*U.S.NRC

United States Nuclear Regulatory Commission

NUREG/CR-7029

Protecting People and the Environment

Lessons Learned in

Detecting, Monitoring,

Modeling and Remediating

Radioactive Ground-Water

Contamination

Office of Nuclear Regulatory Research
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..qov/readinq-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 20402-0001

Internet: bookstore.gpo.gov

Telephone: 202-512-1800

Fax: 202-512-2250

2. The National Technical Information Service

Springfield, VA 22161-0002

www. ntis.gov

1-800-553-6847 or, locally, 703-605-6000

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: DISTRIBUTIONRESOURCE@NRC.GOV

Facsimile: 301-415-2289

Some publications in the NUREG series that are

posted at NRC's Web site address

http://www.nrc.qov/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 atThe NRC Technical Library

Two White Flint North

11545 Rockville Pike

Rockville, MD 20852-2738

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, fromAmerican National Standards Institute

11 West 42 "n Street

New York, NY 10036-8002

www.ansi.org

212-642-4900

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 (NUREG-XXXX) or agency contractors

(NUREG/CR-XXXX), (2) proceedings of

conferences (NUREG/CP-XXXX), (3) reports

resulting from international agreements

(NUREGtIA-XXXX), (4) brochures

(NUREG/BR-XXXX), 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

(NUREG-0750).

DISCLAIMER: This report was prepared as an account of work sponsored by an agency of the U.S. Government.

Neither the U.S. Government nor any agency thereof, nor any employee, makes any warranty, expressed or

implied, or assumes any legal liability or responsibility for any third party's use, or the results of such use, of any

information, apparatus, product, or process disclosed in this publication, or represents that its use by such third

party would not infringe privately owned rights.
* U.S.NRC

United States Nuclear Regulatory Commission

Protecting People and the Environment

NUREG/CR-7029

Lessons Learned in

Detecting, Monitoring,

Modeling and Remediating

Radioactive Ground-Water

Contamination

Manuscript Completed: December 2010

Date Published: April 2011

Prepared by

T. Sullivan, M. Hauptmann, and W. Gunther

Brookhaven National Laboratory

Upton, NY 11973-5000

J. Philip, NRC Project Manager

T. Nicholson, NRC Technical Monitor

NRC Job Code N6937

Office of Nuclear Regulatory Research
NUREG/CR-7029 has been

reproduced from the best available copy.
ABSTRACT

Brookhaven National Laboratory (BNL) is a multi-discipline Department of Energy (DOE)

research institute that has been in operation since 1947. Historical operations included running

accelerators, nuclear research reactors, and other large complex equipment. Some of these

operations caused groundwater contamination. This report discusses the tritium plume from the

High Flux Beam Reactor and several strontium plumes from past operations at the Brookhaven

Graphite Research Reactor, their discovery through monitoring, and their treatment. The tritium

plume discovery led to public outrage; characterization, design, and implementation of a

treatment system within 60 days; and eventual dismissal of Associated Universities Incorporated

from the management of BNL despite the small health risk to employees or the public.

Management of the strontium plume included a major alteration to the original regulatory

cleanup agreement when field data showed the preferred alternative to be economically

impractical. The report documents activities used to manage these contamination issues through

source control, monitoring, modeling, plume and risk management, and communications. The

lessons learned from these cleanup projects have altered the stewardship culture and methods of

performing research, communicating with the public, and conducting work at BNL. These

valuable lessons are highlighted in this report.

iii

CONTENTS

ABSTRACT .................................................................................................................................. iii

EXECUTIVE SUM M ARY .................................................................................................... ix

ACKNOW LEDGMENTS .............................................. ........................................................ xv

ACRONYM S ............................................................................................................................. xvii

1.0 INTRODUCTION ........................................................................................................ 1

1.1 B ackg round ......................................................................................................................... 1

1.2 BNL Hydrogeology .................................................................................................... 4

1.3 C hro n o logy ......................................................................................................................... 5

1.3.1 Tritium from the HFBR ..................................................................................... 5

1.3.2 Strontium-90 Contamination from the BGRR .................................................... 7

1.3.3 Timeline of Major Activities and Accomplishments Since 1997 ....................... 8

1.4 Remedial Action Process ............................................................................................... 8

1.5 Plume Management .......................................................................................................... 10

1.6 Report Objectives: ............................................................................................................ 12

2.0 HFBR Tritium Plume; Source Control and Characterization ............................... 13

2.1 Identification of the problem ......................................................................................... 13

2.2 Commitment to take actions within 60 days ................................................................ 13

2.3 Approach to defining the extent of contamination ........................................................ 14

2.3.1 Evaluation of Potential Sources ....................................................................... 14

2.3.2 Potential Sources within the HFBR Structure ................................................. 14

2.3.3 Results of the Spent Fuel Pool (SFP) Leak Tests ............................................. 15

2.3.4 Sanitary Sewer System ..................................................................................... 15

2.3.5 Horizontal Wells Installed Beneath the HFBR Containment Structure to Further

Isolate the Potential Source of the Tritium Leak ............................................... 16

2.4 Source C ontrol .................................................................................................................. 1 7

2.4.1 HFBR Building Source Control ....................................................................... 17

2.4.2 Modification of the Existing HFBR Building .................................................. 18

2.4.3 Vadose Zone Source Contribution ..................................................................... 19

2.4.4 Immediate Hot Spot Removal .......................................................................... 20

2.5 Detailed characterization of the plume ........................................................................ 20

2.6 Regulatory Actions ............................................................................................................ 23

3.0 M ODELING THE HFBR TRITIUM PLUME ....................................................... 25

3.1 Initial Modeling Objectives (1997) .............................................................................. 27

3.2 U sing the M odel ................................................................................................................ 2 7

4.0 IMPLEMENTATION OF THE SELECTED REMEDY ....................................... 29

4.1 Evaluation of Remedial Alternatives ........................................................................... 29

4.2 R isk A ssessm ent ............................................................................................................... 30

4.3 HFBR Tritium Plume Downgradient Extraction and Recharge System ..................... 30

v
4.4 Low Flow Pumping Groundwater Extraction ............................................................. 32

4.5 Revised Modeling Objectives Activities and Low Flow Pumping ............................... 32

4.6 Low Flow Pumping Implementation ............................................................................ 34

5.0 HFBR PLUME MANAGEMENT ............................................................................ 37

5.1 Triggering E vent .............................................................................................................. 38

5.2 Use of Data Quality Objectives .................................................................................. 40

6.0 STRONTIUM-90 CONTAMINATION ................................................................... 41

6.1 Identification of Sr-90 Contamination ....................................................................... 41

6.2 Strontium Treatment System Remedial Design ........................................................... 41

6.2.1 P ilot Study ....................................................................................................... . . 43

6.2.2 Additional Characterization of the Strontium-90 Groundwater Contamination ....44

6.2.3 Suggested Alternative Treatment System ......................................................... 44

6.3 Institutional Controls for the Groundwater Remediation Program ........................... 45

6.4 P ublic Involvem ent ........................................................................................................... 46

6.5 Sr-90 Plume Management ........................................................................................... 47

7.0 COMM UNICATIONS ............................................................................................... 49

7.1 History of Community Involvement ............................................................................ 49

7.2 Summary of Community Participation Activities ......................................................... 50

7.3 Public Water Hook- Ups ............................................................................................. 51

7.4 Continuing Community Involvement .......................................................................... 53

8.0 SUMMARY ..................................................................................................................... 55

8.1 S ource C on trol ................................................................................................................. 5 6

8.2 M on itoring ....................................................................................................................... 58

8.3 M o d eling .......................................................................................................................... 5 9

8.4 Plume/Risk Management ............................................................................................. 60

8.5 C om m un ication ................................................................................................................ 62

9.0 REFERENCES ................................................................................................................ 63

APPENDIX A: High Flux Beam Reactor Tritium Modeling Studies ............................ A-1

APPENDIX B: Operation of Sr-90 Treatment Systems .................................................. B-i

APPENDIX C: Lessons Learned Applicable to the NRC's Buried Piping Initiative ........ C-1

APPENDIX D: Detecting Leaks from Underground Piping Systems ........................... D-I

vi
List of Figures

Figure 1-1:

Figure 1-2:

Figure 1-3:

Figure 1-4:

Figure 1-5:

Figure 1-6:

Figure 1-7:

Figure 1-8:

Figure 1-9:

Figure 2-1:

Figure 2-2:

Figure 2-3:

Figure 2-4:

Figure 2-5:

Figure 2-6:

Figure 2-7:

Figure 2-8:

Figure 3-1:

Figure 4-1:

Figure 4-2:

Figure 4-3:

Figure 4-4:

Figure 5-1:

Figure 6-1:

Figure 6-2:

Figure 7-1:

Figure 8.1:

Figure 8-2:

Figure 8-3:

Figure 8-4:

Figure 8-5:

Figure 8-6:

Figure 8-7:

Figure 8-8:

Figure 8-9:

Figure B-1:

Figure C- 1:

Figure C-2:

Figure C-3:

Figure D- 1:

L ocation of B N L ......................................................................................................... 1

A erial V iew of BN L-2007 ..................................................................................... 2

Brookhaven Graphite Research Reactor (BGRR) ....................... 3

High Flux Beam Reactor (HFBR) ......................................................................... 3

Generalized Geologic Cross Section in the Vicinity of BNL ................................. 4

Timeline of Major Activities and Accomplishments in 1997 ................................. 6

Monitoring wells installed to characterize Sr-90 Plume ........................................ 7

Basic steps in the Remedial Action Process ........................................................... 9

Overview of Plume M anagement ......................................................................... 11

Conceptual Schematic of the Tritium System ...................................................... 13

Horizontal wells for sampling groundwater below the HFBR ............................. 16

D ouble-lined Spent Fuel Pool .............................................................................. 18

Conceptual Drawing of Vadose Zone Transport Beneath the HFBR ................... 19

Map showing location of sampling wells used to define the tritium plume ...... 21

Cross Section of the Tritium Plume as function of distance from the HFBR ..... 22

Sampling data results associated with the plume characterization ....................... 22

Location of High Flux Beam Reactor, tritium plume, extraction wells, and recharge

b a sin ..................................................................................................................... 2 3

Use of Models in the Decision-making Process .... : .............................................. 27

Hydraulic Containment System for HFBR Tritium Plume ................................... 31

Predicted concentrations at Weaver Drive as a function of dispersivity based on

initial conditions in 2000 (before hot spot removal) and in 2001 ..................... 33

Low flow pumping performance-Goal versus Actual ........................................... 34

Low Flow Pumping Tritium Events ..................................................................... 35

Water table changes leading to increases in tritium concentration ....................... 38

Sr-90 Plumes on the BNL Site and Selected Well Concentration Trends ............ 42

EPA 5 Year Remedy Evaluation Process ............................................................. 48

Location of plumes and treatment systems (boxed areas) .................................. 52

Lessons Learned Summ ary by Topic .................................................................... 55

Potential Vulnerabilities at the HFBR for Impacting the Environment ............... 56

Continuing contribution from the vadose zone .................................................... 56

Continuing Source Term with Increase in the Water Table Level ....................... 57

Low Flow pumping of high concentrations of tritium .......................................... 57

Leakage from underground collection tank (Sr-90) and the HFBR spent fuel pool

(tritiu m ) ............................................................................................................ . . 5 8

Temporary and Permanent Monitoring Wells Used to Characterize the HFBR

T ritium Plum e ............................................................................................... . . 59

Potable and Process W ell Influence ..................................................................... 60

Integration of Modeling and Monitoring to Support Performance Measures ..... 61

BGRR Sr-90 Plum e Distribution-2007 .................................................................. B-2

H FB R P iping L ayout .............................................................................................. C -2

Cross section of spent fuel pool ............................................................................. C -4

Use of Horizontal Wells to Detect Source Location .............................................. C-6

Schematic of Mobile PFT Leak Detection System ................................................ D-2

vii
List of Tables

Table 1-1: Timeline of Events from 1997-2010 ....................................................................... 8

Table 3-1: Summary of Modeling Information ....................................................................... 26

Table C-I: Summary of Potential Sources of Tritium from the HFBR ................................. C-3

Table D-1: PFTs commonly used as tracers, acronyms, names, chemical formulae, molecular

w eights, and boiling points ............................................................................ D -1

viii
EXECUTIVE SUMMARY

Brookhaven National Laboratory (BNL) is a multi-discipline Department of Energy research

institute that has been in operation since 1947. Historical operations included running

accelerators, nuclear reactors, and other large complex equipment. Some of these operations

caused groundwater contamination. This report discusses the tritium plume from the High Flux

Beam Reactor (HFBR) and several strontium plumes from past operations at the Brookhaven

Graphite Research Reactor (BGRR), their discovery through monitoring, and their treatment.

The HFBR operated from 1965 to 1996, and was used solely for scientific research providing

neutrons for materials science, chemistry, biology, and physics experiments. During a routine

maintenance shutdown in 1996, tritium from the spent fuel canal was found in groundwater

south of the reactor. Investigations revealed that the source of the tritium was leakage through

the ceramic tile lined concrete walls of the pool where spent nuclear fuel was stored. The tritium

plume that resulted from this leakage was located entirely within the Laboratory property. The

portion of the plume that exceeded the drinking water standard for tritium (20,000 pCi/1)

extended approximately 4,500 feet north of BNL's southern boundary at depths from 40 to 150

feet below land surface. The 20,000 pCi/l plume was approximately 2,600 feet long and 250 feet

wide. The highest tritium activity detected was 5,100,000 pCi/1 in a monitoring well adjacent to

the HFBR. The tritium plume discovery led to public outrage; characterization, design, and

implementation of a treatment system within 60 days; and eventual dismissal of Associated

Universities Incorporated from the management of BNL.

The BGRR operated from 1950 to 1968. In March of 1997 an underground tank built to collect

drainage from piping associated with the BGRR was found to contain about 750 gallons of water

that showed elevated levels of strontium-90. Initial characterization analysis of temporary

monitoring wells revealed concentrations of Sr-90 in the groundwater as high as 566 pCi/L,

approximately 70 times the drinking water standard of 8 pCi/L.

The timing of the discovery of this contamination coincided with the characterization of the

tritium plume from the HFBR. The already heightened community and media sensitivity to

groundwater contamination created additional outrage at the discovery of this new radiological

groundwater contamination. So even though the Sr-90 contamination was very local to its

source, it received significant media and community attention. Characterization of this and

another Sr-90 plume near a former waste disposal site was conducted in 1997 and 1998 to define

the extent of contamination. At that time, site-specific soil Kd measurements were made and

modeling was performed for each of these plumes and it was projected that Sr-90 would not

leave the BNL site in concentrations exceeding the 8 pCi/1 Drinking Water Standard. This

combined with institutional controls to prevent on-site access of the contaminated water made

this a small risk to the public and BNL employees.

Even though predicted health risks from these plumes were small, the institutional risk due to

public outrage and political pressures necessitated a comprehensive effort by BNL to remedy the

situation. BNL expended substantial resources to characterize, monitor, model, and manage

these plumes. Simultaneously, BNL improved communications with the public and regulators

ix
through regular meetings and updates on the state of all environmental contamination issues at

the facility.

The lessons learned from these cleanup projects have altered the stewardship culture and

methods of performing work at BNL. These valuable lessons have been divided into five

categories: 1) source control, 2) monitoring, 3) modeling, 4) plume/risk management, and 5)

communications. The lessons are highlighted in this report and are summarized below.

Source Control

Source control involves the identification and characterization of all potential sources that can

lead to releases to the environment. For groundwater contamination, source control also includes

containment of the high concentration areas of the plume to prevent migration downgradient (or

off-site). Failure to perform adequate early source control will lead to more difficult and more

expensive cleanup efforts. Major lessons learned at BNL include:

I. Understanding the potential environmental vulnerabilities and quickly identifying the

source of groundwater contamination is critical for achieving credibility with the

regulators and the public. (Section 2.3.2)

2. The release of contaminants from the vadose zone, particularly mobile contaminants such

as tritium, during periods of water table rise needs to be considered as a continuing

source term. Establish field monitoring to achieve early detection of vadose zone

releases. (Section 2.4.3)

3. Early cleanup efforts should focus on eliminating the source. Once the source is

eliminated a more accurate estimate of life cycle remediation and associated costs can be

realized. (Section 2.4)

4. Source hotspots should be controlled even if monitoring and modeling is incomplete.

Inaction at the time of discovery of a hotspot concentration can result in longer and more

complicated remedial activities further downstream. (Section 2.4.4)

5. Tritium treatment and separation technologies found in the literature are not appropriate

for environmental remediation of the relatively low concentrations and large volume of

tritiated water in an aquifer or surface water. (Section 4.1)

Monitoring

Monitoring is the collection and evaluation of data to support all phases of cleanup. It should

start with monitoring of facilities for leakage and include data collection to support decisions

involving remediation and plume management.

6. Facility ground water monitoring is an important defense in the early detection of

unexpected releases to the environment. The realization that tritium was being released

from the HFBR to the groundwater at BNL occurred many years after the release began

due to inadequate facility monitoring. Expansion of the facility monitoring program at

BNL after 1997 uncovered other contaminants that needed to be addressed. (Section 2. 1)

7. In an attempt to pinpoint the source location, horizontal wells were installed beneath the

spent fuel pool. Use of new techniques (horizontal wells for locating the source, in this

x
case) should be carefully planned and limitations fully understood before

implementation. (Section 2.3.5)

8. GeoprobesTM and temporary wells that provided vertical profiles of the contamination

concentrations are effective tools for an "early response" plume characterization.

Vertical characterization of the plume was important at BNL due to the well-defined

(vertically thin) nature of the tritium plume. (Section 2.5)

9. Monitoring well screens should be as short as possible or low-flow purge sampling

methods should be used to ensure the detection of vertically discreet layers of tritium.

(Section 5.0)

10. Tritium's lack of any retardation in groundwater can quickly cause a permanent

monitoring well network to become ineffective in response to rainfall and external

pumping and recharge influences. Therefore temporary monitoring wells should be used

over the life cycle of the remediation to a much greater extent than with "conventional"

plumes. (Section 5.1)

11. Substantial and iterative monitoring data are needed to (Section 5.0):

* identify changes that could warrant modifications to the monitoring program

* validate the groundwater model and other remediation assumptions; and

0 provide feedback to stakeholders on the problem and progress of its mitigation.

Modeling

Modeling is the use of computer tools that predict the movement of groundwater and

contaminants, and their release from the facility through the vadose zone into the groundwater.

12. It is essential to have a calibrated site-wide groundwater model in place that can (Section

3.2):

* help select monitoring locations,

* support risk analysis on the impact of a particular plume

* support evaluation of remedial alternatives, and

* support design (location and pumping rate) of the selected remediation system.

13. It is important that site activities that could impact plume movement are documented and

their potential impacts evaluated. This includes on-site supply well pumping, impacts of

recharge basins, annual rain fall amounts, water table fluctuations, and major spills/leaks.

(Section 3.0)

14. Site-specific soil characterization information for input to the groundwater model

provides better results and should be used. In some cases, additional data collection may

be required to improve model accuracy. The importance of an accurate groundwater

model increases over time when assessing the long term impacts of the plume and its

remediation. (Appendix A)

15. For porous media that do not cause substantial mechanical dispersion, modeling using

finite-difference methods may under predict downgradient concentrations for tritium

unless great care is placed in accounting for numerical dispersion. (Section 3.0)

xi
Plume/Risk Management

Plume/Risk Management is the process by which all decisions are made. It entails use of the

monitoring data and modeling to evaluate alternatives and to support decisions.

16. A well developed process that ensures that all elements are included in a risk based

remediation decision needs to be in place and implemented. The process includes

requirements for contingency plans, regular progress reports, and formal periodic

reviews. The process mandated by CERCLA as used at BNL is an example of a robust

process. (Section 1.5)

17. The required cleanup work should be specified in a performance based format with set

goals rather than specific remedies already determined. A performance based format

allows flexibility to perform the remediation cost effectively and efficiently. (Section 4.4)

18. Pilot studies are extremely useful in evaluating the effectiveness of remedial alternatives

(strontium-90 treatment), providing supporting documentation to improve a final remedy,

and in demonstrating responsiveness to the contamination problem. (Section 6.2.1)

19. There are long term benefits for establishing data quality objectives (DQOs) at the

beginning of the process. (Section 5.2) These benefits include:

a. helping to focus data collection and decisions on the performance goals;

b. forming a basis to demonstrate that sampling frequency can be reduced or should be

increased based on trends in the data;

c. forming a basis for implementing contingency plans when goals are not being met;

and

d. forming a basis to implement an exit strategy, such as turning off an extraction

system, when goals are met.

20. From the perspective of the site owner/operator in discussion of risk assessment, it is

important to factor in risk to the Institution as a result of public outrage and media

attention. At BNL it was often shown that human health and ecological risks were below

typical regulatory levels of concern. However, institutional risks (lack of credibility, loss

of funding) and public concerns often dominated the discussions. (Section 4.2)

21. Adaptive management techniques are useful when evaluating the monitoring data. BNL

has adapted to changes in tritium plume management (hot spot removal) and strontium90 plume remediation (poor performance of original treatment system) that resulted in

long-term positive outcomes. (Section 6.5)

22. Effort should be expended to manage a plume within the facility boundaries. Once offsite migration occurs both real and perceived risk greatly increase. (Section 2.6)

Communication

Communication is needed in all phases of the remediation process and includes describing the

contamination problem, what caused the problem, potential risks to the public from the

contamination, and what is being done to address the problem. Effective communication

requires the willingness to listen to and address, to the extent possible, stakeholder concerns. It

also requires frequent discussions to update stakeholders on the progress of the characterization

and cleanup.

xii
23. Public perception may not always agree with technical facts. Lack of trust between the

community and BNL caused many people to believe they were negatively impacted by

BNL operations when in fact they were not. The lack of trust even caused some

community members to interpret pro-active public water extensions to address perceived

concerns about solvent plumes as a tacit admission of guilt by BNL even though the data

indicated that there were no drinking water wells impacted by the contamination from

BNL. (Section 7.3)

24. Establishing a public involvement process before there is a problem is important (Good

Neighbor Policy). At BNL, it was extremely difficult to establish a Community Advisory

Council (CAC) in a crisis situation. Initially there was a complete lack of trust. (Section

7.1)

25. Communications requires continual effort and providing a venue for regular updates to

environmental regulators, public officials, and the community is essential (e.g.,

Brookhaven Executive Roundtable-BER and the Community Advisory Council-CAG).

(Section 7.4)

26. The BNL experience revealed some initiatives that did not work. This included

providing weekly updates to the media (press releases) of the plume characterization.

Some in the community thought the news was a new problem being discovered each

week. (Section 7.2)

27. Risk communication is important. It is essential to provide a clear message to the public.

BNL had difficulties, explaining co-mingled plumes (tritium from HFBR and VOCs from

other sources). In some cases, BNL provided too much data including contaminant levels

far below the drinking water standards which caused members of the public to believe the

extent of contamination was greater than it actually was. (Section 7.2)

28. Workshops and availability sessions were much more effective than large public

meetings. Specific items of concern could be addressed more readily in the smaller

group settings. (Section 7.2)

xiii

ACKNOWLEDGMENTS

This research is sponsored by the U.S. Nuclear Regulatory Commission. The views presented

represent those of the authors alone and not necessarily those of the NRC. The authors wish to

thank Jacob Phillip, NRC Project Manager, for his guidance and input during the research project

and the NRC Technical Monitor, Thomas Nicholson, for his careful review, recommendations,

and suggestions. We also wish to thank our BNL colleagues, Jim Higgins and Bill Dorsch, for

their insights and helpful comments on earlier drafts of the report.

We also express our appreciation to Maryann Julian for her editorial and organizational support

in producing this report.

xv

ACRONYMS

ARAR Applicable or Relevant and Appropriate Requirements

BGRR Brookhaven Graphite Research Reactor

BNL Brookhaven National Laboratory

CAC Community Advisory Committee

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

DOE U.S. Department of Energy

DWS Drinking Water Standard

EPA U.S. Environmental Protection Agency

HFBR High Flux Beam Reactor

MCL Maximum Concentration Limit

MSL Mean Sea Level

NRC Nuclear Regulatory Commission

NYSDEC New York State Department of Environmental Conservation

OU Operable Unit- A project designation under CERCLA

OU III Operable Unit Three

PFS Pile Fan Sump associated with the Brookhaven Graphite Research Reactor

(BGRR).

PFT Perfluorocarbon Tracer

ROD Record of Decision

RJIFS Remedial Investigation/Feasibility Study

SCDHS Suffolk County Department of Health Services

SFP Spent Fuel Pool

TVOC Total Volatile Organic Compounds

UST Underground Storage Tank

VOC Volatile Organic Compounds

WCF Waste Concentration Facility at BNL

xvii

1.0 INTRODUCTION

1.1 Background

Brookhaven National Laboratory (BNL) is located about 60 miles east of New York City, in

Upton, Suffolk County, New York, near the geographic center of Long Island (Figure 1-1).

Approximately 1.4 million people reside in Suffolk County and approximately 450,000 reside in

Brookhaven Township, within which BNL is situated. BNL has operated since 1947 as a

research facility for national science and technology programs. BNL is owned by the U.S.

Department of Energy (DOE), one of the 17 DOE national laboratories. BNL conducts research

in the physical, biomedical, and environmental sciences, as well as in energy technologies and

national security. The Laboratory also builds and operates major scientific facilities available to

university, industry, and government researchers.

Figure 1-1: Location of BNL (DOE, 2005b)

The BNL property, consisting of over 5,000 acres, is an irregular polygon, and each side is

approximately 2.5 miles long. The developed portion of the BNL Site includes the principal

facilities, which are located near the center of the BNL Site on relatively high ground (Figure 1-

2). The developed portion is approximately 900 acres, 500 acres of which were originally

developed for Army use. The remaining nearly 4000 acres is primarily wooded with gently

rolling terrain. The land lies on the western rim of the shallow Peconic River watershed, with a

tributary of the Peconic River rising in marshy areas in the northern section of the tract.

The sole-source aquifer beneath BNL comprises three water-bearing units: the Moraine and

outwash deposits, the Magothy Formation, and the Lloyd Sand Member of the Raritan

Formation. These units are hydraulically connected and make up a single zone of saturation with

varying physical properties extending from a depth of five to 1,500 feet below the land surface.

These three water-bearing units are designated as a "sole source aquifer" by the U.S.

Environmental Protection Agency (EPA) and serve as the primary source of drinking water for

Nassau and Suffolk Counties.

I
The U.S. Army occupied the BNL Site, formerly Camp Upton, during World Wars I and II.

Between the wars, the Civilian Conservation Corps operated the BNL Site. It was transferred to

the Atomic Energy Commission in 1947, to the Energy Research and Development

Administration in 1975, and to DOE in 1977. Brookhaven Science Associates (BSA) operates

BNL under a contract with DOE. In 1980, the BNL Site was placed on the New York State

Department of Environmental Conservation's (NYSDEC) list of Inactive Hazardous Waste Sites.

On November 21, 1989, the BNL Site was included on EPA's National Priorities List because of

soil and groundwater contamination that resulted from the Laboratory's past operations.

Subsequently, the EPA, NYSDEC, and DOE entered into a Federal Facilities Agreement under

the Comprehensive Environmental Response Compensation & Liability Act (CERCLA) that

became effective in May 1992 to coordinate the cleanup.

Figure 1-2: Aerial View of BNL-2007

The BGRR (Figure 1-3), which was the first reactor in the U.S. built solely to perform

experiments, operated from 1950 to 1968. Deactivation of the facility was initiated in September

1969. In March 1972, the last fuel element was removed from the reactor and shipment of the

fuel to the DOE Savannah River Site was completed shortly thereafter. Fuel handling operations

that occurred during its operating life contributed to the existence of strontium-90 (Sr-90) in the

groundwater at BNL. The Sr-90 plume south of the BGRR is approximately 1,000 feet long and

500 feet wide with concentrations as high as 566 pCi/L.

2
Figure 1-3: Brookhaven Graphite Research Reactor (BGRR); (DOE, 2005b)

Figure 1-4: High Flux Beam Reactor (HFBR); (DOE, 2009)

The HFBR (Figure 1-4) operated from 1965 to 1996, and was used solely for scientific research

providing neutrons for materials science, chemistry, biology, and physics experiments. During a

routine maintenance shutdown in 1996, tritium from the spent fuel canal was found in

groundwater south of the reactor. Investigations revealed that the source of the tritium was

leakage through the ceramic tile lined concrete walls of the pool where spent nuclear fuel was

stored. Operations at the HFBR were suspended and the DOE considered what to do. All of the

spent fuel was removed and sent to DOE's Savannah River Site in 1998. The pool was drained

and a freestanding, double-walled, stainless steel liner with an instrumented low point sump was

installed to eliminate the potential for leakage to the environment. In November 1999, DOE

announced it was permanently closing the reactor.

The tritium plume was always located entirely within the boundaries of the Laboratory. In 1997,

the portion of the plume that exceeds the drinking water standard for tritium (20,000 pCi/i)

extended approximately 4,500 feet north of BNL's southern boundary at depths from 40 to 150

feet below land surface. The dimensions of the 1,000 pCi/I plume were approximately 3,200 feet

long and 625 feet wide. The 20,000 pCi/I plume was approximately 2,600 feet long and 250 feet

3
wide. The highest tritium activity detected was 5,100,000 pCi/l in a monitoring well adjacent to

the HFBR.

1.2 BNL Hydrogeology

This section briefly describes the hydrogeologic environment at BNL and the surrounding area.

Detailed descriptions of the aquifer system underlying BNL and the surrounding areas are found

in the U.S. Geological Survey (USGS) report by Scorca and others (USGS, 1999), Stratigraphy

and Hydrologic Conditions at the Brookhaven National Laboratory and Vicinity, Suffolk County,

New York, 1994-97.

The stratigraphy below BNL consists of approximately 1,300 feet of unconsolidated deposits

overlying bedrock (Figure 1-5). The groundwater monitoring program at BNL focuses on

groundwater quality within the Upper Pleistocene deposits (Upper Glacial aquifer), and the

upper portions of the Matawan Group-Magothy Formation (Magothy aquifer). These aquifers

provide drinking water to Long Islanders.

(NorM) (Soutl)

BNL

(3U 400i

MSL 4 ........ Q MSL

-400- Aut 400 Clay

-800 -800

-1200 -- 1200

-1000 -1600

-000 -- 2000

--- -eCoVA c Conafa Uaovoe We-e k"em'd

-*- mocbo ofE Oaowv**vaw Foo S0oaiUtC TO Scak

Figure 1-5: Generalized Geologic Cross Section in the Vicinity of BNL (BNL, 1998)

The Pleistocene deposits are about 100-200 feet thick and are divided into two primary

hydrogeologic units: undifferentiated sand and gravel outwash and moraine deposits, and the

finer-grained, more poorly sorted Upton Unit. The Upton Unit makes up the lower portion of the

Upper Glacial aquifer beneath several areas of the BNL site. It generally consists of fine- to

medium-grained white to greenish sand with interstitial clay.

4
In addition to these two major hydrogeologic units, there are several other distinct hydrogeologic

units within the Upper Glacial aquifer. They include localized, near-surface clay layers in the

vicinity of the Peconic River (including the Sewage Treatment Plant [STP] area), and reworked

Magothy deposits that characterize the base of the aquifer in several areas. The Gardiners Clay is

a regionally defined geologic unit that is discontinuous beneath BNL and areas to the south.

Typically, it is characterized by variable amounts of green silty clay, sandy and gravelly green

clay, and clayey silt. Where it exists, the Gardiners Clay acts as a confining or semi-confining

unit that impedes the vertical flow and migration of groundwater between the Upper Glacial

aquifer and the underlying Magothy aquifer.

The Magothy aquifer is composed of the continental deltaic deposits of the Cretaceous Age that

unconformably underlie the Pleistocene deposits. The Magothy aquifer at BNL is approximately

800 feet thick, and because it is composed of fine sand interbedded with silt and clay, it is

generally less permeable than the Upper Glacial aquifer. The Magothy aquifer is highly

stratified. Of particular importance at BNL is that the upper portion of the Magothy contains

extensive, locally continuous layers of grey-brown clay (referred to as the Magothy Brown

Clay). Regionally, the Magothy Brown Clay is not interpreted as being continuous; however,

beneath BNL and adjacent off-site areas, it acts as a confining unit (where it exists), impeding

the vertical flow and movement of groundwater between the Upper Glacial and Magothy

aquifers.

Regional patterns of groundwater flow near BNL are influenced by natural and artificial factors.

Under natural conditions, recharge to the regional aquifer system is derived solely from

precipitation. A regional groundwater divide exists immediately north of BNL. It is oriented

roughly east-west, and appears to coincide with the centerline of a regional recharge area.

Groundwater north of this divide flows northward, ultimately discharging to the Long Island

Sound. Shallow groundwater in the BNL area generally flows to the south and east. During high

water-table conditions, that groundwater can discharge into local surface water bodies such as

the Peconic River and adjacent ponds. The BNL site is within a regional deep-flow recharge

area, where downward flow helps to replenish the deep sections of the Upper Glacial aquifer, the

Magothy aquifer, and the Lloyd aquifer. South of BNL, groundwater flow becomes more

horizontal and ultimately flows upward as it moves toward regional discharge areas.

1.3 Chronology

This section focuses on the sequence of events beginning in 1997 when tritium contamination

was found above the drinking water standard near the HFBR and strontium-90 contamination

was found at levels above the drinking water standard in groundwater downgradient of the

BGRR.

1.3.1 Tritium from the HFBR

Discovery of tritium in the groundwater near the Brookhaven National Laboratory High Flux

Beam Reactor (HFBR) in January 1997 initiated an intense effort to locate its source, determine

its extent, and implement remediation methods to mitigate its consequences. The tritium plume

that resulted from the slow, long-term leakage of contaminated water from the HFBR spent fuel

pool at BNL was the subject of much attention by the media, State and Federal regulators, and

5
the public in 1997. Tremendous amounts of resources were dedicated to characterizing the

plume in great detail and in mitigating its consequences (Gunther, 2008).

Timeline- 1997

JAN FES M4AR APR MAY JUN JUL AUG SEP OCT NOV DEC

Pump and Recharge

Fm • i System started on 5/12

-Plume Characterftatie.

-Temporary Wells and ; Emptied Spent

Fuel Pool; 12130197

Horizontal Wells etu* 3/1• HnGW 

HF9R GW Modeling Cww4WXDAI97

-Many prom reteases and mestings with Regulators ad Commeafty Grupstrw~tVw

Permanent GW Weals Coapiated i7i

Figure 1-6: Timeline of Major Activities and Accomplishments in 1997

The tritium plume from the HFBR was determined to be approximately 4,200 feet long. The

source of the plume was a 12-year-old leak from the reactor's spent fuel pool (SFP). This source

of groundwater contamination was removed in December 1997 when the pool was drained.

While plans were being developed to remediate the tritium plume, an Interim Remedial Action

(IRA) consisting of groundwater pumping and upgradient recharge was implemented at the

leading edge of the plume to prevent it from migrating beyond Princeton Avenue, a point

approximately I mile from the site boundary in the direction of groundwater flow. The IRA

system went into operation in May 1997 and was transferred into a standby mode in September

2000 when it was demonstrated that the plume concentrations were lower than specific action

levels specified in the Operable Unit III Record of Decision (ROD) (DOE, 2000).

Figure 1-6 illustrates some of the key events that occurred during 1997 related to the discovery

of tritium near the HFBR. Besides the construction, installation, and operation of the interim

extraction wells in May 1997, other key dates include:

• Installation of two horizontal wells in March 1997

• Installation of over 150 vertical profiles and geoprobes between January and May 1997

" Emptying of the spent fuel pool (source elimination) in December 1997

The ROD had performance based measures that required the restart of the pump and recharge

system if tritium concentrations exceeded trigger levels at pre-specified locations. In 2008 a

6
fourth extraction well was added to the pump and recharge system. This additional well has

been operated since then as part of the contingency plan agreed to in the ROD.

1.3.2 Strontium-90 Contamination from the BGRR

In March of 1997 an underground concrete collection tank (known as the pile fan sump) built to

collect drainage from piping associated with the BGRR was found to contain about 750 gallons

of water that showed elevated levels of strontium-90. Analysis of temporary monitoring wells

revealed concentrations of Sr-90 in the groundwater as high as 566 pCi/L, approximately 70

times the drinking water standard of 8 pCi/L.

{ Building 801

Underround

collection tank

promie G7,j~c - S --

wells F4

Figure 1-7: Monitoring wells installed to characterize Sr-90 Plume (BNL, 2008b)

The timing of the discovery of this contamination coincided with the characterization of the

tritium plume from the HFBR. The all ready heightened community and media sensitivity to

groundwater contamination created additional outrage at the discovery of this new radiological

groundwater contamination. So even though the Sr-90 contamination was very local to its

source, it received significant media and community attention. Characterization of this and

another Sr-90 plume near a former waste disposal site was conducted in 1997 and 1998 to define

the extent of contamination. At that time, site-specific soil Kd measurements were made

(Fuhrmann, 1999). Modeling was performed for each of these plumes and it was projected that

Sr-90 would not leave the BNL site in concentrations exceeding the 8 pCi/I Drinking Water

Standard. This combined with institutional controls to prevent on-site access of the

contaminated water made this a small risk to the public and BNL employees.

7
1.3.3 Timeline of Major Activities and Accomplishments Since 1997

Table 1-1 presents a brief timeline of important activities/milestones that occurred from the

discovery of the tritium plume in 1997 to the present day (2010).

Table 1-1: Timeline of Events from 1997-2010

DATE MILESTONE

January 1997 Discovery of Tritium in the groundwater just south of the HFBR

March 1997 Detection of Strontium-90 in an underground collection pit and in the

groundwater south of the BGRR

1998 Community Advisory Council (CAC) formed

2000 Operable Unit III Record of Decision (ROD) signed

2001 Completed low flow tritium pumping system; removed -100,000 gallons of

tritiated groundwater for off-site disposal

2004 Completed the BGRR Strontium-90 groundwater treatment system

2005 Explanation of Significant Difference Issued; modified the Sr-90 treatment

system and goals

2006 Tritium concentrations exceed trigger levels thereby requiring reactivation of

the Pump and Recharge system.

2008 Installed additional extraction well to capture the downgradient high

concentration tritium slug, as shown by 2008 temporary and permanent well

data

2010 Update provided to CAC- need to further modify the Sr-90 treatment system

to achieve cleanup goals

1.4 Remedial Action Process

The Remedial Action process, Figure 1-8, used at BNL has a number of well-defined steps that

help to insure that cleanup objectives are achieved in an efficient and timely manner.

The initial step involves identifying Applicable or Relevant and Appropriate Requirements

(ARARs). Brookhaven National Laboratory is a Department of Energy facility operated by

Brookhaven Science Associates. BNL operates under DOE Orders and is also a Superfund site.

At BNL, we manage our environmental remediation activities under the CERCLA

(Comprehensive Environmental Response, Compensation, and Liability Act) process as overseen

by the Environmental Protection Agency (EPA). New York State Department of Environmental

Conservation (NYSDEC) is tasked with insuring that State regulations and objectives are met

during remediation. The Suffolk County Department of Health (SCDHS) insures that all local

regulations are followed. Each of these agencies is actively involved in making decisions within

the constraints of being protective of human and ecological health, time, budget, and technical

feasibility.

8
onitorn and_ _T __ Modeling No

Annual

// Performance

\Meaures Met?

Y83 / ... .__, ~rfonnane o 

Measures Met?/

Site Chamacderkon J

IApply MateMatical Modeis using sitespecific data to support

remedy selecton

design and compliance

decsions

Rmedy

No Yes

[~enrynecang]

Inooe~dtDOW

meet Pod mnc

Figure 1-8: Basic steps in the Remedial Action Process

The next step in the process is to develop a conceptual model of the site. This model should

identify the scenarios and exposure pathways. Typical scenarios for groundwater contamination

include on-site workers that may be exposed due to removal actions and either off site residential

exposure, or if institutional control of the site may be lost, a residential scenario located on the

current site. Exposure pathways include:

* Ingestion of contaminated water or food grown with contaminated water.

" Inhalation of volatile compounds.

" Absorption through the skin due to washing with contaminated water or exposure to

contaminated air.

" Direct exposure to ionizing radiation.

The conceptual model should form the basis for the collection of site characterization data.

Site characterization should be performed to support decisions pertaining to remediation. It will

include data to define the regions of contamination as measured by the concentration of the

pollutants. Characterization should also include the evaluation of long-term sources from

industrial processes or, for groundwater contamination, the effects of the vadose zone acting as a

long-term source. Characterization data will also include data to support the models that predict

the transport of contaminants to the receptors. For groundwater flow this will include hydraulic

head measurements, hydraulic conductivity and porosity of the different soil layers. For

contaminants that sorb to the soil, site-specific distribution coefficients should be determined for

9
the different soil layers. Additional characterization data may be needed based on the exposure

scenarios and pathways selected for analysis.

Using the conceptual model as the framework, mathematical models (flow and transport, human

risk, ecological risk, etc.) are used to predict the movement of the contaminants and human and

ecological risks. Modeling is also used to assist in:

" remedy design (for example, capture zone based on flow rate),

" remedy selection through predicting/supplying information to evaluate the costs of the

remedy (for example, volume of water that must be treated, volume of ion exchange resin

needed, etc.), and

" remedy effectiveness through prediction of the removal rate of contaminants and the time

to reach compliance goals.

The modeling results based on site-specific data obtained in the characterization phase are used

to support remedy selection. Typically several remedial alternatives will be evaluated with

alternatives ranging from monitored natural attenuation through more sophisticated and costly

remedies. The selected remedy is proposed by the responsible party (generally the land owner)

and must be justified based on meeting clean up goals, costs, time, technical feasibility, and

protection of human health and the environment. The proposed remedy must be approved by all

regulatory agencies prior to implementation.

1.5 Plume Management

For groundwater contamination problems, the Plume

Management Phase begins once the remedy is Lesson Learned: A well developed

implemented. An overview of this process is presented process that ensures all elements

in Figure 1-9. Plume management involves monitoring are included in a risk based

to confirm that cleanup objectives are being met. The remediation decision needs to be in

monitoring and modeling information should be place and implemented. The process

evaluated annually to determine if the cleanup is going mandated by CERCLA at BNL is an

according to plan. If it is proceeding as expected, an example of a robust process.

evaluation is made to determine if the remediation has

been successfully completed. If it is not, monitoring is continued for another year.

If the expectations for cleanup (often measured using data quality objectives) are not being met,

then additional action is required. At BNL the cleanup agreements include Action Levels

(concentrations above a threshold) that invoke contingency plans. This contingency action

could require more modeling to assess if the remedy will eventually meet cleanup objectives or

if additional treatment measures are needed. If additional measures are needed they could

involve any step in the remedial action process as shown in Figure 1-9.

10
Figure 1-9: Overview of Plume Management

Plume management is often a long-term process. For example, for the Sr-90 plume at BNL, the

goal is to meet drinking water standards in the aquifer after 70 years. Due to incomplete

characterization and imprecise knowledge of the physical properties that govern flow and

transport it is prudent to have an adaptive management scheme that can adjust to unanticipated

changes. A critical component of plume management is to develop performance measures that

can be used to determine if the cleanup is proceeding as expected and to define when the

cleanup is completed. Performance measures can take many forms, for example, lowering

concentrations below drinking water standards or achieving a specified mass of contaminants

removed. The performance measures often have time or cost constraints. These performance

measures can then be used to set Data Quality Objectives (DQOs). The DQOs form the

foundation for collecting monitoring data that is useful in the determination of the success of the

remediation. The monitoring data is collected and evaluated on a routine basis as specified in

agreements with the regulatory agencies.

At BNL a self-evaluation is performed annually. The performance measures used for evaluation

are typically a series of questions such as:

(1) Was the BNL Groundwater Contingency Plan triggered?

(2) Has the plume been controlled?

(3) Is the system operating as planned? Specifically, is the aquifer being restored at the

planned rate identified in the Record of Decision?

(4) Have the cleanup goals been met? Can the groundwater treatment system be shut

down?

II
Based on the answers to these questions, a recommended course of action is provided. The

recommendations can be as simple as changing the monitoring schedule or locations based on

low measured values at certain locations, adding new monitoring locations to better track the

plume, up to substantial changes such as altering the treatment process because the Contingency

Plan was triggered. Any change to existing operating procedures must obtain regulatory

approval. Examples of this process such as the tritium hot spot removal and changing the Sr-90

cleanup period for Sr-90 from 30 years to 70 years because of unexpected poor performance of

the ion exchange media (fouling with non-radioactive contaminants caused excessive use of the

resins) are discussed in more detail in this report.

1.6 Report Objectives

This report provides detailed lessons learned on detecting, monitoring, modeling, and

remediating ground-water contamination and for communicating the information and analyses to

the public within a risk-informed, performance-based approach. It is expected that NRC

Licensing and Regional Inspectors can use the insights and lessons for reviewing ground-water

remediation and monitoring programs, and for communicating the risks to the public and other

government stakeholders.

The technical focus is to obtain lessons learned and insights from the highly detailed, 13-year

effort at Brookhaven National Laboratory (BNL) for detecting, monitoring, modeling and

remediating ground-water contaminants [i.e., H-3, Sr-90, and volatile organic compounds

(VOCs)] at the BNL site. Of significant value is the long-term database available from BNL's

confirmatory monitoring program to illustrate the role and effectiveness of various remediation

remedies for H-3, Sr-90 and VOC's. The DOE Record of Decision (ROD) identifies monitoring

triggers as to when the activation of various combinations of remediation methods are needed for

mitigation of the problem.

Simultaneously, modeling studies were performed to predict the contaminant plumes migration

over time and how various remediation strategies could be employed to mitigate risks to the

public and the environment. There has been considerable interaction with government entities

[i.e., EPA, DOE, New York State Department of Environmental Conservation (NYSDEC) and

Suffolk County], as well as community groups (e.g. the community advisory council) to develop

a consensus on the remediation process.

12
2.0 HFBR TRITIUM PLUME; SOURCE CONTROL AND

CHARACTERIZATION

Tritium was first found above the drinking water standard south of the HFBR during routine

sampling of two newly installed groundwater monitoring wells in January, 1997. In response to

intense political and public pressure after the discovery, an interim accelerated response was

initiated to ensure protection of the public, worker health, and the environment. Accelerated

actions are allowed under CERCLA to execute rapid environmental response actions. This

section describes the accelerated responses taken and highlights the lessons learned associated

with these activities.

2.1 Identification of the Problem

Elevated levels of tritium in the groundwater were first

discovered down-gradient (south) of HFBR in monitoring Lesson Learned: Facility monitoring

wells installed as compensatory measures to satisfy is an important early line of defense

Article 12 of the Suffolk County Sanitary Code, which in an environmental monitoring

covers the regulation of storage facilities for hazardous program. The detection of tritium in

materials. The HFBR Spent Fuel Pool was considered a the groundwater at BNL took many

storage tank without secondary containment and, as such, years due to inadequate facility

required compensatory groundwater monitoring. Two monitoring.

wells were installed in July 1996 and sampled in October.

The initial results reported by BNL in December 1996 through the DOE's Occurrence Reporting

and Processing System was that tritium was detected at roughly 1/10 the drinking water standard.

Additional sampling conducted in January 1997 revealed tritium in the groundwater above

EPA's drinking water standard of 20,000 pCi/L.

2.2 Commitment to Take Actions within 60 Days

Three milestones of 30, 60,

and 90 days were established Ttium and Volatile Organic Compound

by BNL and DOE in Pump-and-Treat/Recharge System

February 1997 to help define

and guide the remediation

efforts planned, and provide North South

a platform for

communication with

stakeholders. The 30 and 90

day commitments dealt with

the spent fuel pool. The 60 Q Y-I."

day milestone established ........ ......... liii...mumI________......_ _ _

was to initiate operation of a

system which would stop any

further migration of the

tritium plume above the Figure 2- 1: Conceptual Schematic of the Tritium System (BNL, 1998)

drinking water standard

13
towards the southern site boundary. The system, shown in figure 2-1, was ready ahead of

schedule but operation was delayed until May 12, 1997 to resolve concerns raised by Suffolk

County. Note that because of the existence of chemical contaminants, a filter system was

installed prior to recharging the pump effluent.

2.3 Approach to Defining the Extent of Contamination

The initial approach contained two major focuses:

" Identification and control of the source of tritium

" Characterization of the plume

2.3.1 Evaluation of Potential Sources

Investigation of the potential source(s) of the HFBR tritium plume was a major focus of the

initial responses to the discovery of tritium in the groundwater beneath and south of the HFBR

building. BNL analyzed potential sources where the tritiated water could have leaked without

being detected and concluded that the HFBR building must have been the source.

The following findings supported the conclusion that the HFBR must have been the principal

source of the tritium in the groundwater:

1) The results of groundwater sampling indicated high tritium concentrations downgradient

of the HFBR building,

2) Only low concentrations of tritium were found immediately upgradient of the HFBR

Building,

3) Significant contamination was found near the top of the water table in the immediate

vicinity of the HFBR Building (suggesting a source near the sample locations based on

the known groundwater flow directions),

4) No unusual levels of tritium were detected in the groundwater flow path except from the

direction of the HFBR Building,

5) Data on concentrations in the plume were consistent with an assumed long-term

continuous source; and,

6) Leak-rate testing confirmed that the leak-rate from the Spent Fuel Pool (SFP) was 6 to 9

gallons per day. (Note: one gallon of leakage was equivalent to a change in level in the

spent fuel pool of. 004 inches.)

2.3.2 Potential Sources within the HFBR Structure

Source identification within the HFBR building Lesson Learned: It is important to

consisted of reviewing reactor components that had the understand the potential sources of

potential to release tritium into the environment, and groundwater contamination. This

testing components for leaks to determine the integrity knowledge permits a rapid

of each of the potential sources containing tritium. In

some cases leak detection was not possible and ienion fo th efsore and

engineering evaluations and visual inspections were critical for achieving credibility with

performed instead. L ..... , .. J :... Ir ere r uuI iua ursou In p JU I.Ci 

14
As a first step the following systems that manage radioactive fluids were identified and

examined:

" Embedded piping, pits and trenches in the HFBR equipment level floor

" Equipment level floor seams and other penetrations

• Sanitary and storm-water piping systems

* Secondary water cooling systems

For those systems that were accessible and for which leak testing was possible, leak tests were

conducted. However, in some cases, certain components either could not be taken out of service

for testing or could not be isolated to conduct a credible leak test. For those systems, other

methods such as detailed engineering evaluations and visual inspections were used to determine

the likelihood of a past release.

2.3.3 Results of the Spent Fuel Pool (SFP) Leak Tests

Two separate leak tests confirmed that the SFP was leaking tritiated water at a rate of 6 - 9

gallons per day. These leak tests performed in 1997 were more accurate than the previous leak

tests and involved covering the spent fuel pool to eliminate evaporation and measuring water

level changes using a laser measurement system. Historical concentrations of tritium in the pool

had been nominally 40 million pCi/l, with an increase to about 140 million pCi/L in 1995. These

concentrations were determined to be consistent with tritium concentrations observed in

groundwater samples from the plume emanating from the HFBR Building (Sullivan and Cheng,

1997).

23.4 Sanitary Sewer System

Prior to 1995, the nominal tritium concentration in the sanitary sewer system, as monitored at the

outlet of the building, varied from about 10,000 pCi/L to 50,000 pCi/L. The largest contributor

to the tritium concentration in the sanitary system prior to 1995 was the condensate which was

collected and drained from equipment level air conditioning units. At that time, the practice was

changed and the condensate from the Equipment Level air conditioners was no longer discharged

to the sanitary system.

An analysis of the sanitary sewer system near the HFBR Building was conducted using available

information and it was concluded that the sanitary system was not a major source of

contamination for the tritium plume. To support this conclusion, a test was conducted to assess

the overall condition of the sanitary piping under the equipment level floor. To be a major

contributor to the plume, a large breach would have to exist in the below-grade portions of the

system. The test showed a worst-case loss rate of approximately 4 to 7 gallons per day,

indicating that the below-grade sanitary piping was in reasonably good condition and confirming

that it could not be a major contributor to the existing tritium contamination (BNL 1998).

15
2.3.5 Horizontal Wells Installed Beneath the HFBR Containment Structure to Further

Isolate the Potential Source of the Tritium Leak

To further characterize the release of tritiated water from the SFP, horizontal wells were installed

at two locations under the HFBR Building in March 1997. The need to define the source

location this accurately (within a few feet) is not common and horizontal wells are not routinely

used for this purpose. The first (downgradient) well was installed 10 feet south, and parallel with

the southern wall of the SFP. The second (upstream) well was installed 17 feet north and parallel

to the north wall of the SFP (Fig. 2-2). By design, the horizontal wells were to be installed

within the uppermost 2 to 3 feet of the saturated zone of the aquifer to allow for the proper

monitoring of the tritium plume and to ensure that the wells would not go dry upon minor

fluctuations of the water table. During the installation of the wells, variability in soil composition

and saturation resulted in minor deviations in the desired borehole position. Although the upgradient well was installed 1.5 to 2.5 feet below the water table, the down-gradient well was

installed slightly lower than designed, at a position 3.5 to 4.5 feet below the water table. This

had a major impact on the utility of these wells. The screened section of both wells was 50 feet.

Discrete samples were collected at intervals of 10 feet along the screened length (using sample

isolating packers) in an effort to pinpoint the source of the leak.

The rationale behind the placement of the two wells was to:

1) determine the extent of leakage along the length of the SFP;

2) determine concentrations of tritium in groundwater directly beneath the SFP; and

3) evaluate whether tritium has been released from other potential up-gradient sources such

as buried pits, piping, and trenches in the equipment level floor.

Figure 2-2: Horizontal wells for sampling groundwater below the HFBR (BNL, 1998)

Uncertainties existed in the actual pathway that the tritiated water followed in the vadose zone

above the water table, and the tritium from the SFP was detected in the upgradient well due to

lateral spreading. Furthermore, based upon groundwater modeling, laminar groundwater flow,

16
and the observed vertical distribution of tritium in wells located immediately downgradient of

the HFBR, it was recognized that the tritium directly below the SFP was likely to reside within

the uppermost 1 to 2 feet of the aquifer. Thus, the downgradient horizontal well was too far

beneath the water table to capture the high concentration section of the plume.

The horizontal wells were first sampled in late March and early Lesson Learned: Use of

April. Following the initial sampling, spring rains resulted in a

steady rise in water table elevation, and the wells were not in a new techni (ho

proper position to accurately monitor the uppermost portion of the sor in the aquifer until August 1997. source, in this case) should

be carefully planned and

From August 1997 through January 1998 five rounds of samples limitations fully understood

were collected from the horizontal wells, with collection periods before implementation.

corresponding to each 0.5 foot drop in water table elevation. The

results from these samples did not conclusively demonstrate that the SFP was the only source of

tritium emanating from the HFBR facility. The highest tritium concentrations were detected in

the upgradient well at a maximum concentration of approximately 383,000 pCi/L, whereas

tritium concentrations in the downgradient well were much lower, with a maximum observed

concentration of approximately 1,700 pCi/I. The observed higher tritium concentrations in the

upgradient horizontal well could have been caused by the well's higher elevation than the

downgradient well and, therefore, sampling closer to the top of the water table where higher

tritium concentrations were expected to occur.

This effort demonstrated that in hydrogeologic conditions where the contamination is within a

few feet of the water table, it is too difficult to install horizontal wells at the desired depth. Near

the point where the contaminated tritium enters the groundwater there is an extremely thin (< a

few feet) vertical distribution of tritium. It is not possible to install the wells perfectly horizontal

to the water table. At BNL the downgradient well was a few feet deeper than the upgradient

horizontal well. Additionally, near the water table, extraction rates have to be low to prevent

drawing the water down to the well depth. All of these factors make accurate definition of the

contaminant distribution by a 2 to 4 inch horizontal well very unlikely.

2.4 Source Control

2.4.1 HFBR Building Source Control

All spent fuel elements were removed from the SFP and

shipped to the Savannah River Site for storage and final Lesson Learned: Initial efforts

disposition. The last shipment left BNL in early September should focus on eliminating the

1997. After disposal of the spent fuel, equipment in the pool source. Once the source is

(such as control rod blades, fuel storage racks, the strike- eliminated -a more accurate estimate

plate, and the spent fuel retard chute) was removed for of life cycle remediation needs and

storage or disposal. associated costs can be determined.

Water from the pool, totaling 65,520 gallons, was pumped to double-walled storage tanks via

double-walled piping installed at Building 811, the Waste Concentration Facility (WCF), in

compliance with SCDHS Article 12.

17
To eliminate the SFP as a potential future source of tritium contamination in the groundwater, a

double walled stainless-steel liner with leak detection and collection capability was installed. A

freestanding double-walled stainless steel liner with an instrumented low point sump was

selected. This renovated SFP is shown in figure 2-3.

Figure 2-3: Double-fined Spent Fuel Pool

Source control is a required component when implementing EPA's Monitored Natural

Attenuation Guidance. At BNL, source control was achieved by draining the SFP allowing the

plume to be managed in situ on the BNL property.

Further discussion on source control is found in Appendix C, Lessons Learned Applicable to

NRC's Buried Piping Initiative. A potential method for detecting leaks from buried piping using

perfluorocarbon gas tracers is discussed in Appendix D.

2.4.2 Modification of the Existing HFBR Building

BNL and DOE worked with SCDHS to ensure all buried piping, pits, and trenches conform to

SCDHS Article 12. SCDHS Article 12 requires that all systems that contain hazardous waste

have secondary containment. Methods of achieving secondary containment included either

rerouting or retrofitting underground and embedded piping, pits, and trenches in the HFBR

Building. When completed, all potential sources of tritiated water had secondary containment,

except for spills to the equipment level floor. BNL also developed a plan to repair and maintain

floor seams and other penetrations within the equipment level floor to mitigate the potential for

future releases from accidental spills of tritiated water.

18
2.4.3 Vadose Zone Source Contribution

A conceptual drawing was generated using available geologic information from below the HFBR

building and an understanding of groundwater flow to illustrate the area where tritium might be

entering the water table. Log readings from foundation borings drilled during the analysis of the

reactor foundation indicated the vadose zone consists of heterogeneous layers of sand mixed

with varying amounts of silt, clay, and gravel. Direct investigation beneath the HFBR building

was not possible at the time due to containment breach issues.

Tritium from the SFP likely moved preferentially along horizontal layers that contain more

coarse grained materials as illustrated in Figure 2-4.

Figure 2-4: Conceptual Drawing of Vadose Zone Transport Beneath the HFBR (BNL, 1998)

(Note that drawing is misleading regarding the width of the clay unit- it is permeable silty clay)

Once the tritium reached the saturated zone of the aquifer, it moved in a thin layer along the top

of the water table under the reactor where there was no downward gradient due to rainwater.

The observed higher concentrations in the upgradient well were explained as being due to two

factors: the upgradient horizontal well was at a higher elevation (closer to the water table with

higher tritium concentrations) than the downgradient well: and the tritium likely has moved

northward during transport through the vadose zone, to the saturated zone.

This effort at source characterization illustrates the difficulty in Lesson Learned: The

defining every flow path close to a potential tritium leak source. release of contaminants

However, at greater distances, the extensive network of temporary from the aquifer's vadose

and permanent monitoring wells was effective in delineating the zone, particularly mobile

plume. contaminants such as

tritium needs to be

considered as a continuing

source term.

19
'1

Tritium released into the vadose zone often migrates into and out of dead-end pores. This causes

a long-slow release of tritium. This effect has been observed at the HFBR and other tritium leaks

at BNL. In addition, water table elevation changes happen on a faster time scale than diffusion.

Therefore, when the water table is rising, tritium just above the previous water table elevation in

the capillary fringe enters the aquifer. This leads to episodic pulses of tritium being released for

transport in the groundwater.

2.4.4 Immediate Hot Spot Removal

Early in the tritium plume investigation the highest Lesson Learned; Hot spot removal in

concentration of tritiated groundwater ranged up to 5.1 LessondLer for mobile

million pCi/L immediately south (downgradient) of the the groundwater for mobile

HFBR containment building. Even before modeling contaminants should be done as soon as

and monitoring were completed it was determined that possible. belays can lead to a longer

removal of these highest concentrations immediately and more complicated cleanup.

downgradient of the HFBR building would be

considered a form of source control and should be performed as soon as possible. Based on

analytical calculations and engineering judgment the lower concentration that would trigger

immediate pumping from a monitoring well close to the HFBR was determined to be 2 million

pCi/L. Source hotspots should be controlled even if monitoring and modeling is not complete.

Inaction at the time of discovery of a hotspot concentration can result in longer and more

complicated remedial activities further downstream.

2.5 Detailed characterization of the plume

In January 1997, tritium was detected in groundwater at a concentration of 44,700 pCi/l in a

monitoring well approximately 100 feet downgradient of the High Flux Beam Reactor (HFBR).

This is in excess of the Federal and State drinking water standard for tritium (20,000 pCi/I).

After discovering the tritium contamination, a swift and extensive characterization program was

initiated to determine the source and extent of the contamination.

Three types of wells were used for characterization. Characterization included forty-five

temporary geoprobe wells drilled to depths of up to 100 feet. These wells were sampled at five

foot intervals and used near the HFBR to determine the plume location and concentrations.

Geoprobe wells were installed upstream and downstream from the HFBR. These wells

confirmed that the HFBR was the source of the tritium.

Twenty-seven permanent monitoring wells were installed downgradient of the HFBR. These

wells provide water table measurements needed for accurate modeling of plume movement and

provide fixed sampling locations. Several permanent wells were installed close to the HFBR and

provide access for withdrawal of high concentration sections of the plume. These wells typically

had 10 foot screens.

Sixty-three temporary vertical profile wells were installed at depths to fully characterize the

plume (< 200 feet below land surface). These wells had 5 foot screens and were sampled at ten

foot intervals from the water table down with approximately 20 sample locations per well. At

20
some sampling locations, VOCs from other sources were found in the groundwater. Therefore,

wells were sampled for tritium, VOCs, and other radionuclides. In all over 1500 samples were

analyzed for tritium and VOCs within a three month period.

Figure 2-5 shows the well locations used for sampling. Key location references and their

approximate distance downgradient from the HFBR in the figure include Cornell Avenue (-100

feet), Temple Place (- 300 feet), Brookhaven Avenue (-750 feet), Rowland Street (- 1500 feet),

Weaver Drive (- 2500 feet) and Princeton Avenue (-3000 feet). These streets on the BNL

property will be referenced in the following discussions of the plume. Figure 2-6 shows the

concentration profile along the centerline of the plume in April of 1997, for approximately 3000

feet from the HFBR and the location where the pump and recharge system was installed, near

Princeton Avenue. The peak tritium concentration measured at this time was 651,000 pCi/L and

the location was just in front of the HFBR (Figure 2-7).

LEGEW TTU )T

* -t r- - * * IfJAN 

STAiUS 61ýii- IS JAN. IM

*

* t~*. - - .4

* *-

**

*9~ *Wt.

*9~9 *Q.99

C

22

1E

Z

_) 0

X

0

WCALE

1

II

II!

Iii *999 - -

~ *~~* - 9--

-9

Figure 2-5: Map showing location of sampling wells used to define the tritium plume

21
The characterization efforts showed that the plume of tritium was

vertically thin (30 feet after 2000 feet of movement

downgradient). Wells installed for tritiated water sampling must

be much more in the center of the plume than is the requirement

for contaminants with non-zero retardation coefficients or

density differences with water (e.g. VOCs). This required a

large number of wells for sampling.

Lesson Learned:

GeoprobesTM and temporary

wells (vertical profiles) are

effective tools for an

.early response" plume

characterization

mom a.

I

S

I

I.,.

-mEI

.IU'

I -'U

Figure 2-6: Cross Section of the Tritium Plume as function of distance from the HFBR (BNL, 2002)

Figure 2-7: Sampling data results associated with the plume characterization (BNL 2002)

Operations at the HFBR were suspended while the source of the tritium was investigated. Wells

just upgradient from the HFBR indicated no tritium contamination and therefore confirmed that

the leak originated in the HFBR.

22
All of these efforts led to a detailed definition of the extent of the tritium contamination.

Groundwater containing tritium at levels above the drinking water standard was found to extend

approximately 2,200 feet south of the reactor; still well within the BNL site. In May 1997, a

pump-and-recharge system was installed at the southern edge of the contamination to prevent it

from spreading further and confine it to Laboratory property, Figure 2-8. This was a temporary

interim action until a formal Record of Decision (ROD) could be obtained for Operable Unit III

(OU II1) which contained other sources of contamination.

Figure 2-8: Location of High Flux Beam Reactor, tritium plume, extraction wells, and recharge

basin (BNL, 2001)

2.6 Regulatory Actions

The remediation of the tritium plume had several

regulatory steps. The first, the Interim Removal Action, Lesson Learned; Effort should be

was reviewed by EPA and NYSDEC under the terms of expended to manage a plume within

the Interagency Agreement (lAG) and is documented in the facility boundaries. Once offthe Final Action Memorandum, Operable Unit (OU) III site migration occurs both real and

Tritium Removal Action (DOE, 2000). This allowed perceived risk greatly increase.

action to begin on source control and preventing off-site

migration of the plume. The proposed method for the long-term remediation of the plume was

determined in the OU III RI/FS (Remedial Investigation/Feasibility Study). This was approved

as the final remedial action and approved in the OU III ROD. The basic requirement of these

actions was to prevent plume growth and off-site migration of the plume.

23

3.0 MODELING THE HFBR TRITIUM PLUME

Prior to the discovery of the tritium contamination, BNL had developed a detailed groundwater

flow model to address other groundwater contamination issues. The computer code

MODFLOW88 was used to simulate groundwater flow around BNL. In 1996 water-level data

from 225 wells, stream flow measurements from 12 gage stations on 4 rivers, and historical data

of groundwater stressors including operational uses (pumping and surface discharge) and

recharge were used in MODFLOW88 to calibrate the groundwater flow model throughout the

entire site. This simulation covered an area of approximately 600 square miles and included all

of Long Island from the Long Island Sound to the Atlantic Ocean with a width of approximately

30 miles. Eight separate layers were used to simulate the vertical hydrogeologic features on

Long Island.

Having a detailed groundwater site model in place was Lesson Learned: It is essential to

critical for the rapid response needed to address concerns

with the tritium contamination. The site model was used have a calibrated site-wide

as the basis for predicting the migration of the tritium groundwater model in place that can

plume over time. However, the spatial resolution of the be used to select monitoring

site model was inadequate to evaluate the movement of locations, and then be employed to

the tritium plume. For this reason, a telescopic mesh obtain more detailed analysis of the

refinement was used that inscribed a subarea that covered impact of a particular plume.

the HFBR vicinity in much greater spatial detail than the

site model. The mesh size was reduced to 10' X 10' X 10' in the refined model. This HFBR

region sub-model incorporates the hydrogeologic and hydrological data from the larger model

and uses the larger model to provide boundary conditions for subsequent calculations. The

HFBR sub-model covered an area approximately one mile wide and three miles long. It

extended slightly more than a mile south of the southern boundary of the BNL facility.

The computer code MT3D was used to simulate the movement of tritium throughout the aquifer.

MT3D is based on a modular structure to permit simulation of transport components

independently or jointly. MT3D interfaces directly with the groundwater flow model,

MODFLOW, for the head solution, and supports all the hydrologic and discretization features of

MODFLOW. The MT3D code has a comprehensive set of solution options, including the

method of characteristics (MOC), the modified method of characteristics (MMOC), a hybrid of

these two methods (HMOC), and the standard finite-difference method (FDM). Use of the MOC

method minimizes numerical dispersion and was used in the simulations of tritium movement at

BNL.

Initial modeling efforts used finite-difference solution

techniques that had a difficult time reproducing the Lesson Learned: For porous media

concentrations measured in the field. The models under that do not cause substantial

estimated the far-field concentrations. This was a result of mechanical dispersion, modeling using

the tritium plume being so narrow in the directions finite-difference methods may

perpendicular to groundwater flow. One process that under predict downgradient

causes spreading of the plume is mechanical dispersion concentrations for tritium unless

which is caused by the porous media. Even though the great care is placed on accounting

refined model used a ten foot grid spacing there was too for numerical disDersion.

25
much spreading of the contamination due to the approximations used to solve the governing

equations (numerical dispersion). Ultimately this was circumvented by entering a value of zero

for parameters that simulate mechanical dispersion.

The particle tracking code MODPATH was used to assist in tracking flow paths. MODPATH

takes output from the MODFLOW88 groundwater flow model to calculate a velocity

distribution, which is then used to trace out the flowpaths of particles allowing easy visualization

of the flow-field. This was extremely useful in identifying additional locations for monitoring

the plume movement.

A summary of the models employed, their focus, and their strengths is captured in table 3-1.

Table 3-1: Summary of Modeling Information

Model Employed Focus Strengths

MODFLOW Groundwater flow Determination of water flow rate and

direction as a function of withdrawals

and recharge (precipitation and

basins).

MT3D Contaminant Determination of concentrations for

Transport comparison to drinking water

standards.

MODPATH Track Flow Path - Determination of capture zone for

particle tracking treatment options

Operational Variables: BNL is an operating research Lesson Learned; It is important to

facility that has water requirements of document and evaluate site activities that

approximately one million gallons per day. There coument plume sit- tis that

are two major well fields that supply this water.

One field, the Western Well Field containing wells on-site supply well pumping, impacts of

4, 6, and 7, is approximately 3000 feet southwest of recharge basins, major spills/leaks. Natural

the HFBR and has a minor effect on flow near the activities (annual rain fall amounts and water

HFBR. The second supply well field, the Eastern table fluctuations) that impact release and

Well Field contains wells 10, 11, and 12 and is transport should also be documented.

approximately 1000 feet north of the HFBR. When

the Eastern Well Field is in use, this reduces the hydraulic gradient near the HFBR and can

reduce the groundwater flow rate by 30 - 50%. It will also change the flow paths followed by

tritium. Much of this water is used for cooling of large machinery and equipment. The cooling

water is discharged into recharge basins. The most dominant influences to the tritium plume

migration near the HFBR from recharge of cooling water is discharges to Basin HO, which is

approximately 500 feet east of the HFBR. Another recharge basin, RA V, which is a few

hundred feet south of the HO basin also impacts flow around the HFBR. The facility uses of

water complicate the flow of tritium away from the HFBR and must be accounted for to track the

plume and define additional monitoring locations. A more detailed description of the models

and their evolution is contained in Appendix A.

26
3.1 Initial Modeling Objectives (1997)

The HFBR sub-model was initially constructed to achieve the following objectives:

• Assist in plume characterization efforts (length, concentration, volume of contaminated

water, location, total curie content).

" Design the location and pumping rates of the HFBR Pump and Recharge System at

Princeton Avenue,

" Perform comparative analysis of various remediation options to support the OU III

Feasibility Study.

An additional model was used to confirm that evaporation of tritium from the recharge basin

would be at concentrations far below the allowable air quality standard

3.2 Using the Model

The site-wide model was essential for the early

evaluation of the potential impact of the tritium oesson Lwasned; The site groundwater

plume. But as illustrated in Figure 3-1 using the model was an essential tool used to:

green highlighted boxes, it, and the plume specific a) evaluate remedial alternatives

model developed from the site-wide model, b) select design criteria including

continue to be important resources for helping BNL appropriate downstream pumping well

evaluate the effectiveness of the treatment systems locations, determine pumping rates and

and determining if changes to them are needed in cations, determie ppropriate and

order to meet performance objectives. Combined capture zones, and locate appropriate well

with the reporting of the actual monitoring data, the intake screen depths.

output from the model provides a mechanism for c) predict the recirculated groundwater ondemonstrating progress to the stakeholders towards site residence time to compare to the design

the ultimate goal of reaching agreement that the criteria.

clean up objectives have been met.

Site Characterizaton j N.

I ~ Determinre chanes Apl1 aheaia needed to

I - -

iet ad Usmp eon sg

Remedy

Figure 3-1: Use of Models in the Decision-making Process

27

4.0 IMPLEMENTATION OF THE SELECTED REMEDY

On April 14, 2000 the OU III ROD was finalized. The OU III ROD covers several VOC

contamination plumes, the Sr-90 plume and the Tritium plume from the HFBR. The cleanup

objectives in the OU III ROD are to meet drinking water standards in groundwater, to complete

the cleanup in a timely manner (for the Upper Glacial aquifer, this goal is 30 years or less), and

to prevent or minimize further migration of high concentrations in groundwater.

4.1 Evaluation of Remedial Alternatives

As part of the CERCLA process, potential remedial

options ranging from no further action through a tiumotret and sepiratuo a

series of potential alternatives must be evaluated, technologies found in the literature are

Initial HFBR tritium plume design activities began not appropriate for environmental

with a tritiated water treatment technology remediation of the low concentrations and

screening effort. Literature searches resulted in a large volume of tritiated water in an

number of potential remediation technologies aquifer or surface water.

ranging from groundwater freezing to tritium separation techniques such as electrolysis.

Additional techniques that came up in the literature search only applied to tritium gas separation.

Tritiated water treatment technologies can be separated into three categories - immobilization,

separation, and, detritiation.

Immobilization involves freezing the groundwater with pipes containing refrigerant

embedded into the volume of aquifer that is to be frozen. This technique is widely used

in cold climate construction projects where the permafrost in a construction zone must be

prevented from melting during the erection of a structure. Freezing the HFBR tritium

plume was considered prohibitively expensive because of energy and installation costs

and infeasible due to the volume of water and the high porosity of the aquifer materials.

Another method of immobilizing groundwater is to install impermeable structures like

steel pylons, mixing grout with augers into a vertical barrier zone, or installing a grout

curtain. These approaches require an impermeable layer that the bottom of the structure

can be keyed into. This type of geologic formation does not exist below the HFBR

plume. In other geologic settings one or more of these approaches may be appropriate.

Separation processes are divided into several types:

Evaporation and distillation - these processes separate the very slightly heavier

tritiated water (HTO) from regular groundwater water (H 20).

Mass transfer based equilibrium processes - these techniques attempt to preferentially

sorb HTO onto a medium or allow H20 to preferentially pass. Examples include

adsorption, the Girdler Sulfide Process, Liquid Phase Catalytic Exchange, Combined

Electrolysis/Catalytic Exchange, and membrane processes.

" Detritiation technologies use electrolysis to separate and capture the hydrogen from HTO

and H20.

29
Ultimately it was determined that none of these technologies were appropriate. Immobilization

was not possible due to high costs and technical limitations. Separation and detritiation

technologies were designed for much higher concentration reactor cooling water applications

and/or the production of heavy water and are not applicable for the low environmental

concentrations found at BNL. Energy usage and structural needs for stripping towers, piping,

catalysts, and chemical reagents make these technologies infeasible for environmental tritium

remediation. This evaluation led to the recommendation of pump and recharge as the treatment

option.

4.2 Risk Assessment

A detailed Risk Assessment was conducted to Lesson Learned; Political and Institutional

determine ecological and human health risks. The Risks may dominate technical risks in the

nine CERCLA risk criteria were evaluated and the decision making process.

results presented in the OU III ROD. The analysis

showed moderate ecological risks (on-site) and minimal human health risks (Cancer risk less

than EPA 10.6 criteria). Predicted off-site tritium concentrations were well below the drinking

water standard. On-site human health risks to employees are prevented by institutional controls.

Risks to on-site personnel that work on the tritium project (sampling) from tritium are also small.

Nevertheless, there was public outrage and large political pressure to act quickly. These

pressures caused large institutional risks which could have severely impacted the future of BNL

had they not been addressed rapidly.

4.3 HFBR Tritium Plume Downgradient Extraction and Recharge System

The pump-and-recharge remediation was an interim action to ensure tritium above the drinking

water standard did not migrate beyond the southern BNL boundary. It also gave BNL and DOE

time to study alternative remediation technologies or monitoring strategies, and to prepare a plan

to address the high levels of tritium found immediately south of the HFBR Building.

BNL designed, constructed, tested, and put into operation an interim system to intercept the

leading downgradient edge of the tritium plume (BNL, 2009). The system consisted of a pumpand-recharge recirculation system that operated between May 1997 to April 2000 to prevent the

leading edge of the plume from migrating further downgradient thereby ensuring that tritium

above the state and federal drinking water standard of 20,000 pCi/I would not leave

Brookhaven's southern site boundary.

The groundwater extraction and recharge system provided a layer of protection to ensure that

tritium did not migrate towards the BNL site boundary. Subsequently, groundwater modeling

predicted the plume would decay and disperse on the BNL property and not leave the site once

source control at the HFBR building was achieved. Groundwater modeling was also used to

specify the pumping well locations and screen depths and to predict the sufficiency of the

expected capture zone.

Three groundwater extraction wells were installed 3,500- feet south of the HFBR Building near

Princeton Avenue (5,000 feet north of the BNL property line), where the maximum tritium

concentration was 6,440 pCi/l. Groundwater was pumped from a depth of about 150 feet below

30
land surface and piped 3,300-feet northward to an existing recharge basin within the BNL site.

Each well pumped tritiated groundwater from the aquifer at a rate of about 40 gallons per

minute.

Before entering the recharge basin, the water passed through activated carbon filters to remove

chemical contamination that was also present in groundwater in the area. The activated carbon

filters installed in the pumping system remove all of the Volatile Organic Compounds (VOCs) as

an added benefit to the system. Samples of treated water were analyzed regularly in accordance

with New York State Discharge Permit conditions to determine the tritium concentrations being

recharged. Typically, as the water entered the recharge basin, the average tritium concentration

was approximately 500 pCi/I, well below the drinking water standard. The decrease in tritium

concentrations discharged to the recharge basin was due to the dilution effects achieved by the

pumping system.

Evaporation of tritiated water from the recharge basin was calculated and shown not to pose a

risk to human health or the environment. Air monitoring stations were established near the

recharge basin and samples analyzed regularly to measure the tritium in the air to confirm the

calculations. Once the water reentered the ground at the recharge basin, it flowed downgradient

(Figure 2-8), taking approximately nineteen (19) years to reach the southern BNL site boundary.

By that time, natural decay and dilution were predicted by the groundwater model to have

diminished tritium levels to nearly undetectable levels. Monitoring wells located at the BNL

boundary provided further assurance that tritium, above the drinking water standard, would not

leave the BNL site.

... t2' .... 2

HFUR TRPTIUM PLUME - -

Figure 4-1: Hydraulic Containment System for HFBR Tritium Plume (BNL, 1998)

31
The tritium plume was co-mingled with a plume containing several VOCs in excess of their

drinking water standard. A carbon filter was used to treat the extracted water and lower VOC

concentrations to below the drinking water standard before recharge. There was a concern that

the spent carbon filter media would be a mixed waste. Tests were performed to verify that

tritium trapped in the filter media could be easily removed by rinsing with clean (non-tritiated)

water. The rinse water was sampled and recharged since the tritium concentrations were well

below drinking water standards.

4.4 Low Flow Pumping Groundwater Extraction

The OU III ROD (DOE, 2000) also contains

r ien fo ilen vOD(DOE,2000)alsoctarious Lesson Learned; The required cleanup work requremnts for implmening varous should be specified in a performance based

contingency actions to address the HFBR tritium fould be secifidli atperforan sed

plume if certain concentrations are observed at rmawith seady rater thn p

specified locations that are not consistent with remedies already determined. A

original model projections. These contingencies performance based format allows flexibility

include: to perform the remediation cost effectively

and efficiently.

1) Evaluate the need to reactivate the Princeton Avenue Pump and Recharge system if

tritium concentrations exceed 25,000 pCi/L at the Chilled Water Plant Road.

2) Reactivate the Princeton Avenue Pump and Recharge system if tritium concentrations

exceed 20,000 pCi/L at Weaver Drive.

3) Implement a low-flow groundwater extraction system in the most concentrated area of

contamination at Cornell Avenue near the HFBR if concentrations exceed 2M pCi/L.

4) Install and operate an additional low-flow groundwater extraction system near Temple

Place. The exact location, operational parameters and treatment and disposal options for

the extracted water were to be developed during design. The ROD further states that

operation of the Temple Place system is to continue for up to one year. As these

extraction wells operate, extensive monitoring is to occur to evaluate the effect of the

extraction locally, as well as the entire plume. The monitoring data is to be evaluated and

used, in conjunction with modeling, to help determine whether continued operation of

this system is needed to achieve the cleanup objectives. The criteria to decide how long

to operate the system was developed during the design and based on preventing

contingency 1) (above) from occurring.

4.5 Revised Modeling Objectives Activities and Low Flow Pumping

To support the actions required by the ROD, the modeling objectives evolved to support the

entire remedial process, including:

a) Assist in characterizing the high concentration areas of the plume,

b) Assist in designing a low flow pumping system at Cornell avenue,

c) Develop a "trigger" level for a low flow pumping system near Temple Place,

d) Assist in evaluating the performance of the low flow pumping system,

32
e) Assist with the development of a groundwater monitoring plan and interpretation

of data,

f) Assist in coordinating site-wide groundwater management decisions that may

have an impact in the migration of the plume,

g) Provide early warning forecasts if trigger levels at Roland and Weaver may be

exceeded, and

h) Assist in the evaluation of supplemental tritium plume control measures (e.g. high

flow pumping, hydraulic control, groundwater recirculation).

Modeling to support objectives b) and c) indicated that drinking water standards (20,000 pCi/L)

would be exceeded at Weaver Drive (thereby triggering contingencies 1) and 2) unless action

was taken to reduce tritium concentrations from the highest concentrations of the plume.

Modeling was used to set a trigger level of 750,000 pCi/L at which groundwater extraction

would begin. The model predicted that it would be necessary to remove groundwater that had

tritium concentrations greater than 500,000 pCi/L. If this was achieved, modeling showed that

no significant plume growth (i.e., no tritiated water above the drinking water standard of 20,000

pC/L would migrate beyond Princeton Avenue and no tritiated water above an action level of

1,000 pCi/L would leave the site boundary) would occur. Additionally the aquifer would be

cleaned up to below drinking water standards with 30 years or less (i.e., the plume would

disperse and decay within the bounds of its current envelope beneath the BNL property).

Figure 4-2 shows the predicted time to reach drinking water standards using a peak concentration

of 750,000 before low flow pumping (year 2000) and after low flow pumping (year 2001). The

figure demonstrates that the likelihood of achieving the ROD goals was greater if low flow

pumping was performed. Dispersion was turned on and off in the model to help bound the

uncertainty of the projections resulting in a range of expected future downgradient

concentrations.

1000000

odto t r t ofr n km in2

10002

rrid-m2 .1~w me Wiwý

1000 - _ _lonra 

g

0 1 210 12 15

iTMe (Ywsm)

Figure 4-2: Predicted concentrations at Weaver Drive as a function of dispersivity based on initial

conditions in 2000 (before hot spot removal) and in 2001 (BNL, 2001)

33
The modeling was also used to estimate the volume of water that was contaminated above the

trigger level, 50,000 gallons, and the total tritium activity in this part of the plume, 0.21 Ci.

These predictions (50,000 gallons of water and extraction of 0.2 curies of tritium) were used for

design and planning of the removal action. However, it was recognized that there were

uncertainties in the model predictions that could lead to the need to remove as much as three

times as much groundwater to achieve the goal of not exceeding the drinking water standard for

tritium at Princeton Avenue.

4.6 Low Flow Pumping Implementation

Due to the movement of the high concentration section of the plume away from near the HFBR,

efforts for hot spot remediation were focused in the Temple Place area approximately 375 - 500

feet downgradient of the HFBR spent fuel pool (ROD contingency 4). Low-flow pumping began

in September 2000. Simultaneously, additional geoprobe wells were installed further

downgradient to collect samples to define areas that had tritium concentration in excess of the

750,000 pCi/L pumping trigger concentration. A permanent well was installed at each geoprobe

location that exceeded this level. This information was used to adaptively determine the

frequency of pumping events and determine the need for additional extraction wells and their

locations. If the tritium concentration remained above 500,000 pCi/L in a particular well,

another extraction cycle was performed at that well. Once the concentration dropped below

500,000 pCi/L another well was chosen for extraction.

Water was extracted at 5 gpm for 16 hours to remove approximately 5000 gallons of water

during each event. This water was pumped to a tanker that transported the waste for off-site

disposal at a licensed facility. Overall, a total of 95,000 gallons of tritium-contaminated

groundwater was removed in 21 pumping events from 10 locations during 2000 and 2001.

Sampling of the extracted water indicated that 0.2 Ci of tritium had been removed from the

plume while removing 95,000 gallons of water. This was approximately 20% of the entire

plume inventory in 2001 and was the amount predicted by the modeling as requiring removal to

avoid plume growth. Figure 4.3 also compares the predicted removal efficiency of low flow

pumping with the actual results. Approximately twice as much groundwater was extracted than

predicted by the model.

HFBR Low Flow Pumping Performance

t ~ 0.200

"o0.150

> 0.100

3

E E0.050 C

M 0.000

b 00 Z b P P b P P 1 b & b P ý O-ýGoal

Cumulative Gallons Pumped - Actual

Figure 4-3: Low flow pumping performance-Goal versus Actual

34
Figure 4-4 shows the location of each low flow extraction well relative to the HFBR and shows

the downgradient migration of the highest plume concentration slugs over time.

f Pumping Event #5a;

! • Summer 2001

Pumping Event

#1; Spring 1999

- Pumping Event

#2; Spring 2000

Pumping Event

#3; Fall 2000

1CM$413 Pumping Event

#4; Spring 2001

asW,

Low Flow Tritium Pumping

> 500,000 pCi/L concentrations

Figure 4-4: Low Flow Pumping Tritium Events (BNL, 2001)

35

5.0 HFBR PLUME MANAGEMENT

In 2000, tritium concentrations dropped to nondetectable levels at the extraction wells for the

HFBR pump and recharge system at Princeton Avenue. With agreement of the regulators, the

system was shut down in.September 2000. In April, 2001 the low-flow pumping action had

successfully reduced all plume concentrations below the 750,000 pCi/L trigger level and lowflow pumping was halted. The dynamic nature of the low-flow extraction process (21 sixteen

hour pumping events at ten locations over nine months) and groundwater movement caused

fragmentation of the high concentration area of the plume. This uncertainty led to an upgraded

monitoring plan to insure that trigger levels in the contingencies would not be exceeded.

A monitoring network with 157 wells (22 new wells Lesson Learned; Monitoring well

in 2001) was designed to provide data to follow the screens should be as short as possible

movement of the plume and verify that trigger levels or low-flow purge sampling methods

were not exceeded. Tritium has no retardation, which used to ensure the detection of

smears the plume, and at BNL there was very little vertically discrete layers of tritium.

dispersion. To compensate for these characteristics,

nested permanent wells with relatively short screens (compared to what would be used for other

contaminants in the same location) and/or temporary well sampling should be used for tritium

plume characterization.

BNL's Regional Groundwater Model was used to assist in the placement of the monitoring

wells.

This model is periodically updated based on the latest monitoring data for hydraulic head.

Over 300 groundwater samples were collected for tritium analysis in the region of the low flow

pumping event over a I V2 year period from April 2001, the last pumping event. None of the

samples exceeded the trigger level of 750,000 pCi/L that would have required additional

pumping to occur. The maximum value recorded was 731,000 pCi/L in July of 2001. This well

and another well that had a concentration in excess of 700,000 pCi/L at this time were resampled

two and four weeks after this occurrence and the concentration was always below 670,000 pCi/L.

Activities in excess of the trigger level have not been detected since completion of the low-flow

pumping action in the Summer of 2001. The detailed monitoring provided a technical basis for

no further low-flow pumping.

Similarly, enhanced monitoring was performed to confirm that trigger levels near the Chilled

Water Plant Road or Princeton Avenue were not exceeded. The fragmentation in the plume and

the high concentrations observed in two wells (> 700,000 pCi/L) in July 2001 could lead to

tritium levels exceeding trigger levels downgradient. Temporary well groundwater sampling

techniques (e.g., Geoprobe) were more effective to monitor tritium plumes than permanent

monitor wells. In addition to the dispersion and retardation issues, permanent monitor wells can

overly dilute the tritiated water during sampling.

As an example of the variability in tritium concentrations in groundwater immediately south of

the HFBR building in monitoring well 075-43 increased from 22,600 pCi/L in 2002, to 130,000

pCi/L in 2003. In 1999, tritium concentrations in this well reached 2,500,000 pCi/L. The

37
concentration increase observed in 2003 is likely Lesson Learned; The release of

due to a rise in the water table elevation and contaminants from the vadose zone during

resulting flushing of residual tritium from the soil periods of water table rise needs to be

beneath the HFBR. Tritium concentrations in considered as a continuing source term.

monitoring well 075-43, located on the HFBR Establish field monitoring to achieve early

lawn, increased to 378,000 pCi/L in February. This detection of vadose zone releases.

is illustrated in figure 4-1 which compares water

table elevation with tritium concentrations. Accounting for the travel time between the spent

fuel pool and the monitoring wells shows a good correlation between peak water table elevation

and tritium concentration. Thus even though the spent fuel was removed from the HFBR in

1997 and there were no further releases from the facility, the vadose zone remained a significant

source to the aquifer for several years. After release to the aquifer, this high level slug of tritium

continued to migrate downgradient, in October it was detected in well 075-245, located just

south of Cornell Avenue, at a concentration of 433,000 pCi/L, a value slightly higher than found

near the facility.

Delay time from Water Table increase to

increase in tritium concentration

... .. 47

1,000,000-

42

500,000 41

.40

4Elevation 0- I I3 (MSL)

Jun-97 Dec-97 Jun-98 Dec-98 Jun-99 Dec-99

Figure 5-1: Water table changes leading to increases in tritium concentration. Tritium

concentrations (red), Water Level Elevations (blue) and travel time from peak in water table to

nearest monitoring well.

5.1 Contingency Pumping Triggering Event Lesson Learned; It is important that site

The downgradient extent of the higher activities that could impact plume movement

concentration segment of the HFBR tritium plume are documented and their potential impacts

was extensively characterized in early 2006. These evaluated. This includes on-site supply well

transects were located to the east of Bell Avenue, pumping, impacts of recharge basins, annual

east of Chilled Water Facility Road, and east of rain fall amounts, water table fluctuations,

and major spills/leaks.

38
Weaver Drive. The purpose of these transects was twofold: to characterize the eastward shift of

the plume since the monitoring well network was originally installed, and to characterize the

location and nature of the high-concentration segment of the plume that had been addressed by

low-flow pumping back in 2000-2001.

A tritium concentration of 80,000 pCi/L was

observed in a temporary geoprobe monitoring well Lesson Learned; Regularly scheduled

on the Chilled Water Facility Road. This exceeded monitoring data must be used to periodically

the OU III ROD contingency trigger value of update modeling projections due to the quick

25,000 pCi/L at this location. This exceedance of response of a tritium plume to any change in

the trigger value required BNL to evaluate the the groundwater flow system, even those

possibility of reactivating the HFBR tritium pump caused by natural fluctuations in

and recharge wells. Additional groundwater precipitation.

characterization was performed in the vicinity of

Weaver Drive where tritium concentrations were observed below the OU III ROD trigger level

of 20,000 pCi/L. In the spring of 2006 it was decided to perform semi-annual monitoring of

tritium in temporary geoprobe wells located near the Chilled Water Plant Road and Weaver

Drive. In addition, the centerline of the plume, south of Brookhaven Avenue, has gradually

shifted to the east since 1997 in response to significantly reduced flows to the HO recharge

basin, the use of the OU III recharge basin, and the overall reduction in pumping from supply

wells 10, 11, and 12 located in the eastern well field. This shift has placed the centerline of the

plume to the east of the monitoring well network, as was verified by the groundwater

characterization work completed in early 2006. The eastward shift required modeling using the

BNL groundwater model and evaluated from the standpoint of whether the Princeton Avenue

pump and recharge wells are optimally located to intercept the plume. A recommendation for

one additional well to capture the plume was made.

The OU III Record of Decision (ROD) contingency of Lesson Learned; Tritium's lack of

20,000 pCi/L tritium at Weaver Drive was triggered retardation in groundwater can cause

with a detection of 2 1,000 pCi/L in a temporary well on a permanent monitoring well network

November 2, 2006. A fourth extraction well (EW-16) to become ineffective in response to

was installed to address the plume in the vicinity of external influences. Temporary

Weaver Drive and began operation in December 2007.

Extraction well EW-16 was installed approximately

400 feet north of the existing pump and recharge wells located on Princeton Avenue. Extraction

wells EW-9, EW- 10, and EW- 11 are being sampled quarterly and EW- 16 is being sampled at a

weekly frequency.

The pump and recharge well(s) will be operated until the tritium concentrations from Weaver

Drive to the new extraction well drop below 20,000 pCi/L. The estimated operational duration of

several years is based on the length of the high-concentration area slug and the time it would take

to be completely captured by the new extraction well. These wells have been operating

continuously to the present (May, 2010) except for planned outages.

The decision to turn the wells back to standby will be based on 1) concentrations of tritium being

less than 20,000 pCi/L in the monitoring wells at Weaver Drive as well as the extraction wells,

39
and 2) verification that the new extraction well has captured concentrations of tritium in this area

greater than 20,000 pCi/L. This decision will be supported with data from additional permanent

and temporary wells as needed.

5.2 Use of Data Quality Objectives

BNL actively manages the tritium plume from the HFBR as described earlier and illustrated in

figure 1-9. A key component of this operation is the use of Data Quality Objectives to focus data

collection and modeling on decisions regarding plume management.

For each of the HFBR tritium plume BNL prepares an annual report that answers the following

questions:

1. Was the BNL Groundwater Contingency Plan triggered?

2. Is the tritium plume growing?

3. Are observed conditions consistent with the attenuation model?

4. Is the tritium plume migrating toward the zone of influence of water supply wells 10, 11,

and 12?

5. Has any segment of the plume migrated outside of the existing monitoring network?

Have the cleanup goals been met? Can the groundwater treatment system be shut down?

Based on the answer to these five questions, BNL provides recommendations to improve the

HFBR tritium plume management. For example, when the triggering event (question 1)

occurred in 2005, BNL recommended the addition of an extraction well located upgradient of

existing extraction wells in the high concentration section of the plume.

• Benefits of the DQO process include: Lesson Learned; There are long

• helping to focus data collection and decisions on the term benefits for establishing performance goals; data quality objectives (DQOs)

" forming a basis to demonstrate that sampling for plume management at the

frequency can be reduced or increased based on beginning of the process.

trends in the data;

" forming a basis for implementing contingency plans when goals are not being met; and

• forming a basis to implement an exit strategy, such as turning off an extraction system,

when goals are met.

40
6.0 STRONTIUM-90 CONTAMINATION

6.1 Identification of Sr-90 Contamination

Groundwater characterization studies identified two strontium-90 (Sr-90) plumes on the BNL

site with concentrations in excess of the Drinking Water Standard of 8 pCi/L. One plume is

downgradient of the former "Chemical Holes" disposal site, which is the source of the

contamination, and a plume located in the middle of the BNL site. The Chemical Holes area

consisted of 55 pits east of the Former Landfill that were used for the disposal of a variety of

laboratory chemicals and animal remains. The buried waste was excavated in 1997, repackaged

and sent off-site for disposal. The second plume on-site is the result of historical leakage from

operations at the Brookhaven Graphite Research Reactor (BGRR), Pile Fan Sump (PFS) near the

BGRR and the Waste Concentration Facility (WCF). The WCF processed waste from the

BGRR and is located approximately 500 feet north of the BGRR.

These plumes are managed as part of Operable Unit III (OU III) at BNL. Characterization of

these plumes was conducted in 1997 and 1998 to define the extent of contamination. At that

time, site-specific soil Kd measurements were made (Fuhrmann, 1999). Modeling was

performed for each of these three plumes and it was projected that Sr-90 would not leave the

BNL site in concentrations exceeding the 8 pCi/l Drinking Water Standard. This combined with

institutional controls to prevent on-site access of the contaminated water makes the excess cancer

risk to the public and BNL employees much less than the CERCLA goal of less than 10-6.

The 1999 OU III Remedial Investigation and Feasibility Study (RI/FS) considered several

remedial alternatives to address this contamination:

- No action

- Natural attenuation with confirmation through monitoring and modeling

- In-situ precipitation with natural attenuation. Continued groundwater monitoring would

be a part of this alternative.

- Groundwater Extraction/Ion Exchange/On-Site Discharge. Continued groundwater

monitoring also would be a part of this alternative.

- Extraction and Treatment at BGRR!Permeable Reactive Wall at Chemical Holes.

Continued groundwater monitoring would also be a part of this alternative.

In the April 2000 Record of Decision (ROD) the groundwater extraction system with ion

exchange and on-site discharge of treated water was the selected remedy. The estimated cost to

install and operate the system over its 30 year lifetime was $6,500,000.

6.2 Strontium Treatment System Remedial Design

It was recognized that there were several technical uncertainties associated with extracting Sr-90

contamination from groundwater and the subsequent use of ion exchange technology to treat

contaminated groundwater. These uncertainties are reflected in the ROD's mandate for a pilot

41
study as a prerequisite to the final remedial design, and the recognition that the final remedy may

be modified based on the results of this pilot study.

Specifically, the ROD states: "The selected remedy, alternative S5a, involves installing

extraction wells and using ion exchange to remove Sr-90 from the extracted water and on-site

discharge of the clean water. Details of the specific number of treatment systems and locations

needed to meet the cleanup objectives will be determined during the design process. Before

implementation of the remedy, a pilot treatability study will be performed to evaluate the

effectiveness of extraction and treatment. The final remedy may potentially be modified based on

the results of this study. Residuals that contain Sr-90 will be disposed of off-site". Figure 6-1

provides a depiction of the plumes and the data trends from samples analyzed in 2001.

Figure 6-1: Sr-90 Plumes on the BNL Site and Selected Well Concentration Trends (BNL, 2006)

42
6.2.1 Pilot Study

The DOE directed the design, installation, and operation of the Sr-90 pilot treatment system in

2003 and 2004. The pilot study treatment system was built to treat the smaller contamination

plume located downgradient of the former "Chemical Holes" disposal site. This treatment

system used one well to extract water at 50 gpm in the area of the highest measured Sr-90

concentration. Two additional well locations were proposed in other areas of the plume;

however, they were to be operated sequentially to limit the flow to the treatment system to 50

gpm.

The pilot study was highly effective in providing

information that was useful and relevant in Lesson Learned; Pilot studies are extremely

determining a remediation plan for Sr-90 useful in evaluating the effectiveness of

groundwater contamination on the BNL site. remedial alternatives forstrontium-90

Major pilot study findings are summarized below: treatment, providing supporting

documentation to improve a final remedy,

- Sr-90 can be effectively extracted from and in demonstrating responsiveness to the

the aquifer. Even after 14 months of contamination problem.

operating at low flow rates, the pilot

treatment system continues to extract groundwater from the aquifer with significant

concentrations (125 pCi/1) of Sr-90.

- The rate of ion exchange resin usage at the elevated flow rates considered in the RI/FS

was significantly higher than anticipated. Although the ion exchange resin is effective in

removing Sr-90 from the extracted groundwater, the minerals and other natural impurities

in groundwater, contribute to a reduction of the service life of the resin. Hence, there is a

disproportionately high rate of resin usage and low-level radioactive waste (LLRW)

generation in relation to relatively small quantities of Sr-90 actually removed from the

groundwater.

- At the flow rates shown in the RI/FS, this increased rate of resin exchange would result in

an increase in the generation, transportation, and disposal of Low Level Radioactive

Waste (LLRW) from 540 cubic feet per year to 2,800 cubic feet per year.

- The original estimated life-cycle project costs in the RI/FS and ROD, including treatment

system operations and maintenance totaled $6,500,000. In order to meet the same cleanup

objective contemplated in the RI/FS and ROD, and driven almost exclusively by

increased resin usage, and increased LLRW packaging, transportation and disposal

volumes, the life-cycle project costs are now estimated at $55,700,000.

The pilot study has demonstrated that Sr-90 can be extracted from the aquifer. However, a scaled

up high flow system to treat Sr-90 groundwater contamination would generate enormous

quantities of spent, contaminated resin that would need to be disposed of as LLRW. It would be

cost prohibitive to operate the system contemplated in the RI/FS and ROD (BNL, 2006).

43
6.2.2 Additional Characterization of the Strontium-90 Groundwater Contamination

Prior to the ROD (DOE, 2000), the highest Sr-90 concentrations originally found in these plumes

were 769 picoCuries per liter (pCi/1) and 566 pCi/I for the Chemical Holes and BGRR/WCF/PFS

plumes, respectively. Sr-90 groundwater contamination has not been detected in areas off of the

BNL site.

During the fall of 20Q03, supplemental characterization was performed to support ongoing

remedial design activities. Supplemental sampling and analysis indicate that the Sr-90

contamination plumes are generally of the same size, in the same location, and at the same depth

as determined after the original characterization events. However, increased concentrations were

found in the Chemical Holes and BGRR/WCF Sr-90 contamination plumes: 2,540 pCi/1 and

3,150 pCi/l, respectively. Again, Sr-90 groundwater contamination has not been detected in areas

off of the BNL site.

6.2.3 Suggested Alternative Treatment System

The OU III ROD treatment remedy relies on active "pump and treat" and continued monitoring

to reach drinking water standards in 30 years. The selected treatment system adopted in the ROD

relies on two extraction wells operated at high flow rates. The significantly higher concentrations

found in the December 2003 characterization work makes it unlikely that the selected treatment

system would meet the goal of having Sr-90 concentrations below the drinking water standard

within 30-years. As previously discussed, the treatment of groundwater using ion exchange

technology is effective for Sr-90 removal. However, the Pilot study showed that removal of

minerals and other natural groundwater impurities contributes to a reduction of the service life of

the resin at high flow rates. This in turn results in a significant increase in the rate of resin usage

and LLRW generation relative to the relatively small amounts of Sr-90 actively removed from

the groundwater.. Increased resin usage and increased LLRW waste disposal costs have resulted

in an almost ten-fold increase in the original $6.5 million life cycle cost estimate with little or no

improvements in the performance and effectiveness of the remedy. For these reasons, the DOE

evaluated other Sr-90 remedial alternatives in light of its pilot study operating experience.

In view of the supplemental characterization data and pilot study findings, seven alternatives

were considered for remediating Sr-90 groundwater contamination. They are described in the

March 5, 2004 Sr-90 Plume Alternatives Evaluation. This report was provided to the EPA,

NYSDEC and SCDHS in March 2004 and placed in the Administrative Record in June 2004.

Based on the proposed alternatives, it was decided that the existing pilot study treatment system

would continue to be operated for approximately ten years to actively treat the Sr-90 plume

downgradient of the former "Chemical Holes" followed by 30 years of natural attenuation and

radioactive decay. The total duration to meet drinking water standards for this plume is expected

to be 40 years.

At the BGRR/WCF Sr-90 contamination plume located in the center of the BNL site, DOE

proposed to install five extraction wells and groundwater treatment system (ion exchange) using

lessons learned during the installation, operation and maintenance of the pilot study treatment

system. Based on models using the supplemental characterization data, the system would be

44
operated for a period of approximately ten years, followed by 60 years of natural attenuation and

radioactive decay. The total duration to meet drinking water standards is 70 years. Hence, the

limiting duration to reach drinking water standards is 70 years in contrast to the 30-year

objective in the OU III ROD. The total estimated life-cycle cost of the Sr-90 remedial alternative

is $14 million.

It should be noted that neither plume is predicted to leave BNL property above drinking water

standards and that no drinking-water wells are near this plume. It should be further noted that

monitoring wells and a sampling program will continue to monitor the location and extent of the

plume.

The DOE proposed an alternative treatment system for the following reasons:

- This alternative provides for active treatment of the Sr-90 groundwater contamination

and hence would be effective in controlling plume growth.

- According to groundwater modeling, the Sr-90 contamination in the BGRR/WCF plume

would not migrate south of Princeton Avenue or within 6,000 feet of the BNL site

boundary above drinking water standards. The Chemical Holes plume likewise would not

migrate within 1,000 feet of the BNL site boundary. Because groundwater never exits the

BNL site above drinking water standards, there are no receptors and hence no human

health risks.

- This alternative provides a 1,800-cubic-foot reduction per year in the packaging,

transportation, and disposal of LLRW in comparison with the reference treatment system

discussed in the ROD.

- At $14 million, still more costly than the original projected $6.5 million, this alternative

results in cost savings of more than $40 million in comparison with the reference

treatment system in the OU 1II ROD.

- There are no credible technical uncertainties and risks associated with the effectiveness of

institutional controls relative to the 70-year duration required to reach Sr-90 drinking

water standards.

6.3 Institutional Controls for the Groundwater Remediation Program

Institutional controls will also be in place to ensure effectiveness of these and all groundwater

remedies. In accordance with the BNL Land Use Management Plan, dated August 2003, the

following institutional controls will continue to be implemented for the groundwater remediation

program:

- Groundwater monitoring, including BNL potable supply systems and SCDHS monitoring

of Suffolk County Water Authority well fields closest to BNL

- Five-year reviews as required by CERCLA will be conducted until cleanup goals are met

and to determine the effectiveness of the groundwater monitoring program

- Prohibitions to the installation of new supply wells

45
- Public water service in plume areas south of BNL

- Prohibitions to the installation of new drinking water wells and other pumping wells

where public water service exists (Suffolk County Sanitary Code Article 4)

- Property access agreements for treatment systems off of BNL property (deed transfer

with property ownership change)

Due to the slow migration of Sr-90 in groundwater, and the slow groundwater flow of the

Magothy Aquifer, there is ample time to respond to unexpected conditions or deviations in

monitoring data for both plumes. An effective groundwater monitoring well network is vital to

assure that the selected remediation approaches are performing as expected and to identify

deviations. Monitoring well data trends and plume movement will be evaluated on an annual

basis. Several sentinel wells will help monitor plume growth over time to ensure that the Sr-90

plumes remain within BNL property. Increasing trends of Sr-90 contamination in these wells will

be evaluated, and if necessary, changes would be made. Changes could include installing

additional monitoring wells or adding additional extraction wells.

In addition, during the required five-year reviews, a comprehensive evaluation will be performed

to ensure that the plumes are behaving as expected and that the remediation approach continues

to be protective of human health. During these reviews, DOE, EPA, and NYSDEC will evaluate

if modification of the remedy is needed to ensure this protectiveness.

A certification was included in the BNL Annual Groundwater Status Report that the institutional

controls put in place for groundwater are unchanged from the previous certification. It will

confirm that nothing has occurred that would impair the ability of the controls to protect human

health or the environment or constitute a violation or failure to comply with any operation and

maintenance requirements or BNL's Land Use Management Plan.

6.4 Public Involvement

Lengthening the time to reach cleanup goals (drinking water standards) was a major change and

required public input. The DOE conducted a public comment period from Wednesday,

December 15, 2004 to Friday, January 21, 2005. It was announced by publishing public notices

and display advertisements in regional newspapers, conducting mass information mailings

including about 2,300 interested community members, posting a notice on the BNL web page,

and conducting interactive discussions at Community Advisory Committee (CAC) and

Brookhaven Executive Roundtable (BER) meetings. Two public information sessions were held

on Tuesday, January 11, one at midday for BNL employees and one that evening for the general

public.

The CAC represents a cross section of the community and its meetings are a forum through

which public opinion is provided to BNL. The CAC was closely involved in consideration of the

changes being proposed. Specifically, during its scheduled meetings, the CAC was given a

detailed presentation on May 13, 2004 and again on December 9, 2004. A special question-andanswer session was held for the CAC on January 6, 2005 and the CAC's final discussions

occurred during its monthly meeting on January 13, 2005.

46
A Responsiveness Summary was prepared that provided the DOE's response to comments

received during the public comment period. Comments received include a survey of opinions of

the CAC members (17 supported the ESD, 4 opposed it and 1 abstained), three letters and three

emails.

The DOE believed that the proposed remedies were appropriate because they were protective of

human health and the environment and minimized plume growth. The plumes are expected to

remain separated and isolated from public drinking water sources on and off of the BNL

property. This will be regularly checked by a network of groundwater monitoring wells. Should a

plume act differently than anticipated, this monitoring program would detect the change far

enough in advance to allow DOE to change the cleanup remedy, when necessary.

Following this review process, DOE was given permission to modify the OU III ROD to permit

a longer cleanup time (DOE 2005a).

6.5 Sr-90 Plume Management

BNL actively manages the three Sr-90 plumes that are on-site using the process illustrated in

Figure 1-9. A detailed discussion of the BGRR and WCF plumes can be found in Appendix B.

As part of the regulatory agreement, DOE used Data Quality Objectives to focus data collection

and modeling on decisions regarding plume management. For each of the three Sr-90 plumes

BNL prepares an annual report that answers the following questions: (Note that these questions

relate to EPA's Approach for reviewing the performance of cleanup alternatives in their 5 year

review process- Figure 6-2)

1. Was the BNL Groundwater Contingency Plan triggered?

2. Has the plume been controlled?

3. Is the system operating as planned? Specifically, is the aquifer being restored at the

planned rate identified in the Explanation of Significant Differences to the OU III Record

of Decision?

4. Have the cleanup goals been met? Can the groundwater treatment system be shut down?

Based on the answer to these four questions, BNL provides recommendations to improve plume

management. For example, for the Chemical Holes plume the original system design was for

one extraction well operating for approximately 10 years to actively treat the Sr-90 plume,

followed by 30 years of natural attenuation and radioactive decay. Based on increased Sr-90

concentrations identified in monitoring wells further downgradient, two additional extraction

wells were installed in 2007 to ensure the cleanup goals would be met. The additional two

extraction wells are also expected to operate approximately 10 years. Recommendations also

included suggestions on removing wells that were no longer effectively treating the plume and

changing the frequency of monitoring.

47
Question A: Is te

remedy funactioin as

documents?

Question B: Are the

exposeur assumption*.

toxicity data and Remedial

Action Objectives used at

tue tune ot remedy

reamedy?

Figure 6-2: EPA 5 Year Remedy Evaluation Process (EPA, 2001)

48
7.0 COMMUNICATIONS

7.1 History of Community Involvement

Historically, public involvement in BNL's Lesson Learned: Establishing a public

environmental restoration activities was low, but involvement process before there is a

after a Community Relations program was problem is important (Good Neighbor Policy).

established in 1991, public interest and contact At BNL, it was difficult to establish a

with BNL increased. Two major "events" spiked Community Advisory Council (CAC) in a crisis

public interest in the Laboratory restoration situation in an atmosphere of distrust.

activities. First, the free public-water hookups

offered to residents directly south of BNL in January, 1996 prompted over 700 people to attend a

public meeting at BNL. A year later, the second event was the identification of a leak in the

spent-fuel pool of the High Flux Beam Reactor that brought significant media attention and

stakeholder concern. Interaction with the community has been a major focus of BNL's

administration and employees since the tritium leak was found. Surveys of employees and the

community have provided a baseline of information on the status of community relations and

revealed avenues for improving them. These avenues were actively pursued.

Laboratory-wide, several new venues for community involvement were established. BNL

employees now can join an "Envoy" program and represent BNL in community groups to which

they already belong. The BNL Speaker's Bureau was re-instituted and employees are going out

into the community and speaking on a wide variety of topics. But by far the most important is an

independent Community Advisory Council (CAC), composed of representatives of established

stakeholders' groups on Long Island, BNL employees, and several other individuals. The CAC

meets monthly to learn about and discuss Laboratory issues and to offer recommendations to

BNL's Director. A new "Community Involvement Plan" was jointly developed by community

members, BNL's staff and the Department of Energy in April, 1999. The plan provides a

framework for involving the community in decision-making at the Laboratory.

Established venues for exchanging information continue. The Brookhaven Executive Roundtable

(BER), established in August 1997, is composed of elected officials (or their representatives),

regulators, and the Suffolk County Water Authority. Community members routinely attend the

meetings and there is an opportunity for public comment available at each meeting. The BER

was created to facilitate and expedite the flow of information from BNL to some of its key

stakeholders on significant environmental, operational, regulatory, and oversight issues. It has

been very successful by providing up-to-date information (background, status, steps forward)

and doing so early in the process.

The goals of the community relations program have been, and are, the following:

" To inform stakeholders (on-site employees and the public) about the issues being

addressed by the Environmental Restoration Division.

" To solicit input from stakeholders about these issues.

49
" To provide stakeholder input to DOE/BNL senior management and regulators to be used

as one of the decision-making criteria for evaluating cleanup alternatives.

" To develop good relationships with on-site employees, community members and leaders,

and community environmental activists.

" To increase regular communication with stakeholders by expanding the ERD stakeholder

mailing list.

7.2 Summary of Community Participation Activities

There were five major areas of community-relations activities for OU III:

" The Removal Action V / Operable Unit I Groundwater Removal Action and Operable

Units I and III Public-Water Hookups

" The HFBR Tritium Remediation Project

" The OU III Off-site Removal Action

" Early Community Input on OU III Cleanup Alternatives

" OU III Remedial Investigation/Risk Assessment Report, Feasibility Study, and Proposed

Plan

The focus of this report is on Community Relations for the HFBR tritium project.

HFBR Tritium Remediation Project

On January 18, 1997, the U.S. Department of Lesson Learned; Having good community

Energy (DOE) and Brookhaven National relations is critical in times when site

Laboratory (BNL) announced that routine operations negatively impact the

monitoring had identified tritium concentrations community, The lack of good relations led

exceeding the drinking water standard in to an extensive multi-year effort to regain

groundwater at the center of the Laboratory site, the trust of our neighbors.

just south of BNL's High Flux Beam Reactor. This

announcement, in combination with previously discovered groundwater contamination by

volatile organic chemicals, led to a lack of public confidence in the Laboratory's commitment to

public health and safety and the protection of the environment.

In response to this public concern, DOE and BNL actively sought and received feedback from

stakeholders, and responded to the media to ensure that accurate information was disseminated in

a timely and consistent manner.

January - June 1997: To understand the community's concerns and to keep people informed,

Community Relations representatives and subject-matter experts attended meetings of civic

associations that surround BNL. Approximately 50 presentations and updates on tritium were

given from January through June. In addition, presentations were given to numerous elected

officials, regulators, environmental committees, Rotary clubs and chamber-of-commerce groups.

50
The community-at-large received two mailings that included a briefing page and a letter, and a

question and answer fact sheet about tritium and letter. Five information / poster sessions were

held in the surrounding area, including one at BNL for employees. These provided stakeholders

the opportunity to interact one-on-one with BNL management and subject matter experts so that

BNL would be aware of the concerns of the community and could answer questions. All

information sessions were advertised in local newspapers and in businesses, and announcement

posters were sent to all Suffolk County libraries. Community Relations personnel visited local

businesses to respond to their concerns.

Two input sessions were held to gather feedback from community leaders on the tritium

remediation proposal, and briefings were conducted with regulators for input on the final

discussion and approval of pump-and-recharge and public communication and involvement.

Superfund Activities: When the tritium remediation project was phased into BNL's Superfund

activities, an Action Memorandum describing the pump-and-recharge system was issued. This

Action Memorandum included a public notice, a newspaper advertisement, fact sheets and a

community letter.

Three issues of the Office of Environmental Restoration's Lesson Learned; Workshops and

newsletter cleanupdate included information on tritium availability sessions were much more

remediation. Two information / poster sessions effective communication tools than

(mentioned above) were conducted. In addition, a large publicmeetings. Specific items

tritium-remediation poster was included and subject- of concern could be addressed more

matter expert attended all subsequent information

sessions / poster sessions held on the HFBR, and at the

Accelerated Cleanup 2006 poster session in July 1997. Well over a dozen tours of the

monitoring-well areas and remediation system were given to community groups.

Media Relations: Between January and December, Lesson Learned; The BNL experience

1997, media relations issued approximately 40 press revealed some public relations initiatives

releases on the tritium remediation project. Personnel that did not work. Providing weekly updates

from Public Affairs and Community Relations of the plume characterization to the media

informed stakeholders before distributing these releases via press releases is one example. Some in

in order to maintain an open dialogue, the community thought that the newspaper

article was a new problem being discovered

Approximately six press conferences/media each week.

availabilities and approximately 1000 media requests

were coordinated and handled. Briefing pages and fact sheets were written. Over 250 calls from

concerned citizens were answered.

7.3 Public Water Hook-ups

A 1995 residential well sampling program in the area south (downgradient) of BNL showed no

radiological or chemical contamination from BNL above drinking water standards (groundwater

solvent contamination thought to originate from a local business south of BNL was found in

some wells).

51
The Agency for Toxic Substances and Disease Registry (ATSDR), a division of the U.S.

Department of Health and Human Services, released its Health Consultation Report and an

equally important Addendum to the report. The Agency began the consultation at the request of

the U.S. Department of Energy (DOE) as part of the ongoing Superfund cleanup at BNL. The

purpose of the Health Consultation was to examine the groundwater quality and determine the

potential impact, if any, to public health if area residents were to use water from their private

wells for drinking or bathing. The Agency stated that "there is no indication that anyone is being

exposed to all the contaminants or all the plumes." Based on the sampling results of private

residential wells, the Agency has concluded that the contamination, which includes volatile

organic compounds (VOCs) and low-level radionuclides, is "not sufficient to produce adverse

health effects."

However, as a precautionary measure, the U.S. Department of Energy (DOE) extended water

mains and offered home and business owners free hookups to the public water supply. The DOE

offer was initiated in January 1996. As of January 1998, 1,500 property owners in North Shirley,

East Yaphank, and Manorville had been connected to public water.

Providing public water to these homes Lesson Learned; Public perception may not

downgradient from BNL guarantees the drinking always agree with technical facts. Lack of

water supply will not be impacted by BNL trus agreenith chnity and L

operations. However, many people in the trust between the communitand BNL

community took this act as tacit proof that caued mavy people to believe they were

contamination may negatively impact their health. negatively impacted by BNL operation.

This reflects the lack of trust between BNL and

the community at that time.

-L

'- ++ ,i • . I

1 ~Ira

P4hbcwukxi nI.xty 

Figure 7-1: Location of plumes and treatment systems (boxed

areas) VOC contamination off-site (BNL, 2008a)

52
7.4 Continuing Community Involvement

The Community Advisory Council (CAC) continues to be an active element in providing a

communication link between the community and the Laboratory on a wide range of issues.

Figure 7-1 shows plume treatment systems operating in 2008. Among other issues, all plumes

are actively followed by the CAC. They meet monthly and provide recommendations to the

Laboratory Director as requested. As noted on their web page

http://www.bnl.gov/communitv/cac/default.asp the CAC was formed in 1998 to advise the

Laboratory Director on selected issues, particularly on the environment, safety, and health. It is

the intent of the Laboratory that the Community Advisory Council (CAC) represents a diverse

range of interests and values of individuals and groups who are interested in or affected by the

actions of the Laboratory. The CAC consists of representatives from 25 local business, civic,

education, activist, environment, employee, emergency, and health organizations.

In September 2008, the CAC celebrated their 10th anniversary. They were presented with a

Certificate of Appreciation from the U.S. Department of Energy acknowledging their role in

regaining the community's confidence and trust in the Laboratory and for their dedication,

curiosity, and guidance. Many New York State and local officials also recognized the CAC for

their contributions and exemplary service to the community.

The CAC sets its own agenda, brings forth issues important to the community, and works to

provide consensus recommendations to Laboratory management. Meetings are held on the

second Thursday of each month.

53

8.0 SUMMARY

Discovery of tritium in the groundwater near the Brookhaven National Laboratory (BNL) High

Flux Beam Reactor (HFBR) in January 1997 initiated an intense effort to locate its source,

determine its extent, and implement remediation methods to mitigate its consequences. The

tritium plume that resulted from the slow, long-term leakage of contaminated water from the

HFBR spent fuel pool at BNL was the subject of much attention by the media, State and Federal

regulators, and the public in 1997. Tremendous amounts of resources were dedicated to

characterizing the plume in great detail and in mitigating its consequences. The subsequent

discovery of strontium-90 in March 1997 at levels exceeding the drinking water standard

exacerbated the situation.

The BNL experience in managing radioactive groundwater contamination has led to several

potentially useful lessons that are presented in this report. The lessons have been divided into

five categories: 1) Source control, 2) Monitoring, 3) Modeling, 4) Plume/Risk Management, and

5) Communications as described in Figure 8.1. The specific lessons that may be of value to the

NRC are summarized in this section.

Source Control

Source control involves the

characterization of all potential

sources and the identification of

the source(s) that can lead to

releases to the environment.

For groundwater contamination,

source control also includes

containment of the high

concentration areas of the

plume to prevent migration

downstream (or off-site).

Monitorine

Monitoring is the collection and evaluation of data to

support all phases of cleanup. It should start with

monitoring of facilities for leakage to the environment and

include data collection to support cleanup decisions such

as the effectiveness of the remedy and the ability to stop

collecting data when the plume migrates away from the

well or the remedy has successfully met its objectives.

Plume/Risk Met.

Plume/Risk Management is the

process by which all decisions are

made. It entails use of the

monitoring data and modeling to

support decisions

Communication

Communication is needed in

all phases of the remediation

process and includes

describing the contamination

problem, what caused the

problem, potential risks to the

public from the contamination,

and what is being done to

address the problem. Effective

communication requires the

willingness to listen to and

address, to the extent

possible, stakeholder

concerns. It also requires

frequent discussions to update

stakeholders on the progress

of the cleanup

Modeline

Modeling is the use of

computer tools that

predict the movement

of groundwater and

contaminants, and

their release from the

facility through the

vadose zone into the

groundwater.

Figure 8.1: Lessons Learned Summary by Topic

55
8.1 Source Control

1. Understanding the potential environmental vulnerabilities and identifying the source

of groundwater contamination is critical for achieving credibility with the regulators

and the public.

Figure 8-2: Potential Vulnerabilities at the HFBR for Impacting the Environment

At BNL, a loss of credibility occurred.when initial groundwater monitoring results could not be

explained. It took several months to evaluate all of the potential sources and determine that

previous testing of leakage from the spent fuel pool had been inadequate. Ultimately,

groundwater monitoring data and modeling simulations led to the identification of the spent fuel

pool as the only source that could provide the concentrations of tritium being measured in the

groundwater. Contributions from other potential sources involved a multi-disciplinary approach

- including system engineers and hydrogeologists. Completion of a vulnerability analysis can

provide immeasurable benefit

2. The release of contaminants from the vadose zone, particularly mobile contaminants

such as tritium, during periods of water table rise needs to be considered as a

continuing source term. Establish field monitoring to achieve early detection of vadose

zone releases.

Figure 8-3: Continuing contribution from the vadose zone

56
Figure 8-4: Continuing Source Term with Increase in the Water Table Level

3. Source hotspots should be controlled even if monitoring and modeling is not complete.

Inaction at the time of discovery of a hotspot concentration can result in longer and

more complicated remedial activities further downgradient.

+

~- .~ - "-,

~- ~-

Figure 8-5: Low Flow pumping of high concentrations of tritium (BNL, 2001)

At BNL, a total of about 100,000 gallons of tritiated water with concentrations greater than

500,000 pCi/L were extracted using low flow pumping (5 gallons per minute) over a two year

period to reduce the source term. Reducing the source term at BNL had a measureable impact on

reducing the downgradient concentrations of tritium.

57
8.2 Monitoring

BNL did not adequately monitor leakage from HFBR systems, particularly the small losses from

the spent fuel pool. The detection of strontium-90 in the groundwater near the BGRR also

indicated the need to expand facility monitoring to include auxiliary drain lines and subsystems

where contaminated water could accumulate. The key lessons learned for the monitoring area

are:

4. Facility monitoring is an important defense in the early detection of unexpected

releases to the environment. The realization that tritium was being released from the

HFBR to the groundwater at BNL occurred many years after the release began due to

inadequate facility monitoring. Expansion of the facility monitoring program at BNL

after 1997 uncovered other contaminants that needed to be addressed.

91

-\~ -.-- ---

Figure 8-6: Leakage from underground collection tank (Sr-90) and the HFBR spent fuel pool

(tritium)

5. GeoprobesTM and temporary wells that provided vertical profiles of the contamination

concentrations are effective tools for an "early response" plume characterization.

Vertical characterization of the plume was important at BNL due to the well-defined

(vertically thin) nature of the tritium plume.

58
|

|

11080 ~ * -- ~f

* m I * *in n I * ~--

* ---

(. '~9*~

~L

STATUG A~TE 16JILI

I

*$*** ~4Ilbq

II

aJ

h C. - -

Figure 8-7: Temporary and Permanent Monitoring Wells Used to Characterize the HFBR Tritium

Plume

8.3 Modeling

Modeling is the use of computer tools that predict the movement of groundwater and

contaminants, their release from the facility through the vadose zone into the groundwater. The

availability of a site-wide model prior to the discovery of tritium and strontium-90 in the

groundwater greatly enhanced the ability to evaluate the potential impacts of the contamination

on public health and safety and the environment.

6. It is essential to have a calibrated site-wide groundwater model in place that can be

used to:

" select monitoring locations,

" support risk analysis on the impact of a particular plume

" support evaluation of remedial alternatives, and

" support design (location and pumping rate) of the selected remediation system.

59
Having a detailed groundwater site model in place was critical for the rapid response needed to

address concerns with the tritium contamination. The site model was used as the basis for

predicting the migration of the tritium plume over time. However, the spatial resolution of the

site model was inadequate to evaluate the movement of the tritium plume. For this reason, a

telescopic mesh refinement was used that inscribed a subarea that covered the HFBR vicinity in

much greater spatial detail than the site model. The HFBR sub-model covered an area

approximately one mile wide and three miles long. It extended slightly more than a mile south

of the southern boundary of the BNL facility.

7. It is important that site activities that could impact plume movement are documented

and their potential impacts evaluated. This includes on-site supply well pumping,

impacts of recharge basins, annual rain fall amounts, water table fluctuations, and

major spills/leaks.

1, %MN

Water Supl Sorc Water Areas

Figure 8-8: Potable and Process Well Influence

8.4 Plume/Risk Management

Plume/Risk Management is the process by which all decisions are made. It entails use of the

monitoring data and modeling to support decisions.

8. A well developed process that ensures that all elements are included in a risk based

remediation decision needs to be in place and implemented. The process includes

requirements for contingency plans, regular progress report, and formal periodic

reviews. The process mandated by CERCLA as used at BNL is an eicample of a robust

process.

60
At BNL a self-evaluation is performed annually. The performance measures used for evaluation

are typically a series of questions such as:

(1) Was the BNL Groundwater Contingency Plan triggered?

(2) Has the plume been controlled?

(3) Is the system operating as planned? Specifically, is the aquifer being restored at the

planned rate identified in the Record of Decision?

(4) Have the cleanup goals been met? Can the groundwater treatment system be shut

down?

This kind of approach leads to the next two lessons learned:

______________ Mcmtoring and IIdentify Regulatory 1oeigN Rsquka.menb

_ m

Deeo Ineedadl Y46

I Model using ane Imos" Me" Mst Met?, 1enmedy ure paty

desirmin andangesi

Figure 8-9: Integration of Modeling and Monitoring to Support Performance Measures

9. There are long term benefits for establishing data quality objectives (DQOs) at the

beginning of the process. These benefits include:

• helping to focus data collection and decisions on the performance goals;

" forming a basis to demonstrate that sampling frequency can be reduced/increased

based on trends in the data;

• forming a basis for implementing contingency plans when goals are not being met;

and

" forming a basis to implement an exit strategy, such as turning off an extraction

system, when goals are met.

61
10. In discussion of risk assessment, it is important to factor in risk to the Institution as a

result of public outrage and media attention. At BNL it can often be shown that

human health and ecological risks are below typical regulatory levels of concern.

However, institutional risks (lack of credibility, loss of funding) and public concerns

are often not trivial

8.5 Communication

Communication is needed in all phases of the remediation process and includes describing the

contamination problem, what caused the problem, potential risks to the public from the

contamination, and what is being done to address the problem. Effective communication

requires the willingness to listen to and address, to the extent possible, stakeholder concerns. It

also requires frequent discussions to update stakeholders on the progress of the cleanup.

Because the contaminants at BNL are common with those being found at decommissioned and

operating commercial plants, the following lessons learned are applicable:

11. Public perception may not always agree with technical facts. Lack of trust between the

community and BNL caused many people to believe they were negatively impacted by

BNL operations. The lack of trust even caused some community members to interpret

pro-active public water extensions as a tacit admission of guilt by BNL even though the

data indicated that there were no substantive human health risks.

12. Establishing a public involvement process before there is a problem is important (Good

Neighbor Policy). At BNL, it was extremely difficult to establish a Community

Advisory Council (CAC) in a crisis situation. Initially there was a complete lack of

trust.

13. Communications requires continual effort and providing a venue for regular updates

to environmental regulators, public officials, and the community (Brookhaven

Executive Roundtable-BER and the Community Advisory Council-CA C) is essential

14. The BNL experience revealed some initiatives that did not work This included

providing weekly updates to the media (press releases) of the plume characterization.

Some in the community thought the news was a new problem being discovered each

week

15. Risk communication is important. It is essential to provide a clear message to the

public. BNL had difficulties explaining co-mingled plumes (tritium from HFBR and

VOCs from other sources). In some cases, BNL provided too much data including

contaminant levels far below the drinking water standards which caused members of

the public to believe the extent of contamination was greater than it actually was.

16. Workshops and availability sessions were much more effective than large public

meetings. Specific items of concern could be addressed more readily.

62
9.0 REFERENCES

BNL (2010). BNL Technical Report BNL-52676-2010; BNL Environmental Monitoring Plan

(EMP); 2010 Annual Update; 1/1/2010.

BNL (2009). Operation and Maintenance Manual for the High Flux Beam Reactor Tritium

Plume Pump and Recharge System, February 2009, Rev. 1.

BNL (2008a). BNL Site Environmental Report, Volume 2- Groundwater Status Report.

BNL (2008b). Operation and Maintenance Manual for the Strontium-90 Groundwater Treatment

System; November 14, 2008, Rev. 1.

BNL (2008c). BNL Procedure EM-SOP-309; Groundwater Protection Contingency PlanResponse to Unexpected Monitoring Results; 9/11/08.

BNL (2006). Final Five-Year Review Report for BNL Superfund Site; July 2006.

BNL (2002). BNL Site Environmental Report- 2001 Groundwater Status Report, 6/13/02.

BNL (2001). Operable Unit III, High Flux Beam Reactor, Tritium Low-Flow Pumping

Evaluation Report; September 14, 2001.

BNL (1999). Proposed Plan for Operable Unit III, Brookhaven National Laboratory, March

1999.

BNL (1998). Summary Report- Tritium Remediation Project: High Flux Beam Reactor; March

1998.

Dietz, Russell, Leak Location in Fluid Filled Cables Using the PFT Method, in IEEE

Transactions on Power Delivery, Vol. 14, No. 1, January 1999.

DOE (2009). Final Record of Decision for Area of Concern 31-High Flux Beam Reactor

(HFBR); CERCLIS No. NY 7890008975, 2/09.

DOE (2005a). Operable Unit III Explanation of Significant Differences; CERCLIS No.

NY7890008975, February 8, 2005.

DOE (2005b). Brookhaven Graphite Research Reactor Final Record of Decision; CERCLIS

Number NY7890008975, 1/31/2005.

DOE (2000). Operable Unit III Record of Decision; April 14, 2000.

Dorsch, Bill, Groundwater Update- Review of Treatment System/Plume Status, Performance,

and Proposed Modifications. Presentation to the CAC, 11/13/08.

63
EPA (2001). Comprehensive Five-Year Review Guidance; EPA 540-R-01-007, June 2001.

EPA (2003). Considerations in Risk Communication; A Digest of Risk Communication as a

Risk Management Tool; EPA/625/R-02/004, November 2003.

Fuhrmann, M. BNL Technical Report 82426-2009-IR, "Radionuclide Partition Coefficients for

the BNL Site- For the Saturated and Unsaturated Zones", February 1999.

Geraghty & Miller, Regional Groundwater Model for Brookhaven National Laboratory;

November 1996.

Gunther, W., Hauptmann, M., Sullivan, T (2008); 'The Use of Predictive Modeling in the

Characterization and Remediation of the High Flux Beam Reactor Tritium Plume", Eos

Trans. AGU, 2008 Fall Meeting, Abstract H41L-02, December 2008.

Heiser, J. and Sullivan, T., Long-term Verification of Cover Systems Using Perfluorocarbon

Tracers, BNL-74670-2005-JA, July 2004.

NEI 07-07, Nuclear Energy Institute, Industry Groundwater Protection Initiative-Final Guidance

Document, August 2007.

NRC (2010). Buried Pipes at Nuclear Reactors, Fact Sheet, February 2010.

NRC (2009). SECY-09-0174, Staff Progress in Evaluation of Buried Piping at Nuclear Reactor

Facilities, 12/2/09.

NRC (2006a). Liquid Radioactive Release Lessons Learned Task Force Final Report, 9/1/06.

NRC (2006b). NRC Information Notice 2006-13, Ground-Water Contamination due to

Undetected Leakage of Radioactive Water, 7/10/06.

Price, V. et al., NUREG/CR-6948, Vol. 2; Integrated Ground-Water Monitoring Strategy for

NRC-Licensed Facilities and Sites: Case Study Applications, November 2007.

Sullivan, T. M. and Cheng, L. Y., Modeling Analysis Performed to Estimate the Leak Rate,

Source, and Duration of the Tritium Plume Observed South of the High Flux Beam Reactor,

3/10/97.

USGS (1999). Stratigraphy and Hydrologic Conditions at the Brookhaven National Laboratory

and Vicinity, Suffolk County, New York, 1994-97, Report 99-4086.

64
APPENDIX A: HIGH FLUX BEAM REACTOR TRITIUM MODELING

STUDIES

Prior to the discovery of the tritium contamination, BNL had developed a detailed groundwater

flow model to address other groundwater contamination issues. The. computer code

MODFLOW88 was used to simulate groundwater flow around BNL. In 1996 water-level data

from 225 wells, stream flow measurements from 12 gage stations on 4 rivers, and historical data

of groundwater stressors including operational uses (pumping and surface discharge) and

recharge were used in MODFLOW88 to calibrate the groundwater flow model throughout the

entire site. This simulation covered an area of approximately 600 square miles and included all

of Long Island from the Long Island Sound to the Atlantic Ocean with a width of approximately

30 miles. Eight separate layers were used to simulate the vertical hydrogeologic features on

Long Island.

Having a detailed groundwater site model in place was critical for the rapid response needed to

address concerns with the tritium contamination. The site model was used as the basis for

predicting the migration of the tritium plume over time. However, the spatial resolution of the

site model was inadequate to evaluate the movement of the tritium plume. For this reason, a

telescopic mesh refinement was used that inscribed a subarea that covered the HFBR vicinity in

much greater spatial detail than the site model. The mesh size was reduced to 10' X 10' X 10' in

the refined model. This HFBR region sub-model incorporates the hydrogeologic and

hydrological data from the larger model and uses the larger model to provide boundary

conditions for subsequent calculations. The HFBR sub-model covered an area approximately

one mile wide and three miles long. It extended slightly more than a mile south of the southern

boundary of the BNL facility.

The computer code MT3D was used to simulate the movement of tritium throughout the aquifer.

MT3D is based on a modular structure to permit simulation of transport components

independently or jointly. MT3D interfaces directly with the groundwater flow model,

MODFLOW, for the head solution, and supports all the hydrologic and discretization features of

MODFLOW. The MT3D code has a comprehensive set of solution options, including the

method of characteristics (MOC), the modified method of characteristics (MMOC), a hybrid of

these two methods (HMOC), and the standard finite-difference method (FDM). Use of the MOC

method minimizes numerical dispersion and was used in the simulations of tritium movement at

BNL.

A set of model predictions of tritium distribution.downgradient from the HFBR over time were

performed using the refined HFBR subregion mode. Initial tritium concentrations for the model

were obtained from the site-specific data collected during characterization. At that time, the

peak measured tritium concentration was 651,000 pCi/L. Model predictions included:

Tritium plume location and concentration over 30 years based on historic groundwater

conditions with and without source control. These studies indicated that tritium would

not pass the BNL site boundary in excess of the drinking water standard even without

source control.

A-I
Optimization of Pump and Recharge system in terms of well locations, screened depths

and pumping rate. The treatment system design specified three wells separated

approximately 75 feet at Princeton Avenue. The wells are screened at a depth of 130 -

150 feet with each well removing 40 gpm. This water was sent through carbon filters to

remove VOC contamination from another source on-site. This filtered water was sent to

recharge basin RA V. Tritium concentrations in this water were predicted to be between

1000 - 2000 pCi/L.

Impacts of recharge on tritium transport pathways. The selected recharge basin, RA V,

was close enough to the HFBR plume that the discharge of 120 gpm to the basin alters

the hydraulic gradient in the vicinity and slightly changes the flow direction. Model

predictions suggested that this could shift the tritium plume to the west by 50 - 300 feet

at Princeton Avenue. This shift impacts future monitoring plans and could require

additional extraction wells.

Location and concentration of tritium plume emerging from the recharge basin. Although,

tritium concentrations in the water extracted from Princeton Avenue were expected to be

between 1000 - 2000 pCi/L, a full transport analysis was done for tritium. The travel time to the

sight boundary from this recharge basin is 19 years and predicted concentrations crossing the site

boundary would be less than 200 pCi/L, which is 1% of the drinking water standard.

Application of the Groundwater Models at BNL

Two types of model simulations were run using the detailed HFBR submodel; a long-term

transient historical simulation and a predictive steady-state simulation. The goal of the transient

historical analysis was to evaluate the ability of the model to simulate the evolution of the tritium

plume. The goal of the predictive simulation was to determine the fate of the tritium plume after

30 years of transport. As noted above, a regional model had been developed in 1996 that was

used as the basis for the HFBR submodel that was completed in 1998. However, prior to the

development of the transient and predictive submodels, the regional groundwater model was

recalibrated by inputting the water level data obtained in the vicinity of the HFBR in January

1997. According to G&M, this minor modification resulted in a subtle change in flow direction

that improved the ability of the model to simulate the current observed path of the plume. This

minor change came from incorporating in the model additional vertical layers to improve the

resolution of the shallow portion of the aquifer. Testing showed that an improvement resulted in

the ability of the model to simulate the observed migration path of the tritium plume. This was a

good example of how specific permeability data that was obtained during well drilling could

improve the predictive accuracy of the model. Fine tuning the model to reflect the current plume

characteristics comes with some risk since one may not be aware of other variables that could

have contributed to the plume's current configuration that may not be relevant in the future.

For the historical transient analysis, actual pumping data from on-site wells was input into the

model. Precipitation records were also reviewed to determine the amount of recharge for each

time period (quarterly time periods over 33-years was used to reflect the operation of the HFBR).

A-2
Model Assumptions:

> A constant source at the reactor pool was simulated using three injection wells totaling 9

gallons a day at a concentration of 40 million pCi/L. It was assumed that this source of

tritium from the pool began in 1964 and that the plume contained 6.32 curies of tritium. This

information was not critical to the model since monitoring well data were used as the initial

input conditions to the model. However, the calculated amount of tritium was used to

perform a mass balance to account for the tritium in the future simulations.

For simulations including dispersivity, a 10 to 1 ratio was fixed between longitudinal and

lateral dispersivity. Vertical dispersivity was assumed to be negligible.

> Little historical data exists for the distribution of water discharged to on-site basins so current

data was used for the predictive analysis. The construction of new facilities such as the

Center for Functional Nanomaterials (CFN) and NSLS-II could alter the on-site recharge

characteristics enough to warrant a modification to the model, because of their proximity to

the plume.

> The performance of the low-flow high tritium concentration system was not modeled

directly. The groundwater model assumed that the system worked as designed and that the

concentration of the source term was reduced to 100,000 pCi/L at that point. This may be a

contributor to the fact that the model is under predicting the concentrations of tritium in the

upgradient part of the plume (Dorsch 2003).

> The plume was simulated to migrate under existing long-term average regional hydrologic

conditions.

> The groundwater recharge rate is assumed to be 23 inches per year. This is based on an

average precipitation rate of 48 inches per year (BNL historical records) and an average of

50% recharge and a small % lost to evapotranspiration.

> Horizontal hydraulic conductivity of 160 to 175 feet per day. This is substantiated by on-site

pumping tests in the Upper Glacial aquifer.

> An effective porosity of 0.20 to 0.24 was used.

> The model assumes that the source term has been eliminated as a result of the spent fuel pool

being emptied. However, the release of tritium from the unsaturated zone during periods of

natural water table rise was not considered. (Current monitoring data indicates that this is in

fact occurring). This is a very important assumption for simulating the plume near the

HFBR. If the source term has not been eliminated, then the simulation that shows the plume

disappearing near the HFBR is not accurate. For the purposes of the remediation system,

however, it is not relevant since the pumps are in place to capture the plume if concentrations

exceed the 750,000 pCi/L threshold.

> Overall, the detailed modeling, supported by the extensive monitoring effort, resulted in

accurate predictions that have been effective tools for managing the contamination and have

helped to foster community and regulatory trust.

A-3
Transport Model Calibration:

Transport in porous media is governed by the processes of advection, dispersion, molecular

diffusion, and sorption. Molecular diffusion is not an important transport mechanism at BNL

due to the groundwater flow rates being around 0.5 - 1.0 ft/day. Tritium does not exhibit

sorption. Thus, advection and dispersion are the dominant transport mechanisms. Advection is

dependent on water flow. The site wide groundwater flow went through extensive calibration

efforts as described in the initial paragraph of this Appendix. The calibrated groundwater flow

model was used to generate groundwater velocity values used in the transport analysis.

Prior to the tritium plume BNL typically used values of 30 feet, 3 feet, and 0.5 feet for

longitudinal (along the flow path), transverse (perpendicular to the flow path in the horizontal

plane), and vertical dispersivity (perpendicular to the flow path in the vertical plane). The

tritium contamination data showed that these values were far too large, particularly in the vertical

plane which showed a very narrow band of tritium (low dispersion). Calibration of an analytical

model to the initial monitoring data (1997 data) showed the best match between model

predictions and the data was achieved with longitudinal dispersivity between 3 and 10 feet,

lateral dispersivity of 10% of longitudinal dispersivity, and transverse dispersivity of 0.01 to

0.005 feet.

Numerical modeling using the method of characteristics in the code MT3D led to over prediction

of dispersion and the best fit to the monitoring data was obtained by setting all dispersion

parameters to zero. Thus, the models inherent numerical dispersion was sufficient to account for

the actual physical dispersion caused by non-uniform flow paths.

A-4
APPENDIX B: OPERATION OF SR-90 TREATMENT SYSTEMS

BGRRJWCF Strontium-90 Treatment System

The OU III Brookhaven Graphite Research Reactor (BGRR)/Waste Concentration Facility

(WCF) Treatment System addresses the Sr-90 plumes in groundwater downgradient of these

facilities. Some of the wells included in the OU III BGRR/WCF network are also monitored as

part of the OU III HFBR Tritium program. These wells are sampled concurrently for all of these

programs to avoid duplication of effort.

The BGRR/WCF remedy consists of:

" Operation of five extraction wells using ion exchange to remove Sr-90, with on-site

discharge of the clean water to injection wells

" Operation of the system to minimize plume growth and meet DWS by 2070

" Continued monitoring and evaluation of data to ensure protectiveness

" Institutional controls and five-year reviews

System Description

System operations for this treatment system began in January 2005. There are two extraction

wells (SR-I and SR-2) located south of the WCF and three extraction wells (SR-3, SR-4, and

SR-5) located south of the BGRR. The treatment system typically operates at an average rate of

25 gpm total from the five extraction wells. Groundwater from the five extraction wells is

transported through pipelines to an ion exchange treatment system. The vessels of ion exchange

media are designed to treat groundwater contaminated with Sr-90 to below the 8 pCi/L DWS. In

addition, the influent is also treated for low-level concentrations (less than 10 jig/L) of TVOCs

using liquid-phase activated carbon. Effluent is recharged to the Upper Glacial aquifer via three

drywells approximately 850 feet west of the treatment system. A New York SPDES equivalency

permit regulates this discharge.

Groundwater Monitoring

Well Network

A network of 86 monitoring wells is used to monitor the Sr-90 plumes associated with the

BGRR, WCF, and Pile Fan Sump (PFS) areas. For the WCF plume in the vicinity of the HFBR,

this network is currently being supplemented with temporary wells to monitor the high

concentration Sr-90 and tritium slugs from an accelerator operation ("g-2 ") identified in this area

in 2007 and 2008. Temporary wells were installed in this area during the fourth quarter of 2008

and the first quarter of 2009.

Sampling Frequency and Analysis

In 2008, the sampling frequency for the BGRR and PFS plumes was shifted from a start-up to

O&M phase (semiannual to annual) for most wells. The WCF plume remained at a semiannual

frequency in order to obtain sufficient data to characterize this plume and support pre-design

groundwater modeling for system modification. The well samples are analyzed for Sr-90.

B-i
Monitoring Well/Temporary Well Data

The Sr-90 plume distribution map is shown on Figure B-1. The distribution of Sr-90 throughout

the BGRR, WCF, and PFS areas is depicted based on groundwater data obtained from the fourthquarter 2008 and first-quarter 2009 sampling of the monitoring well network and temporary

wells. The following cross-sectional views are also provided:

Figure B-I: BGRR Sr-90 Plume Distribution-2007

Historically, the highest overall Sr-90 concentration (3,150 pCi/L) occurred in 2003 in a

temporary well installed approximately 200 feet south of the BGRR and slightly upgradient of

the current location of extraction well SR-3. The highest historical Sr-90 concentration in the

WCF area (1,560 pCi/L) occurred in April 2003 in a temporary well installed immediately

downgradient of the six former underground storage tanks (USTs A/B) and approximately 25

feet north of the WCF (Building 811). This area within the WCF is upgradient of the current

location of extraction well SR-i. The highest historical Sr-90 concentration in the former PFS

area (566 pCi/L) occurred in March 1997 in a temporary well installed downgradient of the PFS.

The following is a summary of the 2008 monitoring well data for the three Sr-90 plumes.

System Operations

In accordance with the SPDES equivalency permit, the required frequency for Sr-90 and VOC

sampling is monthly and the pH measurement is weekly. However, samples from the influent,

effluent, and midpoint locations of the treatment system were collected twice a month throughout

2008 in order to optimize resin usage. All system samples were analyzed for Sr-90 and VOCs.

B-2
The influent was also analyzed for tritium, and both the influent and effluent were analyzed

weekly for pH.

January - September 2008 Well SR-1 was off from January to May and well SR-3 was off

February through April due to electrical and mechanical problems. The entire system was off

from August 11 to 26 due to damage from a lightning strike. A resin vessel change-out was

performed from July 11 to August 6, during which time the system was down. A second resin

change-out was performed in February 2008.

October - December 2008." The treatment system ran normally for the entire period.

Extraction Well Operational Data: During 2008, approximately 8.5 million gallons were

pumped and recharged by the OU III BGRR/WCF SR-90 Treatment Systems, with an average

flow rate of 16 gpm.

System Operational Data During 2008, influent concentrations of Sr-90 ranged from 26 to 137

pCi/L, with the highest concentration observed in January. The highest influent tritium

concentration during 2008 was 324 pCi/L in April. During 2008, Sr-90 was detected once in the

effluent samples, at a concentration of 1.7 pCi/L in January. This detection was below the limit

of 8.0 pCi/L. There were no VOCs detected above the SPDES Equivalency Permit discharge

limits in the 2008 influent or effluent samples. During 2008, approximately 8.8 million gallons

of groundwater were processed through the system.

Cumulative Mass Removal Average flow rates for each monitoring period were used, in

combination with the Sr-90 influent concentrations, to calculate the number of milliCuries (mCi)

removed. During 2008, the flow averaged 17 gpm. Approximately 2.7 mCi of Sr-90 was

removed during 2008, for a total of 16.9 mCi removed since system start-up in 2005

Extraction Wells

Maximum Sr-90 concentrations in each of the extraction wells during 2008 were as follows:

* SR-I 113 pCi/L in January

* SR-2 146 pCi/L in October

* SR-3 269 pCi/L in January

* SR-4 23 pCi/L in January

* SR-5 116 pCi/L in January

* During 2008, no VOCs were detected above the drinking water standard in the extraction

wells.

System Evaluation. The OU III BGRR/WCF Strontium-90 Pump and Treat System and

Monitoring Program was evaluated in the context of four basic decisions established for this

program using the groundwater DQO process:

B-3
1. Was the BNL Groundwater Contingency Plan triggered?

WCF Plume: No. There were no unusual or unexpected concentrations in the monitoring

wells associated with this program during 2008.

BGRR Plume: No.

2. Has the plume been controlled?

WCF Plume: No. Based on the monitoring well data, the area of high Sr-90 contamination

near the WCF is controlled and captured by extraction wells SR-I and SR-2. However, based

on the additional temporary well data collected in the vicinity of the HFBR in 2007 through

early 2009, there are high Sr-90 concentrations that are not actively controlled. Preliminary

groundwater modeling of the recent data indicates that if left untreated, the OU III ESD

cleanup objective of meeting the DWS by 2070 would not be met.

BGRR Plume: Yes. Based on the monitoring well data, the high concentration portion of the

plume is being captured by extraction wells SR-3, SR-4, and SR-5.

3. Is the system operating as planned? Specifically, is the aquifer being restored at the planned

rate identified in the Explanation of Significant Differences to the OU III Record of

Decision?

WCF Plume: The hydraulic capture performance of the system is operating as modeled in the

system design. The system has been removing Sr-90 from the aquifer and the resin is

effectively treating the Sr-90 to below MCLs. However, based on current model projections

on the long-term restoration of the aquifer, the elevated Sr-90 concentrations identified just

north of the HFBR indicate that the ESD cleanup objective of meeting DWS by 2070 may

not be met. Additional extraction wells will be necessary to reduce the high concentration

slug (identified as part of the recent characterization effort) to levels that will attenuate in

accordance with the cleanup goal. A complication to addressing the high concentration slug

is that it is co-located with tritium from the g-2 plume, well in excess of the DWS. This will

not permit pumping of the Sr-90 high concentration slug for the next six months to a year.

The g-2 tritium slug has been well defined, and is moving in the aquifer at a rate five to 10

times faster than Sr-90. Once the tritium slug has moved south of this area it will be possible

to pump and treat this segment of the plume.

BGRR Plume: The hydraulic capture performance of the system is operating as modeled in

the system design, and the system has been removing Sr-90 from the aquifer. The resin is

effectively treating the Sr-90 to below DWS. The ESD objectives are expected to be met.

4. Have the cleanup goals been met? Can the groundwater treatment system be shut down?

WCF Plume: No. The cleanup goal of meeting the DWS in the aquifer has not yet been met.

However, the system is minimizing plume growth of the higher concentrations of Sr-90 near

the WCF. Based on the temporary well data from 2007 through March 2009, the OU III

cleanup goal will not be met if the high concentration areas of the plume near the HFBR are

not actively addressed.

B-4
BGRR Plume: No. The cleanup goal of achieving the DWS in the aquifer has not been met,

but the system is preventing and minimizing plume growth of the higher concentrations of

Sr-90.

Recommendations. The following are the 2008 recommendations for the BGRR/WCF

Groundwater Treatment System and Monitoring Program:

" Perform groundwater modeling for modifying the system to address the high

concentration Sr-90 area in the vicinity of the HFBR. Utilize the fourth-quarter 2008

permanent and temporary well data and the first-quarter 2009 temporary well data for

model initialization. Determine the number and placement of extraction wells necessary

to remediate this area and reduce Sr-90 concentrations to levels that will allow for

achievement of OU III ROD cleanup goals.

" Install additional extraction wells to address the Sr-90 hot spot identified in the WCF

plume. The modification to the existing Sr-90 treatment system will consist of several

new extraction wells. The location and exact number of wells will depend on the

distribution of the hot spot following the departure/attenuation of the g-2 tritium slug

from this area. It is currently estimated that the modification will be implemented in

2010.

" For the BGRR Sr-90 plume, install temporary wells to determine the width of the

downgradient portion of the plume.

* Install a temporary well adjacent to monitoring well 075-664 to determine if a permanent

well screened at a shallower depth is necessary at this location.

" Eliminate sampling at monitoring wells 065-11 and 065-177. These wells are

significantly outside of the current plume position and have not detected more than trace

levels of Sr-90 over a number of years.

B-5

APPENDIX C: LESSONS LEARNED APPLICABLE TO THE NRC'S

BURIED PIPING INITIATIVE

"The headlines have not been pretty. As a scientist, I know the relative risk of tritium. In the grand scheme

of radiation, it is well down the scale, but in the area of public perception, it takes on greater significance.

People are asking legitimate questions- what's leaking, where's it leaking, how much is leaking, andmost importantly-what's being done to deal with the problem? The NRC always inspects licensees who

have such leaks and in each case makes certain that licensees are taking the appropriate steps to find

the source, and to protect the public and the environment." (NRC Chairman Jaczko's speech of 2/17/10)

Nuclear power plants have extensive piping systems. Some of these pipes are buried and

transport water that may contain slightly elevated levels of radioactive isotopes, most commonly

tritium. While leakage from some of these pipes has occurred, so far these incidents have not

jeopardized public health and safety. Nonetheless, the NRC and the nuclear power industry are

reexamining the issue of buried piping to determine whether any changes are required in the

current approach to the design, maintenance, and inspection of buried piping.

In 2006, leakage of tritium into the groundwater from different sources at several nuclear power

plants led the NRC to establish a Tritium Task Force. Their investigation resulted in nearly two

dozen recommendations, several of which are applicable to this report:

1. The NRC should develop guidance to the industry for detecting, evaluating, and monitoring

releases from operating facilities via unmonitored pathways.

2. The NRC should evaluate the need to enact regulations and/or provide guidance to address

remediation.

3. The staff should provide guidance to the industry which expands the use of historical information

and data in their 50.75(g) files to the operational phase of the plant. The data provides good

information on current and future potential radiological hazards that are important during routine

operation, and can aid in planning survey and monitoring programs.

4. The NRC should require adequate assurance that leaks and spills will be detected before

radionuclides migrate offsite via an unmonitored pathway.

5. NRC should evaluate whether the present decommissioning funding requirements adequately

address the potential need to remediate soil and groundwater contamination, particularly if the

licensee has no monitoring program during plant operation to identify such contamination.

In his speech of 2/27/10, Chairman Jaczko went on to discuss the need to reevaluate these

recommendations in light of the recent events at nuclear power plants regarding tritium in the

groundwater. He stated:

"Following reports of leaks at a few plants, the NRC created a special task force in 2006 to conduct a

lessons-learned review of these incidents. The task force made more than two dozen

recommendations-a great many of those have been incorporated in the guidance we provide to plants.

While there are NRC requirements for documenting releases into the groundwater and soil and for

ensuring that any releases offsite are below the regulatory limits, the NRC also has relied on licensees to

adhere to certain measures as best practice. Guidance is one thing. A regulatory requirement is another.

Therefore, I intend to ask the staff to relook at the 2006 lessons learned recommendations and determine

whether any changes in this area might be advisable." (NRC Chairman Jaczko's speech of 2/17/10)

C-1
HFBR Lessons Learned

Investigation of the potential source(s) of the HFBR tritium plume was a major focus of the

initial responses to the discovery of tritium in the groundwater beneath and south of the HFBR

building. BNL analyzed potential sources where the tritiated water could have leaked without

being detected and concluded that the HFBR building must be the source.

The following findings supported the conclusion that the HFBR must have been the principal

source of the tritium in the groundwater:

1) The results of groundwater sampling indicated high tritium concentrations downgradient

of the HFBR building,

2) Only low concentrations of tritium were found immediately upgradient of the HFBR

Building,

3) Significant contamination was found near the top of the water table in the immediate

vicinity of the HFBR Building (suggesting a source nearby the sample locations based on

the known groundwater flow directions),

4) No unusual levels of tritium were detected in the groundwater flow path except from

direction of the HFBR Building, and

5) Data on concentrations in the plume were consistent with an assumed long-term

continuous source

Note: Subsequent leak-rate testing confirmed that the leak-rate from the SFP was 6 to 9 gallons

per day.

Potential Sources within the HFBR Structure

Source identification within the HFBR building consisted of reviewing reactor components that

had the potential to release tritium into the environment, and testing components for leaks to

determine the integrity of each of the potential sources containing tritium. In some cases leak

detection was not possible and engineering evaluations and visual inspections were performed

instead where possible. Figure C- 1 provides a general view of the piping and potential sources

of tritium from the HFBR as identified below.

Figure C-I: HFBR Piping Layout (DOE, 2009)

C-2
As a first step the following systems that manage radioactive fluids were identified and

examined:

" Embedded piping, pits and trenches in the HFBR equipment level floor

° Equipment level floor seams and other penetrations

" Sanitary and storm-water piping systems

* Secondary water cooling systems

Table C-lsummarizes the sources that have been identified that have the potential to release

tritium into the environment. Additionally, all records were reviewed to identify past spills of

both primary coolant and light water that may have released tritium to the environment via

leaking floor seams and other floor penetrations (e.g., electrical conduits, pipes, and drains).

Table C-i: Summary of Potential Sources of Tritium from the HFBR

7 7 ..-- -~

Potential Source Description Investigations Pedormed

Leal" 1r

f n~rcicn SI K !o

Primary Coolant

Purification System Piping

I.P-120 & P123 Poe Legs)

Ertedded piping m equipment level floor from

reactor to the trenches listed below. Always

press•rized during operation.

Engineering evaluation. Leak tested at

425 psig during construction.

Primary Coolant Purification

System Trenhes

Trenc.es containing tillers and resin

beds located northeasl od SFE Prma,,

leak detection provided by leak tape and

buildino's airorne monitoring system,

Visual inspection and air leak test using

Leak-Tec. No air sýown to be inlim-atino a,

0.7 inches rregatie pressure in building.

I's Jim

DA Drain, D.0 Transfer i . d Piping, and 9;0 St.orage

Cotlecls: stores, and replaces D.0 from the

pn maiy. shutdon, and experimental sys,

lems. Orairis, vents, siorage lanks: and

transfer equoprmert and embedded piping

connected to -l y water storage tank.

Visual insection and air leak lest usOg

Leak-lec. No air shown to be ýfiltrating

FA101 Pit a: 0.7 inches negative pressure

in buildrng. Su•m filled with water and no

leakage observed.

During I

corn6ruciion;

also piarrned I

CD Floor Drains Floor drains in A, B. and shutdovm cells for

heavy water routed to heavy water storage

tank.

Engineeringevaluation. Leak tested at 50

psig during construction. Additional leak testing planned to demonstrate compliance with

SCDHSAdicle 12 requirements.

Sent Fuel Pool Water

Purilication System Piping

Circulates SFP wvater for cooling and to

auxiliary purilication system. Piping is

continuously full of SFP water.

The discharge ping to and from purificaion system vas tested at 150 psig. Supply

and retum lines isoated and leak tested a! 50

psig. No toss in system pressure obseved.

D-Waste 'A Floor Drain Pi•ng

and Surp

Drinage systam collects Tadioactive ligbl

water from various areas and discharges to

the D0Aste sump.

Engineering evaluation only. Leak tested at

50 psig ouring construction. D-waste sump

and asso.ated drain 0pjipi was leak tested

during TRP.

C-3
Each of the potential sources identified in Table C-I was evaluated to determine if it was feasible

to conduct a leak test, and, if not, to determine other methods that could be used to evaluate the

system's integrity. For those systems that were accessible and for which leak testing was

possible, leak tests were conducted. However, in some cases, certain components either could

not be taken out of service for testing or could not be isolated to conduct credible leak test. For

those systems other methods such as detailed engineering evaluations and visual inspections

were used to determine the likelihood of a release in the past.

Results of the Spent Fuel Pool (SFP) Leak Tests

Two separate leak tests confirmed that the SFP was leaking tritiated water. An initial test

indicated a leak rate of 7 to 14 gallons per day, and a second test, conducted over a longer period

of time that considered the uncertainties of evaporation and temperature, indicated leakage at a

rate of 6 to 9 gallons per day. Additionally, historical concentrations of tritium in the pool have

been nominally 40 million pCi/l, with a noted increase to about 140 million pCi/L in 1995. These

concentrations are consistent with an assumed source that would produce the tritium

concentrations observed in samples from the plume emanating from the HFBR Building.

3' Thick

Sett~ om.A to 

Z' Florq m Pw ts nt Sides

Figure C-2: Cross section of spent fuel pool (BNL, 1998)

The results of leak tests performed on other systems revealed that floor seams and penetrations

within all three HFBR cells (A, B, and shutdown cells) on the equipment level accepted small

amounts of water. Cells are rooms within the HFBR Building. Therefore, these seams and

penetrations were suspected pathways for primary coolant that spilled in these areas in 1995 to

migrate from the HFBR Building.

Sanitary Sewer System

An analysis of the sanitary sewer system near the HFBR Building was conducted using available

information and it was concluded that the sanitary system was not a major source of

contamination for the tritium plume (Wood 1997a). To support this conclusion, a test was

conducted to assess the overall condition of the sanitary piping under the equipment level floor

(Ports 1998). To be a major contributor to the existing plume, a large breach would have to exist

C-4
in the below-grade portions of the system. The test showed a worst-case loss rate of

approximately 4 to 7 gallons per day, indicating that the below-grade sanitary piping was in

reasonably good condition and confirming that it could not be a major contributor to the existing

tritium contamination.

Prior to 1995, the nominal tritium concentration in the sanitary sewer system, as monitored at the

outlet of the building, varied from about 10,000 pCi/L to 50,000 pCi/L. Short duration spikes of

up to 300,000 pCi/L were observed several times since 1993. Changes in concentration resulted

from operational and maintenance activities and also seasonal changes in atmospheric

temperature and relative humidity. The largest contributor to the tritium concentration in the

sanitary system prior to 1995 was the condensate which was collected and drained from

equipment level air conditioning units. At that time, the practice was changed and the condensate

from the Equipment Level air conditioners was no longer discharged to the sanitary system.

The average tritium concentration of the air conditioning condensate was typically about 150

million pCi/1. The volume discharged from the air conditioners varied due to seasonal variations

in relative humidity. This source of tritium was subsequently diluted in the sanitary header by

other water being discharged from the building; in particular, once- through cooling water from

the building air compressors and the SFP cooler. The flow through these systems was estimated

to be about 35 gpm. There were also smaller diluting flows from other once-through cooling

sources and routine sanitary discharges from such items as sinks, showers, and toilets. The total

sanitary flow from the building was estimated to be between 50 and 75 gpm.

Since the air conditioning condensate discharges into the sanitary system were historically

discrete sources of tritium with relatively high concentrations, the tritium concentration in the

sanitary system was not necessarily uniform. The test confirmed that there were no large breaks

in the embedded portions of the sanitary system and, therefore, it could not have been a major

contributor to the existing plume.

Accidental discharge to the sanitary drains within the HFBR Building was unlikely because the

sanitary drains are elevated off the floor. For a leak or spill to exit through the sanitary system,

the spill would have to be approximately 1/2-inch deep. This had never occurred, and was

unlikely to occur considering that the SFP, elevator shafts, and D-waste drains are the lowest

points in the floor, and spills would flow to these locations first.

To further characterize the release of tritiated water from the SFP, horizontal wells were installed

at two locations under the HFBR Building in March 1997. The first (downgradient) well was

installed 10 feet south, and parallel with the southern wall of the SFP. The second (upgradient)

well was installed 17 feet north and parallel to the north wall of the SFP.

The rationale behind the placement of the two wells was to:

1) determine the extent of leakage along the length of the SFP;

2) determine concentrations of tritium in groundwater directly beneath the SFP; and

3) to evaluate whether tritium has been released from other potential up-gradient sources

such as buried pits, piping, and trenches in the equipment level floor.

C-5
IL

N;;~m~ dl7 6WdnFigure C-3: Use of Horizontal Wells to Detect Source Location

However, uncertainties existed in the actual pathway that the tritiated water followed in the

vadose zone above the water table (Fig. C-3) and the tritium from the SFP may be detected in the

upgradient well due to lateral spreading. Furthermore, based upon groundwater modeling,

laminar groundwater flow, and the observed vertical distribution of tritium in wells located

immediately downgradient of the HFBR, it was recognized that the tritium directly below the

SFP was likely to reside within the uppermost 1 to 2 feet of the aquifer.

By design, the horizontal wells were to be installed within the uppermost 2 to 3 feet of the

saturated zone of the aquifer to allow for the proper monitoring of the tritium plume and to

ensure that the wells would not go dry upon minor fluctuations of the water table. During the

installation of the wells, variability in soil composition and saturation resulted in minor

deviations in the desired borehole position. Although the up-gradient well was installed 1.5 to

2.5 feet below the water table, the down-gradient well was installed slightly lower than designed,

at a position 3.5 to 4.5 feet below the water table.

The horizontal wells were first sampled in late March and early April. However, the initial

sampling technique resulted in possible dilution of the samples, making it more difficult to

obtain meaningful estimates on peak tritium concentrations within the plume. Following the

initial sampling, spring rains resulted in a steady rise in water table elevation, and the wells were

not again in a proper position to accurately monitor the uppermost portion of the aquifer until

August 1997.

From August 1997 through January 1998 five rounds of samples were collected from the

horizontal wells, with collection periods corresponding to each 0.5 foot drop in water table

elevation. The results from these samples did not conclusively demonstrate that the SFP was the

only source of tritium emanating from the HFBR facility. The highest tritium concentrations

were detected in the upgradient well at a maximum concentration of approximately 383,000

pCi/L, whereas tritium concentrations in the downgradient well were much lower, with a

maximum observed concentration of approximately 1,700 pCi/l. The observed higher tritium

concentrations in the upgradient well could have been caused by the well's higher elevation than

the downgradient well and, therefore, closer to the top of the water table where higher tritium

C-6
concentrations are expected to occur. Obtaining discrete groundwater samples from the

uppermost foot of the aquifer in the downgradient well was complicated by a steadily rising

water table following heavy rains in mid January 1998.

To assess the area where tritium might be entering the water table, a conceptual drawing was

generated using available geologic information from below the HFBR Building and an

understanding of groundwater flow (BNL, 1998). Log readings from foundation borings drilled

during the analysis of the reactor foundation indicated the vadose zone consists of heterogeneous

layers of sand mixed with varying amounts of silt, clay, and gravel. Because of the layering,

tritium from the SFP likely moved preferentially along horizontal layers that contain more coarse

grained materials.

Another possible explanation for tritium's horizontal and upgradient spread from the SFP was

that it resulted from equilibration of the moisture in the drier soil under the building with the

more moist soil outside the building footprint.

Once the tritium reached the saturated zone of the aquifer, it moved in a thin layer along the top

of the water table under the reactor where there was no downward gradient due to rainwater.

Because the upgradient horizontal well was at a higher elevation (closer to the water table with

higher tritium concentrations) than the downstream well, and because the tritium may move

northward in the vadose zone, the observed higher concentrations in the up-gradient well were

explainable.

This effort at source characterization illustrates the difficulty in defining every flow path close to

a potential tritium leak source. However, at greater distances, the extensive network of temporary

and permanent monitoring wells made the task of delineating the plume more effective.

HFBR Building Source Control

All spent fuel elements were removed from the SFP and shipped to the Savannah River Site for

storage and final disposition. The last shipment left BNL in early September 1997. After disposal

of the spent fuel, equipment in the pool (such as control rod blades, fuel storage racks, the strikeplate, and the spent fuel retard chute) was removed for storage or disposal. Water from the pool,

totaling 65,520 gallons, was pumped to double-walled storage tanks via double-walled piping

installed at Building 811, the Waste Concentration Facility (WCF), in compliance with SCDHS

Article 12.

To eliminate the SFP as a potential future source of tritium contamination in the groundwater, a

double walled stainless-steel liner with leak detection and collection capability was installed. A

freestanding double-walled stainless steel liner with an instrumented low point sump was

selected.

C-7
Modification of the Existing HFBR Building

BNL and DOE worked with SCDHS to ensure all buried piping, pits, and trenches conform with

SCDHS Article 12. SCDHS Article 12 requires that all systems that contain hazardous waste

have secondary containment. Methods of achieving secondary containment included either

rerouting or retrofitting underground and embedded piping, pits, or trenches in the HFBR

Building. When completed, all potential sources of tritiated water had secondary containment,

except for spills to the equipment level floor. BNL also developed a plan to repair and maintain

floor seams and other penetrations within the equipment level floor to mitigate the potential for

future releases from accidental spills of tritiated water.

Subsequently, the Secretary of Energy made a decision to permanently shut down the HFBR. It

is currently in the process of being decommissioned. The double lined spent fuel pool has been

used to temporarily store the highly radioactive components being removed from the facility.

C-8
APPENDIX D: DETECTING LEAKS FROM UNDERGROUND PIPING

SYSTEMS

Background

Perfluorocarbon Tracer (PFT) technology has been widely used to study air movement and leak

detection since the early 1980s. BNL has used PFTs to study atmospheric transport and

dispersion on local, regional, and national scales. These studies have led to increased

understanding of the movement of pollutants and other hazardous substances in the atmosphere

and to improvement and validation of atmospheric transport models. These research programs

have application to issues of critical national and global importance such as homeland security,

air quality, and climate change. BNL has used PFTs for leak detection to study infiltration into

Nuclear Power Plant Control rooms (Dietz, 2002) and the integrity of subsurface pipes, ducts and

barriers (Sullivan, 1998, Heiser, 2001, Heiser, 2002, Heiser, 2005).

There are seven different PFTs that can be analyzed simultaneously. This allows great flexibility

in the design and implementation of tests to localize the source of a leak. In addition, PFTs make

good tracers because of their physical characteristics and because they are present in the

atmosphere at low levels. Background concentrations are several parts in 1015 (parts per

quadrillion by volume, ppqv) so the release of small amounts of PFT results in unambiguous

signals. The large numbers of fluorine atoms and the structure of these molecules cause them to

have high electron affinities, approximately 3 eV. They are detectable at femtogram (10-15)

levels using an electron capture detector (ECD) or using negative ionization chemical ionization

mass spectrometry (NICI-MS). Their relatively low vapor pressures allow PFTs to be

concentrated on adsorbents so the sampling process can be used to increase the PFT signal.

PFTs typically used as tracers are given in Table D- 1.

Table D-1: PFTs commonly used as tracers, acronyms, names, chemical formulae,

molecular weights, and boiling points. .

Acronym Chemical Name

PDCB Perfluorodimethylcyclobutane . . . . P. . . . . . . . . . . . . . . . . . . . . . . . . .

PMCP Perfluoromethylcyclopentane

PMCH Perfluoromethylcyclohexane

o-PDCH iPerfluoro-l,2-dimethylcyclohexane

Molecular Weight 1(Formulag mol')

C6F12 300 .. . . .. . . I . . . . . . . . . . . . . . . . . . .

C6F 12 300

C7F14 350

Boiling Point

45.0

48.1

176

C 8F 16

PECH Perfluoroethylcyclohexane

i-PPCH Perfluoroisopropylcyclohexane

PTCH Perfluorotrimethylcyclohexane

'C8F16

C9F18

C9F18

'400

,400

450

1450

102

1102

1130

1125

D-1
Subsurface Leak Detection from Dielectric Fluid Filled Pipes

Brookhaven's commercially-accepted perfluorocarbon tracer (PFT) technology for underground

leak detection of utility industry dielectric fluids can cost-effectively detect fuel pipeline system

leaks to about 1 gallon per hour (GPH)-3 orders-of-magnitude better than any on-line system

(Ghafurian, 1999).

Figure D-1 provides a schematic diagram of the subsurface pipe leak detection process. To find

a subsurface dielectric fluid (OF) leak, a very small amount of a PFT liquid-- which is itself an

excellent dielectric fluid, is dissolved uniformly into the existing OF in the cable along its entire

length. The PFT liquids are environmentally and biologically benign, and are compatible with

cable system. When a leak occurs, the leaking cable OF wets an area of subsurface soil. The

dissolved PFT in the dielectric fluid evaporates into the soil air. The PFT is then transported by

conventional driving forces (diffusion, barometric pumping, wind-induced pressure gradients,

etc.), ultimately venting into the air above the street. This venting generally occurs close to the

subsurface leak location. Usually the emissions of PFT vapors into the air reach steady state in

less than 24 hours. Based on the tagging levels used, the magnitude of the leak, the prevailing

meteorology, and a number of other site conditions (e.g., depth to the feeder and the

street/above-ground interface conditions), the typical PFT concentrations in the air above the

street at a leak site are in the few to several hundred parts-per-quadrillion (ppq or 10,15) range.

This can be easily detected using an almost real time Dual Trap Analyzer housed in a van that

can go up to 15 - 20 mph. The dual trap analyzer has one trap sampling the air as the van drives

along while the other trap is being analyzed with a two minute analysis time. This continuing

process provides an integrated PFT signal along the pipeline route; the magnitude should be at

the ambient background unless a leak site has been passed.

Mobile PFT

Detection System

Ground surface 1

PFT vapor

Pipe

Leak

Figure D-1: Schematic of Mobile PFT Leak Detection System

D-2
If elevated concentrations are determined while driving, the location of the leak is confirmed by

repeated driving through the area of elevated concentrations at slower speeds. Further

localization is obtained by driving sample probes into the subsurface and sampling the soil vapor

for PFTs. With subsurface sampling, the leak location can be determined within less than 10

feet. The magnitude of detected leaks can be calculated based on meteorological conditions.

Mobile surveys (such as those used periodically in the gas pipeline industry) at about 15 - 20

miles per hour would allow such small leaks to be detected by tagging the fluid with 10-ppb of

perfluorocarbon tracer under worst-case meteorological dispersion conditions. Smaller leaks

could be detected by proportionately larger tagging concentrations. PFTs have been successfully

used to pinpoint leaks in power lines contained in fluid-filled pipes under the streets of Boston,

Chicago, Detroit, and New York City. Consolidated Edison purchased their own mobile PFT

analyzer to conduct leak hunts.

References for PFTs

Dietz, R. N. Multi-tracer control room air in leakage protocol and simulated primary and

extended multi-zone results. Informal Report, BNL-69105, 2002.

Ghafurian, R., Dietz, R. N., Rodenbaugh, T., Dominguez, J., and Tai, N. Leak location in fluid

filled cables using the PFT method. IEEE Trans. on Power Delivery 14, 18-22 (1999).

BNL-65969

Heiser, J. and Sullivan, T. "The Brookhaven National Laboratory perfluorocarbon tracer

technology: A proven and cost effective method to verify integrity and monitor long-term

performance of walls, floors, caps, and cover systems." BNL-52657, Formal Report, March

11, 2002.

Heiser, J., Sullivan, T., Kalb, P., Milian, L. Wilke, R., Newson, C, and Lilimpakis, M.

"Characterization of Leak Pathways in the Below Grade Ducts of the Brookhaven Graphite

Research Reactor Using Perfluorocarbon Tracers," BNL-52629 Formal Report, April, 2001.

Heiser, J., T. Sullivan, and M. Serrato, "Long-term Verification of Cover Systems Using

Perfluorocarbon Tracers" Journal of Environmental Engineering, 131, No. 6, pp. 952 - 960,

June, 2005.

Sullivan, T. M., Heiser, J., Gard, A., and Senum, G. Monitoring subsurface barrier integrity

using perfluorocarbon tracers. J. Environ. Eng. 124, 490-497 (1998).

D-3

NRC FORM 335 U.S. NUCLEAR REGULATORY COMMISSION 1. REPORT NUMBER

(9.2004) (Assigned by NRC, Add Vol., Supp., Rev.,

NRCMD 3.7 and Addendum Numbers, If any.)

BIBLIOGRAPHIC DATA SHEET

(See instructions on the reverse) N U REG/CR-7029

2. TITLE AND SUBTITLE 3. DATE REPORT PUBLISHED

Lessons Learned in Detecting, Monitoring, Modeling and Remediating Radioactive MONTH YEAR

Ground-Water Contamination April 2011

4. FIN OR GRANT NUMBER

N6937

5. AUTHOR(S) 6. TYPE OF REPORT

T. Sullivan, M. Hauptmann and W. Gunther, Brookhaven National Laboratory Technical

7. PERIOD COVERED (Inclusive Dates)

September 2009- May 2010

8. PERFORMING ORGANIZATION - NAME AND ADDRESS (if NRC, provide Division, Office or Region, U.S. Nuclear Regulatory Commission, and mailing address; if contractor,

provide name and mailing address.)

Brookhaven National Laboratory

P.O. Box 5000

Upton, NY 11973-5000

9. SPONSORING ORGANIZATION - NAME AND ADDRESS (if NRC, type "Same as above"; if contractor, provide NRC Division, Office or Region, U.S. Nuclear Regulatory Commission,

and mailing address.)

Division of Risk Analysis

Office of Nuclear Regulatory Research

U.S. Nuclear Regulatory Commission

Washington, DC 20555-0001

10. SUPPLEMENTARY NOTES

Jacob Philip, NRC Proiect Manaqer and Thomas Nicholson, Technical Monitor

11. ABSTRACT (200 words or less)

Brookhaven National Laboratory (BNL) is a multi-discipline Department of Energy (DOE) research institute that has been in

operation since 1947. Historical operations included running accelerators, nudear research reactors, and other large complex

equipment. Some of these operations caused groundwater contamination. This report discusses the tritium plume from the High

Flux Beam Reactor and several strontium plumes from past operations at the Brookhaven Graphite Research Reactor, their

discovery through monitoring, and their treatment. The tritium plume discovery led to public outrage; characterization, design,

and implementation of a treatment system within 60 days; and eventual dismissal of Associated Universities Incorporated from

the management of BNL. Management of the strontium plume included a major alteration to the original regulatory cleanup

agreement when field data showed the preferred alternative to be economically impractical. The report documents activities

used to manage these contamination issues through source control, monitoring, modeling, plume and risk management, and

communications. The lessons learned from these cleanup projects have altered the stewardship culture and methods of

performing research and conducting work at BNL. These valuable lessons are highlighted in this report

12. KEY WORDS/DESCRIPTORS (List words or phrases that will assist researchers in locating the report.) 13. AVAILABILITY STATEMENT

characterization of contaminant sources unlimited

contaminant modeling 14. SECURITY CLASSIFICATION

contaminant plumes (This Page)

ground water unclassified

monitoring radionuclides (This Report)

radioactivity unclassified

remediation and cleanup

tritium migration 15. NUMBER OF PAGES

strontium migration

16. PRICE

NRC FORM 335 (9-2004) PRINTED ON RECYCLED PAPER
Federal Recycling Program

NUREGICR-7029 Lessons Learned in Detecting, Monitoring, Modeling, and Remediating

Radioactive Groundwater Contamination

April 2011

UNITED STATES

NUCLEAR REGULATORY COMMISSION

WASHINGTON, DC 20555-0001

OFFICIAL BUSINESS