9, Table 1-1 

Permit Dates can be up-dated/corrected. 

Type 3 Reclaimed Water General Permit expiration 

Date should be changed from 6/22/2010 to 

3/24/2015. The Pipeline Repair & Maintenance 

Permit FA 20020002 Issue date should be changed 

from 8/18/2005 to 1/7/2002 and the Expiration Date 

should be changed from 7/31/2010 to “Not Listed.” 

The Non-Title V Air Permit Expiration date should 

be changed from 7/31/2010 to 7/31/2015. 

Text 

changed to 

address this 

issue. 
Appendix A 

NUREG-1437, Supplement 43 A-46 December 2010

5 

Page 2-1, 

Section 2.1, 

Line 14, and 

Page 2-29, 

Section 2.2.1, 

Lines 4 – 5. 

On Page 2-1 the Draft states that there are 

approximately 605 surface acres of water on the 

site. On Page 2-29 the Draft states that there are 

approximately 790 surface acres of water, including 

three evaporation ponds covering 660 acres. The 

report should state that there are approximately 

780 surface acres of water, including three 

evaporation ponds covering 650 acres. This is 

based on the 45 and 85 acre reservoirs and 

Evaporation Ponds 1, 2 and 3 being 250 acres, 220 

acres, and 180 acres respectively. 

Text 

changed to 

consistent 

use of 780 

acres for the 

total surface 

acres of 

water and 

650 surface 

acres of 

water for the 

Evaporation 

Ponds. 

6 

Page 2-7, 

Section 2.1.3, 

Line 11 

The Draft Report states that the Special Approval 

Permit (Permit #7-368, Category D18) is applicable 

to sludge from the PVNGS Water Reclamation 

Facility. For clarity, and in accordance with our 

Environmental Report, should add the words “and 

cooling towers” after “Water Reclamation Facility.” 

Text 

changed to 

address this 

issue. 

7 

Page 2-8 

Section 2.1.3.1 

Revise the wording regarding the Pollution 

Prevention Plan for clarity. 

Remove the word “each” from line 21, and use the 

plural forms of “waste, emission, or toxic 

substance” in line 22. Remove the words “and 

newsletter” from line 28, and in line 30 and 31 

replace “...and by implementing a P2 (Pollution 

Prevention) award program for their employees” 

with “...and by implementing an EHS Excellence 

award program for their employees.” 

Text 

changed to 

address this 

issue. 

8 

Page 2-10, 

Section 2.1.5, 

Lines 27 and 

28 

The Draft Report states that “Saguaros that are 

close enough to lines to pose this risk are 

transplanted outside of the border zone. In 

addition to transplanting these Saguaros can be 

trimmed. Add a statement at the end of the 

paragraph that states the Saguaros can be 

transplanted outside of the border zone or trimmed. 

Text 

changed to 

address this 

issue. 

9 

Page 2-14, 

Section 

2.1.6.3, Line 

29 

The Reclaimed Water General Permit No. 105317 

is not for the operation of the Water Reclamation 

facility. Permit No. 105317 is used to allow the 

discharge of Water Reclamation Pipeline water to 

farmers fields during certain maintenance activities. 

There is no specific operating permit for the Water 

Reclamation Facility. Remove the sentence “It 

operates under a Type 3 Reclaimed Water General 

Permit (ADEQ Inventory # R105317).” 

Text 

changed to 

address this 

issue. 

10 

Page 2-14, 

Section 

2.1.6.3, Line 

34 – 35 

The Draft states that WRF-treated water is also 

used for dust suppression at PVNGS as required 

by Air Permit # 8600896. This permit number does 

not exist at Palo Verde. Recommend removing 

the statement in parenthesis. 

Text 

changed to 

address this 

issue. 
Appendix A

December 2010 A-47 NUREG-1437, Supplement 43

11 

Page 2-15, 

Section 

2.1.7.1, Line 

37 

Lines 37 and 38 of this page in the Draft Report 

make it sound like the Water Reclamation Pipeline 

is 36 miles of gravity fed pipe up to the 

Hassayampa Pump Station. In reality the total 

length of the pipeline is 36 miles, with the portion 

between 91st Avenue and the Hassayampa Pump 

station being gravity fed (first approximately 28 

miles). Clarify that the entire length of the pipeline 

is 36 miles. 

Text 

changed to 

address this 

issue. 

12 

Page 2-16, 

Section 

2.1.7.2, Line 

25 

The Draft Report states that the Firing Range Well 

is used primarily for dust control. This well was 

never used for dust control but rather was used as 

a potable water source. The reference for this 

statement (APS-2004) does not indicate that the 

well was used for dust control. The reference 

states that the well is an exempt well, with its 

primary purpose being “Industrial.” However, this 

does not mean dust control, but rather it was used 

to provide drinking water to a non-public 

population. Revise statement to state that 

Groundwater from the range well was used to 

provide potable water to the firing range. 

Text 

changed to 

address this 

issue. 

13 

Page 2-19, 

Section 

2.1.7.4, Line 

34 

This section of the Draft Report is discussing both 

the 85 and 45 Acre Reservoirs. The sentence 

starting at the end of Line 34 states “It has a 

maximum depth of about 46 feet...” The “It” refers 

to the 45-Acre Reservoir. Suggest replacing “It” 

with “The 45-Acre Reservoir.” 

Text 

changed to 

address this 

issue. 

14 

Page 2-20, 

Table 2.1.7-2 

The Table lists facilities regulated by our Aquifer 

Protection Permit – but it does not list the 

Sedimentation Basins. The main impact of the 

APP regarding the Sedimentation Basins is that it 

requires monitoring of Unauthorized (or NonExempt) Discharges to the Sedimentation Basins 

and it addresses final Closure of the Sedimentation 

Basins. Recommend adding Sedimentation 

Basins 1 and 2 to Table 2.1.7.2 as detailed in our 

Site Aquifer Protection Permit (the current 

reference for the Table). 

Text 

changed to 

address this 

issue. 

15 

Page 2-21, 

Section 

2.1.7.4, Line 7 

- 10 

The Draft report states that Evaporation Ponds #1 

and #2 are both double-lined and both have an 

Underdrain System. This is not accurate; see Site 

APP Sections 5, and 6. Since Evaporation Pond 

#2 is currently being rebuilt, and Evaporation Pond 

#1 will be rebuilt after Evaporation Pond #2 is 

complete, suggest changing the wording to state 

that both ponds are lined surface impoundments, 

and remove any reference to an underdrain system 

for these ponds. 

Text 

changed to 

address this 

issue. 
Appendix A 

NUREG-1437, Supplement 43 A-48 December 2010

16 

Page 2-21, 

Section 

2.1.7.4, Line 

16 

The Draft Report states that the average annual 

flow rate to each pond is 3,125 gpm (the provided 

reference is our site Aquifer Protection Permit – 

APP). The provided reference could be read as 

stating that this is the average annual flow rate to 

each pond, but it is meant to state that this is the 

estimated average annual flow to all of the 

evaporation ponds combined. Suggest removing 

the word “each” and replacing with “all evaporation 

ponds combined.” 

Text 

changed to 

address this 

issue. 

17 

Page 2-22, 

Section 

2.1.7.4, Lines 

31 - 37 

The Draft Report appears to refer to the “STP 

Retention Tanks.” These are two separate 

facilities. Suggest adding a comma between STP 

and Retention Tanks in lines 31 and 32, and 

remove “STP” between the words “exempt” and 

“retention” in Line 36. 

Text 

changed to 

address this 

issue. 

18 

Page 2-22, 

Section 

2.1.7.4, Line 

39 

The draft report indicates that the APP is designed 

to protect the drinking water aquifer in the vicinity of 

PVNGS. The purpose of the state’s aquifer 

protection program is to protect all Aquifers. 

Suggest removing the words “drinking water” in 

Line 39. 

Text 

changed to 

address this 

issue. 

19 

Page 2-23, 

Section 2.1.7.4 

Line 39 

The Draft Report states that the APP requires 

cooling tower sludge and WTF (Wastewater 

Treatment Facility) sludge be analyzed prior to 

disposal in the sludge landfill. The site APP does 

require analysis of cooling tower sludge prior to 

disposal, but allows sampling of WTF sludge in 

place. Suggest wording such as “The APP 

requires that cooling tower sludge be sampled prior 

to disposal, and WTF (Wastewater Treatment 

Facility) sludge be sampled on a twice per year 

basis.” 

Text 

changed to 

address this 

issue. 
Appendix A

December 2010 A-49 NUREG-1437, Supplement 43

20 

Page 2-26, 

Section 

2.1.7.4, Line 

25 - 31 

The Draft report refers to three downgradient wells 

(APP-01, APP-10, and APP-11) drilled to depths of 

80 – 90 feet. The correct well numbers are: APP-9, 

APP-10, and APP-12, and they were drilled to 

depths of 110 – 180 feet. The report also states 

that tritium has not been detected above the 

Arizona Water Quality Standard of 20,000 pCi/L in 

these wells or in groundwater from other site 

monitoring wells. The downgradient wells are 

actually APP-9, APP-10, and APP-12, and they 

were drilled to a depth of 110 – 180 feet. 

Assuming that the Draft Report is referring to these 

downgradient wells and other Aquifer Monitoring 

Wells when it states that tritium has not been 

detected above the Arizona Water Quality 

Standard of 20,000 pCi/L – it would be more 

appropriate to state that Tritium has never been 

detected in any of these wells. 

Text 

changed to 

address this 

issue. 

21 

Page 2-32, 

Section 

2.2.2.1, Line 1 

The “3” after PTE and the “4” after HAPs should be 

superscript since they refer to footnotes. 

Text 

changed to 

address this 

issue. 

22 

Page 2-32, 

Footnote #4 

The Draft report States that a Major Source of 

HAPs is a Stationary Source that emits more than 

5 tons per year of any single HAP. This should 

state 10 tons per year of any single HAP. 

Text 

changed to 

address this 

issue. 

23 

Page 2-41, 

Section 2.2.5, 

Line 10 

The draft report refers to “three large lined storage 

reservoirs.” There are only two storage reservoirs: 

the 85 and 45 Acre Reservoirs. Change the “three 

large” to “two large” lined storage reservoirs. 

Text 

changed to 

address this 

issue. 

24 

Page 2-54, 

Section 

2.2.8.2, Line 

19 

The Draft Report states that PVNGS provides 

almost 100 ten-passenger vans. Our 

Environmental report stated that we have a fleet of 

169 vans. Suggest revising the report to state that 

PVNGS provides more than 100 ten-passenger 

vans. 

Text 

changed to 

address this 

issue. 

25 

Page 2-56, 

Section 

2.2.8.4, Lines 

20 – 22 

The Draft Report states that height of the plume 

from the cooling towers can be 1,900 feet on an 

average summer morning and 870 feet on an 

average winter morning. This statement is not 

referenced. It would appear that these numbers 

are reversed. During the cooler winter months the 

plume from our cooling towers is typically higher 

than on a summer morning. 

Text 

changed to 

address this 

issue. 
Appendix A 

NUREG-1437, Supplement 43 A-50 December 2010

Comment PV-AO-1: Ecological Risk

The DSEIS (pp. 2-41, 2-42) refers to a 1996 study of aquatic life in ponds and reservoirs at Palo 

Verde Nuclear Generating Station (PVNGS), which found selenium in the ponds but did not find 

"metals and contaminants that are typically of concern for these processes." It is unclear what 

parameters were investigated in that study, which also did not investigate bioaccumulation of 

contaminants or biomagnification up the food chain. Nuclear Regulatory Commission (NRC) 

staff conclude that the chemical and physical environment of the reservoirs and ponds should 

not have changed in the 14 years since the study. The reasons behind this conclusion are 

unclear. For example, does monitoring show that concentrations of all parameters are 

essentially the same as they were in 1996? How often are sludges dredged from the ponds and 

reservoirs? It is unclear from the DSEIS whether compliance with the Arizona Water Quality 

Standards ensures against ecological risk through exposure, bioaccumulation, and 

biomagnification of metals or other contaminants that concentrate in the water, sludge, and 

sediment in the water storage reservoirs, evaporation ponds, and sedimentation basins. 

Recommendation: EPA recommends that the Final Supplemental Environmental Impact 

Statement (FSEIS) provide updated information regarding the parameters and 

26 

Page 2-61, 

Section 

2.2.8.6, Line 

12 

The Draft Report states that Maricopa County 

collected between $3.3 and $4.3 billion in property 

tax revenues from all PVNGS owners (see Table 

2.2.8.6-3). Table 2.2.8.6-3 is correct, but the 

verbiage on page 2-61, Section 2.2.8.6 is incorrect. 

The $3.3 and $4.3 billion figures are total county 

tax revenues. Also recommend that Table 2.2.8.6-

3 be revised by replacing “APS” in the Description 

of the Table, and in columns 3 and 4 with 

“PVNGS.” 

Text 

changed to 

address this 

issue. 

27 

Page 4-4, 

Section 

4.3.4.1, Line 

11 

The draft report states that tritium was not detected 

in any monitoring wells at PVNGS in 2008. For 

clarification suggest adding the word “aquifer” 

between “any” and “monitoring well” due to the 

shallow tritium impacted water that has been found 

around certain piping features. 

Text 

changed to 

address this 

issue. 

28 

Page 4-4, 

Section 

4.3.4.2, Lines 

30 – 35 

In lines 30 and 34 the acronym WRS is used for 

Water Storage Reservoir instead of WSR. 

Text 

changed to 

address this 

issue. 

29 

Page 4-14, 

Section 4.8.3, 

Lines 33 and 

34 

The Draft Report states in the second sentence of 

the paragraph that a new criterion has been added 

to the NESC for power lines with voltages 

exceeding 98 kV. The criterion being discussed (5 

mA induced currents due to static effects) was in 

effect when the Palo Verde transmission lines were 

built. Suggest removing the second sentence of 

the 3rd paragraph of Section 4.8.3. 

Text 

changed to 

address this 

issue. 

30 

Page 5-11, 

Section 5.3.1 

Lines 24 and 

25 

The reference to the NRC’s SAMA review should 

be changed from Appendix G to Appendix F 

because Appendix F contains the SAMA review. 

Text 

changed to 

address this 

issue. 
Appendix A

December 2010 A-51 NUREG-1437, Supplement 43

concentrations found in the water, sludge, and sediment in the water storage reservoirs, 

evaporation ponds, and sedimentation basins. We recommend an ecological risk 

assessment be conducted to determine the potential effects of wildlife exposure to these 

facilities. The FSEIS should discuss the findings of this assessment and identify 

measures that could be implemented to mitigate any adverse impacts. If mitigation 

measures are needed, the FSEIS and decision record should include commitments to 

implement them. 

Response: Comment PV-AO-1 above contains questions and recommendations that will be 

addressed in the order asked. First, the comment asks what parameters were investigated in 

the 1996 study. The 1996 study referred to in the comment was performed in response to a 

specific incident which took place in the winter of 1994 – 1995. In November 1994 through 

January 1995, PVNGS identified 829 dead waterfowl primarily in the PVNGS evaporation 

ponds, the majority of which were Northern shovelers (Anas clypeata) and ruddy ducks (Oxyura 

jamaicensis) (APS 2008a). In response to the die-off, APS partnered with the Arizona Game 

and Fish Department, the USFWS, the USGS National Wildlife Health Center, and multiple 

university labs to determine the cause of the event and to prevent future waterfowl die-offs at 

PVNGS (APS 2008a). 

A sampling program that lasted more than one year was initiated to identify biological toxins and 

chemical concentrations and to characterize the chemistry of the ponds. Parameters tested 

included biological oxygen demand, total dissolved solids, pH, conductivity, dissolved oxygen, 

ammonia, nitrate, nitrite, phosphate, salinity, temperature, 29 volatile organic compounds, 56 

semi-volatile organic compounds, algae and micro-organisms. In addition,19 non-organic 

compounds including the following were tested for: arsenic, barium, cadmium, chromium, lead, 

mercury, selenium, and silver. (Analytical and trend results are available in “Evaporation Pond 

Investigation Report” (Hillmer 1996) at ADAMS Accession Nos. ML101380158, ML101380163, 

ML101380198, ML101380203.) University of Arizona and USGS’s National Wildlife Heath 

Center also performed necropsies to identify bacterial infections, viruses, or chemical 

contaminants that may have caused the bird mortalities (APS 2008a). 

As a result of the sampling program and necropsy study, Hillmer (1996) concluded that neither 

biological conditions (resident algae and micro-organisms) nor chemical parameters in the 

evaporation ponds had caused the mortality. The author noted that within the Pacific Flyway, 

four other major migratory bird die-offs had occurred within the same time frame as the PVNGS 

die-off and affected species included Northern shovelers and/or ruddy ducks (Hillmer 1996). 

These die-offs were attributed to either Botulism type C or Avian Cholera. Though Hillmer 

(1996) was unable to conclusively determine the cause of the PVNGS die-off to be diseaserelated, University of Arizona laboratory personnel suspected Avian Botulism as a likely cause 

and also noted that the birds were likely infected prior to arriving at PVNGS. 

Second, Comment PV-AO-1 asks for the reasons behind the NRC staff conclusion that the 

chemical and physical environment of the reservoirs and ponds should not have changed in the 

14 years since the study. The primary reason behind this NRC staff conclusion is that the main 

source of water to the evaporation ponds continues to be the cooling tower blowdown stream 

and the main source of water to the Water Storage Reservoirs (WSR) continues to be the 

tertiary treated water from the Water Reclamation Facility. 

NRC staff considered available data for performing an examination of pond water changes over 

time. Analysis of water contained in the evaporation ponds and in the WSRs is provided in the 

Annual Monitoring and Compliance Reports. PVNGS uses the analysis provided in these 

reports to demonstrate compliance with its aquifer protection permit and to protect groundwater. 

However, comparing the data from the Annual Monitoring and Compliance Reports with data 
Appendix A 

NUREG-1437, Supplement 43 A-52 December 2010

from the 1996 “Evaporation Pond Investigation Report” is of limited value because the data 

collected for each serves two distinctly different purposes. The data from these two sources 

was not designed for comparison of pond changes over time. For example, evaporation pond 

characteristics change with the seasons and also change with the amount of influent into a 

given pond which changes throughout the year. The once or twice per year sampling and 

analysis of the Annual Monitoring and Compliance Reports do not take into account seasonal 

variability and pond management changes. Overall, NRC staff concludes there is limited value 

in examining the pond water changes over time. 

Next, Comment PV-AO-1 recommends that the FSEIS provide updated information regarding 

the parameters and concentrations found in the water, sludge, and sediment in the water 

storage reservoirs, evaporation ponds, and sedimentation basins. Page 2-23 of the DSEIS 

provides a brief discussion of the parameters tested for and concentrations found in the ponds. 

This discussion will be modified in the FSEIS to include a statement that the PVNGS 2004 

through 2008 Annual Monitoring and Compliance Reports containing information on parameters 

tested for and concentrations found in the ponds are available at ADAMS Accession Nos. 

ML101540025, ML101540061, ML101540107, ML101550312, and ML101550341. 

Finally, Comment PV-AO-1 recommends an ecological risk assessment be conducted to 

determine the potential effects of wildlife exposure to these facilities. The NRC staff considered 

conducting an ecological risk assessment, but concluded that one was not necessary for the 

following reasons: (1) no other bird die-off has occurred at PVNGS before or since the 1994-95 

event (APS 2008a); (2) Hillmer (1996) did not conclusively link the cause of the event with 

PVNGS operation (the cause of the die-off was suspected to be Avian Botulism, which was 

likely contracted by the birds before arriving at PVNGS); and, (3) PVNGS is a fenced, limitedaccess facility in a desert environment.

Comment PV-AO-2: Air Quality 

Table 2.2.2.1 discloses PVNGS 2004-2008 emissions for criteria air pollutants and hazardous 

air pollutants (HAPs), but does not include emissions of some greenhouse gases such as 

carbon dioxide. In addition, the DSEIS (p. 2-32) only identifies benzene as one example of a 

HAP emitted by the PVNGS, but does not identify other HAPs or provide emission rates for 

specific HAPs. 

Recommendation: EPA recommends that the FSEIS provide this information. 

Response: Emissions of carbon dioxide has been added to Table 2.2.2-1 for 2004 – 2008. 

Also, HAPs other than benzene are provided on page 2-32 and information on the contribution 

of individual HAPs is provided in Table 2.2.2-1. 

Comment PV-AO-3: Air Quality 

The DSEIS (p. 4-12) states that the Radiological Environmental Monitoring Program (REMP) 

reports from 2004 through 2008 were reviewed by NRC staff for unusual trends, and none were 

observed. It is unclear why a trend analysis was only conducted for the previous five-year 

period rather than for the entire period since the REMP was established in 1979. This would 

provide a more thorough cumulative analysis of radiological exposures and impacts. 

Recommendation: EPA recommends that the FSEIS include an REMP trend analysis 

for the period from 1979 to present. 

Response: In order to address the comments, it is important to understand NRC’s license 

renewal process which classifies environmental and human health issues as either Category 1 

(generic to all nuclear power plants) or 2 (requires a site specific evaluation). For license 

renewal, the NRC performed a comprehensive evaluation of all nuclear power plants in the 
Appendix A

December 2010 A-53 NUREG-1437, Supplement 43

United States to assess the scope and impact to public health and safety and the environment 

from radioactive material released from a nuclear power plant for an additional 20 years of 

operation. 

The impact evaluation performed by the staff and presented in the Generic Environmental 

Impact Statement for License Renewal of Nuclear Plants NUREG-1437 (GEIS) identified 92 

environmental issues that were considered for the license renewal evaluation for power reactors 

in the U.S. Stakeholders, such as members of the public, Federal, state, and local 

governmental agencies, the nuclear power industry, and citizen groups commented on and 

helped identify these 92 issues during the preparation of the GEIS. For each of the identified 92 

issues, the staff evaluated existing data from all operating power plants throughout the U.S. 

From this evaluation, the staff determined which issues could be considered generically and 

which issues are not appropriate for generic consideration. The GEIS divides the 92 issues that 

were assessed into two principle categories: 

Category 1 (generic) issues are those that meet all of the following criteria: 

1) The environmental impacts associated with the issue have been determined to apply either to 

all plants or, for some issues, to plants having a specific type of cooling system or other 

specified plant or site characteristic. 

2) A single significance level (i.e., SMALL, MODERATE, or LARGE) has been assigned to the 

impacts (except for collective offsite radiological impacts from the fuel cycle and from high-level 

waste and spent fuel disposal) for all plants. 

3) Mitigation of adverse impacts associated with the issue has been considered in the analyses, 

and it has been determined that additional plant-specific mitigation measures are not likely to be 

sufficiently beneficial to warrant implementation. 

Category 1 issues are termed “generic” issues because the conclusions related to their 

environmental impacts were found to be common to all plants. For Category 1 issues, a single 

level of significance was common to all plants, mitigation was considered, and the NRC 

determined that it was not likely to be beneficial. Issues that were resolved generically are not 

reevaluated in the site-specific supplement to the generic environmental impact statement on 

license renewal (SEIS) because the conclusions reached would be the same as in the GEIS, 

unless new and significant information is identified that would lead the NRC staff to reevaluate 

the GEIS’s conclusions. During the environmental reviews of license renewal applications, the 

NRC staff makes a concerted effort to determine whether any new and significant information 

exists that would change the generic conclusions for Category 1 issues. 

Category 2 issues are those that require a site-specific review. For each of the Category 2 

issues applicable to the site under review, the staff evaluates site-specific data provided by the 

applicant, other Federal agencies, state agencies, Tribal and local governments, as well as 

information from the open literature and members of the public. From this data, the staff makes 

a site-specific evaluation of the particular issues and presents its analyses and conclusions in 

the SEIS for the facility. 

The GEIS evaluated the radiological impacts on human health and the environment from the 

operation of nuclear power facilities and concluded that the impacts were well within NRC 

requirements in each instance. The NRC expects its licensees to continue to comply with its 

radiation protection standards during the period of license renewal; therefore, there is no reason 

to expect radioactive effluents to significantly increase during the period of renewal license. In 

addition, the NRC performs periodic on-site inspections of each facility to verify its compliance 

with NRC regulations. Even though the radiological impacts to members of the public and the 

environment are Category 1 issues, the NRC staff evaluates each license renewal application 

and visits the site to determine if there is new and significant information that would change the 
Appendix A 

NUREG-1437, Supplement 43 A-54 December 2010

conclusion in the GEIS and require a site-specific evaluation. 

The staff notes that effective use of radioactive waste treatment systems and practices at 

nuclear power plants have minimized the discharge of radioactive effluents into the 

environment. This is demonstrated by the calculated annual dose to members of the public 

being well within NRC’s as low as is reasonably achievable (ALARA) dose criteria contained in 

Appendix I to 10 CFR Part 50, as well as the low levels of radioactivity typically measured in 

environmental samples. 

Since the REMP is a Category 1 issue, the staff’s policy is to review five years of radiological 

environmental monitoring data. A five-year period provides a representative data set that 

covers a broad range of activities that occur at a nuclear power plant such as refueling outages, 

non-refueling outage years, routine operation, operational occurrences, and years where there 

may be significant maintenance activities for the staff to observe a discernable trend. For 

license renewal, the staff’s assessment of the REMP data specifically focuses on trends that 

may, over the license renewal period, reach the NRC’s reporting standards for radioactivity in 

environmental media. If an adverse trend was observed, the staff would conduct a thorough 

investigation. The investigation would explore the cause of the increased radioactivity levels 

and the licensee’s plan to reverse or mitigate the trend. If appropriate, the staff would review 

radioactive effluent and REMP data as far back as needed to thoroughly evaluate the issue. 

The results of the staff’s evaluation would be included in the SEIS. 

The REMP provides a mechanism for determining the levels of radioactivity in the environment 

to determine if there is an accumulation of radionuclides in the environment attributable to 

radioactive effluents from the power plant or from other sources (i.e., natural background, fallout 

from past atmospheric atomic weapons tests and from Chernobyl). While in-plant radioactive 

effluent monitoring program is used to ensure that the dose to members of the public is within 

the dose limits in 10 CFR 20.1301 and the ALARA design criteria in Appendix I to 10 CFR Part 

50, the REMP provides direct verification of any environmental impact that may result from plant 

effluents. If there was a build-up of radionuclides in the environment around the Palo Verde 

site, the REMP data would show it. The observed levels are typically very low, slightly above 

background radiation levels which do not represent a hazard to the public or the environment. 

However, as reported in the Palo Verde draft SEIS, the staff did not observe an unusual or 

adverse trend and the data showed that there was no measurable impact to the environment 

from operations at the Palo Verde site. Based on the GEIS’s extensive evaluation of radioactive 

effluent and environmental monitoring data from NRC licensed nuclear power plants, the GEIS 

concluded that the impacts for all nuclear power plants was small. Given that PVNGS’s REMP 

data was consistent with the GEIS and there was no new and significant information at PVNGS, 

the staff concludes that no further investigation beyond the five-year review is warranted. 

Comment PV-AO-4: Air Quality 

The DSEIS (p. 4-13) provides the REMP calculated annual doses to members of the public 

located outside the PVNGS site boundary from radioactive gaseous effluents released during 

2008. The DSEIS indicates that the 2008 radiological effluent data are consistent, with 

reasonable variation attributable to operating conditions and outages, with the historical 

radiological effluent releases and resultant doses. However, it is unclear what the variation is 

for these doses over the years of operation. 

Recommendation: EPA recommends that the FSEIS provide this information. 

Response: The staff agrees that additional information should be added to the discussion on 

radiation doses to members of the public from radioactive effluents to clarify what is meant by 

“reasonable variation.” 
Appendix A

December 2010 A-55 NUREG-1437, Supplement 43

The final EIS will clarify that the amount of radioactive effluents discharged from PVNGS vary 

from year to year based on the plant operating conditions and the number and type of refueling 

outages or maintenance work, and that the radiation doses were well within the radiation dose 

limits in 10 CFR 20.1301 and the ALARA dose criteria in Appendix I to 10 CFR Part 50. 

A.3 REFERENCES 

10 CFR Part 20. Code of Federal Regulations, Title 10, Energy, Part 20, “Standards for 

Protection Against Radiation.” 

10 CFR Part 50. Code of Federal Regulations, Title 10, Energy, Part 50, “Domestic Licensing of 

Production and Utilization Facilities.” 

Arizona Public Service Company (APS). 2008a. Palo Verde Nuclear Generating Station, Units 

1, 2, and 3, Applicant’s Environmental Report, License Renewal Operating Stage. December. 

ADAMS No. ML083510615, Appendix E. 

Hillmer, T. 1996. Evaporation Pond Investigation Report. Produced by EH&S for Arizona 

Public Service Company. ADAMS Nos. ML101380158, ML101380163, ML101380198, 

ML101380203 

APPENDIX B. 

NATIONAL ENVIRONMENTAL POLICY ACT ISSUES FOR LICENSE 

RENEWAL OF NUCLEAR POWER PLANTS 

December 2010 B-1 NUREG-1437, Supplement 43

B. NATIONAL ENVIRONMENTAL POLICY ACT ISSUES FOR 

LICENSE RENEWAL OF NUCLEAR POWER PLANTS 

NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Power 

Plants (referred to as the GEIS), documents the results of the NRC staff’s systematic approach 

to evaluating the environmental impacts of renewing the licenses of individual nuclear power 

plants. Of the 92 total environmental issues the NRC staff identified in the GEIS, the staff 

determined that 69 are generic to all plants (Category 1), while 21 issues must be discussed on 

a site-specific basis (Category 2). Two other issues, environmental justice and the chronic 

effects of electromagnetic fields, are uncategorized and must be evaluated on a site-specific 

basis. 

The table below is a listing of all 92 environmental issues, including the possible environmental 

significance (SMALL, MODERATE, LARGE, or uncategorized) as appropriate. This table is 

provided in Chapter 9 of the GEIS, is codified in the NRC regulations as Table B-1 in Appendix 

B, Subpart A, to Title 10 of the Code of Federal Regulations (CFR) Part 51, and is provided here 

for convenience. 

Table B-1. Summary of Issues and Findings 

Issue Type of Issue Finding 

Surface Water Quality, Hydrology, and Use 

Impacts of 

refurbishment on 

surface water quality 

Generic 

SMALL. Impacts are expected to be negligible during 

refurbishment because best management practices are expected 

to be employed to control soil erosion and spills. 

Impacts of 

refurbishment on 

surface water use 

Generic SMALL. Water use during refurbishment will not increase 

appreciably or will be reduced during plant outage. 

Altered current 

patterns at intake and 

discharge structures 

Generic 

SMALL. Altered current patterns have not been found to be a 

problem at operating nuclear power plants and are not expected 

to be a problem during the license renewal term. 

Altered salinity 

gradients Generic 

SMALL. Salinity gradients have not been found to be a problem 

at operating nuclear power plants and are not expected to be a 

problem during the license renewal term. 

Altered thermal 

stratification of lakes Generic 

SMALL. Generally, lake stratification has not been found to be a 

problem at operating nuclear power plants and is not expected to 

be a problem during the license renewal term. 

Temperature effects 

on sediment transport 

capacity 

Generic 

SMALL. These effects have not been found to be a problem at 

operating nuclear power plants and are not expected to be a 

problem during the license renewal term. 

Scouring caused by 

discharged cooling 

water 

Generic 

SMALL. Scouring has not been found to be a problem at most 

operating nuclear power plants and has caused only localized 

effects at a few plants. It is not expected to be a problem during 

the license renewal term. 

Eutrophication Generic 

SMALL. Eutrophication has not been found to be a problem at 

operating nuclear power plants and is not expected to be a 

problem during the license renewal term. 

Discharge of chlorine 

or other biocides Generic 

SMALL. Effects are not a concern among regulatory and 

resource agencies, and are not expected to be a problem during 

the license renewal term. 
Appendix B 

NUREG-1437, Supplement 43 B-2 December 2010

Issue Type of Issue Finding 

Discharge of sanitary 

wastes and minor 

chemical spills 

Generic 

SMALL. Effects are readily controlled through National Pollutant 

Discharge Elimination System (NPDES) permit and periodic 

modifications, if needed, and are not expected to be a problem 

during the license renewal term. 

Discharge of other 

metals in wastewater Generic 

SMALL. These discharges have not been found to be a problem 

at operating nuclear power plants with cooling-tower-based heat 

dissipation systems and have been satisfactorily mitigated at 

other plants. They are not expected to be a problem during the 

license renewal term. 

Water use conflicts 

(plants with 

once-through cooling 

systems) 

Generic 

SMALL. These conflicts have not been found to be a problem at 

operating nuclear power plants with once-through heat dissipation 

systems. 

Water use conflicts 

(plants with cooling 

ponds or cooling 

towers using make-up 

water from a small 

river with low flow) 

Site-specific 

SMALL OR MODERATE. The issue has been a concern at 

nuclear power plants with cooling ponds and at plants with cooling 

towers. Impacts on instream and riparian communities near these 

plants could be of moderate significance in some situations. See 

§ 51.53(c)(3)(ii)(A). 

Aquatic Ecology 

Refurbishment Generic 

SMALL. During plant shutdown and refurbishment there will be 

negligible effects on aquatic biota because of a reduction of 

entrainment and impingement of organisms or a reduced release 

of chemicals. 

Accumulation of 

contaminants in 

sediments or biota 

Generic 

SMALL. Accumulation of contaminants has been a concern at a 

few nuclear power plants but has been satisfactorily mitigated by 

replacing copper alloy condenser tubes with those of another 

metal. It is not expected to be a problem during the license 

renewal term. 

Entrainment of 

phytoplankton and 

zooplankton 

Generic 

SMALL. Entrainment of phytoplankton and zooplankton has not 

been found to be a problem at operating nuclear power plants and 

is not expected to be a problem during the license renewal term. 

Cold shock Generic 

SMALL. Cold shock has been satisfactorily mitigated at operating 

nuclear plants with once-through cooling systems, has not 

endangered fish populations or been found to be a problem at 

operating nuclear power plants with cooling towers or cooling 

ponds, and is not expected to be a problem during the license 

renewal term. 

Thermal plume barrier 

to migrating fish Generic 

SMALL. Thermal plumes have not been found to be a problem at 

operating nuclear power plants and are not expected to be a 

problem during the license renewal term. 

Distribution of aquatic 

organisms Generic 

SMALL. Thermal discharge may have localized effects but is not 

expected to affect the larger geographical distribution of aquatic 

organisms. 

Premature emergence 

of aquatic insects Generic 

SMALL. Premature emergence has been found to be a localized 

effect at some operating nuclear power plants but has not been a 

problem and is not expected to be a problem during the license 

renewal term. 
Appendix B 

December 2010 B-3 NUREG-1437, Supplement 43 

Issue Type of Issue Finding 

Gas supersaturation 

(gas bubble disease) Generic 

SMALL. Gas supersaturation was a concern at a small number of 

operating nuclear power plants with once-through cooling systems 

but has been satisfactorily mitigated. It has not been found to be 

a problem at operating nuclear power plants with cooling towers 

or cooling ponds and is not expected to be a problem during the 

license renewal term. 

Low dissolved oxygen 

in the discharge Generic 

SMALL. Low dissolved oxygen has been a concern at one 

nuclear power plant with a once-through cooling system but has 

been effectively mitigated. It has not been found to be a problem 

at operating nuclear power plants with cooling towers or cooling 

ponds and is not expected to be a problem during the license 

renewal term. 

Losses from predation, 

parasitism, and 

disease among 

organisms exposed to 

sublethal stresses 

Generic 

SMALL. These types of losses have not been found to be a 

problem at operating nuclear power plants and are not expected 

to be a problem during the license renewal term. 

Stimulation of 

nuisance organisms 

(e.g., shipworms) 

Generic 

SMALL. Stimulation of nuisance organisms has been 

satisfactorily mitigated at the single nuclear power plant with a 

once-through cooling system where previously it was a problem. It 

has not been found to be a problem at operating nuclear power 

plants with cooling towers or cooling ponds and is not expected to 

be a problem during the license renewal term. 

Aquatic Ecology (for plants with once-through and cooling pond heat dissipation systems) 

Entrainment of fish and 

shellfish in early life 

stages 

Site-specific 

SMALL, MODERATE, OR LARGE. The impacts of entrainment 

are small at many plants but may be moderate or even large at a 

few plants with once-through and cooling-pond cooling systems. 

Further, ongoing efforts in the vicinity of these plants to restore 

fish populations may increase the numbers of fish susceptible to 

intake effects during the license renewal period, such that 

entrainment studies conducted in support of the original license 

may no longer be valid. See § 51.53(c)(3)(ii)(B). 

Impingement of fish 

and shellfish Site-specific 

SMALL, MODERATE, OR LARGE. The impacts of impingement 

are small at many plants but may be moderate or even large at a 

few plants with once-through and cooling-pond cooling systems. 

See § 51.53(c)(3)(ii)(B). 

Heat shock Site-specific 

SMALL, MODERATE, OR LARGE. Because of continuing 

concerns about heat shock and the possible need to modify 

thermal discharges in response to changing environmental 

conditions, the impacts may be of moderate or large significance 

at some plants. See § 51.53(c)(3)(ii)(B). 

Aquatic Ecology (for plants with cooling-tower-based heat dissipation systems) 

Entrainment of fish and 

shellfish in early life 

stages 

Generic 

SMALL. Entrainment of fish has not been found to be a problem 

at operating nuclear power plants with this type of cooling system 

and is not expected to be a problem during the license renewal 

term. 

Impingement of fish 

and shellfish Generic 

SMALL. The impingement has not been found to be a problem at 

operating nuclear power plants with this type of cooling system 

and is not expected to be a problem during the license renewal 

term. 

Heat shock Generic 

SMALL. Heat shock has not been found to be a problem at 

operating nuclear power plants with this type of cooling system 

and is not expected to be a problem during the license renewal 

term. 
Appendix B 

NUREG-1437, Supplement 43 B-4 December 2010

Issue Type of Issue Finding 

Groundwater Use and Quality 

Impacts of 

refurbishment on 

groundwater use and 

quality 

Generic 

SMALL. Extensive dewatering during the original construction on 

some sites will not be repeated during refurbishment on any sites. 

Any plant wastes produced during refurbishment will be handled 

in the same manner as in current operating practices and are not 

expected to be a problem during the license renewal term. 

Groundwater use 

conflicts (potable 

and service water; 

plants that use 

<100 gpm) 

Generic SMALL. Plants using less than 100 gallons per minute (gpm) 

are not expected to cause any ground-water use conflicts. 

Groundwater use 

conflicts (potable and 

service water, and 

dewatering plants that 

use >100 gpm) 

Site-specific 

SMALL, MODERATE, OR LARGE. Plants that use more than 

100 gpm may cause ground-water use conflicts with nearby 

ground-water users. See § 51.53(c)(3)(ii)(C). 

Groundwater use 

conflicts (plants using 

cooling towers 

withdrawing makeup 

water from a small 

river) 

Site-specific 

SMALL, MODERATE, OR LARGE. Water use conflicts may 

result from surface water withdrawals from small water bodies 

during low flow conditions which may affect aquifer recharge, 

especially if other groundwater or upstream surface water users 

come on line before the time of license renewal. See § 

51.53(c)(3)(ii)(A). 

Groundwater use 

conflicts (Ranney 

wells) 

Site-specific 

SMALL, MODERATE, OR LARGE. Ranney wells can result in 

potential ground-water depression beyond the site boundary. 

Impacts of large ground-water withdrawal for cooling tower 

makeup at nuclear power plants using Ranney wells must be 

evaluated at the time of application for license renewal. See § 

51.53(c)(3)(ii)(C). 

Groundwater quality 

degradation (Ranney 

wells) 

Generic 

SMALL. Ground-water quality at river sites may be degraded by 

induced infiltration of poor-quality river water into an aquifer that 

supplies large quantities of reactor cooling water. However, the 

lower quality infiltrating water would not preclude the current uses 

of groundwater and is not expected to be a problem during the 

license renewal term. 

Groundwater quality 

degradation (saltwater 

intrusion) 

Generic SMALL. Nuclear power plants do not contribute significantly to 

saltwater intrusion. 

Groundwater quality 

degradation (cooling 

ponds in salt marshes) 

Generic 

SMALL. Sites with closed-cycle cooling ponds may degrade 

ground-water quality. Because water in salt marshes is brackish, 

this is not a concern for plants located in salt marshes. 

Groundwater quality 

degradation (cooling 

ponds at inland sites) 

Site-specific 

SMALL, MODERATE, OR LARGE. Sites with closed-cycle 

cooling ponds may degrade ground-water quality. For plants 

located inland, the quality of the groundwater in the vicinity of the 

ponds must be shown to be adequate to allow continuation of 

current uses. See § 51.53(c)(3)(ii)(D). 
Appendix B 

December 2010 B-5 NUREG-1437, Supplement 43 

Terrestrial Ecology 

Refurbishment impacts Site-specific 

SMALL, MODERATE, OR LARGE. Refurbishment impacts are 

insignificant if no loss of important plant and animal habitat 

occurs. However, it cannot be known whether important plant and 

animal communities may be affected until the specific proposal is 

presented with the license renewal application. See § 

51.53(c)(3)(ii)(E). 

Cooling tower impacts 

on crops and 

ornamental vegetation 

Generic 

SMALL. Impacts from salt drift, icing, fogging, or increased 

humidity associated with cooling tower operation have not been 

found to be a problem at operating nuclear power plants and are 

not expected to be a problem during the license renewal term. 

Cooling tower impacts 

on native plants Generic 

SMALL. Impacts from salt drift, icing, fogging, or increased 

humidity associated with cooling tower operation have not been 

found to be a problem at operating nuclear power plants and are 

not expected to be a problem during the license renewal term. 

Bird collisions with 

cooling towers Generic 

SMALL. These collisions have not been found to be a problem at 

operating nuclear power plants and are not expected to be a 

problem during the license renewal term. 

Cooling pond impacts 

on terrestrial resources Generic SMALL. Impacts of cooling ponds on terrestrial ecological 

resources are considered to be of small significance at all sites. 

Power line right-of-way 

management (cutting 

and herbicide 

application) 

Generic SMALL. The impacts of right-of-way (ROW) maintenance on 

wildlife are expected to be of small significance at all sites. 

Bird collisions with 

power lines Generic SMALL. Impacts are expected to be of small significance at all 

sites. 

Impacts of 

electromagnetic fields 

on flora and fauna 

Generic 

SMALL. No significant impacts of electromagnetic fields on 

terrestrial flora and fauna have been identified. Such effects are 

not expected to be a problem during the license renewal term. 

Floodplains and 

wetland on power line 

ROW 

Generic 

SMALL. Periodic vegetation control is necessary in forested 

wetlands underneath power lines and can be achieved with 

minimal damage to the wetland. No significant impact is expected 

at any nuclear power plant during the license renewal term. 

Threatened and Endangered Species 

Threatened or 

endangered species Site-specific 

SMALL, MODERATE, OR LARGE. Generally, plant 

refurbishment and continued operation are not expected to 

adversely affect threatened or endangered species. However, 

consultation with appropriate agencies would be needed at the 

time of license renewal to determine whether threatened or 

endangered species are present and whether they would be 

adversely affected. See § 51.53(c)(3)(ii)(E). 

Air Quality 

Air quality during 

refurbishment 

(nonattainment and 

maintenance areas) 

Site-specific 

SMALL, MODERATE, OR LARGE. Air quality impacts from plant 

refurbishment associated with license renewal are expected to be 

small. However, vehicle exhaust emissions could be cause for 

concern at locations in or near nonattainment or maintenance 

areas. The significance of the potential impact cannot be 

determined without considering the compliance status of each site 

and the numbers of workers expected to be employed during the 

outage. See § 51.53(c)(3)(ii)(F). 

Air quality effects of 

transmission lines Generic 

SMALL. Production of ozone and oxides of nitrogen is 

insignificant and does not contribute measurably to ambient levels 

of these gases. 

Land Use 
Appendix B 

NUREG-1437, Supplement 43 B-6 December 2010

Onsite land use Generic 

SMALL. Projected onsite land use changes required during 

refurbishment and the renewal period would be a small fraction of 

any nuclear power plant site and would involve land that is 

controlled by the applicant. 

Power line ROW Generic 

SMALL. Ongoing use of power line ROWs would continue with 

no change in restrictions. The effects of these restrictions are of 

small significance. 

Human Health 

Radiation exposures to 

the public during 

refurbishment 

Generic 

SMALL. During refurbishment, the gaseous effluents would result 

in doses that are similar to those from current operation. 

Applicable regulatory dose limits to the public are not expected to 

be exceeded. 

Occupational radiation 

exposures during 

refurbishment 

Generic 

SMALL. Occupational doses from refurbishment are expected to 

be within the range of annual average collective doses 

experienced for pressurized-water reactors and boiling-water 

reactors. Occupational mortality risk from all causes including 

radiation is in the mid-range for industrial settings. 

Microbiological 

organisms 

(occupational health) 

Generic 

SMALL. Occupational health impacts are expected to be 

controlled by continued application of accepted industrial hygiene 

practices to minimize worker exposures. 

Microbiological 

organisms (public 

health)(plants using 

lakes or canals, or 

cooling towers or 

cooling ponds that 

discharge to a small 

river) 

Site-specific 

SMALL, MODERATE, OR LARGE. These organisms are not 

expected to be a problem at most operating plants except 

possibly at plants using cooling ponds, lakes, or canals that 

discharge to small rivers. Without site-specific data, it is not 

possible to predict the effects generically. See § 

51.53(c)(3)(ii)(G). 

Noise Generic 

SMALL. Noise has not been found to be a problem at operating 

plants and is not expected to be a problem at any plant during the 

license renewal term. 

Electromagnetic 

fields—acute effects 

(electric shock) 

Site-specific 

SMALL, MODERATE, OR LARGE. Electrical shock resulting 

from direct access to energized conductors or from induced 

charges in metallic structures have not been found to be a 

problem at most operating plants and generally are not expected 

to be a problem during the license renewal term. However, 

site-specific review is required to determine the significance of the 

electric shock potential at the site. See § 51.53(c)(3)(ii)(H). 

Electromagnetic 

fields—chronic effects Uncategorized 

UNCERTAIN. Biological and physical studies of 60-Hz 

electromagnetic fields have not found consistent evidence linking 

harmful effects with field exposures. However, research is 

continuing in this area and a consensus scientific view has not 

been reached. 

Radiation exposures to 

public (license renewal 

term) 

Generic SMALL. Radiation doses to the public will continue at current 

levels associated with normal operations. 

Occupational radiation 

exposures (license 

renewal term) 

Generic 

SMALL. Projected maximum occupational doses during the 

license renewal term are within the range of doses experienced 

during normal operations and normal maintenance outages, and 

would be well below regulatory limits. 

Socioeconomic Impacts 
Appendix B 

December 2010 B-7 NUREG-1437, Supplement 43 

Housing impacts Site-specific 

SMALL, MODERATE, OR LARGE. Housing impacts are 

expected to be of small significance at plants located in a medium 

or high population area and not in an area where growth control 

measures that limit housing development are in effect. Moderate 

or large housing impacts of the workforce associated with 

refurbishment may be associated with plants located in sparsely 

populated areas or in areas with growth control measures that 

limit housing development. See § 51.53(c)(3)(ii)(I). 

Public services: public 

safety, social services, 

and tourism, and 

recreation 

Generic SMALL. Impacts to public safety, social services, and tourism 

and recreation are expected to be of small significance at all sites. 

Public services: public 

utilities Site-specific 

SMALL OR MODERATE. An increased problem with water 

shortages at some sites may lead to impacts of moderate 

significance on public water supply availability. See § 

51.53(c)(3)(ii)(I). 

Public services: 

education 

(refurbishment) 

Site-specific 

SMALL, MODERATE, OR LARGE. Most sites would experience 

impacts of small significance but larger impacts are possible 

depending on site- and project-specific factors. See § 

51.53(c)(3)(ii)(I). 

Public services: 

education (license 

renewal term) 

Generic SMALL. Only impacts of small significance are expected 

Offsite land use 

(refurbishment) Site-specific 

SMALL OR MODERATE. Impacts may be of moderate 

significance at plants in low population areas. See § 

51.53(c)(3)(ii)(I). 

Offsite land use 

(license renewal term) Site-specific 

SMALL, MODERATE, OR LARGE. Significant changes in land 

use may be associated with population and tax revenue changes 

resulting from license renewal. See § 51.53(c)(3)(ii)(I). 

Public services: 

transportation Site-specific 

SMALL, MODERATE, OR LARGE. Transportation impacts (level 

of service) of highway traffic generated during plant refurbishment 

and during the term of the renewed license are generally 

expected to be of small significance. However, the increase in 

traffic associated with the additional workers and the local road 

and traffic control conditions may lead to impacts of moderate or 

large significance at some sites. See § 51.53(c)(3)(ii)(J). 

Historic and 

archaeological 

resources 

Site-specific 

SMALL, MODERATE, OR LARGE. Generally, plant 

refurbishment and continued operation are expected to have no 

more than small adverse impacts on historic and archaeological 

resources. However, the National Historic Preservation Act 

requires the Federal agency to consult with the State Historic 

Preservation Officer to determine whether there are properties 

present that require protection. See § 51.53(c)(3)(ii)(K). 

Aesthetic impacts 

(refurbishment) Generic SMALL. No significant impacts are expected during refurbishment. 

Aesthetic impacts 

(license renewal term) Generic SMALL. No significant impacts are expected during the license renewal term. 

Aesthetic impacts of 

transmission lines 

(license renewal term) 

Generic SMALL. No significant impacts are expected during the license 

renewal term. 
Appendix B 

NUREG-1437, Supplement 43 B-8 December 2010

Postulated Accidents 

Design basis accidents Generic 

SMALL. The Nuclear Regulatory Commission (NRC) staff has 

concluded that the environmental impacts of design basis 

accidents are of small significance for all plants. 

Severe accidents Site-specific 

SMALL. The probability weighted consequences of atmospheric 

releases, fallout onto open bodies of water, releases to 

groundwater, and societal and economic impacts from severe 

accidents are small for all plants. However, alternatives to 

mitigate severe accidents must be considered for all plants that 

have not considered such alternatives. See § 51.53(c)(3)(ii)(L). 

Uranium Fuel Cycle and Waste Management 

Offsite radiological 

impacts (individual 

effects from other than 

the disposal of spent 

fuel and high level 

waste) 

Generic 

SMALL. Off-site impacts of the uranium fuel cycle have been 

considered by the Commission in Table S-3 of this part. Based 

on information in the Generic Environmental Impact Statement 

(GEIS), impacts on individuals from radioactive gaseous and 

liquid releases including radon-222 and technetium-99 are small. 

Offsite radiological 

impacts (collective 

effects) 

Generic 

The 100-year environmental dose commitment to the U.S. 

population from the fuel cycle, high level waste and spent fuel 

disposal excepted, is calculated to be about 14,800 person 

roentgen equivalent man (rem), or 12 cancer fatalities, for each 

additional 20-year power reactor operating term. Much of this, 

especially the contribution of radon releases from mines and 

tailing piles, consists of tiny doses summed over large 

populations. This same dose calculation can theoretically be 

extended to include many tiny doses over additional thousands of 

years as well as doses outside the U.S. The result of such a 

calculation would be thousands of cancer fatalities from the fuel 

cycle, but this result assumes that even tiny doses have some 

statistical adverse health effect, which will not ever be mitigated 

(for example no cancer cure in the next thousand years), and that 

these doses projected over thousands of years are meaningful. 

However, these assumptions are questionable. In particular, 

science cannot rule out the possibility that there will be no cancer 

fatalities from these tiny doses. For perspective, the doses are 

very small fractions of regulatory limits, and even smaller fractions 

of natural background exposure to the same populations. 

Nevertheless, despite all the uncertainty, some judgment as to the 

regulatory NEPA implications of these matters should be made 

and it makes no sense to repeat the same judgment in every 

case. Even taking the uncertainties into account, the Commission 

concludes that these impacts are acceptable in that these impacts 

would not be sufficiently large to require the NEPA conclusion, for 

any plant, that the option of extended operation under 10 CFR 

Part 54 should be eliminated. Accordingly, while the commission 

has not assigned a single level of significance for the collective 

effects of the fuel cycle, this issue is considered Category 1 

[Generic]. 
Appendix B 

December 2010 B-9 NUREG-1437, Supplement 43 

Offsite radiological 

impacts (spent fuel 

and high level waste 

disposal) 

Generic 

For the high level waste and spent fuel disposal component of the 

fuel cycle, there are no current regulatory limits for offsite releases 

of radionuclides for the current candidate repository site. 

However, if we assume that limits are developed along the lines of 

the 1995 National Academy of Sciences (NAS) report, “Technical 

Bases for Yucca Mountain Standards,” and that in accordance 

with the Commission’s Waste Confidence Decision, 10 CFR 

51.23, a repository can and likely will be developed at some site, 

which will comply with such limits, peak doses to virtually all 

individuals will be 100 millirem per year or less. However, while 

the Commission has reasonable confidence that these 

assumptions will prove correct, there is considerable uncertainty 

since the limits are yet to be developed, no repository application 

has been completed or reviewed, and uncertainty is inherent in 

the models used to evaluate possible pathways to the human 

environment. The NAS report indicated that 100 millirem per year 

should be considered as a starting point for limits for individual 

doses, but notes that some measure of consensus exists among 

national and international bodies that the limits should be a 

fraction of the 100 millirem per year. The lifetime individual risk 

from 100 millirem annual dose limit is about 3 x 10-3. 

Estimating cumulative doses to populations over thousands of 

years is more problematic. The likelihood and consequences of 

events that could seriously compromise the integrity of a deep 

geologic repository were evaluated by the Department of Energy 

in the “Final Environmental Impact Statement: Management of 

Commercially Generated Radioactive Waste,” October 1980. The 

evaluation estimated the 70-year whole-body dose commitment to 

the maximum individual and to the regional population resulting 

from several modes of breaching a reference repository in the 

year of closure, after 1,000 years, after 100,000 years and after 

100,000,000 years. Subsequently, the NRC and other Federal 

agencies have expended considerable effort to develop models 

for the design and for the licensing of a high level waste 

repository, especially for the candidate repository at Yucca 

Mountain. More meaningful estimates of doses to population may 

be possible in the future as more is understood about the 

performance of the proposed Yucca Mountain repository. Such 

estimates would involve very great uncertainty, especially with 

respect to cumulative population doses over thousands of years. 

The standard proposed by the NAS is a limit on maximum 

individual dose. The relationship of potential new regulatory 

requirements, based on the NAS report, and cumulative 

population impacts has not been determined, although the report 

articulates the view that protection of individuals will adequately 

protect the population for a repository at Yucca Mountain. 

However, EPA's generic repository standards in 40 CFR Part 191 

generally provide an indication of the order of magnitude of 

cumulative risk to population that could result from the licensing of 

a Yucca Mountain repository, assuming the ultimate standards will 

be within the range of standards now under consideration. The 

standards in 40 CFR Part 191 protect the population by imposing 

amount of radioactive material released over 10,000 years. 

(continued) 
Appendix B 

NUREG-1437, Supplement 43 B-10 December 2010

Offsite radiological 

impacts (spent fuel 

and high level waste 

disposal) (continued) 

Generic 

The cumulative release limits are based on EPA's population 

impact goal of 1,000 premature cancer deaths worldwide for a 

100,000 metric ton (MTHM) repository. 

Nevertheless, despite all the uncertainty, some judgment as to the 

regulatory NEPA implications of these matters should be made 

and it makes no sense to repeat the same judgment in every 

case. Even taking the uncertainties into account, the Commission 

concludes that these impacts are acceptable in that these impacts 

would not be sufficiently large to require the NEPA conclusion, for 

any plant, that the option of extended operation under 10 CFR 

Part 54 should be eliminated. Accordingly, while the Commission 

has not assigned a single level of significance for the impacts of 

spent fuel and high level waste disposal, this issue is considered 

in Category 1 [Generic]. 

Nonradiological 

impacts of the uranium 

fuel cycle 

Generic 

SMALL. The nonradiological impacts of the uranium fuel cycle 

resulting from the renewal of an operating license for any plant 

are found to be small. 

Low-level waste 

storage and disposal Generic 

SMALL. The comprehensive regulatory controls that are in place 

and the low public doses being achieved at reactors ensure that 

the radiological impacts to the environment will remain small 

during the term of a renewed license. The maximum additional 

onsite land that may be required for low-level waste storage 

during the term of a renewed license and associated impacts will 

be small. 

Nonradiological impacts on air and water will be negligible. The 

radiological and nonradiological environmental impacts of 

long-term disposal of low-level waste from any individual plant at 

licensed sites are small. In addition, the Commission concludes 

that there is reasonable assurance that sufficient low-level waste 

disposal capacity will be made available when needed for facilities 

to be decommissioned consistent with NRC decommissioning 

requirements. 

Mixed waste storage 

and disposal Generic 

SMALL. The comprehensive regulatory controls and the facilities 

and procedures that are in place ensure proper handling and 

storage, as well as negligible doses and exposure to toxic 

materials for the public and the environment at all plants. License 

renewal will not increase the small, continuing risk to human 

health and the environment posed by mixed waste at all plants. 

The radiological and nonradiological environmental impacts of 

long-term disposal of mixed waste from any individual plant at 

licensed sites are small. In addition, the Commission concludes 

that there is reasonable assurance that sufficient mixed waste 

disposal capacity will be made available when needed for facilities 

to be decommissioned consistent with NRC decommissioning 

requirements. 

Onsite spent fuel Generic 

SMALL. The expected increase in the volume of spent fuel from 

an additional 20 years of operation can be safely accommodated 

onsite with small environmental effects through dry or pool 

storage at all plants. if a permanent repository or monitored 

retrievable storage is not available. 

Nonradiological waste Generic 

SMALL. No changes to generating systems are anticipated for 

license renewal. Facilities and procedures are in place to ensure 

continued proper handling and disposal at all plants. 
Appendix B 

December 2010 B-11 NUREG-1437, Supplement 43 

Transportation Generic 

SMALL. The impacts of transporting spent fuel enriched up to 5 

percent uranium-235 with average burnup for the peak rod to 

current levels approved by NRC up to 62,000 megawatt days per 

metric ton of uranium (MWd/MTU) and the cumulative impacts of 

transporting high-level waste to a single repository, such as Yucca 

Mountain, Nevada, are found to be consistent with the impact 

values contained in 10 CFR 51.52(c), Summary Table S–4 – 

Environmental Impact of Transportation of Fuel and Waste to and 

from One Light-Water-Cooled Nuclear Power Reactor. If fuel 

enrichment or burnup conditions are not met, the applicant must 

submit an assessment of the implications for the environmental 

impact values reported in § 51.52. 

Decommissioning 

Radiation doses Generic 

SMALL. Doses to the public will be well below applicable 

regulatory standards regardless of which decommissioning 

method is used. Occupational doses would increase no more 

than 1 man-rem caused by buildup of long-lived radionuclides 

during the license renewal term. 

Waste management Generic 

SMALL. Decommissioning at the end of a 20-year license 

renewal period would generate no more solid wastes than at the 

end of the current license term. No increase in the quantities of 

Class C or greater than Class C wastes would be expected. 

Air quality Generic 

SMALL. Air quality impacts of decommissioning are expected to 

be negligible either at the end of the current operating term or at 

the end of the license renewal term. 

Water quality Generic 

SMALL. The potential for significant water quality impacts from 

erosion or spills is no greater whether decommissioning occurs 

after a 20-year license renewal period or after the original 40-year 

operation period, and measures are readily available to avoid 

such impacts. 

Ecological resources Generic 

SMALL. Decommissioning after either the initial operating period 

or after a 20-year license renewal period is not expected to have 

any direct ecological impacts. 

Socioeconomic 

impacts Generic 

SMALL. Decommissioning would have some short-term 

socioeconomic impacts. The impacts would not be increased by 

delaying decommissioning until the end of a 20-year relicense 

period, but they might be decreased by population and economic 

growth. 

Environmental Justice 

Environmental Justice Uncategorized NONE. The need for and the content of an analysis of 

environmental justice will be addressed in plant-specific reviews. 
Appendix B 

NUREG-1437, Supplement 43 B-12 December 2010

B.1 REFERENCES 

10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

Protection Regulations for Domestic Licensing and Related Regulatory Functions.” 

Department of Energy (DOE). 1980. “Final Environmental Impact Statement: Management of 

Commercially Generated Radioactive Waste,” October 1980. 

National Academy of Sciences (NAS). 1995. “Technical Bases for Yucca Mountain Standards. 
APPENDIX C. 

APPLICABLE REGULATIONS, LAWS, AND AGREEMENTS 

December 2010 C-1 NUREG-1437, Supplement 43

C. APPLICABLE REGULATIONS, LAWS, AND AGREEMENTS 

The Atomic Energy Act (42 USC § 2021) authorizes the U.S. Nuclear Regulatory Commission 

(NRC) to enter into agreement with any State to assume regulatory authority for certain 

activities. For example, through the Agreement State Program, Arizona assumed regulatory 

responsibility over industrial x-rays and the disposal of water reclamation facility sludge 

contaminated by nuclear material. This Arizona Agreement State Program is administered by 

the Arizona Radiation Regulatory Agency. 

In addition to implementing some Federal programs, State legislatures develop their own laws. 

State statutes supplement as well as implement Federal laws for protection of air, water quality, 

and groundwater. State legislation may address solid waste management programs, locally 

rare or endangered species, and historic and cultural resources. 

The Arizona Department of Environmental Quality, Arizona Department of Health Services, and 

the Arizona Department of Water Resources address issues from operation of the Palo Verde 

Nuclear Generating Station (PVNGS) related to groundwater impacts and environmental 

compliance. 

Federal and State Environmental Requirements 

PVNGS is subject to Federal and State requirements regarding its environmental program. 

Those requirements are briefly described below. See Section 1.9 for PVNGS’s compliance 

status with these requirements. 

Table C-1 provides a list of the principal Federal and State environmental regulations and laws 

that are applicable to the review of the environmental resources that could be affected by this 

project that may affect license renewal applications for nuclear power plants. 

Table C-1. Federal and State Environmental Requirements 

Law/Regulation Requirements 

Current Operating License and License Renewal 

10 CFR Part 51. Code of 

Federal Regulations (CFR), 

Title 10, Energy, Part 51 

“Environmental Protection Regulations for Domestic Licensing and Related 

Regulatory Functions.” This part contains environmental protection regulations 

applicable to NRC's domestic licensing and related regulatory functions. 

10 CFR Part 54 10 CFR Part 54. “Requirements for Renewal of Operating Licenses for Nuclear 

Power Plants.” Part 54 of 10 CFR focuses on managing adverse effects of aging, 

rather than identification of all aging mechanisms. The rule is intended to ensure 

that important systems, structures, and components will continue to perform their 

intended function in the period of extended operation. 

10 CFR Part 50 Regulations promulgated by the NRC pursuant to the Atomic Energy Act of 1954, as 

amended (68 Stat. 919), and Title II of the Energy Reorganization Act of 1974 (88 

Stat. 1242), provide for the licensing of production and utilization facilities. This part 

also gives notice to all persons who knowingly provide to any licensee, applicant, 

contractor, or subcontractor, components, equipment, materials, or other goods or 

services, that relate to a licensee's or applicant's activities subject to this part, that 

they may be individually subject to NRC enforcement action for violation of § 50.5. 
Appendix C 

NUREG-1437, Supplement 43 C-2 December 2010

Air Quality Protection 

Clean Air Act (CAA) (42 

U.S.C. §7401 et seq.) 

The CAA is a comprehensive Federal law that regulates air emissions. Under the 

CAA, Federal actions cannot thwart State and local efforts to remedy long-standing 

air quality problems that threaten public health issues associated with the six 

criteria air pollutants (i.e., ozone, nitrogen dioxide, sulfur dioxide, particulate matter, 

carbon monoxide, and lead). 

Water Resources Protection 

Arizona Water Quality Control 

(A.R.S. 49-2); A.A.C. R-18-9 

Article 7 

A.A.C. R-12-15-1214; A.R.S. 

Title 45, Chapter 2 

The Arizona Department of Environmental Quality has issued Aquifer Protection 

permits to PVNGS to protect against potential impacts to groundwater. 

The Arizona Department of Water Resources has issued permits for PVNGS to 

operate evaporation ponds and permits for groundwater withdrawal. 

Waste Management and Pollution Prevention 

Resource Conservation and 

Recovery Act (RCRA) (42 

USC § 6901et seq.) 

Before a material can be classified as a hazardous waste, it must first be a solid 

waste as defined under the RCRA. Hazardous waste is classified under Subtitle C 

of the RCRA. Parts 261 and 262 of Title 40 CFR contain all applicable generators 

of hazardous waste regulations. Part 261.5 (a) and (e) contains requirements for 

Conditionally Exempt Small Quantity Generators (CESQGs). Part 262.34(d) 

contains requirements for Small Quantity Generators (SQGs). Parts 262 and 

261.5(e) contain requirements for Large Quantity Generators (LQGs) 

Pollution Prevention Act (42 

U.S.C. § 13101 et seq.) 

Formally established a national policy to prevent or reduce pollution at its source 

whenever feasible. The Act provides funds for State and local pollution prevention 

programs through a grant program to promote the use of pollution prevention 

techniques by business. 

Endangered Species 

Endangered Species Act 

(ESA) (16 U.S.C. § 1531 et 

seq.) 

Forbids any government agency, corporation, or citizen from taking (harming or 

killing) endangered animals without an Endangered Species Permit. 

Historic Preservation 

National Historic Preservation 

Act (NHPA) (16 U.S.C. § 470 

et seq.) 

Directs Federal agencies to consider the impact of their actions on historic 

properties. NHPA also encourages state and local preservation societies. 
APPENDIX D. 

CONSULTATION CORRESPONDENCES 

December 2010 D-1 NUREG-1437, Supplement 43

D. CONSULTATION CORRESPONDENCES 

The Endangered Species Act of 1973, as amended, the Magnuson-Stevens Fisheries 

Management Act of 1996, as amended; and the National Historic Preservation Act of 1966 

require that Federal agencies consult with applicable State and Federal agencies and groups 

prior to taking action that may affect threatened and endangered species, essential fish habitat, 

or historic and archaeological resources, respectively. This appendix contains consultation 

documentation. 

Table D-1 provides a list of the consultation documents sent between the U.S. Nuclear 

Regulatory Commission (NRC) and other agencies. The NRC staff is required to consult with 

these agencies based on the National Environmental Policy Act of 1969 (NEPA) requirements. 

Table D-1. Consultation Correspondences 

Author Recipient Date of Letter

U.S. Nuclear Regulatory Commission 

(D. Wrona) 

Office of Historic Preservation 

Arizona State Parks 

(J. Garrison) 

May 21, 2009 

(ML091070394) 

U.S. Nuclear Regulatory Commission 

(D. Wrona) 

Fort McDowell Yavapai Tribal Council 

(Dr. Clinton M. Pattea) 

June 1, 2009(a) 

(ML091390581) 

U.S. Nuclear Regulatory Commission 

(D. Wrona) 

Arizona Ecological Services Field Office 

U.S. Fish and Wildlife Service 

(S. Spangle) 

June 12, 2009 

(ML091600427) 

U.S. Nuclear Regulatory Commission 

(D. Wrona) 

Arizona Game and Fish Department 

(R. Davidson) 

June 12, 2009 

(ML091600441) 

Arizona Ecological Services Field Office 

U.S. Fish and Wildlife Service 

(S. Spangle) 

U.S. Nuclear Regulatory Commission 

(D. Wrona) 

July 15, 2009 

(ML101100631) 

Arizona Game and Fish Department 

(G. Ritter) 

U.S. Nuclear Regulatory Commission 

(D. Wrona) 

July 16, 2009 

(ML093100184) 

(a) Similar letters went to twelve other Native American Tribes listed in Section 1.8. 

D.1 CONSULTATION CORRESPONDENCE 

The following pages contain copies of the letters listed in Table D-1 

 
Appendix D 

NUREG-1437, Supplement 43 D-2 December 2010
Appendix D 

December 2010 D-3 NUREG-1437, Supplement 43 
Appendix D 

NUREG-1437, Supplement 43 D-4 December 2010

 
Appendix D 

December 2010 D-5 NUREG-1437, Supplement 43 
Appendix D 

NUREG-1437, Supplement 43 D-6 December 2010

 
Appendix D 

December 2010 D-7 NUREG-1437, Supplement 43 
Appendix D 

NUREG-1437, Supplement 43 D-8 December 2010
Appendix D 

December 2010 D-9 NUREG-1437, Supplement 43 
Appendix D 

NUREG-1437, Supplement 43 D-10 December 2010
Appendix D 

December 2010 D-11 NUREG-1437, Supplement 43 
Appendix D 

NUREG-1437, Supplement 43 D-12 December 2010
Appendix D 

December 2010 D-13 NUREG-1437, Supplement 43 
Appendix D 

NUREG-1437, Supplement 43 D-14 December 2010

 
Appendix D 

December 2010 D-15 NUREG-1437, Supplement 43 
Appendix D 

NUREG-1437, Supplement 43 D-16 December 2010
Appendix D 

December 2010 D-17 NUREG-1437, Supplement 43 

APPENDIX E. 

CHRONOLOGY OF ENVIRONMENTAL REVIEW 

December 2010 E-1 NUREG-1437, Supplement 43

E. CHRONOLOGY OF ENVIRONMENTAL REVIEW 

This appendix contains a chronological listing of correspondence between the U.S. Nuclear 

Regulatory Commission (NRC) and external parties as part of its environmental review for Palo 

Verde Nuclear Generating Station. All documents, with the exception of those containing 

proprietary information are available electronically from the NRC’s Public Electronic Reading 

Room found on the Internet at the following Web address: http://www.nrc.gov/reading-rm.html. 

From this site, the public can gain access to the NRC’s Agency-wide Document Access and 

Management System (ADAMS), which provides text and image files of NRC’s public documents 

in ADAMS. The ADAMS accession number for each document is included below. 

E.1 ENVIRONMENTAL REVIEW CORRESPONDENCE 

December 11, 2008 Letter from APS forwarding the application for renewal of operating 

license for Palo Verde Nuclear Generating Station, Units 1, 2 and 3., 

requesting an extension of operating license for an additional 20 years 

(ADAMS Accession Nos. ML083510611, 12, 14, 15). 

January 12, 2009 Letter to APS, “Receipt and Availability of the License Renewal 

Application for the Palo Verde Nuclear Generating Station Units 1, 2 

and 3” (ADAMS Accession No. ML083530426). 

February 13, 2009 Letter to APS, “Review Status of the License Renewal Application for 

the Palo Verde Nuclear Generating Station” (ADAMS Accession No. 

ML090360279). 

February 25, 2009 Letter from APS providing a plan to resolve a deficiency in the License 

Renewal Application for the Palo Verde Nuclear Generating Station 

(ADAMS Accession No. ML090750614). 

April 14, 2009 Letter from APS forwarding Supplement 1 to the application for 

renewal of operating license for Palo Verde Nuclear Generating 

Station, Units 1, 2 and 3 (ADAMS Accession No ML091130221). 

May 18, 2009 Letter to APS, “Notice of Intent to Prepare an Environmental Impact 

Statement and Conduct Scoping Process Receipt for License 

Renewal for the Palo Verde Nuclear Generating Station Units 1, 2 and 

3 (TAC NOS. ME0261, ME0262, ME0263)” (ADAMS Accession No. 

ML091100086). 

May 21, 2009 Letter to Mr. James W. Garrison, State Historic Preservation Officer, 

Office of Historic Preservation, Arizona State Parks, “Palo Verde 

Nuclear Generating Station License Renewal Application Review 

(SHPO NO. 2007-1713)” (ADAMS Accession No. ML091070394). 

June 1, 2009 Letter to Dr. Clinton M. Pattea, President, Fort McDowell Yavapai 

Tribal Council, “Request for Scoping Comments Concerning the Palo 

Verde Nuclear Generating Station, Units 1, 2, and 3, License Renewal 

Application Review” (ADAMS Accession No. ML091390581). 
Appendix E 

NUREG-1437, Supplement 43 E-2 December 2010

June 1, 2009 Letter to Ms. Diane Enos, President, Salt River Pima-Maricopa Indian 

Community Council, “Request for Scoping Comments Concerning the 

Palo Verde Nuclear Generating Station, Units 1, 2, and 3, License 

Renewal Application Review” (ADAMS Accession No. ML091390581). 

June 1, 2009 Letter to Ms. Wendsler Noise, Sr., Chairperson, San Carlos Tribal 

Council, “Request for Scoping Comments Concerning the Palo Verde 

Nuclear Generating Station, Units 1, 2, and 3, License Renewal 

Application Review” (ADAMS Accession No. ML091390581). 

June 1, 2009 Letter to Mr. Ned Norris, Jr., Chairperson, Tohono O’odham Nation, 

“Request for Scoping Comments Concerning the Palo Verde Nuclear 

Generating Station, Units 1, 2, and 3, License Renewal Application 

Review” (ADAMS Accession No. ML091390581). 

June 1, 2009 Letter to Mr. Ronnie Lupe, Chairman, White Mountain Apache Tribe, 

“Request for Scoping Comments Concerning the Palo Verde Nuclear 

Generating Station, Units 1, 2, and 3, License Renewal Application 

Review” (ADAMS Accession No. ML091390581). 

June 1, 2009 Letter to Mr. Thomas Beauty, Chairman, Yavapai-Apache Nation 

Tribal Council, “Request for Scoping Comments Concerning the Palo 

Verde Nuclear Generating Station, Units 1, 2, and 3, License Renewal 

Application Review” (ADAMS Accession No. ML091390581). 

June 1, 2009 Letter to Mr. Peter Yucupicio, Chairman, Pascua Yaqui Tribe, 

“Request for Scoping Comments Concerning the Palo Verde Nuclear 

Generating Station, Units 1, 2, and 3, License Renewal Application 

Review” (ADAMS Accession No. ML091390581). 

June 1, 2009 Letter to Mr. Ivan Smith, Chairman, Tonto Apache Tribe, “Request for 

Scoping Comments Concerning the Palo Verde Nuclear Generating 

Station, Units 1, 2, and 3, License Renewal Application Review” 

(ADAMS Accession No. ML091390581). 

June 1, 2009 Letter to Mr. Ernest Jones, Sr., President, Yavapai-Prescott Board of 

Directors, “Request for Scoping Comments Concerning the Palo 

Verde Nuclear Generating Station, Units 1, 2, and 3, License Renewal 

Application Review” (ADAMS Accession No. ML091390581). 

June 1, 2009 Letter to Ms. Delia M. Carlyle, President, Ak Chin Indian Community 

Council, “Request for Scoping Comments Concerning the Palo Verde 

Nuclear Generating Station, Units 1, 2, and 3, License Renewal 

Application Review” (ADAMS Accession No. ML091390581). 

June 1, 2009 Letter Mr. William R. Rhodes, Governor, Gila River Indian Community 

Council, “Request for Scoping Comments Concerning the Palo Verde 

Nuclear Generating Station, Units 1, 2, and 3, License Renewal 

Application Review” (ADAMS Accession No. ML091390581). 

June 3, 2009 Memo to David Wrona, NRC, “Forthcoming Meeting to Discuss the 
Appendix E 

December 2010 E-3 NUREG-1437, Supplement 43 

License Renewal Process and Environmental Scoping for Palo Verde 

Nuclear Generating Station, Units 1, 2 and 3, License Renewal 

Application Review” (ADAMS Accession No. ML091480348). 

June 12, 2009 Letter to Mr. Steven Spangle, Arizona Ecological Services Field 

Office, U.S. Fish and Wildlife Service, “Request for List of Federal 

Protected Species within the Area under Evaluation for the Palo 

Verde Nuclear Generating Station, Units 1, 2, and 3, License Renewal 

Application Review” (ADAMS Accession No. ML091600427). 

June 12, 2009 Letter to Ms. Rebecca Davidson, Project Evaluation Supervisor, 

Arizona Game and Fish Department, “Request for List of State 

Protected Species within the Area under Evaluation for the Palo 

Verde Nuclear Generating Station, Units 1, 2, and 3, License Renewal 

Application Review” (ADAMS Accession No. ML091600441). 

July 15, 2009 Letter from Arizona Game Ecological Services Field Office, U.S. Fish 

and Wildlife Service, U.S. Department of the Interior, response to 

request for list of State Protected Species within the area under 

evaluation for Palo Verde Nuclear Generating Facility License 

Renewal Application Review” (ADAMS Accession No. ML101100631). 

July 16, 2009 Letter from Arizona Game and Fish Department, “Special Status 

Species Information for Palo Verde Nuclear Facility and Transmission 

Line License Renewal Review” (ADAMS Accession No. 

ML093100184). 

August 4, 2009 Memo from L. Regner, “Summary of Public Environmental Scoping 

Meetings Related to the review of the Palo Verde License Renewal 

Application (TAC NOS. ME0261, ME0262, ME0263)” (ADAMS 

Accession No. ML091900138). 

August 7, 2009 Letter to APS, “Palo Verde Nuclear Generating Station, Units 1, 2 and 

3 License Renewal Application Online Reference Portal (TAC NOS. 

ME0261, ME0262, ME0263)” (ADAMS Accession No. ML091900244). 

September 22, 2009 Letter to Mr. Richard Milanovich, Chairperson, Agua Caliente Tribal 

Council, “Request for Scoping Comments Concerning the Palo Verde 

Nuclear Generating Station, Units 1, 2, and 3, License Renewal 

Application Review” (ADAMS Accession No. ML092570673). 

September 22, 2009 Letter to Mr. Eldred Enas, Chairperson, Colorado River Tribal Council, 

“Request for Scoping Comments Concerning the Palo Verde Nuclear 

Generating Station, Units 1, 2, and 3, License Renewal Application 

Review” (ADAMS Accession No. ML092570673). 

September 22, 2009 Letter to Mr. Mike Jackson Sr., President, Fort Yuma-Quechan, 

“Request for Scoping Comments Concerning the Palo Verde Nuclear 

Generating Station, Units 1, 2, and 3, License Renewal Application 

Review” (ADAMS Accession No. ML092570673). 
Appendix E 

NUREG-1437, Supplement 43 E-4 December 2010

September 29, 2009 Letter to APS, “Environmental Site Audit Regarding Palo Verde 

Nuclear Generating Station Units 1, 2 and 3” (ADAMS Accession No. 

ML073310128). 

September 30, 2009 Letter to APS, “Request for Additional Information for the 

Environmental Review of the Palo Verde Nuclear Generating Station 

License Renewal Application (ME0261, ME0262, ME0263)” (ADAMS 

Accession No. ML092470551). 

September 30, 2009 Memo, “Summary of Telephone Conference Call Held on September 

3, 2009, between the U.S. Nuclear Regulatory Commission and 

Arizona Public Service Company Pertaining to the Palo Verde Nuclear 

Generating Station, Units 1, 2 and 3, License Renewal Application 

Review” (ADAMS Accession No. ML092470463). 

October 14, 2009 Letter from APS forwarding Amendment 1 to the application for 

renewal of operating license for Palo Verde Nuclear Generating 

Station, Units 1, 2 and 3., providing a revised Environmental Report 

Figure 3-2 and Table 4-2 for the Hassayampa No. 3 Transmission 

Line (ADAMS Accession No. ML092950484). 

November 10, 2010 Letter from APS forwarding response to September 30, 2009 Request 

for Additional Information regarding severe accident mitigation 

alternatives for the review of the license renewal application for Palo 

Verde Nuclear Generating Station, Units 1, 2 and 3 Amendment #2 

(ADAMS Accession No. ML093230225). 

November 17, 2009 Letter to APS, “Environmental Project Manager Change for the 

License Renewal Project for Palo Verde Nuclear Generating Station 

Units 1, 2 and 3 (TAC NOS. ME0261, ME0262, ME0263)” (ADAMS 

Accession No. ML0793140009). 

December 23, 2009 Letter from APS providing environmental documents for NRC review 

of the license renewal application for Palo Verde Nuclear Generating 

Station, Units 1, 2 and 3 (ADAMS Accession No. ML101110129). 

January 13, 2010 Letter from APS forwarding follow-up clarification to the response to 

September 2009 Request for Additional Information regarding severe 

accident mitigation alternatives for the review of the license renewal 

application for Palo Verde Nuclear Generating Station, Units 1, 2 and 

3 (ADAMS Accession No. ML100270290). 

April 8, 2010 Letter to APS, “Request for Additional Information for the review of the 

Palo Verde Nuclear Generating Station Units 1, 2 and 3, License 

Renewal Application” (TAC NOS. ME0261, ME0262, ME0263)” 

(ADAMS Accession No. ML1009603672). 

April 26, 2010 Letter to APS, “Issuance of Environmental Scoping Summary Report 

associated with the Staff’s review of Application by Arizona Public 

Service Company for Renewal of the Operating License for Palo 

Verde Nuclear Generating Station, Units 1, 2, and 3, (TAC NOS. 
Appendix E 

December 2010 E-5 NUREG-1437, Supplement 43 

ME0261, ME0262, ME0263)” (ADAMS Accession No. ML100820451). 

April 29, 2010 Letter from APS responding to “Request for Additional Information for 

the review of the Palo Verde Nuclear Generating Station Units 1, 2 

and 3, License Renewal Application” (TAC NOS. ME0261, ME0262, 

ME0263)” (ADAMS Accession No. ML101310227).May 17, 2010

 Letter to APS, “Revision of schedule for review for Palo Verde 

Nuclear Generating Station Units 1, 2 and 3, License Renewal 

Application” (TAC NOS. ME0261, ME0262, ME0263)” (ADAMS 

Accession No. ML101310090). 

August 12, 2010 Letter to Arizona Game and Fish Department, “Notice of availability of 

draft Plant-Specific Supplement 43 to the Generic Environmental 

Impact Statement for License Renewal of Nuclear Plants regarding 

Palo Verde Nuclear Generating Station.” (ADAMS Accession No. 

ML102150576). 

August 12, 2010 Letter to U. S. Fish and Wildlife Service, “Notice of availability of draft 

Plant-Specific Supplement 43 to the Generic Environmental Impact 

Statement for License Renewal of Nuclear Plants regarding Palo 

Verde Nuclear Generating Station.” (ADAMS Accession No. 

ML102150566). 

August 12, 2010 Letter to Arizona, Office of Historic Preservation, “Notice of availability 

of draft Plant-Specific Supplement 43 to the Generic Environmental 

Impact Statement for License Renewal of Nuclear Plants regarding 

Palo Verde Nuclear Generating Station.” (ADAMS Accession No. 

ML102150334). 

August 12, 2010 Letter to Arizona, U. S. Environmental Protection Agency, “Notice of 

availability of draft Plant-Specific Supplement 43 to the Generic 

Environmental Impact Statement for License Renewal of Nuclear 

Plants regarding Palo Verde Nuclear Generating Station.” (ADAMS 

Accession No. ML102110220). 

August 12, 2010 Letter to APS, “Notice of availability of draft Plant-Specific Supplement 

43 to the Generic Environmental Impact Statement for License 

Renewal of Nuclear Plants regarding Palo Verde Nuclear Generating 

Station.” (ADAMS Accession No. ML102110221). 

August 12, 2010 Letter to Dr. Clinton M. Pattea, President, Fort McDowell Yavapai 

Tribal Council, “Notice of availability of draft Plant-Specific 

Supplement 43 to the Generic Environmental Impact Statement for 

License Renewal of Nuclear Plants regarding Palo Verde Nuclear 

Generating Station” (ADAMS Accession No. ML102170106). 
Appendix E 

NUREG-1437, Supplement 43 E-6 December 2010

August 12, 2010 Letter to Ms. Diane Enos, President, Salt River Pima-Maricopa Indian 

Community Council, “Notice of availability of draft Plant-Specific 

Supplement 43 to the Generic Environmental Impact Statement for 

License Renewal of Nuclear Plants regarding Palo Verde Nuclear 

Generating Station” (ADAMS Accession No. ML102170106). 

August 12, 2010 Letter to Ms. Wendsler Noise, Sr., Chairperson, San Carlos Tribal 

Council, “Notice of availability of draft Plant-Specific Supplement 43 to 

the Generic Environmental Impact Statement for License Renewal of 

Nuclear Plants regarding Palo Verde Nuclear Generating Station” 

(ADAMS Accession No. ML102170106). 

August 12, 2010 Letter to Mr. Ned Norris, Jr., Chairperson, Tohono O’odham Nation, 

“Notice of availability of draft Plant-Specific Supplement 43 to the 

Generic Environmental Impact Statement for License Renewal of 

Nuclear Plants regarding Palo Verde Nuclear Generating Station” 

(ADAMS Accession No. ML102170106). 

August 12, 2010 Letter to Mr. Ronnie Lupe, Chairman, White Mountain Apache Tribe, 

“Notice of availability of draft Plant-Specific Supplement 43 to the 

Generic Environmental Impact Statement for License Renewal of 

Nuclear Plants regarding Palo Verde Nuclear Generating Station” 

(ADAMS Accession No. ML102170106). 

August 12, 2010 Letter to Mr. Thomas Beauty, Chairman, Yavapai-Apache Nation 

Tribal Council, “Notice of availability of draft Plant-Specific 

Supplement 43 to the Generic Environmental Impact Statement for 

License Renewal of Nuclear Plants regarding Palo Verde Nuclear 

Generating Station” (ADAMS Accession No. ML102170106). 

August 12, 2010 Letter to Mr. Peter Yucupicio, Chairman, Pascua Yaqui Tribe, “Notice 

of availability of draft Plant-Specific Supplement 43 to the Generic 

Environmental Impact Statement for License Renewal of Nuclear 

Plants regarding Palo Verde Nuclear Generating Station” (ADAMS 

Accession No. ML102170106). 

August 12, 2010 Letter to Mr. Ivan Smith, Chairman, Tonto Apache Tribe, “Notice of 

availability of draft Plant-Specific Supplement 43 to the Generic 

Environmental Impact Statement for License Renewal of Nuclear 

Plants regarding Palo Verde Nuclear Generating Station” (ADAMS 

Accession No. ML102170106). 

August 12, 2010 Letter to Mr. Ernest Jones, Sr., President, Yavapai-Prescott Board of 

Directors, “Notice of availability of draft Plant-Specific Supplement 43 

to the Generic Environmental Impact Statement for License Renewal 

of Nuclear Plants regarding Palo Verde Nuclear Generating Station” 

(ADAMS Accession No. ML102170106). 
Appendix E 

December 2010 E-7 NUREG-1437, Supplement 43 

August 12, 2010 Letter to Ms. Delia M. Carlyle, President, Ak Chin Indian Community 

Council, “Notice of availability of draft Plant-Specific Supplement 43 to 

the Generic Environmental Impact Statement for License Renewal of 

Nuclear Plants regarding Palo Verde Nuclear Generating Station” 

(ADAMS Accession No. ML102170106). 

August 12, 2010 Letter Mr. William R. Rhodes, Governor, Gila River Indian Community 

Council, “Notice of availability of draft Plant-Specific Supplement 43 to 

the Generic Environmental Impact Statement for License Renewal of 

Nuclear Plants regarding Palo Verde Nuclear Generating Station” 

(ADAMS Accession No. ML102170106). 

August 24, 2010 Memo to Jay Robinson, “Forthcoming meeting to discuss the Draft 

Supplemental Environmental Impact Statement for Palo Verde 

Nuclear Generating Station.” (ADAMS Accession No. ML102310254) 

October 13, 2010 Summary of Public Meetings Conducted to Discuss the Draft 

Supplemental Environmental Impact Statement Related to the Review 

of the Palo Verde Nuclear Generating Station License Renewal 

Application. (ADAMS Accession No. ML102780257)

 

APPENDIX F. 

U.S. NUCLEAR REGULATORY COMMISSION STAFF EVALUATION OF 

SEVERE ACCIDENT MITIGATION ALTERNATIVES FOR PALO VERDE 

NUCLEAR GENERATING STATION IN SUPPORT OF LICENSE 

RENEWAL APPLICATION REVIEW 
 
 

December 2010 F-1 NUREG-1437, Supplement 43 

F. U.S. NUCLEAR REGULATORY COMMISSION STAFF 

EVALUATION OF SEVERE ACCIDENT MITIGATION ALTERNATIVES 

FOR PALO VERDE NUCLEAR GENERATING STATION IN SUPPORT 

OF LICENSE RENEWAL APPLICATION REVIEW 

F.1 INTRODUCTION 

Arizona Public Service Company (APS) submitted an assessment of severe accident mitigation 

alternatives (SAMAs) for the Palo Verde Nuclear Generating Station (PVNGS) as part of the 

environmental report (ER) (APS 2008a). Supplemental information on the SAMA assessment 

was provided in Supplement 1 to the license renewal application (APS 2009a). This 

assessment was based on the most recent PVNGS probabilistic risk assessment (PRA) 

available at that time, a plant-specific offsite consequence analysis performed using the 

MELCOR Accident Consequence Code System 2 (MACCS2) computer code (NRC 1998a), and 

insights from the PVNGS Individual Plant Examination (IPE) (APS 1992) and Individual Plant 

Examination of External Events (IPEEE) (APS 1995). In identifying and evaluating potential 

SAMAs, APS considered SAMA candidates that addressed the major contributors to core 

damage frequency (CDF) and population dose at PVNGS, as well as SAMA candidates for 

other operating plants which have submitted license renewal applications. APS identified 23 

potential SAMA candidates. This list was reduced to 13 SAMA candidates by eliminating 

SAMAs that are not applicable to APS due to design differences or have already been 

implemented at APS, or have estimated implementation costs that would exceed the dollar 

value associated with completely eliminating all severe accident risk at PVNGS. APS assessed 

the costs and benefits associated with each of the potential SAMAs, and concluded in the ER 

that several of the candidate SAMAs evaluated are potentially cost-beneficial. 

Based on a review of the SAMA assessment, the U.S. Nuclear Regulatory Commission (NRC) 

issued a request for additional information (RAI) to APS by letter dated September 30, 2009 

(NRC 2009). Key questions concerned: changes to the PRA model since the IPE, and internal 

and external reviews of the updated model; the process used to map Level 1 results into the 

Level 2 analysis and to group containment event tree (CET) end states into release categories;

source term and release category assignment assumptions; justification for the multiplier used 

for external events; population assumptions used in the Level 3 analysis; and further information 

on the cost benefit analysis of several specific candidate SAMAs and low cost alternatives. 

APS submitted additional information by letters dated November 10, 2009 (APS 2009b), and 

January 13, 2010 (APS 2010). In response to the RAIs, APS provided a description of the 

major changes to the PRA model since the IPE and the internal and external review comments 

on the updated model; a description of the process for mapping Level 1 results into the Level 2 

analysis and for assigning CET sequences to release categories; a description of how fission 

product release fractions were developed for each release category; a revised SAMA analysis 

reflecting a higher external events multiplier; further details on the development of the 

population estimates used in the Level 3 analysis; and additional information regarding several 

specific SAMAs. APS’s responses addressed the NRC staff’s concerns, and resulted in the 

identification of additional potentially cost-beneficial SAMAs. 
Appendix F 

NUREG-1437, Supplement 43 F-2 December 2010

 An assessment of SAMAs for PVNGS is presented below. 

F.2 ESTIMATE OF RISK FOR PVNGS 

APS’s estimates of offsite risk at PVNGS are summarized in Section F.2.1. The summary is 

followed by the NRC staff’s review of APS’s risk estimates in Section F.2.2. 

F.2.1 APS’s Risk Estimates 

Two distinct analyses are combined to form the basis for the risk estimates used in the SAMA 

analysis: (1) the PVNGS Level 1 and 2 PRA model, which is an updated version of the IPE 

(APS 1992), and (2) a supplemental analysis of offsite consequences and economic impacts 

(essentially a Level 3 PRA model) developed specifically for the SAMA analysis. The SAMA 

analysis is based on the most recent PVNGS Level 1 and Level 2 PRA model available at the 

time of the ER, referred to as the PVNGS PRA (Revision 15, September 2007 model). The 

scope of the Level 1 model includes both internal and external (fire) initiating events; the 

PVNGS Fire PRA model is integrated with the internal events Level 1 model. The scope of the 

Level 2 model does not include external events. 

The PVNGS CDF is approximately 5.07 × 10-6 per year for internal events (not including internal 

flooding) and 2.72 × 10-6 per year for fire events, as determined from quantification of the 

Level 1 PRA model. When determined from the sum of the containment event tree (CET) 

sequences, or Level 2 PRA model, the release frequency is approximately 5.24 × 10-6 per year 

for internal events. The latter value was used in the SAMA evaluations (APS 2008a). The total 

release frequency is greater than the internal events CDF in part because the Level 2 model 

uses a truncation value of 1.0 x 10-13 per year while the Level 1 model uses a truncation value of 

1.0 x 10-12 per year. APS accounted for the potential risk reduction benefits associated with 

external events by applying a multiplier to the estimated benefits for internal events. A different 

approach was used in the Phase I and Phase II analyses. In the Phase I analysis reported in 

the ER, APS applied a multiplier of 2.0 to the estimated dollar value associated with completely 

eliminating all internal events at PVNGS (referred to as the maximum averted cost risk or 

MACR) and used this modified MACR value in the Phase I SAMA screening process. This 

effectively assumes that the risk from external events at PVNGS (and the external event risk 

reduction potential of the candidate SAMAs) is equal to that from internal events. In the Phase 

II analysis reported in the ER, APS separately quantified the benefits using the internal event 

and fire event models. For internal event-related SAMAs, APS accounted for the potential 

additional risk reduction benefits associated with non-fire external events (e.g., seismic, high 

wind, and other events) by multiplying the estimated benefits for internal events by a factor of 

0.464. The factor of 0.464 derives from an assumption that the external events CDF is equal to 

the internal events CDF and that fire events account for 53.6 percent of the external events CDF 

(with the remaining 46.4 percent from non-fire external events). For fire-related SAMAs, APS 

separately estimated the risk reduction benefits using the PVNGS Fire PRA model. The 

estimated SAMA benefits for internal events, fire events, and non-fire external events were then 

summed to provide an overall benefit. This is discussed further in Sections F.2.2 and F.6.2. 

The breakdown of CDF by initiating event is provided in Table F-1a and F-1b for internal events 

and fire events, respectively. As shown in Table F-1a, events initiated by station blackout, loss 

of an engineered safeguard feature (ESF) train, unplanned reactor trips, and loss of condensate 

feedwater are the dominant contributors to the internal event CDF. As shown in Table F-1b, the 

dominant contributors to fire CDF are fires in the Control Room, the main turbine bearings area, 

and the Train A Essential Switchgear Room. 
Appendix F 

December 2010 F-3 NUREG-1437, Supplement 43 

 

Table F-1a. PVNGS Core Damage Frequency for Internal Events 

Initiating Event CDF 

(per year)a

% Contribution 

to CDF 

Station Blackout 1.2 × 10-6 23 

Loss of Engineered Safeguard Feature (ESF) Train A or B Bus 8.9 × 10-7 18 

Uncomplicated (Unplanned) Reactor Trips 5.9 × 10-7 12 

Loss of Condensate Feedwater or Vacuum 5.5 × 10-7 11 

Anticipated Transient Without Scram (ATWS) 4.6 × 10-7 9 

Loss of Off-Site Power (LOOP) 3.5 × 10-7 7 

Turbine Trip 2.9 × 10-7 6 

Small Break Loss of Coolant Accident (LOCA) 2.5 × 10-7 5 

Other 1.7 × 10-7 3 

Medium and Large Break LOCAs 1.5 × 10-7 3 

Steam Generator Tube Rupture (SGTR) 1.0 × 10-7 2 

Loss or DC Power 3.5 × 10-8 1 

Interfacing Systems LOCA 1.5 × 10-8 <1 

Loss of Off-Site Power to Train A or B 1.0 × 10-8 <1 

Loss of Vital 120V AC 5.1 × 10-9 <1 

Total CDF (internal events)b 5.07 × 10-6 100

(a) Based on percent contribution from response to RAI 1.e (APS 2009b, APS 2010) and total CDF. 

(b) Column totals may be different due to round off. 

Based on the response to an NRC staff RAI, the Level 2 PRA model that forms the basis for the 

SAMA evaluation represents a revision of the original IPE Level 2 model (APS 2009b). The 

current Level 2 model utilizes two containment event trees (CETs) containing both 

phenomenological and systemic events. The Level 1 core damage sequences are binned into 

one of five Plant Damage State (PDS) bins which provide the interface between the Level 1 

analysis and Level 2 CET analysis. The CET probabilistically evaluates the progression of the 

damaged core with respect to release to the environment. CET nodes are evaluated using 

supporting fault trees and logic rules. The CET end states then are examined for considerations 

of timing and magnitude of release and assigned to release categories.

The result of the Level 2 PRA is a set of 12 release categories, also referred to as source term 

categories, with their respective frequency and release characteristics. The results of this 

analysis for PVNGS are provided in Table 2.E.III-1 of the RAI responses (APS 2009b). The 

frequency of each release category was obtained by summing the frequency of the individual 

accident progression CET endpoints binned into the release category. Source terms were 

developed for each of the 12 release categories using the results of Modular Accident Analysis 

Program (MAAP) computer code calculations for a representative sequence in each release 

category. In response to an NRC staff RAI, APS stated that MAAP Version 4.0.5 was used in 

the PVNGS analysis (APS 2009b). 
Appendix F 

NUREG-1437, Supplement 43 F-4 December 2010

Table F-1b. Important PVNGS Fire Compartments and their Contribution to Fire CDF 

Fire 

Compartment Fire Compartment Description CDF 

(per year) 

% Contribution 

to CDFa

FZ 17 Main Control Room 7.2 × 10-7 27 

FZ TB9 Main Turbine Bearings Areas 5.7 × 10-7 21 

FZ 5A Train A Essential Switchgear Room 3.5 × 10-7 13 

FZ COR2A Corridor Building – 120 foot 2.5 × 10-7 9 

FZ TB1 Turbine Building – 100 foot West 2.3 × 10-7 8 

FZ TB5 Turbine Building – 140 foot West 1.8 × 10-7 7 

FZ TB3B Feedwater Pumps Area 1.1 × 10-7 4 

FZ TB4B DC Equipment Room 3.3 × 10-8 1 

FZ 5B Train B Essential Switchgear Room 3.3 × 10-8 1 

FZ 42A Electrical Penetration Room – Train A, 

Channel A 

2.9 × 10-8 1 

 Other Fire Compartmentsb 2.1 × 10-7 8 

Total Fire CDF 2.72 × 10-6 100

(a) Based on Fire CDF contribution in ER (APS 2008a) and total Fire CDF. 

(b) CDF value derived as the difference between the total Fire CDF and the sum of the fire CDFs reported 

for the 10 dominant fire compartments. 

The offsite consequences and economic impact analyses use the MACCS2 code to determine 

the offsite risk impacts on the surrounding environment and public. Inputs for these analyses 

include plant-specific and site-specific input values for core radionuclide inventory, source term 

and release characteristics, site meteorological data, projected population distribution (within an 

80-kilometer (50-mile) radius) for the year 2040, emergency response evacuation modeling, and 

economic data. The core radionuclide inventory corresponds to long-term operation of a single 

PVNGS unit operating at 3990 megawatt-thermal (MWt). The magnitude of the onsite impacts 

(in terms of clean-up and decontamination costs and occupational dose) is based on information 

provided in NUREG/BR-0184 (NRC 1997a). 

In the ER, APS estimated the dose to the population within 80 kilometers (50 miles) of the 

PVNGS site to be approximately 0.136 person-Sievert (Sv) (13.6 person-rem) per year. The 

breakdown of the total population dose by containment release mode is summarized in 

Table F-2. Late containment over-pressure failures and SGTR-initiated accidents dominate the 

population dose risk at PVNGS. 
Appendix F 

December 2010 F-5 NUREG-1437, Supplement 43 

 

Table F-2. Breakdown of Population Dose by Containment Release Mode 

Containment Release Mode 

Population Dose 

(Person-Rem(a) Per Year) 

Percent 

Contribution 

Containment Over-pressure Failure (Late) 10.5 77 

Basemat Melt-Through (Late) 0.5 4 

Steam Generator Tube Rupture 2.3 17 

Containment Isolation Failure 0.2 1 

Interfacing Systems LOCA 0.1 1 

Intact Containment negligible negligible 

Total 13.6 100

(a) One person-rem = 0.01 person-Sv 

F.2.2 Review of APS’s Risk Estimates 

APS ’s determination of offsite risk at PVNGS is based on the following three major elements of 

analysis: 

• the Level 1 and 2 risk models that form the bases for the 1992 IPE submittal (APS 1992) 

and the external event analyses of the 1995 IPEEE submittal (APS 1995), 

• the major modifications to the IPE model that have been incorporated in the APS PRA, 

and 

• the MACCS2 analyses performed to translate fission product source terms and release 

frequencies from the Level 2 PRA model into offsite consequence measures. 

Each of these analyses was reviewed to determine the acceptability of the PVNGS risk 

estimates for the SAMA analysis, as summarized below.

The NRC staff's review of the APS IPE is described in an NRC report dated July 1, 1994 (NRC 

1994). Based on a review of the original IPE submittal and responses to RAIs, the NRC staff 

concluded that the IPE submittal met the intent of Generic Letter 88-20, “Individual Plant 

Examination of External Events (IPEEE) for Severe Accident Vulnerabilities - 10CFR 50.54(f)” 

(NRC 1988); that is, the licensee’s IPE process is capable of identifying the most likely severe 

accidents and severe accident vulnerabilities. Although no vulnerabilities were identified in the 

IPE, improvements to the plant or procedures were identified and implemented. These 

improvements are discussed in Section F.3.2. 

There have been 17 revisions to the PRA model since the 1992 IPE submittal. A listing of the 

major changes in each revision of the PRA was provided by APS in the ER (APS 2008a) and in 

response to an NRC staff RAI (APS 2009b, APS 2010) and is summarized in Table F-3. A 

comparison of the internal events CDF between the 1992 IPE and Revision 15 of the PVNGS 

PRA model used for the SAMA evaluation indicates a decrease of over 90 percent (from 

8.6 × 10-5 per year to 5.07 × 10-6 per year). 
Appendix F 

NUREG-1437, Supplement 43 F-6 December 2010

The CDF value from the 1992 PNGNS IPE (8.6 × 10-5 per year) is in the middle of the range of 

the CDF values reported in the IPEs for CE plants. Figure 11.6 of NUREG-1560 shows that the 

IPE based internal events CDF for CE plants range from about 1 × 10-5 per year to 3 × 10-4 per 

year, with an average CDF for the group of about 7 × 10-5 per year (NRC 1997b). It is 

recognized that other plants have updated the values for CDF subsequent to the IPE submittals 

to reflect modeling and hardware changes. The internal events CDF result for PVNGS used for 

the SAMA analysis (5.07 × 10-6 per year) is at the lower end of the range of internal event CDF 

for other plants of similar vintage and characteristics. 

APS explained in the ER that the PVNGS PRA model is representative of Unit 1 design and 

operation but that it is essentially representative of all three PVNGS units since the units are 

nearly identical and that differences between the units are primarily due to the phased 

implementation of the same modifications at all three units during succeeding outages (APS 

2008a). The one exception to this is that the PVNGS PRA model includes automatic static 

transfer switches for the Vital AC, which have been installed on Units 2 and 3 but not on Unit 1. 

APS explained that this difference has no material impact on the SAMA evaluation since the 

probability of failure of the automatic static transfer switch is of the same order of magnitude as 

the human error probability associated with the manual static transfer switch. In response to an 

NRC staff RAI, APS further clarified that the automatic static transfer switch has an estimated 

failure probability of 3.0E-3 per demand, while the probability that the operator fails to perform 

the transfer of a manual switch is estimated to be 5.6E-03 based on the results of a human 

reliability assessment (APS 2009b). The human error probability for the operator action is 

based on an action that is in PVNGS procedures, is practiced by the plant operators, and is a 

relatively simple action that does not involve performance shaping factors that would diminish 

operator success at performing the action. Based on this clarification, the NRC staff concurs 

that the design difference between Unit 1 and Units 2 and 3 is not likely to impact the results of 

the SAMA evaluation and that use of Revision 15 of the PVNGS PRA model to represent all 

three units is reasonable. 
Appendix F 

December 2010 F-7 NUREG-1437, Supplement 43 

 

Table F-3. PVNGS PRA Historical Summary 

PRA 

Version Summary of Changes from Prior Model 

CDF 

(per year) 

1992 IPE Submittal 8.6 x 10-5 

Revision 0 

1/1999 

- Revised Level 1 model to model specific plant maintenance configurations and 

correct modeling errors 

3.9 x 10-5

Revision 1 

2/1999 

- Updated mean values of basic events used in the importance analysis and 

corrected an error in an initiating event frequency 

3.9 x 10-5

Revision 2 

5/1999 

- Corrected modeling errors including the incorrect application of a human reliability 

analysis (HRA) 

4.2 x 10-5

Revision 3 

8/1999 

- Added downcomer block valve to the model 

- Updated station blackout initiating event frequency 

- Incorporated change in test intervals associated with engineered safety features 

actuation system 

5.8 x 10-5

Revision 4 

3/2000 

- Revised Level 1 model to model equipment taken out of service while still 

maintaining correct cutsets and recoveries 

- Removed credit for 125 VDC power when the bus battery is failed 

- Updated initiating event data 

7.0 x 10-5

Revision 5 

9/2000 

- Updated documentation 7.0 x 10-5

Revision 6 

1/2001 

- Updated the revision numbers of various references used by the PRA model 7.0 x 10-5

Revision 7 

7/2001 

- Added recovery rules 

- Added modeling of the back-up power supplies for the new digital feedwater 

control system 

- Corrected modeling of several plant systems 

- Added credit for a check valve in the charging system flow path 

2.1 x 10-5

Revision 8 

10/2001 

- Updated documentation 2.1 x 10-5

Revision 9 

3/2002 

- Addressed internal and Combustion Engineering Owners Group (CEOG) peer 

review comments 

- Added credit for alternate paths to carry power to the mitigating systems 

1.8 x 10-5

Revision 10 

2/2003 

- Corrected modeling of Loss of Offsite Power (LOOP) non-recovery probabilities 

- Incorporated new Loss of Coolant Accident (LOCA) success criteria 

- Updated unavailability data 

1.8 x 10-5

Revision 11 

4/2003 

- Incorporated changes to LOOP non-recovery probabilities 

- Removed LOOP events having two recovery actions 

1.8 x 10-5

Revision 12 

5/2003 

- Incorporated changes for new Rudd Transmission Line installation 1.4 x 10-5
Appendix F 

NUREG-1437, Supplement 43 F-8 December 2010

Table F-3. PVNGS PRA Historical Summary 

Revision 13 

6/2004 

- Corrected modeling of several plant systems 

- Removed credit for atmospheric dump valves in an Steam Generator Tube 

Rupture (SGTR) event 

- Updated test intervals for auxiliary feedwater valves and relays 

- Updated turbine bypass modeling logic 

- Added potential for an ATWS in an SGTR and small LOCA event 

- Updated the human reliability probability for containment spray header flange failto-restore 

- Credited use of the reactor makeup water tank as a water source for the auxiliary 

feedwater 

- Added turbine cooling water isolation valves for instrument air (IA) compressor 

coolers 

- Updated values for feedwater isolation valve recovery actions 

- Updated dependence of the steam bypass control and reactor power cutback 

systems on non-vital AC and station DC 

1.3 x 10-5

Revision 14 

1/2006 

- Updated failure data 

- Updated common-cause methodology 

1.4 x 10-5

Revision 15a 

9/2007 

- Revised modeling of diesel-generator (DG) and pump control faults 

- Added credit for feeding either steam generator (SG) after SGTR and removed 

alternate feedwater 

- Revised SGTR top logic for cooldown and depressurization 

- Made occurrence of main steam isolation signal (MSIS) with SGTR conditional 

upon operator failure to control SG level 

- Revised failure data for the condensate storage tank (CST) and refueling water 

tank (RWT) 

- Removed the reactor water makeup tank (RWMT) as a back-up to the CST 

- Revised instrument failure probabilities 

- Removed engineered safeguard feature (ESF) pump room dependency on HVAC 

- Removed HRAs for overriding MSIS in order to use non-safety FW pump and to 

open an MSIV to provide steam to the condenser 

- Revised HRAs for auxiliary feedwater (AFW) and alternate feedwater 

5.1 x 10-6

Revision 16b 

12/2008 

- Revised the station blackout event tree 

- Revised the DG failure modes to align with the mitigating systems performance 

index (MSPI) program 

- Updated recovery rules for AFW, alternative feedwater, and DG failure modes 

- Added credit for providing main feedwater (MFW) for the full 24-hour mission time 

and for recovering loss of all feedwater with restarting MFW 

- Updated MSPI system unavailability parameters 

5.0 x 10-6

(a) PVNGS PRA version used as the basis for the SAMA analysis. 

(b) CDF reported in the RAI response (APS 2010) is the sum of CDF for internal events and internal fire 

events. 

The NRC staff considered the peer reviews performed for the PVNGS PRA and the potential 

impact of the review findings on the SAMA evaluation. In the ER and in response to an NRC 

staff RAI (APS 2009b), APS described the Combustion Engineering Owner’s Group (CEOG) 

peer review conducted on Revision 3 of the PVNGS PRA model in 1999. The peer review 

identified 8 Level A (important and necessary to address before the next regular PRA update) 
Appendix F 

December 2010 F-9 NUREG-1437, Supplement 43 

 

and 26 Level B (important and necessary to address, but disposition may be deferred until the 

next PRA update) Facts and Observations (F&Os). APS stated in the ER that all Level A and 

Level B F&Os have been subsequently addressed and all but one Level B F&O are considered 

closed, with all final disposition of comments incorporated in Revision 15 of the PVNGS PRA 

model. 

The one Level B F&O still open is that the PVNGS PRA model does not address internal 

flooding events. APS explained that incorporating an internal flood model into the PVNGS PRA 

model has been a low priority because of the low internal flooding CDF estimated in the PVNGS 

IPE. For the purposes of the SAMA evaluation, APS reviewed the IPE internal flooding analysis 

for PVNGS. The IPE internal flooding analyses employed a two step process as follows: 

(1) screen out PVNGS plant flood zones determined to contribute negligibly to overall PVNGS 

CDF and (2) quantify the contribution to CDF of all unscreened zones deemed to have a 

significant impact on total CDF (APS 1992). All 144 flood zones were screened from further 

analysis based on the following criteria: (1) the zone is not susceptible to a flood or spray event 

because it does not contain any “critical” equipment and contains no flood source (82 zones 

screened out), (2) the maximum postulated flood or spray event for the zone does not cause an 

initiating event and does not degrade the ability to shut the plant down (49 zones screened out), 

or (3) the estimated flood frequency for the zone is less than 1 × 10-4 per year and loss of 

equipment does not have a significant impact on plant risk (13 zones screened out). Of the 13 

zones for which a frequency estimate was developed, all contributed less than 1 × 10-8 per year 

to CDF. APS’s evaluation of potential SAMAs to address internal flooding events is discussed 

in Section F.3.2. 

The NRC staff asked APS to identify and describe the results of any other more recent internal 

or external reviews that have been conducted on the PVNGS PRA model (NRC 2009). In 

response to the RAI, APS described the following additional reviews: (1) a February/March 

2001 external review of Revision 6 of the PRA model by ERIN Engineering that evaluated and 

prioritized the technical issues identified in the CEOG peer review, evaluated the actions taken 

and responses to the peer review issues, and evaluated the PVNGS PRA update procedures 

and process, (2) an August 2001 external review of Revision 7 of the PRA model by RELCONAB that evaluated certain model attributes, including common cause modeling, event and fault 

trees, boundary conditions, reliability models, success criteria, and others identified in the RAI 

response, (3) a February 2003 external review of the Fire PRA associated with Revision 10 of 

the PRA model by ERIN Engineering that assessed the transparency of the documentation, 

assessed the use of acceptable methodology, and identify obvious errors, misapplications, and 

deficiencies, and (4) a September 2008 internal self-assessment of Revision 15 of the PRA 

model against NRC Regulatory Guide 1.200, Revision 1, "An Approach for Determining the 

Technical Adequacy of Probabilistic Risk Assessment (PRA) Results for Risk-Informed 

Activities," and its capability category II supporting requirements (NRC 2007). APS stated that 

there are no open items from the first three reviews (APS 2009b). For the September 2008 

internal self-assessment, APS provided a summary of the supporting requirements determined 

to not meet capability category II and the results of an assessment of their impact on the SAMA 

analysis, which are summarized as follows:

• Lack of internal flood model. This deficiency was addressed separately in the SAMA 

evaluation as discussed above. 

• No evidence of cross-comparison of plant initiating events with other similar plants. APS 

explained that PVNGS initiating events are consistent with NRC and Electric Power 
Appendix F 

NUREG-1437, Supplement 43 F-10 December 2010

Research Institute (EPRI) publications and that there are no open items from either the 

1999 CEOG peer review or the CEOG cross-comparison of PWR initiating events to 

other plants. 

• No credit taken in the Large Early Release Frequency (LERF) analysis for post-core 

damage repairs or human actions. APS explained that the SAMA analysis results are 

conservative relative to this deficiency since taking credit for equipment repairs and for 

human actions not already credited would result in a decrease in LERF as compared to 

the LERF used in the SAMA evaluation. 

• Insufficient uncertainty analyses in the CDF and LERF analyses. APS explained that the 

uncertainty analysis performed for the SAMA evaluation, which used the 95th percentile 

CDF as discussed in Section F.6.2, addresses this deficiency. 

• Documentation issues. APS explained that no numerical deficiencies in the CDF or 

LERF analyses were identified from this deficiency. 

The NRC staff considers APS’s explanation for each deficiency reasonable and concludes that 

final resolution of the deficiencies is not likely to impact the results of the SAMA analysis. 

The NRC staff asked APS to identify any changes to the plant, including physical and 

procedural modifications, since Revision 15 of the PVNGS PRA model that could have a 

significant impact on the results of the SAMA analysis (NRC 2009). In response to the RAI, 

APS described the major changes to the PRA model since Revision 15, which are summarized 

in Table G-3 for Revision 16 of the PVNGS PRA model (APS 2009b). The CDF for Revision 16 

reported in Table G-3 of 5.0 × 10-6 per year, which includes internal fire events, is a decrease 

from Revision 15 and is primarily due to additional credit being taken for longer operation of 

main feedwater following a transient. APS also compared the Revision 16 and Revision 15 

Level 1 importance lists and found that use of PRA Revision 16 in the SAMA identification 

process would not have resulted in addition of any new basic events or SAMAs. APS further 

stated that there have been no plant modifications since Revision 16 that would have 

significantly impacted CDF or LERF. Based on the fact that CDF has decreased since Revision 

15 of the PVNGS PRA model used for the SAMA analysis, that Revision 16 of the PRA model 

does not result in additional basic events on the Level 1 importance list, and that there have 

been no major plant changes since Revision 16, the NRC staff concurs with APS’s conclusion 

that changes to the PVNGS PRA model since Revision 15 of the model are not likely to impact 

the results of the SAMA analysis. 

In the ER, APS described the quality control process in use at PVNGS (APS 2008a). The 

model is updated typically every 2 years to incorporate plant changes. The entire process of 

monitoring potential plant changes, tracking items that may lead to model changes, making 

model changes, documenting the changes, software quality control, independent reviews, and 

qualification of PRA staff are governed by APS procedures and programs. 

Given that the PVNGS internal events PRA model has been peer reviewed and the peer review 

findings were all addressed, and that APS has satisfactorily addressed NRC staff questions 

regarding the PRA, the NRC staff concludes that the internal events Level 1 PRA model is of 

sufficient quality to support the SAMA evaluation. 

As indicated above, APS maintains a current PVNGS external events PRA model that explicitly 

models fire-initiated core damage accidents but does not include non-fire external events. The 
Appendix F 

December 2010 F-11 NUREG-1437, Supplement 43 

 

PVNGS Fire PRA model is described in the ER. In the absence of an analysis of non-fire 

external events, APS used the PVNGS IPEEE to identify the highest risk accident sequences 

and the potential means of reducing the risk posed by those sequences, as discussed below 

and in Section F.3.2. 

The PVNGS IPEEE was submitted in June 1995 (APS 1995) in response to Supplement 4 of 

Generic Letter 88-20 (NRC 1991). This submittal included a seismic margins analysis, an 

internal fire PRA, and a screening analysis for other external events. While no fundamental 

weaknesses or vulnerabilities to severe accident risk in regard to the external events were 

identified, a number of opportunities for risk reduction were identified as discussed below. In a 

letter dated July 2, 1999, the NRC staff concluded that the submittal met the intent of 

Supplement 4 to Generic Letter 88-20, and that the licensee’s IPEEE process is capable of 

identifying the most likely severe accidents and severe accident vulnerabilities (NRC 1999). 

The seismic portion of the IPEEE consisted of a full-scope seismic evaluation using the Electric 

Power Research Institute (EPRI) methodology for Seismic Margins Assessment (SMA) (EPRI 

1991). This method is qualitative and does not provide numerical estimates of the CDF 

contributions from seismic initiators. For this assessment, plant walkdowns were performed in 

which components and structures were screened against the review level earthquake (RLE) of 

0.3g based on the EPRI guidelines, and specific high confidence low probability of failure 

(HCLPF) capacities were calculated for components required to perform following a seismic 

event. The PVNGS IPEEE seismic evaluation identified no significant changes to plant design 

that were required to mitigate the RLE. However, the IPEEE walkdown identified one 

enhancement to improve plant seismic capacity, which is to improve the anchorage on the 

bookshelves located behind the Unit 3 control cabinets. This enhancement has been 

implemented (APS 2008a). 

For purposes of the SAMA evaluation, APS assumed a seismic CDF of 1.0 × 10-6 per year in the 

development of the external events multiplier (APS 2008a). The NRC staff noted that in a riskinformed license amendment request for an extended containment integrated leak rate test 

(ILRT) interval, APS estimated a seismic CDF for PVNGS of 7.49 × 10-6 per year (APS 2008b). 

The APS estimate was based on the simplified-hybrid approximation method described in a 

paper by Robert P. Kennedy, entitled “Overview of Methods for Seismic PRA and Margin 

Analysis Including Recent Innovations” (Kennedy 1999) and seismic hazard data specific to 

PVNGS. The NRC staff requested APS to provide justification for not using the APS estimated 

seismic CDF in the SAMA evaluation (NRC 2009). In response to the RAI, APS re-calculated 

the seismic CDF to be 4.75 × 10-6 per year by performing a more realistic interpolation between 

data points on the PVNGS seismic hazard curve and provided a revised SAMA evaluation using 

this seismic CDF, which is discussed further below. The NRC staff finds the APS approach to 

estimating the PVNGS seismic CDF acceptable and concludes that the revised seismic CDF of 

4.75 × 10-6 per year is reasonable for the SAMA analysis. 

The APS IPEEE fire analysis employed EPRI’s fire-induced vulnerability evaluation (FIVE) 

methodology (EPRI 1993) to perform a qualitative screening of fire areas and compartments not 

important from a fire impact standpoint followed by a progressive probabilistic evaluation of 

unscreened fire compartments that considers the sequence of events necessary for a fire to 

result in a complete loss of a safe shutdown function. This evaluation determined ignition 

sources and frequency for each unscreened fire compartment and redundant/alternate 

shutdown system unavailability, and, if necessary, considered fire growth and propagation, 

component damage, and fire detection and suppression effectiveness. A fire compartment was 
Appendix F 

NUREG-1437, Supplement 43 F-12 December 2010

screened from further analysis once the fire-induced core damage frequency dropped below 

1 × 10-6 per year. Lastly, a plant walkdown and verification process was employed to verify that 

all assumptions and calculations were supported by the physical condition of the plant. Several 

additions and improvements to plant administrative controls, procedures, and training were 

identified and implemented. The total fire CDF, found by summing the values for all 

compartments in Table 4-6 of the IPEEE, is 8.7 × 10-5 per year. 

While no physical plant changes were found to be necessary as a result of the IPEEE fire 

analysis, the analysis did credit three plant design changes that had not been implemented at 

that time. The enhancements credited were (1) installation of a switch to remotely disconnect 

the essential air cooling unit (ACU) for the Train B DC equipment rooms from the main control 

room (MCR), (2) modification to reconfigure the fire damper control panels to provide separation 

between the fire panel control circuits for the Train A and Train B essential switchgear rooms, 

and (3) installation of additional fuses to eliminate common fuses for certain safe shutdown and 

non-safe shutdown control circuits. These plant modifications have all been implemented (APS 

2008a). 

Subsequent to the IPEEE, APS created a fire PRA that was used in the SAMA evaluation. The 

fire CDF by PVNGS fire compartment is provided in Table F-1b. The total fire CDF, found by 

summing the values for all compartments in Table F-1b, is 2.72 × 10-6 per year. The ER 

describes the fire PRA model as being integrated with, and having many of the same 

characteristics of, the internal events PRA model. In response to an NRC staff RAI (NRC 

2009), APS provided additional information on the fire PRA model. The model is a substantial 

update to the IPEEE fire PRA model and was originally incorporated into Revision 7 of the 

PVNGS internal events PRA model (APS 2009b). The NRC notes that while the internal events 

and fire PRA models are integrated, APS reports the CDF contribution from internal events and 

fire events separately in the ER and in responses to the RAIs. The fire PRA model was 

developed using the EPRI fire PRA methodology (EPRI 1995) and fire events database, and its 

development was subject to the staff qualification and independent verification requirements of 

PVNGS administrative controls as described above. The updated model results in fire CDF 

values that are substantially reduced from those reported for the IPEEE fire PRA model. APS 

explained that, while the changes to the fire PRA model since the IPEEE are too numerous to 

list, the model was peer reviewed in 2003 because of the substantial changes made since the 

IPEEE and that all Level A or B F&Os from this peer review were subsequently resolved in later 

revisions of the fire PRA model. APS clarified that no internal or external reviews of the fire 

PRA have been made since the 2003 peer review (APS 2010). However, APS identified a 

number of conservatisms in the fire PRA model, as summarized below (APS 2008a): 

• A revised NRC fire events database indicates a trend toward lower frequency and less 

severe fires than assumed in the PVNGS fire PRA model. 

• Crediting of manual fire suppression is limited outside the MCR. 

• Bounding fire modeling is generally used to assess the immediate effects of a fire and 

fire propagation. For example, failure of a suppression system in a fire compartment is 

generally assumed to result in the loss of all equipment in the fire compartment. 

• Because of a lack of industry experience with regard to crew performance during the 

types of fires modeled in the fire PRA, the characterization of crew actions in the fire 

PRA is generally conservative. 
Appendix F 

December 2010 F-13 NUREG-1437, Supplement 43 

 

Considering that the PVNGS fire PRA model has been peer reviewed and the peer review 

findings were all addressed, that the model contains some conservatisms, and that APS has 

satisfactorily addressed NRC staff RAIs regarding the fire PRA, the NRC staff concludes that 

the fire PRA model is of sufficient quality to support the SAMA evaluation. 

The APS IPEEE analysis of high winds, tornadoes, external floods, and other external events 

followed the screening and evaluation approaches specified in Supplement 4 to GL 88-20 (NRC 

1991). For high winds, external floods, and accidents at nearby facilities, the IPEEE concluded 

that APS meets the 1975 Standard Review Plan criteria (NRC 1975) and therefore the 

contribution from these hazards to CDF is less than the 1.0 × 10-6 per year criterion (APS 1995). 

For lightning, sandstorms, and extreme heat hazards, the IPEEE concluded that none posed a 

threat to the plant. 

In the ER, APS noted that the review of the IPEEE analysis of tornado events revealed that the 

PVNGS design basis tornado was assumed to have a maximum wind speed of 360 miles per 

hour (mph) while the APS Updated Final Safety Analysis Report (UFSAR) describes the design 

basis tornado to have a maximum wind speed of 300 mph. APS re-assessed the frequency of a 

Category F5 tornado, defined as having wind speeds between 260 and 318 mph, and 

developed a beyond-design-basis-tornado CDF of 5.75 × 10-9 per year. APS further explained 

that while there may potentially be tornadoes having wind speeds greater than 318 mph, the 

majority of the F5 tornado wind speed spectrum is below 300 mph and that, therefore, use of 

the F5 tornado frequency includes a significant wind speed spectrum that does not pose a 

threat to the PVNGS structures. The NRC staff finds the APS approach to estimating the 

PVNGS beyond design-basis-tornado CDF acceptable. 

As previously discussed, in the Phase I analysis reported in the ER, APS multiplied the 

estimated benefits for internal events by a factor of 2.0 to account for external events, and in the 

Phase II analysis separately quantified the internal event and fire event benefits and estimated 

the benefits in non-fire external events by applying a multiplier of 0.464 to the internal events 

benefits. Based on the aforementioned results, however, the external events CDF is 

approximately 1.5 times the internal events CDF (based on a seismic CDF of 4.75 × 10-6 per 

year, a fire CDF of 2.72 × 10-6 per year, a negligible contribution from other external events, and 

an internal events CDF of 5.07 × 10-6 per year). This would suggest that the external event 

multiplier used in the Phase I screening should be 2.5 rather than 2.0. Similarly, given the 

higher seismic CDF discussed above, the non-fire external events multiplier should be about 

0.95 rather than 0.464 (based on a seismic CDF of 4.75 × 10-6 per year, a negligible contribution 

from other external events, and an internal events CDF of 5.07 × 10-6 per year). In response to 

an NRC staff RAI, APS provided a revised SAMA evaluation using a Phase I multiplier of 2.5 

and a Phase II multiplier of 0.955 to account for external events (APS 2009b). This is discussed 

further in Section F.6.2. 

The NRC staff reviewed the general process used by APS to translate the results of the Level 1 

PRA into containment releases, as well as the results of the Level 2 analysis, as described in 

the ER and in response to NRC staff requests for additional information (APS 2009b). The 

current Level 2 model is completely revised from the model used in the IPE and utilizes two 

CETs based on WCAP-16341-P (Westinghouse 2005), containing both phenomenological and 

systemic events, which are linked to the Level 1 event trees. WCAP-16341-P was developed 

with the intent that Level 2 models developed using its methodology would meet the Capability 

Category II supporting requirements in Regulatory Guide 1.200, Revisions 1 and 2 for PRAs 

(NRC 2007). Each Level 1 core damage sequence was, based on a set of boundary conditions, 
Appendix F 

NUREG-1437, Supplement 43 F-14 December 2010

evaluated using three attributes: (1) is there a station blackout, (2) is the containment 

bypassed, and (3) is the reactor coolant system (RCS) pressure high. After assignment of 

attributes, the Level 1 core damage sequences are binned into one of five plant damage state 

(PDS) bins defined by the PVNGS-specific combination of attributes and boundary conditions, 

which provide the interface between the Level 1 and Level 2 analysis. APS noted that a total of 

seven PDS bins were defined, however, no Level 1 core damage sequences were identified for 

two of the PDS bins. The PDS bins, boundary conditions, and CETs are described in the 

response to an NRC staff RAI (APS 2009b). 

Each PDS is analyzed through the Level 2 CETs to evaluate the phenomenological progression 

of the sequence. The process of assigning Level 2 CET sequences to release categories is 

described in the ER and in response to NRC staff RAIs (APS 2009b). The CET end states are 

assigned to one of 12 release categories based on characteristics that determine the timing and 

magnitude of the release, whether or not the containment remains intact, and isotopic 

composition of the release material. The frequency of each release category was obtained by 

summing the frequency of the individual accident progression CET endpoints binned into the 

release category. 

Source term release fractions were developed for each of the 12 release categories based on 

the results of plant-specific calculations using the Modular Accident Analysis Program (MAAP) 

Version 4.0.5 (APS 2009b). A single MAAP calculation was performed for each of the 12 

release categories (APS 2009b). The release categories and their frequencies and release 

characteristics are presented in Tables D.2-2 and D.3-2 of Appendix D to the ER (APS 2008a) 

and in Tables 2.E.ii-1 and 2.E.iii-1 of the RAI responses (APS 2009b). 

The revisions to the Level 2 model since the IPE to update the methodology and to address 

peer review recommendations are described in Section D.2 of the ER and in response to NRC 

staff RAIs (APS 2009b). While the revised Level 2 PRA model was not included in the 1999 

CEOG peer review, it was included in the September 2008 self-assessment mentioned 

previously. As discussed previously, only one deficiency identified in the self-assessment 

specifically involves the Level 2 analysis and APS determined that the Level 2 PRA model used 

in the SAMA evaluation relative to this deficiency was conservative (APS 2009b). The NRC 

staff considers APS’s explanation for this deficiency reasonable and concludes that final 

resolution of the deficiency is not likely to impact the results of the SAMA analysis. Based on 

the NRC staff’s review of the Level 2 methodology, that APS has adequately addressed NRC 

staff RAIs, that the Level 2 PRA model was reviewed in more detail as part of the September 

2008 self-assessment, and that the deficiencies from the self-assessment have been 

adequately addressed, the NRC staff concludes that the Level 2 PRA provides an acceptable 

basis for evaluating the benefits associated with various SAMAs. 

As indicated in the ER, the reactor core radionuclide inventory used in the consequence 

analysis was based on the licensed thermal power of 3990 MWt. In response to an NRC staff 

RAI, APS stated that there are currently no plans to request a power uprate in any of the three 

PVNGS units (APS 2009b). 

The NRC staff reviewed the process used by APS to extend the containment performance 

(Level 2) portion of the PRA to an assessment of offsite consequences (essentially a Level 3 

PRA). In response to an NRC staff RAI, APS clarified that although a Level 3 model was 

developed for the IPE, a new Level 3 model was developed for the SAMA analysis (APS 

2009b). The staff review included consideration of the source terms used to characterize fission 

product releases for the applicable containment release categories and the major input 
Appendix F 

December 2010 F-15 NUREG-1437, Supplement 43 

 

assumptions used in the offsite consequence analyses. The MACCS2 code was utilized to 

estimate offsite consequences. Plant-specific input to the code includes the source terms for 

each release category and the reactor core radionuclide inventory (both discussed above), sitespecific meteorological data, projected population distribution within an 80 kilometer (50-mile) 

radius for the year 2040, emergency evacuation modeling, and economic data. This information 

is provided in Section D.3 of Attachment D to the ER (APS 2008a) and in response to NRC staff 

RAIs (APS 2009b). 

All releases were modeled as occurring at ground level. The thermal content of each of the 

releases is assumed to be at ambient (buoyant plume rise was not modeled). Wake affects for 

the 64-meter (210-foot) high and 47-meter (154-foot) diameter containment building were 

included in the model. Sensitivity analyses were performed for the elevation, wake effects and 

thermal content of the releases. Increasing the release height from ground level to the top of 

containment increased the population dose risk by 7 percent and the offsite economic cost risk 

by 8 percent. Increasing the release heat to 1 MW in up to 4 segments increased the 

population dose risk by 2 percent and the offsite economic cost risk by 1 percent. Decreasing 

the building proximity wake effects by 50 percent decreased the population dose risk and offsite 

economic cost risk by 3 percent and 4 percent, respectively, while increasing the building wake 

effects to 200 percent of the baseline assumption increased the population dose risk and offsite 

economic cost risk by 4 percent and 6 percent, respectively. During the internal review of the 

SAMA analysis, APS discovered that the Level 3 analysis used a wake height based on the total 

height of the containment building (210 feet) rather than the height above grade (190 feet). A 

corrected wake height results in a decrease of less than 1 percent in both population dose risk 

and offsite economic cost risk. Use of a lower surface roughness, simulating a desert instead of 

a suburban area, decreased the population dose risk by 7 percent and the offsite economic cost 

risk by 10 percent. Based on the information provided, the NRC staff concludes that the release 

parameters utilized are acceptable for the purposes of the SAMA evaluation. 

APS used site-specific meteorological data for the 2003 calendar year as input to the MACCS2 

code. The development of the meteorological data is discussed in Section D.3.5 of 

Attachment D to the ER. The data were collected from the onsite meteorological tower located 

west-northwest of the reactor buildings. Data from 2004 and 2005 were also considered, but 

the 2003 data were chosen because they were found to result in the maximum economic cost 

and dose risks (APS 2008a). Specifically, using the year 2004 and 2005 meteorological data 

decreased the population dose risk and offsite economic cost risk by 14 to 16 percent and 16 to 

17 percent, respectively. Missing data were filled in by (in order of preference): using 

corresponding data from another level (taking the relationship between the levels as determined 

from immediately preceding hours), interpolation (if the data gap was less than 4 hours), or 

using data from the same hour and a nearby day of a previous year. The base case analysis 

assumed perpetual rainfall in the last spatial segment of the model (40-50 miles) to assure 

conservatively high wet deposition of radionuclides within the model domain. A sensitivity 

analysis showed that removing the assumption of perpetual rainfall in the last segment 

surrounding the site would result in a 40 percent reduction in population dose risk and a 

49 percent reduction in offsite economic cost risk. The NRC staff notes that previous SAMA 

analyses results have shown little sensitivity to year-to-year differences in meteorological data 

and concludes that the approach taken for collecting and applying the meteorological data in the 

SAMA analysis is reasonable. 
Appendix F 

NUREG-1437, Supplement 43 F-16 December 2010

The population distribution the licensee used as input to the MACCS2 analysis was estimated 

for the year 2040 using year 2000 U.S. Census Bureau Data, as accessed by the SECPOP2000 

program (NRC 2003), and the expected annual population growth rate. The population 

distribution was determined for each of 16 directions and each of 10 concentric rings. In cases 

where a sector consisted of more than one county, an area-fraction weighting factor was applied 

to the projected county contributions. The population estimate for the year 2040 was projected 

using an exponential growth rate calculated based on state county population projections 

(Arizona Department of Economic Security 2006) and the 2000 U.S Census Bureau Data 

(USCB 2000). In response to an NRC staff RAI, APS identified that standard exponential 

population growth equations were used for population growth (APS 2009b). Although 

population growth is sometimes represented by a linear equation, the use of the exponential 

equation conservatively projects a larger population. According to the 2005 Palo Verde 

Evacuation Time Analysis (Maricopa 2005), other than the plant staff, there is no significant 

transient population within the 10-mile radius. Therefore, only resident population was used in 

the analysis. In response to an NRC staff RAI, APS provided the year 2040 population 

distribution for the 50-mile radius at 10-mile intervals (APS 2009b). The NRC staff considers 

the methods and assumptions for estimating population reasonable and acceptable for 

purposes of the SAMA evaluation. 

The emergency evacuation model was modeled as a single evacuation zone extending out 

16 kilometers (10 miles) from the plant. APS assumed that 95 percent of the population would 

evacuate. This assumption is conservative relative to the NUREG-1150 study (NRC 1990), 

which assumed evacuation of 99.5 percent of the population within the emergency planning 

zone (EPZ). The evacuated population was assumed to move at an average speed of 

approximately 2.9 meters per second (6.6 miles per hour) with a delayed start time of 

75 minutes after declaration of a general emergency. The evacuation speed was estimated by 

multiplying the year 2005 evacuation speed of 3.4 m/sec (Maricopa 2005) by the ratio of the 

year 2005 and year 2040 EPZ populations. In response to an NRC staff RAI, APS provided the 

year 2005 EPZ population distribution for the 10-mile radius at 1-mile intervals (APS 2009b). A 

sensitivity analysis was performed in which the evacuation speed was increased to the year 

2005 evacuation speed of 3.4 m/sec (7.6 mph). The results were less than a one percent 

decrease in the total population dose. The NRC staff noted that the evaluation speed for the 

year 2040 is about 13 percent lower than the baseline evacuation speed while the population 

growth is approximately double from 2006 to 2040 and requested APS clarify this discrepancy 

(NRC 2009). In response to the RAI, APS clarified that the population growth in the EPZ is 

about 16 percent, which compares well with the assumed reduction in evacuation speed (APS 

2009b). The NRC staff concludes that the evacuation assumptions and analysis are reasonable 

and acceptable for the purposes of the SAMA evaluation. 

Much of the site-specific economic data was provided from the 2002 Census of Agriculture 

(USDA 2004) for each of the five counties surrounding the plant to a distance of 50 miles. 

These included the fraction of land devoted to farming, annual farm sales, the fraction of farm 

sales resulting from dairy production, and information on regional crops. The value of farm and 

non-farm land were taken from state and local analyses (Arizona 2003, GPEC 2005). In 

addition, generic economic data that applies to the region as a whole was taken from the 

MACCS2 sample problem input. This included parameters describing the cost of evacuating 

and relocating people, land decontamination, and property condemnation. An escalation factor 

of 1.86 (USDL 2007) was applied to these parameters to account for cost escalation from 1986 

(the year the input was first specified) to 2007. No economic parameters were derived using the 

SECPOP2000 code and, therefore, the problems recently identified with that portion of the code 

have no impact on the SAMA analysis. 
Appendix F 

December 2010 F-17 NUREG-1437, Supplement 43 

 

The NRC staff concludes that the methodology used by APS to estimate the offsite 

consequences for PVNGS provides an acceptable basis from which to proceed with an 

assessment of risk reduction potential for candidate SAMAs. Accordingly, the NRC staff based 

its assessment of offsite risk on the CDF and offsite doses reported by APS. 

F.3 POTENTIAL PLANT IMPROVEMENTS 

The process for identifying potential plant improvements, an evaluation of that process, and the 

improvements evaluated in detail by APS are discussed in this section. 

F.3.1 Process for Identifying Potential Plant Improvements 

APS's process for identifying potential plant improvements (SAMAs) consisted of the following 

elements: 

• Review of the most significant basic events from the current, plant-specific PRA, 

• Review of potential plant improvements identified in the PVNGS IPE and IPEEE, 

• Review of SAMA candidates identified for license renewal applications for six other U.S. 

Combustion Engineering and Westinghouse PWR plants, and 

• Review of other industry documentation discussing potential plant improvements. 

Based on this process, an initial set of 23 candidate SAMAs, referred to as Phase I SAMAs, was 

identified. In Phase I of the evaluation, APS performed a screening of the initial list of SAMAs 

and eliminated SAMAs from further consideration using the following criteria: 

• The SAMA is not applicable to APS due to design differences or has already been 

implemented at APS or 

• The SAMA has estimated implementation costs that would exceed the dollar value 

associated with completely eliminating all severe accident risk at PVNGS. 

Based on this screening, 10 SAMAs were eliminated leaving 13 for further evaluation. The 

remaining SAMAs, referred to as Phase II SAMAs, are listed in Table D.5-4 of Attachment D to 

the ER (APS 2008a). In Phase II, a detailed evaluation was performed for each of the 13 

remaining SAMA candidates, as discussed in Sections F.4 and F.6 below. 

As previously discussed, APS accounted for the potential risk reduction benefits associated with 

each SAMA by separately quantifying the benefits using the internal event and fire event 

models. For internal event-related SAMAs, APS accounted for the potential additional risk 

reduction benefits associated with non-fire external events (e.g., seismic, high wind, and other 

events) by multiplying the estimated benefits for internal events by a factor of 0.464. For firerelated SAMAs, APS separately estimated the risk reduction benefits using the PVNGS Fire 

PRA model. The estimated SAMA benefits for internal events, fire events, and non-fire external 

events were then summed to provide an overall benefit.

F.3.2 Review of APS’s Process 
Appendix F 

NUREG-1437, Supplement 43 F-18 December 2010

APS’s efforts to identify potential SAMAs focused primarily on areas associated with internal 

initiating events, but also included explicit consideration of potential SAMAs for fire events. The 

initial list of SAMAs generally addressed the accident sequences considered to be important to 

CDF from functional, initiating event, and risk reduction worth (RRW) perspectives at PVNGS, 

and included selected SAMAs from prior SAMA analyses for other plants. 

APS provided a tabular listing of the Level 1 PRA basic events sorted according to its RRW 

(APS 2008a). SAMAs impacting these basic events would have the greatest potential for 

reducing risk. APS used a RRW cutoff of 1.01, which corresponds to about a one percent 

change in CDF given 100-percent reliability of the SAMA. This equates to a benefit of 

approximately $58,000, after the benefits have been multiplied by a factor of 2.5 to account for 

external events (APS 2009b) and implementation at the three units at PVNGS. All basic events 

in the Level 1 listing were reviewed to identify potential SAMAs. All but one of the basic events 

was addressed by one or more SAMAs (APS 2008a). APS explained that no actions have been 

identified to improve the reliability of the one basic event not addressed, 1HLI-3HR-OP-2HR, 

which is an operator action that is proceduralized, is performed by operators in the plant 

simulator, and, as a result, is already assumed to have a reasonable reliability (2.0E-03). Based 

on the use of a relatively low probability of failure for an operator action and the low RRW 

(1.013) for this basic event, the NRC staff agrees that a SAMA to address this event is not likely 

to be cost beneficial. 

APS also provided and reviewed the Level 2 PRA basic events, down to a RRW of 1.01, for the 

release categories contributing over 97 percent of the population dose-risk. The Level 2 basic 

events for the remainder of the release categories were not included in the review so as to 

prevent high frequency-low consequence events from biasing the importance listing. All but two 

of the basic events were addressed by one or more of the SAMAs (APS 2008a). The two basic 

events not addressed either had no physical meaning (flag event) or provided no risk insights 

(split fraction having a probability of 1.0). As a result of the review of the Level 1 and Level 2 

basic events, 17 SAMAs were identified. 

APS reviewed the Phase II SAMAs from prior SAMA analyses for one Westinghouse PWR and 

five Combustion Engineering PWR sites. APS’s review determined that the majority of these 

Phase II SAMAs were already represented by a SAMA identified from the Level 1 and 2 

importance list reviews, have low potential for risk reduction at PVNGS ( i.e., address basic 

events having an RRW less than 1.01), were already implemented at PVNGS, or were not 

applicable to PVNGS. This review resulted in one additional SAMA being identified. 

APS considered the potential plant improvements described in the IPE in the identification of 

plant-specific candidate SAMAs for internal events. The PVNGS IPE identified four 

improvements associated with core damage as follows: (1) change the source of power for the 

main steam and feedwater isolation valve logic cabinets, (2) change the loss of power failure 

mode of the Train A steam generator downcomer containment isolation valves to fail open, 

(3) provide a backup source of control power for the Train N auxiliary feedwater pump circuit 

breaker, and (4) install temperature detectors in the DC equipment rooms, with an alarm in the 

main control room. The four improvements have been implemented at PVNGS (APS 2008a). 

As discussed in Section F.2.2, the PVNGS PRA model does not include internal flooding 

events. Accordingly, APS reviewed the IPE internal flooding analysis for PVNGS for the 

purpose of identifying potential SAMAs. Using the assumed internal flooding CDF of 1.0 × 10-7

per year for PVNGS, and assuming that this risk was distributed among the Level 2 release 

categories in the same proportion as for the internal events CDF, APS determined that even a 
Appendix F 

December 2010 F-19 NUREG-1437, Supplement 43 

 

low-cost procedure SAMA that eliminated all internal flooding risk would not be cost effective. 

The NRC staff concludes that the opportunity for internal flooding-related SAMAs has been 

adequately explored and that it is unlikely that there are any cost-beneficial, internal floodingrelated SAMA candidates. 

As discussed in Section F.2.2, automatic static transfer switches for the Vital AC have been 

installed in Units 2 and 3 but not in Unit 1 (APS 2008a). In response to an NRC staff RAI asking 

APS to provide an assessment of a SAMA to install an automatic static transfer switch in Unit 1, 

APS explained that the transfer switches have a low risk significance in the PRA model and that 

the PVNGS corrective action program already includes an action to install the automatic transfer 

switches in Unit 1 (APS 2009b). Since the basic event for failure of the automatic transfer 

switches is not on the Level 1 or Level 2 importance lists, confirming the APS statement that the 

static transfer switches have a low risk significance, the NRC staff agrees that a SAMA to install 

automatic static transfer switches in Unit 1 is not likely to be cost beneficial. 

Based on this information, the NRC staff concludes that the set of SAMAs evaluated in the ER, 

together with those identified in response to NRC staff RAIs, addresses the major contributors 

to internal event CDF. 

Although the IPEEE did not identify any fundamental vulnerabilities or weaknesses related to 

external events, three improvements related to internal fire events and one improvement related 

to seismic events were identified. The four improvements have been implemented at PVNGS 

(APS 2008a). 

In a further effort to identify external event SAMAs, APS reviewed the top 10 fire compartments 

contributing to fire CDF based on the results of the PVNGS Fire model. These compartments 

contribute over 92 percent (2.51 × 10-6 per year) of the total fire CDF (2.72 × 10-6 per year). The 

eleventh largest fire compartment contributes less than one percent of the total fire CDF. As a 

result of this review, APS identified five Phase I SAMAs to reduce fire risk (APS 2008a). The 

NRC staff concludes that the opportunity for fire-related SAMAs has been adequately explored 

and that it is unlikely that there are additional potentially cost-beneficial, fire-related SAMA 

candidates. 

For seismic events, APS reviewed the PVNGS IPEEE seismic results to determine if: (1) there 

were any unfinished plant enhancements required to ensure that the equipment on the safe 

shutdown list would be capable of withstanding the review level earthquake (RLE), (2) there 

were any additional plant enhancements that were identified to reduce seismic risk but were not 

implemented at PVNGS, and (3) there were any outlier issues that were screened in the IPEEE 

that could impact seismic risk. APS did not identify any additional SAMAs as a result of this 

review (APS 2008a). The NRC staff concludes that the opportunity for seismic-related SAMAs 

has been adequately explored and that it is unlikely that there are any cost-beneficial, seismicrelated SAMA candidates. 

As stated earlier, the APS IPEEE analysis of other external hazards (high winds, tornadoes, 

external floods, and other external events) did not identify opportunities for improvements for 

these events. However, APS’s review of the IPEEE analysis of tornado events revealed that the 

PVNGS design basis tornado was assumed to have a maximum wind speed of 360 miles per 

hour (mph) when the APS Updated Final Safety Analysis Report (UFSAR) describes the design 

basis tornado to have a maximum wind speed of 300 mph. APS developed a beyond design 

basis tornado CDF of 5.75 × 10-9 per year, estimated a cost-risk associated with this tornado 

frequency, and concluded that there were no plant improvements, including low-cost procedure 
Appendix F 

NUREG-1437, Supplement 43 F-20 December 2010

changes, that would be cost effective even if the entire tornado risk were eliminated. Based on 

this result and the results of the IPEEE, the licensee concluded that the other external hazards 

would be negligible contributors to overall core damage and did not consider any plant specific 

SAMAs for these events. 

The NRC staff questioned APS about lower cost alternatives to some of the SAMAs evaluated 

(NRC 2009), including: 

• Modify procedures to shed component cooling water (CCW) loads on loss of essential 

raw cooling water to extend component cooling water heat-up time. 

• Install backwash filters in place of existing service water pump discharge strainers to 

reduce probability of common cause failures. 

In response to the RAIs, APS addressed the suggested lower cost alternatives (APS 2009b). 

This is discussed further in Section F.6.2. 

The NRC staff notes that the set of SAMAs submitted is not all-inclusive, since additional, 

possibly even less expensive, design alternatives can always be postulated. However, the NRC 

staff concludes that the benefits of any additional modifications are unlikely to exceed the 

benefits of the modifications evaluated and that the alternative improvements would not likely 

cost less than the least expensive alternatives evaluated, when the subsidiary costs associated 

with maintenance, procedures, and training are considered. 

The NRC staff concludes that APS used a systematic and comprehensive process for 

identifying potential plant improvements for PVNGS, and that the set of SAMAs evaluated in the 

ER, together with those evaluated in response to NRC staff inquiries, is reasonably 

comprehensive and, therefore, acceptable. This search included reviewing insights from the 

plant-specific risk studies, and reviewing plant improvements considered in previous SAMA 

analyses. While explicit treatment of external events in the SAMA identification process was 

limited, it is recognized that the prior implementation of plant modifications for fire risks and the 

absence of external event vulnerabilities reasonably justifies examining primarily the internal 

events risk results for this purpose. 

F.4 RISK REDUCTION POTENTIAL OF PLANT IMPROVEMENTS 

APS evaluated the risk-reduction potential of the 13 remaining SAMAs that were applicable to 

PVNGS. The SAMA evaluations were performed using realistic assumptions with some 

conservatism. On balance, such calculations overestimate the benefit and are conservative.

APS used model re-quantification to determine the potential benefits. The CDF and population 

dose reductions for internal events were estimated using the PVNGS PRA model, Rev. 15. The 

fire CDF reduction for fire events was estimated using the PVNGS Fire PRA model. The 

population dose reduction for fire events was not directly calculated since the fire PRA model 

does not include a Level 2 model. Rather, it was assumed that the reduction in total fire risk for 

each SAMA was directly proportional to the calculated reduction in fire CDF for each SAMA. 

The changes made to the model to quantify the impact of SAMAs are detailed in Section D.6 of 

Attachment D to the ER (APS 2008a). Table F-5 lists the assumptions considered to estimate 

the risk reduction for each of the evaluated SAMAs, the estimated risk reduction in terms of 
Appendix F 

December 2010 F-21 NUREG-1437, Supplement 43 

 

percent reduction in CDF and population dose, and the estimated total benefit (present value) of 

the averted risk. The estimated benefits reported in Table F-5 reflect the combined benefit in 

both internal and external events. The determination of the benefits for the various SAMAs is 

further discussed in Section F.6. 

The NRC staff questioned the assumptions used in evaluating the benefits or risk reduction 

estimates of certain SAMAs provided in the ER (NRC 2009). For example, SAMA 6, “develop 

procedures to guide recovery actions for spurious electrical protection faults,” SAMA 11, 

“alternate cooling flow to SDC heat exchangers,” and SAMA 13, “mitigate loss of Turbine 

Building Cooling Water (TCW) events: provide permanent, hard-piped connections between the 

fire protection system and critical loads,” were each reported in the ER to result in no reduction 

in fire CDF. In response to an RAI, APS explained that the basic events addressed by SAMAs 

6 and 13 do contribute to the PVNGS fire CDF but that their contribution is very low (APS 

2009b). Relative to SAMA 11, APS explained that since the enhancement is to use fire water to 

provide an alternate means of cooling the shutdown cooling system (SDC) heat exchangers, 

this enhancement cannot be credited to mitigate fire events because the availability of fire water 

is already credited in the fire PRA to provide fire suppression. SAMA 11 therefore provides no 

reduction in fire CDF. The NRC staff considers the assumptions, as clarified, to be reasonable 

and acceptable for purposes of the SAMA evaluation. 

In another RAI, the NRC staff noted that the approach used by APS to calculate the reduction in 

fire risk (based on the percent fire CDF reduction) is not conservative for SAMAs in which the 

benefit is dominated by the reduction in population dose risk or offsite economic cost risk, and 

requested that APS provide an assessment of the impact of this non-conservative approach on 

the SAMA analysis (NRC 2009). In response to the RAI, APS agreed that the reduction in 

population dose risk and offsite economic cost risk results for SAMA 4, “SBO mitigation (gas 

turbine generator system (GTGS) not available),” SAMA 8, “add auto start/load capability to the 

GTGS,” and SAMA 15, “100 percent capacity battery chargers,” would be greater than the 

reduction in internal event CDF because a disproportionate portion of the CDF for these SAMAs 

is allocated to release categories that contribute a large portion of the population dose risk 

and/or offsite economic cost risk for PVNGS (APS 2009b). APS further provided a revised 

evaluation of SAMA 4, SAMA 8, and SAMA 15, assuming the reduction in fire risk was 

proportional to the smaller of: (1) the ratio of the internal events population dose calculated for 

the SAMA to the baseline population dose or (2) the ratio of the internal events offsite economic 

risk for the SAMA to the baseline offsite economic risk (APS 2009b). The NRC staff considers 

the revised approach for SAMAs 4, 8, and 15 to be reasonable and conservative for purposes of 

the SAMA evaluation. The results of the revised evaluations of these SAMAs are described in 

Section F.6.2. 

For SAMA 17, “modify the procedures to preclude reactor coolant pump (RCP) operations that 

would clear the water seals in the cold leg after core damage,” which was identified to mitigate 

temperature-induced SGTR events, there was no reduction in internal or fire CDF since 

changes were only made to the Level 2 model. However, temperature-induced STGR 

scenarios can also occur in fire scenarios. To account for the reduction in fire risk from this 

SAMA, the reduction in total fire risk was assumed to be directly proportional to the reduction in 

the steam generator tube rupture (SGTR) release category frequency in internal events. 

For the SAMAs that specifically address fire events (i.e., SAMAs 19, 20, 21, and 22), a 

bounding estimate of the SAMA benefits was made. The steps used to perform this calculation 

involved estimating: the approximate contribution to total cost-risk (MACR) from external 

events; the fraction of the external event cost-risk attributable to fire events; and the portion of 
Appendix F 

NUREG-1437, Supplement 43 F-22 December 2010

the fire-related cost-risk attributable to fire compartments affected by the candidate SAMA. APS 

conservatively assumed that all of the risk associated with all fire compartments affected by the 

SAMA is eliminated. (Because population dose was not directly calculated, this is noted as “Not 

Estimated” in Table G-5). These SAMAs were assumed to have no additional benefits in 

internal events. 

The NRC staff has reviewed APS’s bases for calculating the risk reduction for the various plant 

improvements and concludes that the rationale and assumptions for estimating risk reduction 

are reasonable and generally conservative (i.e., the estimated risk reduction is higher than what 

would actually be realized). Accordingly, the NRC staff based its estimates of averted risk for 

the various SAMAs on APS’s risk reduction estimates. 
Appendix F 

December 2010 F-23 NUREG-1437, Supplement 43 

 

Table F-5. SAMA Cost/Benefit Screening Analysis for PVNGS(a)

SAMA Assumptions 

 % Risk Reduction Total Benefit ($)(b)

Cost ($)

CDF(d) Population

Dose 

Baseline 

(Internal + 

External) 

Baseline With 

Uncertainty 

4 – SBO Mitigation 

(gas turbine generators 

(GTGs) not available) 

Modify fault tree to include a new 

basic event, having a failure 

probability of 5.0E-02, representing 

the unavailability of the new 480V AC 

generator. 

IE: 20

Fire: 

2 

34 1.8M(c) 4.8M(c) 5.5M 

5 – Install an 

Automatic Transfer 

Switch for the NonSafety Auxiliary 

Feedwater (AFW) 

Pump (AFN-P01) 

Power Supply 

Modify fault tree to include 

connection of the existing AFN-P01 

logic to the existing alternate power 

supply logic for AFW Train B. 

IE: 19

Fire: 

62 

16 1.6M 4.4M 6.8M 

6 – Develop 

Procedures to Guide 

Recovery Actions for 

Spurious Electrical 

Protection Faults 

Reduce the probability that 

spurious electrical protection on 

Train A and B engineered safety 

feature (ESF) buses locks out all 

power sources from 6.50E-06 to 0. 

IE: 10

Fire: 

0 

9 490K 1.3M 360K 

8 – Add Auto 

Start/Load Capability 

to the GTGs 

Reduce the probability of failure to 

operate the GTGs from 1.6E-01 to 

5.0E-04 in the internal events 

model and from 4.8E-01 to 5.0E-04 

in the fire model. 

IE: 8 

Fire: 

7 

22 1.4M(c) 3.8M(c) 3.1M 

10 – Provide a Backup 

AFW Start Signal on a 

Lower Steam 

Generator (SG) Level 

and Use it for all Three 

AFW Pumps 

Reduce the probability of failure to 

operate the non-safety AFW (AFN) 

pump to 5.0E-04 and modify the fault 

tree to “AND” auto-start of the nonsafety AFW pump to auto-start of the 

safety-related AFW pumps. 

IE: 9 

Fire: 

5 

5 370K 1.0M 3.0M 

11 – Alternate Cooling 

Flow to Shutdown 

Cooling (SDC) Heat 

Exchangers 

Modify fault tree to include 

connection of the fire protection 

system to the SDC heat exchangers 

and a new basic event, having a 

failure probability of 5.0E-02, 

representing both hardware and 

operator alignment failure. 

IE: 2 

Fire: 

0 

4 170K 450K 3.0M 

12 – Install an 

Automatic Transfer 

Switch for the AFW 

Pump AFB-P01 Power 

Supply 

Modify fault tree to include 

connection of the existing AFB-P01 

logic to the existing alternate power 

supply logic for AFW Train A. 

IE: 15

Fire: 

23 

11 890K 2.4M 6.8M 

13 – Mitigate Loss of 

Turbine Building 

Cooling Water (TCW) 

Events: Provide 

Permanent, Hardpiped Connections 

Between the Fire 

Protection System and 

Critical Loads 

Reduce the probability of loss of 

TCW initiating event from 8.92E-03 

to 8.92E-04. Modify fault tree to 

include connection of the fire 

protection system to the critical loads 

and a new basic event, having a 

probability of failure of 1.0E-02, 

representing both hardware and 

operator alignment failure. 

IE: 2 

Fire: 

0 

1 63K 170K 3.0M 
Appendix F 

NUREG-1437, Supplement 43 F-24 December 2010

SAMA Assumptions 

 % Risk Reduction Total Benefit ($)(b)

Cost ($)

CDF(d) Population

Dose 

Baseline 

(Internal + 

External) 

Baseline With 

Uncertainty 

14 – Provide a 

Permanent, Hardpiped Suction Line 

from the Reactor 

Makeup Water Tank 

(RMWT) to AFN-P01 

Modify fault tree to include 

connection of the RMWT to AFW and 

a new HEP event, having a failure 

probability of 2.3E-03, representing 

failure of the operator to align AFW to 

RMWT. 

IE: 3 

Fire: 

2 

2 140K 380K 6.6M 

15 – 100 Percent 

Battery Chargers 

Modify fault tree to include the DC 

battery chargers as a viable power 

source for most loads. 

IE: 4 

Fire: 

3 

9 580K(c) 1.56M(c) 1.64M 

17 – Modify the 

Procedures to 

Preclude RCP 

Operations that 

would Clear the 

Water Seals in the 

Cold Leg after Core 

Damage 

Reduce the probability that the 

RCP loop seal will be cleared after 

core damage from 1.4E-01 to 1.4E02. 

IE: 0 

Fire: 

0 

2 240K 650K 410K 

19 – Install Heat 

Sensors at Likely 

Ignition Sources to 

Allow Early Automatic 

Suppression Initiation 

Eliminate all fire risk for fire 

compartments FZ 5A and FZ 5B. 

IE: 0 

Fire: 

14 

Not 

Estimated 

180K 480K 4.7M 

20 – Install Fire 

Barriers Between Fire 

Zone TB1 and TB5 

Eliminate all fire risk for fire 

compartment FZ TB5. 

IE: 0 

Fire: 

7 

Not 

Estimated 

83K 220K 3.6M 

21 – Install Fire 

Resistant Cable Wrap 

on Selected Cables in 

Fire Compartment 

TB4B 

Eliminate all fire risk for fire 

compartment FZ TB4B. 

IE: 0 

Fire: 

1 

Not 

Estimated 

15K 41K 3.4M 

22 – Enhance the 

MCC M71 Fire Barriers 

Eliminate all fire risk for fire 

compartment FZ 42A. 

IE: 0 

Fire: 

1 

Not 

Estimated 

14K 37K 3.3M 

23 – Enhance 

Procedures to Direct 

Steam Generator 

Flooding for Release 

Scrubbing 

Eliminate all releases for 

sequences in which makeup to the 

steam generators is available. 

IE: 0 

Fire: 

0 

3 160K 440K 420K 

(a) SAMAs in bold are potentially cost-beneficial. 

(b) Estimated benefits reflect revised values provided in response to NRC staff RAI 3.c (APS 2009b). 

(c) Estimated benefits reflect revised values provided in response to NRC staff RAI 5.a.ii (APS 2009b). 

(d) IE: internal events; Fire: internal fire events. 
Appendix F 

December 2010 F-25 NUREG-1437, Supplement 43 

 

F.5 COST IMPACTS OF CANDIDATE PLANT IMPROVEMENTS 

APS estimated the costs of implementing the 13 candidate SAMAs through the development of 

site-specific cost estimates and use of other licensees’ estimates for similar improvements. The 

cost estimates conservatively did not include the cost of replacement power during extended 

outages required to implement the modifications (APS 2008a). The cost estimates provided in 

the ER did not account for inflation, which is considered another conservatism. 

The NRC staff reviewed the bases for the applicant’s cost estimates (presented in Table D.5-3 

of Attachment D to the ER and in APS 2008c). For certain improvements, the NRC staff also 

compared the cost estimates to estimates developed elsewhere for similar improvements, 

including estimates developed as part of other licensees’ analyses of SAMAs for operating 

reactors. The NRC staff noted that the estimated cost of $1.8M for SAMA 4, “SBO Mitigation 

(GTGs not available),” is significantly higher than the estimated cost of $230K to $494K for 

similar improvements evaluated as SAMAs at three other plants that have applied to the NRC 

for license renewal, i.e., Susquehanna, Brunswick, and Indian Point nuclear power plants (NRC 

2009). In response to the RAI, APS clarified that the APS portable 480V AC generator must be 

capable of supporting a battery charger for long-term auxiliary feedwater operation and at least 

two charging pumps for reactor coolant system makeup (APS 2009b). APS further noted that 

the size of this portable generator is larger than the portable generators evaluated for the other 

plants because those portable generators were only needed to maintain control power and level 

instrumentation. APS estimated the cost to just procure each portable generator to be $640K. 

The NRC staff considers the estimated cost for PVNGS to be reasonable and acceptable for 

purposes of the SAMA evaluation. 

APS stated in the ER that the estimated cost of $360K, $410K, and $420K for SAMA 6,

“develop procedures to guide recovery actions for spurious electrical protection faults,” SAMA 

17, “modify the procedures to preclude RCP operations that would clear the water seals in the 

cold leg after core damage,” and SAMA 23, “enhance procedures to direct steam generator 

flooding for release scrubbing,” respectively, are significantly higher than the $50K to $100K 

generally assumed in other SAMA analyses for new or modified procedures because the scope 

of the PVNGS procedures is greater than the scope of the industry procedure SAMAs, which 

involve only minor procedure modifications (APS 2008a). In response to an NRC staff RAI 

requesting further clarification and justification for the cost of these procedure SAMAs, APS 

stated that it has decided to implement these SAMAs at PVNGS and that further evaluation of 

these SAMAs is therefore not necessary (APS 2009b). Although the NRC staff believes that the 

cost estimates for these procedure-related SAMAs appear high, given that these SAMAs were 

determined to be potentially cost beneficial even with a high implementation cost, and that APS 

has committed to implement these SAMAs, the NRC staff finds this response acceptable.

The NRC staff requested additional clarification on why the estimated cost of $2.3M is the same 

for both SAMA 5, “install an automatic transfer switch for the non-safety AFW pump (AFN-P01) 

power supply,” and SAMA 12, “install an automatic transfer switch for the AFW Pump AFB-P01 

power supply,” when SAMA 5 involves installation of a non-safety automatic transfer switch 

while SAMA 12 involves installation of a safety-related transfer switch (NRC 2009). In response 

to the RAI, APS clarified that the these estimates were “order of magnitude” estimates not 

developed at a sufficient level of detail to distinguish between the design differences for the two 

SAMAs (APS 2009b). APS further noted that since the cost estimate for SAMA 5 is 

substantially higher than the estimated benefit (even after accounting for both external events 

and uncertainty), a more in-depth cost analysis would not likely reduce the cost estimate 

sufficiently to result in the SAMA becoming cost beneficial. The NRC staff further questioned 
Appendix F 

NUREG-1437, Supplement 43 F-26 December 2010

why the cost of installing the automatic transfer switches for the AFW pumps was $2.3M when 

the estimated implementation cost for installing automatic transfer switches for the vital AC on 

Unit 1 was $180K. APS responded that the cost difference was due to significant differences in 

the scope of the modifications, including: (1) the engineering work for the vital AC switches has 

already been completed since the transfer switches have already been installed in Units 2 and 

3; (2) larger voltage breakers are required for the AFW pumps due to significantly higher 

electrical load and voltage that the AFW pump switches would have to transfer; (3) the 4.16 kV 

switchgear may need to be expanded to provide capacity for the AFW pump breakers; (4) an 

Appendix R electrical panel for the emergency diesel generator B may need to be relocated to 

provide room for the AFW pump transfer switch modification; (5) installation of the AFW pump 

transfer switches will require numerous changes to electrical calculations and procedures, new 

medium voltage cabling, and power supply interlocks not required for the vital AC transfer 

switches; and (6) new wiring may need to be run into the main control room for the AFW pump 

transfer switch modification (APS 2010). Based on this additional information, the NRC staff 

considers these estimated costs to be reasonable and acceptable for purposes of the SAMA 

evaluation. 

The NRC staff concludes that the cost estimates provided by APS are sufficient and appropriate 

for use in the SAMA evaluation. 

F.6 COST-BENEFIT COMPARISON 

PVNGS cost-benefit analysis and the NRC staff’s review are described in the following sections. 

F.6.1 APS’s Evaluation 

The methodology used by APS was based primarily on NRC’s guidance for performing 

cost-benefit analysis, i.e., NUREG/BR-0184, Regulatory Analysis Technical Evaluation 

Handbook (NRC 1997a). The guidance involves determining the net value for each SAMA 

according to the following formula: 

Net Value = (APE + AOC + AOE + AOSC) - COE where, 

APE = present value of averted public exposure ($) 

AOC = present value of averted offsite property damage costs ($) 

AOE = present value of averted occupational exposure costs ($) 

AOSC = present value of averted onsite costs ($) 

COE = cost of enhancement ($). 

If the net value of a SAMA is negative, the cost of implementing the SAMA is larger than the 

benefit associated with the SAMA and it is not considered cost beneficial. APS’s derivation of 

each of the associated costs is summarized below. 

NUREG/BR-0058 has recently been revised to reflect the agency's policy on discount rates. 

Revision 4 of NUREG/BR-0058 states that two sets of estimates should be developed, one at 

3 percent and one at 7 percent (NRC 2004a). APS provided a base set of results using the 

3 percent discount rate and a sensitivity study using the 7 percent discount rate (APS 2008a). 
Appendix F 

December 2010 F-27 NUREG-1437, Supplement 43 

 

Averted Public Exposure (APE) Costs

The APE costs were calculated using the following formula: 

APE = Annual reduction in public exposure (Δ person-rem per year) 

x monetary equivalent of unit dose ($2000 per person-rem) 

x present value conversion factor (15.04 based on a 20-year period with a 

 3-percent discount rate). 

As stated in NUREG/BR-0184 (NRC 1997a), it is important to note that the monetary value of 

the public health risk after discounting does not represent the expected reduction in public 

health risk due to a single accident. Rather, it is the present value of a stream of potential 

losses extending over the remaining lifetime (in this case, the renewal period) of the facility. 

Thus, it reflects the expected annual loss due to a single accident, the possibility that such an 

accident could occur at any time over the renewal period, and the effect of discounting these 

potential future losses to present value. For the purposes of initial screening, which assumes 

elimination of all severe accidents due to internal events, APS calculated an APE of 

approximately $410,000 for the 20-year license renewal period (APS 2008a). 

Averted Offsite Property Damage Costs (AOC)

The AOCs were calculated using the following formula: 

AOC = Annual CDF reduction 

x offsite economic costs associated with a severe accident (on a per-event basis) 

x present value conversion factor. 

For the purposes of initial screening, which assumes all severe accidents due to internal events 

are eliminated, APS calculated an annual offsite economic risk of about $14,900 based on the 

Level 3 risk analysis. This results in a discounted value of approximately $225,000 for the 

20-year license renewal period (APS 2008a). 

Averted Occupational Exposure (AOE) Costs 

The AOE costs were calculated using the following formula: 

AOE = Annual CDF reduction 

 x occupational exposure per core damage event 

 x monetary equivalent of unit dose 

 x present value conversion factor. 

APS derived the values for averted occupational exposure from information provided in 

Section 5.7.3 of the regulatory analysis handbook (NRC 1997a). Best estimate values provided 

for immediate occupational dose (3300 person-rem) and long-term occupational dose 

(20,000 person-rem over a 10-year cleanup period) were used. The present value of these 

doses was calculated using the equations provided in the handbook in conjunction with a 

monetary equivalent of unit dose of $2000 per person-rem, a real discount rate of 3 percent, 

and a time period of 20 years to represent the license renewal period. For the purposes of initial 

screening, which assumes all severe accidents due to internal events are eliminated, APS 

calculated an AOE of approximately $3,100 for the 20-year license renewal period (APS 2008a). 
Appendix F 

NUREG-1437, Supplement 43 F-28 December 2010

Averted Onsite Costs

Averted onsite costs (AOSC) include averted cleanup and decontamination costs and averted 

power replacement costs. Repair and refurbishment costs are considered for recoverable 

accidents only and not for severe accidents. APS derived the values for AOSC based on 

information provided in Section 5.7.6 of NUREG/BR-0184, the regulatory analysis handbook 

(NRC 1997a). 

APS divided this cost element into two parts–the onsite cleanup and decontamination cost, also 

commonly referred to as averted cleanup and decontamination costs, and the replacement 

power cost. 

Averted cleanup and decontamination costs (ACC) were calculated using the following formula: 

ACC = Annual CDF reduction 

 x present value of cleanup costs per core damage event 

 x present value conversion factor. 

The total cost of cleanup and decontamination subsequent to a severe accident is estimated in 

the regulatory analysis handbook to be $1.5 x 109

 (undiscounted). This value was converted to 

present costs over a 10-year cleanup period and integrated over the term of the proposed 

license extension. For the purposes of initial screening, which assumes all severe accidents 

due to internal events are eliminated, APS calculated an ACC of approximately $99,000 for the 

20-year license renewal period. 

Long-term replacement power costs (RPC) were calculated using the following formula: 

 

 RPC = Annual CDF reduction 

 x present value of replacement power for a single event 

x factor to account for remaining service years for which replacement power is 

 required 

 x reactor power scaling factor 

APS based its calculations on the rated PVNGS net electric output of 1338 megawatt-electric 

(MWe) per unit and scaled up from the 910 MWe reference plant in NUREG/BR-0184 (NRC 

1997). Therefore APS applied a power scaling factor of 1338/910 to determine the replacement 

power costs. For the purposes of initial screening, which assumes all severe accidents due to 

internal events are eliminated, APS calculated an RPC of approximately $41,000 and an AOSC 

of approximately $140,000 for the 20-year license renewal period (APS 2008a). 

Using the above equations, APS estimated the total present dollar value equivalent associated 

with completely eliminating severe accidents from internal events at PVNGS to be about 

$778,000 for a single unit. Use of a multiplier of 2.0 to account for external events increases the 

value to $1,556,000. Because all SAMA costs and benefits were provided on a site basis, APS 

tripled this value to obtain the three-unit site value of $4,668,000. This represents the dollar 

value associated with completely eliminating all internal and external event severe accident risk 

at all three PVNGS units, and is also referred to as the Modified Maximum Averted Cost Risk 

(MMACR).
Appendix F 

December 2010 F-29 NUREG-1437, Supplement 43 

 

APS’s Results

If the implementation costs for a candidate SAMA exceeded the calculated benefit, the SAMA 

was considered not to be cost beneficial. In the baseline analysis contained in the ER (using a 

3 percent discount rate), APS identified no potentially cost-beneficial SAMAs. Based on the 

consideration of analysis uncertainties, APS identified two potentially cost-beneficial SAMAs 

(SAMAs 6 and 17). In response to NRC staff RAIs, APS provided the results of revised 

baseline and uncertainty analyses in which the multipliers used to account for additional SAMA 

benefits in external events were increased to account for a potentially larger seismic CDF. Use 

of the revised multipliers resulted in identification of one potentially cost-beneficial SAMA in the 

baseline analysis (SAMA 6), and two potentially cost-beneficial SAMAs when uncertainties are 

considered (SAMAs 17 and 23). 

In response to another NRC staff RAI, APS provided the results of a revised baseline and 

uncertainty analyses for three SAMAs assuming the reduction in fire risk was proportional to the 

smaller of: (1) the ratio of the internal events population dose calculated for the SAMA to the 

baseline population dose or (2) the ratio of the internal events offsite economic risk for the 

SAMA to the baseline offsite economic risk. The revised uncertainty analysis resulted in the 

identification of one additional potentially cost-beneficial SAMA (SAMA 8). 

The potentially cost-beneficial SAMAs are: 

• SAMA 6 – Develop procedures to guide recovery actions for spurious electrical 

protection faults. 

• SAMA 8 – Add auto start/load capability to the GTGS. 

• SAMA 17 – Modify the procedures to preclude RCP operations that would clear the 

water seals in the cold leg after core damage. 

• SAMA 23 – Enhance procedures to direct steam generator flooding for release 

scrubbing. 

The potentially cost-beneficial SAMAs, and APS’s plans for further evaluation of these SAMAs 

are discussed in more detail in Section F.6.2. 

F.6.2 Review of APS’s Cost-Benefit Evaluation 

The cost-benefit analysis performed by APS was based primarily on NUREG/BR-0184 

(NRC 1997a) and discount rate guidelines in NUREG/BR-0058 (NRC 2004), and was executed 

consistent with this guidance. 

SAMAs identified primarily on the basis of the internal events analysis could provide benefits in 

certain external events, in addition to their benefits in internal events. APS accounted for the 

potential risk reduction benefits associated with external events by applying a multiplier to the 

estimated benefits for internal events. As previously discussed, in the Phase I analysis reported 

in the ER, APS multiplied the estimated benefits for internal events by a factor of 2.0 to account 

for external events, and in the Phase II analysis separately quantified the internal event and fire 

event benefits and estimated the benefits in non-fire external events by applying a multiplier of 

0.464 to the internal events benefits. For fire-related SAMAs (SAMAs 19 through 22), APS 
Appendix F 

NUREG-1437, Supplement 43 F-30 December 2010

separately estimated the risk reduction benefits using the PVNGS Fire PRA model. The 

estimated SAMA benefits for internal events, fire events, and non-fire external events were then 

summed to provide an overall benefit. In response to NRC staff RAIs, APS revised the Phases I 

and II analyses to reflect a higher seismic CDF as discussed in Section F.2.2 (APS 2009b). For 

the Phase I analysis, APS multiplied the estimated benefits for internal events by a factor of 2.5 

to account for external events (based on a seismic CDF of 4.75 × 10-6 per year, a fire CDF of 

2.72 × 10-6 per year, a negligible contribution from other external events, and an internal events 

CDF of 5.07 × 10-6 per year). Similarly, for the Phase II analysis, APS multiplied the estimated 

benefits for internal events by a factor of 0.955 to account for non-fire external events (based on 

a seismic CDF of 4.75 × 10-6 per year, a negligible contribution from other external events, and 

an internal events CDF of 5.07 × 10-6 per year). As a result of the revised baseline analysis of 

the Phase I and II SAMAs (using a 3 percent real discount rate), APS found one SAMA (SAMA 

6, as described above) to be potentially cost beneficial. In response to NRC staff RAI 5.c, APS 

committed to implement this SAMA at PVNGS (APS 2009b). 

APS considered the impact that possible increases in benefits from analysis uncertainties would 

have on the results of the SAMA assessment. In the ER and in response to NRC staff RAIs, 

APS presents the results of an uncertainty analysis of the internal events CDF which indicates 

that the 95th percentile value is a factor of 2.7 times the point estimate CDF for PVNGS. APS 

considered whether any additional Phase I SAMAs might be retained for further analysis if the 

benefits from internal events, fire events, and non-fire external events were increased by a 

factor of 2.7. Seven such SAMAs were identified: 

• SAMA 2 – Replace one low pressure condensate pump with a high pressure motor 

driven pump (or add a booster pump) and add hotwell makeup controls to the main 

control room (MCR) from a non-condensate storage tank (CST) source. 

• SAMA 3 – Install an independent AFW system with a dedicated power supply. 

• SAMA 5 – Install an automatic transfer switch for the non-safety AFW pump (AFN-P01) 

power supply. 

• SAMA 7 – Add auto start capability to AFN-P01 on low steam generator level and an 

automatic power transfer switch to address loss of main feedwater (MFW) cases with 

Division 1 power failures and operator start errors. 

• SAMA 9 – Install a backup control element assembly drive mechanism. 

• SAMA 12 – Install an automatic transfer switch for the AFW pump AFB-P01 power 

supply. 

• SAMA 14 – Provide a permanent, hard-piped suction line from the RMWT to AFN-P01. 

However, based on further consideration of the limited benefit of eliminating the events 

addressed by SAMAs 2, 3, 7, and 9, APS concluded that these four SAMAs would not be cost 

beneficial even if they were completely reliable. The specific rationale is provided in the 

response to NRC staff RAI 3.c (APS 2009b). The NRC staff considers the applicant’s rationale 

for eliminating SAMAs 2, 3, 7, and 9 from further consideration in the Phase II evaluation to be 

reasonable. 
Appendix F 

December 2010 F-31 NUREG-1437, Supplement 43 

 

APS also considered the impact on the Phase II screening if the estimated benefits from internal 

events, fire events, and non-fire external events were increased by a factor of 2.7. The 

additional Phase I SAMAs, SAMA 5, 12 and 14 as described above, were included in this 

sensitivity analysis. Two SAMAs became cost beneficial in APS’s analysis (SAMAs 17 and 23, 

as described above). Although not cost-beneficial in the baseline analysis, APS has committed 

to implement these two SAMAs at PVNGS (APS 2009b). 

APS provided the results of additional sensitivity analyses in the ER, including use of a 

7 percent discount rate and variations in MACCS2 input parameters. These analyses did not 

identify any additional potentially cost-beneficial SAMAs (APS 2008a). 

As discussed in Section F.4, in response to an NRC staff RAI, APS provided a revised 

evaluation of SAMA 4, “SBO mitigation (gas turbine generator system (GTGS) not available),” 

SAMA 8, “add auto start/load capability to the GTGS,” and SAMA 15, “100 Percent battery 

chargers,” assuming the reduction in fire risk was proportional to the smaller of (1) the ratio of 

the internal events population dose calculated for the SAMA to the baseline population dose or 

(2) the ratio of the internal events offsite economic risk for the SAMA to the baseline offsite 

economic risk (APS 2009b). As a result of the revised baseline and uncertainty analysis for 

these Phase II SAMAs (using a 3 percent real discount rate), SAMA 8 became potentially cost 

beneficial. In response to a follow-up NRC staff RAI, APS stated that SAMA 8 would be 

considered for further implementation at PVNGS (APS 2010). 

As indicated in Section F.3.2, for certain SAMAs considered in the ER, there may be 

alternatives that could achieve much of the risk reduction at a lower cost (NRC 2009). The NRC 

staff asked the applicant to evaluate additional lower cost alternatives to the SAMAs considered 

in the ER, as summarized below: 

• Modify procedures to shed CCW loads on loss of essential raw cooling water to extend 

component cooling water heat-up time. In response to the NRC staff RAI, APS noted 

that for many nuclear plants, loss of the essential raw water cooling system results in 

failure of: (1) RCP seal cooling, which requires essential raw water for heat removal, 

and (2) RCP seal injection, which is provided by the charging pumps and which, in turn, 

requires essential raw water to provide pump or lube oil cooling (APS 2009b). APS 

clarified that for PVNGS, the essential cooling water system provides backup cooling to 

the nuclear cooling water system, which provides RCP seal cooling. APS reviewed the 

basic events importance lists and determined that the loss of nuclear cooling water 

initiating event has a Level 1 RRW of 1.002 and a Level 2 RRW of 1.001, both of which 

are well below the RRW cutoff threshold of 1.01 used by APS to identify basic events for 

which SAMAs would have the greatest potential for reducing risk. APS further clarified 

that the PVNGS charging pumps do not require a separate system to provide cooling 

and therefore loss of essential cooling water does not result in a loss of seal injection. 

Based on this logic, APS concluded that no further evaluation of this alternative is 

warranted. The NRC staff agrees with this conclusion. 

• Install backwash filters in place of existing service water pump discharge strainers to 

reduce probability of common cause failures. In response to the NRC staff RAI, APS 

clarified that the functions provided by the service water system at other plants appears 

to be provided by the essential spray pond at PVNGS (APS 2009b). APS further 

indicated that common cause plugging or blocking of the discharge path in the PVNGS 

essential spray pond system has not been identified as a contributor to severe accident 
Appendix F 

NUREG-1437, Supplement 43 F-32 December 2010

risk at PVNGS. As a result, APS did not identify a SAMA to address essential spray 

pond discharge path plugging. The NRC staff concludes that this alternative has been 

adequately addressed. 

The NRC staff notes that all of the potentially cost-beneficial SAMAs (SAMAs 6, 8, 17, and 23) 

identified in APS’s original or revised baseline or uncertainty analyses are included within the 

set of SAMAs that APS plans to further evaluate for implementation. The NRC staff concludes 

that, with the exception of the potentially cost-beneficial SAMAs discussed above, the costs of 

the other SAMAs evaluated would be higher than the associated benefits. 

F.7 CONCLUSIONS 

APS compiled a list of 23 SAMAs based on a review of the most significant basic events from 

the plant-specific PRA, insights from the plant-specific IPE and IPEEE, Phase II SAMAs from 

license renewal applications for other plants, and review of other industry documentation. An 

initial screening removed SAMA candidates that (1) are not applicable to APS due to design 

differences or have already been implemented at PVNGS, or (2) have estimated implementation 

costs that would exceed the dollar value associated with completely eliminating all severe 

accident risk at PVNGS. Based on this screening, 10 SAMAs were eliminated leaving 13 

candidate SAMAs for evaluation. 

For the remaining SAMA candidates, a more detailed design and cost estimate were developed 

as shown in Table F-5. The cost-benefit analyses, as revised in response to NRC staff RAIs, 

showed that one of the SAMA candidates was potentially cost beneficial in the baseline analysis 

(i.e., SAMA 6). APS performed additional analyses to evaluate the impact of parameter choices 

and uncertainties on the results of the SAMA assessment. As a result, two additional SAMAs 

were identified as potentially cost beneficial (SAMAs 17 and 23). In response to another NRC 

staff RAI regarding the method used to assess the fire-related population dose and offsite 

economic cost reduction for certain SAMAs, APS identified one additional potentially costbeneficial SAMA (SAMA 8). APS has committed to implement the first three SAMAs (SAMA 6, 

17, and 23) and also indicated that it will further consider the last SAMA (SAMA 8) for potential 

implementation. 

The NRC staff reviewed the APS analysis and concludes that the methods used and the 

implementation of those methods was sound. The treatment of SAMA benefits and costs 

support the general conclusion that the SAMA evaluations performed by APS are reasonable 

and sufficient for the license renewal submittal. Although the treatment of SAMAs for external 

events was somewhat limited, the likelihood of there being cost-beneficial enhancements in this 

area was minimized by improvements that have been realized as a result of the IPEEE process, 

separate analysis of fire events and fire-related SAMAs, and inclusion of a multiplier to account 

for non-fire external events. 

The NRC staff concurs with APS’s identification of areas in which risk can be further reduced in 

a cost-beneficial manner through the implementation of the identified, potentially cost-beneficial 

SAMAs. Given the potential for cost-beneficial risk reduction, the NRC staff agrees that further 

evaluation of these SAMAs by APS is warranted. However, these SAMAs do not relate to 

adequately managing the effects of aging during the period of extended operation. Therefore, 

they need not be implemented as part of license renewal pursuant to Title 10 of the Code of 

Federal Regulations, Part 54. 
Appendix F 

December 2010 F-33 NUREG-1437, Supplement 43 

 

F.8 REFERENCES 

Arizona (State of Arizona). 2003. Effects of Eliminating the Distinction Between Full Cash and 

Net Limited Property Value on Property Tax. Citizen’s Finance Review Commission. Available 

at: 

http://www.azcfrc.az.gov/files/CFRC%20Eliminating%20the%20Distiniction%20b_t%20Full%20

Costs%20...pdf. Accessed September 2003. 

Arizona (Arizona Department of Economic Security). 2006. Arizona Population Projections 

2006-2055. Research Administration, Population Statistics Unit. March 31, 2006. 

Arizona Public Service Company (APS). 1992. Letter from William F. Conway, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2 

and 3, Docket Nos. STN 50-528, 50-529, and 50-530, Submittal of PVNGS Individual Plant 

Examination for Severe Accident Vulnerabilities (Response to Generic Letter 88-20),” Phoenix, 

Arizona. April 28, 1992. ADAMS No. ML080040089 and ML082940053. 

Arizona Public Service Company (APS). 1995. Letter from William L. Stewart, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2 

and 3, Docket Nos. STN 50-528/529/530, Individual Plant Examination of External Events 

(IPEEE) for Severe Accident Vulnerabilities (Generic Letter No. 88-20, Supplement 4),” 

Phoenix, Arizona. June 30, 1995. ADAMS No. ML080040087. 

Arizona Public Service Company (APS). 2008a. Palo Verde Nuclear Generating Station, Units 

1, 2, and 3, Applicant’s Environmental Report, License Renewal Operating Stage. ADAMS No. 

ML083510615, Appendix E. 

Arizona Public Service Company (APS). 2008b. Letter from John H. Hesser, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2 

and 3, Docket Nos. STN 50-528, 50-529, and 50-530, Request for Amendment to Technical 

Specification 5.5.16, Containment Leakage Rate Testing Program,” Phoenix, Arizona. October 

1, 2008. ADAMS No. ML082820029. 

Arizona Public Service Company (APS). 2008c. Letter from William D. Chapin (APS) to Richard 

F. Schaller (APS), ID# 433-00524-WDC/mht, Phoenix, Arizona. July 2, 2008. 

Arizona Public Service Company (APS). 2009a. Letter from Dwight C. Mims, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Stations (PVNGS), Units 1, 

2 and 3, Docket Nos. STN 50-528, 50-529, and 50-530, Supplement 1 to License Renewal 

Application,” Phoenix, Arizona. April 10, 2009. ADAMS No. ML091130221. 

Arizona Public Service Company (APS). 2009b. Letter from John H. Hesser, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Stations (PVNGS), Units 1, 

2 and 3, Docket Nos. STN 50-528, 50-529, and 50-530, Response to Severe Accident 

Mitigation Alternatives for the Review of the PVNGS License Renewal Application, and License 

Renewal Application Amendment No. 2,” Phoenix, Arizona. November 10, 2009. ADAMS No. 

ML093230225. 

Arizona Public Service Company (APS). 2010. Letter from Dwight C. Mims, APS, to NRC 

Document Control Desk. Subject: “Palo Verde Nuclear Generating Stations (PVNGS), Units 1, 

2 and 3, Docket Nos. STN 50-528, 50-529, and 50-530, Follow-up Clarification to the Response 

to September 30, 2009, Request for Additional Information Regarding Severe Accident 

Mitigation Alternatives for the Review of the PVNGS License Renewal Application, and License 

Renewal Application Amendment No. 7,” Phoenix, Arizona. January 13, 2010. ADAMS No. 

ML100270290. 
Appendix F 

NUREG-1437, Supplement 43 F-34 December 2010

Electric Power Research Institute (EPRI). 1991. “A Methodology for Assessment of Nuclear 

Power Plant Seismic Margin,” EPRI NP-6041-SL, Revision 1. Palo Alto, CA. August 1991. 

Electric Power Research Institute (EPRI). 1995. “Fire PRA Implementation Guide,” EPRI TR105928. Palo Alto, CA. December 1995. 

Greater Phoenix Economic Council (GPEC). 2005. Arizona Property Classification and 

Assessment Ratios. Available at: 

http://www.nass.usda.gov/Census/Create_Census_US_CNTY.jsp. 

Maricopa (Maricopa County). 2005. Palo Verde Evacuation Time Analysis. 

U.S. Census Bureau (USCB). 2000. Census 2000 Summary File 1 (SF 1) 100-Percent Data. 

Available at: http://factfinder.gov. Accessed March 22, 2007. 

U.S. Department of Agriculture (USDA). 2004. “2002 Census of Agriculture.” Volume 1, 

Geographic Area Series. State-County Data. June 2002. Available at: 

http://www.nass.usda.gov/Census_of_Agriculture/index.asp. 

U.S. Department of Labor (USDL). 2007. Consumer Price Index Inflation Calculator. Bureau of 

Labor Statistics. Available at: http://www.bls.gov/cpi/home.htm. Accessed March 27, 2007. 

U.S. Nuclear Regulatory Commission (NRC). 1975. Standard Review Plan for the Review of 

Safety Analysis Report for Nuclear Power Plants. NUREG-0800. Washington, D.C. November 

1975. 

U.S. Nuclear Regulatory Commission (NRC). 1988. Generic Letter 88-20, “Individual Plant 

Examination for Severe Accident Vulnerabilities.” November 23, 1988. 

U.S. Nuclear Regulatory Commission (NRC). 1990. Severe Accident Risks: An Assessment 

for Five U.S. Nuclear Power Plants. NUREG-1150. Washington, D.C. 

U.S. Nuclear Regulatory Commission (NRC). 1991. Generic Letter No. 88-20, Supplement 4, 

Individual Plant Examination of External Events for Severe Accident Vulnerabilities, NUREG1407. Washington, D.C. June 28, 1991. 

U.S. Nuclear Regulatory Commission (NRC). 1994. “Staff Evaluation of the Palo Verde 

Nuclear Generating Station Individual Plant Examination (IPE) for Internal Events – Unit Nos. 1, 

2, and 3 (TAC No. M74445, M74446, and M74447).” Washington, D.C. July 1, 1994. 

U.S. Nuclear Regulatory Commission (NRC). 1997a. Regulatory Analysis Technical Evaluation 

Handbook. NUREG/BR-0184. Washington, D.C. 

U.S. Nuclear Regulatory Commission (NRC). 1997b. Individual Plant Examination Program: 

Perspectives on Reactor Safety and Plant Performance. NUREG-1560. Washington, D.C. 

U.S. Nuclear Regulatory Commission (NRC). 1998. Code Manual for MACCS2: Volume 1, 

User’s Guide. NUREG/CR-6613. Washington, D.C. May 1998. 

U.S. Nuclear Regulatory Commission (NRC). 1999. “Individual Plant Examination of External 

Events Review for the Palo Verde Nuclear Generating Station (TAC Nos. M83654, M83655, and 

M83656).” Washington, D.C. July 2, 1999. 

U.S. Nuclear Regulatory Commission (NRC). 2003. SECPOP2000: Sector Population, Land 

Fraction, and Economic Estimation Program. NUREG/CR-6525, Revision 1. Washington, D.C. 

August 2003. 

U.S. Nuclear Regulatory Commission (NRC). 2004a. Regulatory Analysis Guidelines of the 

U.S. Nuclear Regulatory Commission. NUREG/BR-0058, Rev. 4. Washington, D.C. 
Appendix F 

December 2010 F-35 NUREG-1437, Supplement 43 

 

U.S. Nuclear Regulatory Commission (NRC). 2004b. An Approach for Estimating the 

Frequencies of Various containment Failure modes and Bypass Events. NUREG/CR-6595 

Revision 1, Washington, D.C., 2004. 

U.S. Nuclear Regulatory Commission (NRC). 2007. “An Approach for Determining the 

Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities.” 

Regulatory Guide 1.200, Rev. 1 (January 2007) and Rev. 2 (March 2009). Washington, D.C. 

U.S. Nuclear Regulatory Commission (NRC). 2009. Letter from Lisa M. Regner, U.S. NRC, to 

Randall K. Edington, APS. Subject: Request for Additional Information for the Environmental 

Review of the Palo Verde Nuclear Generating Station License Renewal Application (ME0261, 

ME0262, and ME0263). September 30, 2009. ADAMS No. ML092470551. 

Westinghouse. Simplified Level 2 Modeling Guidelines, WCAP-16341-P, November 2005. 




UNITED STATES 

NUCLEAR REGULATORY COMMISSION

WASHINGTON, DC 20555-0001

--------------------

OFFICIAL BUSINESS
Final 

NUREG-1437, Supplement 43 Generic Environmental Impact Statement for License Renewal of

Nuclear Plants: Regarding Palo Verde Nuclear Generating Station 

January 2011