POLICY ISSUE 

INFORMATION 

May 25, 2011 SECY-11-0071

FOR: The Commissioners 

FROM: Eric J. Leeds, Director 

 Office of Nuclear Reactor Regulation 

SUBJECT: STATUS REPORT ON POWER UPRATES 

PURPOSE: 

This information paper summarizes the power uprate program accomplishments and challenges 

since the last update in SECY-10-0070, “Status Report on Power Uprates,” dated May 20, 2010. 

This paper does not address any new commitments or resource implications. 

BACKGROUND: 

The staff provides the Commission with an annual update of significant power uprate activities, 

in accordance with the Staff Requirements Memorandum dated February 8, 2002, entitled 

“Briefing on Status of Nuclear Reactor Safety” (SRM-M020129). 

DISCUSSION: 

Since the last update, the U.S. Nuclear Regulatory Commission (NRC) staff has approved 

10 plant-specific power uprates. The staff is currently reviewing 11 power uprates. Over the 

next 5 years, the staff expects that licensees will submit an additional 34 power uprate 

applications. The enclosed status report provides detailed information on the power uprates 

approved since May 20, 2010; applications under review; applications expected in the future; 

accomplishments; challenges associated with power uprates; and program performance. 

CONTACT: Thomas W. Alexion, NRR/DPR 

 (301) 415-1326
The Commissioners - 2 - 

The staff generally met its timeliness goals for six of the eight measurement uncertainty 

recapture (MUR) power uprates approved since May 20, 2010 (for Prairie Island Units 1 and 2, 

LaSalle Units 1 and 2, and Surry Units 1 and 2). The staff exceeded the 6-month review goal for 

the Limerick Units 1 and 2 MUR power uprates by 5 months in order to resolve a staff-identified 

fracture toughness compliance issue regarding the low-pressure coolant injection nozzles and 

some water-level instrumentation nozzles on the reactor vessel. 

The staff exceeded the 12-month review goal for the Point Beach Units 1 and 2 extended power 

uprates (EPUs) by 6 months because additional review time was needed to review key technical 

issues, including (1) a significant upgrade to and modification of the auxiliary feedwater system, 

(2) a reconstituted high-energy line break analysis, which included an onsite audit by the staff, 

and (3) a linked alternate source term license amendment request, which needed to be 

approved first. 

The use of containment accident pressure credit in the safety analyses of some EPU 

applications continues to be an area of discussion between the Advisory Committee on Reactor 

Safeguards and the staff. This issue has delayed the staff’s reviews of the Browns Ferry 

Units 1, 2, and 3, and Monticello EPU applications. The staff prepared SECY-11-0014, “Use of 

Containment Accident Pressure in Analyzing Emergency Core Cooling System and Containment 

Heat Removal System Pump Performance in Postulated Accidents,” dated January 31, 2011, to 

obtain Commission direction on this issue. The staff proposed two options that involve policy 

issues. Both options include resuming work on EPU applications consistent with existing risk 

review guidance and recently-developed deterministic guidance. 

In response to SECY-11-0014, Staff Requirements Memorandum SRM-SECY-11-0014, “Use of 

Containment Accident Pressure in Analyzing Emergency Core Cooling System and Containment 

Heat Removal System Pump Performance in Postulated Accidents,” was issued on March 15, 

2011. SRM-SECY-11-0014 approved the staff’s recommended Option 1. The staff is therefore 

proceeding with Option 1 and plans to resume the CAP portion of the delayed EPU reviews. 

The evaluation of potential adverse effects of increased steam flow rates associated with power 

uprates continues to be a challenge. Two independent industry topical reports were submitted 

for NRC review and approval, which could ultimately provide the industry with two independent 

integrated evaluation approaches and acceptance criteria for steam dryers. Additional details 

and review status are provided in the enclosure. The staff will resume its reviews of the topical 

reports after they are supplemented or resubmitted to address staff technical issues. 

The continuing goal is for the staff to conduct timely power uprate reviews of appropriate scope 

and depth for each of the technical areas while ensuring that safety is maintained. 
The Commissioners - 3 - 

COORDINATION: 

The Office of the General Counsel reviewed this report and has no legal objection. 

/RA Bruce A. Boger for/ 

Eric J. Leeds, Director 

Office of Nuclear Reactor Regulation 

Enclosure: 

Power Uprate Program Status Report 
The Commissioners - 3 - 

COORDINATION: 

The Office of the General Counsel reviewed this report and has no legal objection. 

Eric J. Leeds, Director 

Office of Nuclear Reactor Regulation 

Enclosure: 

Power Uprate Program Status Report 

ADAMS Accession No.: ML110770147 WITS 200200020/EDATS: SECY-2010-0366 

 *via e-mail 

OFFICE PGCB/PM PGCB/LA TECH ED* EMCB/BC SCVB/BC PGCB/BC 

NAME TAlexion CHawes JDougherty MKhanna RDennig SRosenberg 

DATE 03/18/11 03/18/11 03/22/11 04/01/11 03/29/11 04/07/11 

OFFICE OGC (NLO) DORL/D DPR/D NRR/D 

NAME MSpencer JGiitter TMcGinty 

(TBlount for) 

ELeeds 

(BBoger for) 

 

DATE 04/14/11 04/11/11 05/12/11 05/25/11 

OFFICIAL RECORD COPY 
ENCLOSURE 

Power Uprate Program Status Report 

May 2011

Power uprates are categorized based on the magnitude of the power increase and the methods 

used to achieve the increase. Measurement uncertainty recapture (MUR) power uprates result 

in power-level increases of less than 2 percent and are achieved by implementing enhanced 

techniques for calculating reactor power. Stretch power uprates (SPUs) typically result in 

power-level increases of up to 7 percent and generally do not involve major plant modifications. 

Extended power uprates (EPUs) result in greater power-level increases than SPUs and usually 

require significant modifications to major plant equipment. The U.S. Nuclear Regulatory 

Commission (NRC) has approved EPUs for increases as high as 20 percent. 

Power Uprates Approved since May 2010

Power uprates approved since May 20, 2010, have added 884 megawatts thermal (MWt) or 

approximately 295 megawatts electric (MWe) to the Nation=s electric generating capacity. This 

brings the total number of power uprates approved since 1977 to 139, resulting in a combined 

increase of about 18,063 MWt (6,021 MWe) in the Nation=s electric generating capacity. Table 1 

provides information on the power uprates approved since May 20, 2010; details on program 

performance versus established goals for these approved power uprates appear later in this 

report. 

Table 1 - Power Uprates Approved since May 20, 2010

No. Plant % Uprate MWt Application Date Approval Date Type 

1 Prairie Island 1 1.6 27 12/28/2009 08/18/2010 MUR 

2 Prairie island 2 1.6 27 12/28/2009 08/18/2010 MUR 

3 LaSalle 1 1.6 57 01/27/2010 09/16/2010 MUR 

4 LaSalle 2 1.6 57 01/27/2010 09/16/2010 MUR 

5 Surry 1 1.6 41 01/27/2010 09/24/2010 MUR 

6 Surry 2 1.6 41 01/27/2010 09/24/2010 MUR 

7 Limerick 1 1.6 57 03/25/2010 04/08/2011 MUR 

8 Limerick 2 1.6 57 03/25/2010 04/08/2011 MUR 

9 Point Beach 1 17 260 04/07/2009 05/03/2011 EPU 

10 Point Beach 2 17 260 04/07/2009 05/03/2011 EPU 

 Total 884 
The Commissioners - 2 - 

Power Uprate Applications Currently under Staff Review

As illustrated in Table 2, power uprates currently under review could add 4,118 MWt or 

approximately 1,372 MWe to the Nation’s electric generating capacity, if approved. 

Table 2 - Power Uprate Applications under Review

No. Plant % Uprate MWt Application 

Date 

Projected 

Completion Date Type 

1 Browns Ferry 2 14.3 494 06/25/2004 To Be Determined EPU 

2 Browns Ferry 3 14.3 494 06/25/2004 To Be Determined EPU 

3 Browns Ferry 1 14.3 494 06/28/2004 To Be Determined EPU 

4 Monticello 12.9 229 11/05/2008 To Be Determined EPU 

5 Nine Mile Pt. 2 15 521 05/27/2009 Fall 2011 EPU 

6 Grand Gulf 1 13.1 510 09/08/2010 Fall 2011 EPU 

7 Turkey Point 3 15 344 10/21/2010 Fall 2011 EPU 

8 Turkey Point 4 15 344 10/21/2010 Fall 2011 EPU 

9 St. Lucie 1 11.9 320 11/22/2010 To Be Determined EPU 

10 St. Lucie 2* 11.9 320 02/25/2011 To Be Determined EPU 

11 Harris 1* 1.6 48 04/28/2011 To Be Determined MUR 

 Total 4,118 

* These applications are currently undergoing NRC acceptance review. 

Expected Power Uprate Applications

Table 3 estimates future power uprate applications based on a survey of all licensees conducted 

in December 2010. 

Table 3 - Projected Future Power Uprate Applications

Fiscal 

Year 

Power Uprates 

Expected 

MUR Power 

Uprates SPUs EPUs MWt MWe 

2011 10 8 0 2 1,095 365 

2012 15 9 0 6 2,486 829 

2013 0 0 0 0 0 0 

2014 8 5 0 3 1504 501 

2015 1 0 0 1 435 145 

Total 34 22 0 12 5,520 1840 
The Commissioners - 3 - 

Accomplishments since May 20, 2010

The NRC staff accomplishments since May 20, 2010, are as follows: 

• Approved ten plant-specific power uprates, specifically eight MUR power uprates (Prairie 

Island Units 1 and 2, LaSalle Units 1 and 2, Surry Units 1 and 2, and Limerick Units 1 

and 2) and two EPUs (Point Beach Units 1 and 2). 

• Issued acceptance letters for the EPU applications for Grand Gulf Unit 1, Turkey Point 

Units 3 and 4, and St. Lucie Unit 1 (which was resubmitted). 

• Presented information on the Point Beach Units 1 and 2 EPU application to the Advisory 

Committee on Reactor Safeguards (ACRS) Subcommittee on Power Uprates and the 

ACRS Full Committee. 

• Presented general power uprate information at the International Atomic Energy Agency 

Regional Workshop on Regulatory Review of Safety Submittals in Moscow, Russia, 

which included information in the areas of power uprate background, review process, 

and current technical issues. 

• Supported the Integrated Regulatory Review Service Mission by answering questions 

about general licensing processes and specific questions on power uprates, and by 

providing information regarding the staff’s power uprate review process. 

• Issued a revision to an internal office instruction entitled “Power Uprate Process” 

primarily to provide a format to document late power uprate reviews (i.e., those reviews 

that are exceeding the review duration performance goals discussed later in this paper). 

Challenges Associated with Power Uprates

Containment Accident Pressure Credit 

EPUs result in an increase in the temperature of the sump water (in pressurized-water reactors) 

and suppression pool water (in boiling-water reactors) during certain postulated accidents or 

abnormal events. This could affect the performance of the emergency core cooling system 

(ECCS) pumps taking suction from these water sources. In some cases, licensees have 

included containment accident pressure (CAP) in their safety analyses to demonstrate 

acceptable performance of the ECCS pumps. The ACRS recommended changes to this 

practice in a letter to the Executive Director for Operations (EDO) dated March 18, 2009. 

The staff responded to the ACRS by letter dated June 4, 2009. The staff informed ACRS that it 

was carefully reviewing the recommendations of the March 18, 2009, letter and would brief the 

Committee on the results of its review. The staff response also stated that it would consider 

delaying approval of licensing actions that included the use of CAP credit. 

In September and October 2009, the NRC informed two licensees requesting EPUs (i.e., the 

licensees for Browns Ferry Units 1, 2, and 3, and Monticello), which take credit for CAP and are 

currently undergoing NRC staff review, that the agency needed more time to develop additional 
The Commissioners - 4 - 

regulatory guidance to ensure the technical adequacy of their applications. This resulted in 

delays in the staff’s review of these applications. 

By letters dated March 1 and 24, 2010, the NRC provided draft guidance to the Boiling Water 

Reactor Owners Group (BWROG) and the Pressurized Water Reactor Owners Group, 

respectively, and requested that they meet with the NRC staff to discuss it. The staff discussed 

the draft guidance with the BWROG on April 14, 2010, and presented it to the ACRS Power 

Uprate Subcommittee and ACRS Full Committee on April 23 and May 6, 2010, respectively. 

The ACRS made recommendations in a letter to the EDO dated May 19, 2010, that included the 

following: (1) that licensees should first demonstrate the plant-specific impracticality of making 

plant modifications to eliminate need for CAP credit, (2) that licensees complement their 

deterministic analyses with plant-specific probabilistic analyses of the impact of CAP credit, 

(3) support for the staff’s reassessment of potential problems associated with operation of 

pumps near or below the pump’s required net positive suction head (NPSH), (4) support for the 

staff’s draft guidance on consideration of uncertainty in the required NPSH, and (5) criteria for 

when CAP credit can be deemed small enough that it is acceptable. The ACRS’s May 19, 2010, 

letter reiterated the Committee’s concern about the defense-in-depth philosophy for accident 

mitigation and the independence of barriers. Subsequently, the ACRS met with the Commission 

on June 9, 2010, and discussed CAP credit along with other topics. 

On June 25, 2010, Staff Requirements Memorandum SRM M100609B, “Meeting with the 

Advisory Committee on Reactor Safeguards,” was issued. It directed that the staff’s forthcoming 

paper on CAP should discuss where the staff aligns and disagrees with the ACRS regarding 

CAP credit, including use of risk information, defense-in-depth implications, and need to assess 

the practicality of hardware changes to eliminate the need for CAP credit. 

On January 31, 2011, the staff provided SECY-11-0014, “Use of Containment Accident Pressure 

in Analyzing Emergency Core Cooling System and Containment Heat Removal System Pump 

Performance in Postulated Accidents.” SECY-11-0014 proposed two options that involve policy 

issues. The staff recommended Option 1, which proposed resuming reviews of EPU 

applications taking CAP credit, as well as reviewing future applications for new or increased use 

of CAP credit. Under this Option, the staff proposed to conduct these reviews consistent with 

staff practice in implementing the current risk review guidance and the recently-developed 

deterministic guidance based on ACRS recommendations to include uncertainty and margins in 

CAP calculations. The staff also proposed to update the regulatory guidance to remove the 

specific guidance disfavoring the use of CAP in determining NPSH margin. 

In response to SECY-11-0014, Staff Requirements Memorandum SRM-SECY-11-0014, “Use of 

Containment Accident Pressure in Analyzing Emergency Core Cooling System and Containment 

Heat Removal System Pump Performance in Postulated Accidents,” was issued on March 15, 

2011. The SRM approved the staff’s recommended Option 1. The SRM also directed the staff 

to revise Regulatory Guide 1.174, “An Approach for Using Probabilistic Risk Assessment in 

Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis,” and other 

regulatory guidance, using precise language to assure that the defense-in-depth philosophy is 

interpreted and implemented consistently. The staff is therefore proceeding with Option 1 and 

plans to resume the CAP portion of the delayed EPU reviews. 
The Commissioners - 5 - 

Potential Adverse Flow Effects 

At power uprate conditions, nuclear power plants can experience significant increases in steam 

flow velocities. Plant experience has shown that as the higher velocity main steamline flow 

passes over branch lines, it can create an acoustic resonance in the steamlines that can vary 

greatly from one plant to another, depending on the routing of the main steamlines and the 

steam dryer vintage and geometry. The acoustic resonance can create pressure waves that 

strike the steam dryer in boiling-water reactors (BWRs) with significant force. This force could 

cause the stress in the steam dryer to exceed the material fatigue limits, which may result in 

steam dryer cracking. The acoustic resonance can also cause excessive vibration that may 

damage steamline and feedwater line components, such as relief valves and piping. 

To address this issue, BWR applicants for EPUs have provided complex steam dryer analyses 

to demonstrate the structural integrity of the steam dryers at uprated power levels. However, it 

has been challenging for licensees to provide acceptable steam dryer analyses and this has 

significantly contributed to the delays in the EPU reviews for several BWR plants. Reasons for 

these delays typically include: licensees introducing new refinements to analytical methods not 

used in previous EPU applications, the NRC identifying new issues with licensees’ acoustic 

circuit models, licensees needing to make steam dryer modifications to address analysis issues, 

and lack of adequate plant measurement data needed for the steam dryer analyses. 

To address this issue, two independent industry topical reports have been submitted to the NRC 

for review and approval. These reports present two independent integrated evaluation 

approaches and acceptance criteria for steam dryers. GE Hitachi Nuclear Energy submitted 

NEDC-33436P, “GEH Boiling Water Reactor Steam Dryer - Plant Based Load Evaluation,” on 

November 7, 2008. The Electric Power Research Institute resubmitted BWRVIP-194, 

“Methodologies for Demonstrating Steam Dryer Integrity for Power Uprate,” on December 18, 

2008. By letters dated June 30, 2009, and September 15, 2009, the NRC accepted topical 

reports BWRVIP-194 and NEDC-33436P, respectively, for a detailed technical review. 

However, the NRC letters also identified the need for complementary or related topical reports, 

as well as additional information, to continue its review. The staff will resume its reviews of the 

topical reports after they are supplemented or resubmitted to address staff technical issues. If 

the NRC ultimately approves these topical reports, licensees referencing them will only need to 

provide the plant-specific items (which the NRC will develop) for the NRC’s review. This process 

should improve the review timeliness of future requests that involve evaluation of potential 

adverse flow effects on steam dryers. 

Program Performance versus Established Goals

The established performance goals for power uprate review durations are the following: 

6 months for reviewing MUR power uprate applications, 9 months for reviewing SPU 

applications, and 12 months for reviewing EPU applications.1

 The staff will continue to ensure 

that protection of public health and safety is not compromised through its efforts to meet these 

 1 These goals do not include the duration of the staff's acceptance review, which the staff conducts upon 

receipt of the initial application.
The Commissioners - 6 - 

timeliness goals. Individual applications may require more or less review time, depending on the 

nature of the technical issues. 

Completed Reviews 

The staff generally met its timeliness goals for six of the eight MUR power uprates approved 

since May 20, 2010 (for Prairie Island Units 1 and 2, LaSalle Units 1 and 2, and Surry Units 1 

and 2). The staff met the 6-month review goal for the Prairie Island Units 1 and 2 MUR power 

uprates. The staff slightly exceeded the 6-month review goal for the LaSalle Units 1 and 2 MUR 

power uprates by two weeks partly because of a linked alternate source term (AST) license 

amendment request, that needed to be approved first, and partly because of the need to resolve 

internal-staff comments to ensure a quality safety evaluation. The staff slightly exceeded the 

6-month review goal for the Surry Units 1 and 2 MUR power uprates by 3 weeks in order to 

resolve internal-staff comments to ensure a quality safety evaluation. 

The staff exceeded the 6-month review goal for the Limerick Units 1 and 2 MUR power uprates 

by 5 months in order to resolve a staff-identified compliance issue with Title 10 of the Code of 

Federal Regulations (10 CFR) Part 50, “Domestic Licensing of Production and Utilization 

Facilities,” Appendix G, “Fracture Toughness Requirements,” regarding the low-pressure coolant 

injection nozzles and some water-level instrumentation nozzles on the reactor vessel. The staff 

exceeded the 12-month review goal for the Point Beach Units 1 and 2 EPUs by 6 months 

because additional review time was needed to review key technical issues, including (1) a 

significant upgrade to and modification of the auxiliary feedwater system, (2) a reconstituted 

high-energy line break analysis, which included an onsite audit by the staff, and (3) a linked AST 

license amendment request, which needed to be approved first. 

Delayed Ongoing Reviews 

The Nine Mile Point Unit 2 EPU review has been delayed primarily in order to resolve concerns 

with the licensee’s steam dryer analyses. The staff identified that the licensee’s application of its 

methodology of the acoustic circuit model (ACM) Revision 4.0 for determining the steam dryer 

loading was nonconservative. This nonconservatism existed because the licensee was taking 

credit for items that were inconsistent with the ACM Revision 4.0 benchmarking. This results in 

underestimation of the steam dryer loads and underprediction of the steam dryer stresses. In 

response to the staff’s initial request for additional information (RAI) questions of March 2010, 

the licensee opted to revise its ACM code to Revision 4.1 to address the staff’s concerns. This 

approach involved extensive rebenchmarking and analysis by the licensee, who submitted a 

partial response to the associated supplemental RAIs in December 2010. The staff anticipates 

the need for additional followup RAIs as the licensee provides the remainder of its response in 

support of the staff’s evaluation of the new ACM Revision 4.1 methodology. 

The Browns Ferry Units 1, 2, and 3, and Monticello EPU reviews have been delayed primarily 

because of staff concerns with the licensees’ steam dryer analyses and analyses that take credit 

for CAP. General discussion of these issues appeared previously in the “Challenges Associated 

with Power Uprates” section of this report. Specific details pertaining to these EPU reviews are 

discussed below. 
The Commissioners - 7 - 

The staff plans to resume the CAP portion of the Browns Ferry Units 1, 2, and 3, and Monticello 

EPU reviews. With respect to the Monticello EPU review, the staff is discussing with the 

licensee the information needed to complete the CAP portion of the review. With respect to the 

Browns Ferry EPU reviews, the licensee informed the staff in a December 15, 2010, public 

meeting that it will submit its plans regarding CAP in March 2012. At that time, the staff will 

resume the CAP portion of those reviews. 

Regarding the steam dryer portion of the delayed EPU reviews, the steam dryer was replaced 

earlier this year at Monticello and there are plans to replace the steam dryers at Browns Ferry 

Units 1, 2, and 3. The staff has issued RAIs regarding the replacement steam dryer at 

Monticello and recently conducted an audit to identify any additional information needed to 

complete its review. With respect to the Browns Ferry EPU reviews, the licensee informed the 

staff in a December 15, 2010, public meeting that it will submit its replacement steam dryer 

analyses in February 2012. At that time, the staff will resume the steam dryer portion of the 

Browns Ferry EPU reviews. 

General Observation: Licensees Bundling Other Requests with the Power Uprate Request 

The staff notes that some licensees use power uprate requests as an opportunity to include (i.e., 

bundle) other requests that perhaps could have been submitted separately by the licensee and 

approved by the NRC, before the licensee submits the power uprate request. Based on 

preapplication meetings with licensees, it appears that this trend may continue. Sometimes the 

staff can accommodate these requests within the normal power uprate review schedule. 

However, in some cases, this bundling results in review durations that are significantly longer 

than would otherwise be the case. 

The staff has encouraged licensees to have preapplication interactions (e.g., meetings, phone 

calls) with the staff to discuss any new, different or complex issues with regard to their planned 

power uprate application as compared to other NRC-approved power uprates, and to discuss 

any other requests that they plan on bundling with their power uprate request. In some of these 

preapplication interactions, the staff has requested that licensees voluntarily limit the number 

and/or complexity of certain other requests that they plan on bundling with the power uprate 

request, depending on the specific issues and circumstances under consideration. The staff will 

continue to request that licensees voluntarily limit the amount of bundling in future preapplication 

interactions, as appropriate and on a case-by-case basis.