POLICY ISSUE

INFORMATION

June 4, 2007 SECY-07-0090

FOR: The Commissioners

FROM: Luis A. Reyes

Executive Director for Operations

SUBJECT: STATUS REPORT ON POWER UPRATES

PURPOSE:

This information paper summarizes the power uprate program accomplishments and

challenges since the last update in SECY-06-0136, dated June 9, 2006. This paper does not

address any new commitments or resources. 

BACKGROUND:

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

in accordance with the staff requirements memorandum (SRM) dated February 8, 2002

(SRM-M020129).

DISCUSSION:

Since the last update, the staff has approved four 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 27 power uprate applications. The enclosed status report provides

detailed information on the power uprates approved since June 9, 2006; applications under

review; applications expected in the future; accomplishments; operating experience; and

program performance.

CONTACT: Thomas W. Alexion

(301) 415-1326
The Commissioners -2- 

The staff completed the four plant-specific power uprate reviews consistent with the established

timeliness goals. In addition, the staff's timely and rigorous acceptance reviews of three power

uprate applications resulted in expeditious supplements by the licensees that provided the

information needed for the staff to accept the applications.

As discussed in last year's status report on power uprates, the staff is looking for opportunities

to improve the process for reviewing extended power uprate applications by using audits. Since

last year's status report, the staff has determined that a working-level public meeting will serve

the same purpose as an audit. Therefore, the staff will consider the use of audits and/or

working-level meetings in its review of the new extended power uprate applications.

The staff has revised and issued its review guidance to address operating experience in the

area of potential adverse flow effects from power uprates. In addition, when the staff completes

its reevaluation of the generic approvals of ultrasonic flow meters used for measurement

uncertainty recapture power uprates, the staff will consider issuing additional guidance for these

types of power uprate applications.

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 providing continued assurance that safety will

be maintained.

COORDINATION:

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

/RA William F. Kane Acting for/

Luis A. Reyes

Executive Director

 for Operations

Enclosure: 

Power Uprate Program Status Report
The Commissioners -2- 

The staff completed the four plant-specific power uprate reviews consistent with the established

timeliness goals. In addition, the staff's timely and rigorous acceptance reviews of three power

uprate applications resulted in expeditious supplements by the licensees that provided the

information needed for the staff to accept the applications.

As discussed in last year's status report on power uprates, the staff is looking for opportunities

to improve the process for reviewing extended power uprate applications by using audits. Since

last year's status report, the staff has determined that a working-level public meeting will serve

the same purpose as an audit. Therefore, the staff will consider the use of audits and/or

working-level meetings in its review of the new extended power uprate applications.

The staff has revised and issued its review guidance to address operating experience in the

area of potential adverse flow effects from power uprates. In addition, when the staff completes

its reevaluation of the generic approvals of ultrasonic flow meters used for measurement

uncertainty recapture power uprates, the staff will consider issuing additional guidance for these

types of power uprate applications.

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 providing continued assurance that safety will

be maintained.

COORDINATION:

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

/RA William F. Kane Acting for/

Luis A. Reyes

Executive Director

 for Operations

Enclosure: 

Power Uprate Program Status Report

ADAMS Accession No. ML070930101 *Concurred via email WITS 200200020

OFFICE PGCB/PM PGCB/LA* TECH ED* PGCB/BC OGC

NAME TAlexion CHawes HChang CJackson JMoore

DATE 04/16/07 04/03/07 04/06/07 04/18/07 05/01/07

OFFICE DOLR/D DPR/D NRR/D EDO

NAME CHaney

(TMcGinty for)

MCase JDyer 

(JWiggins w/comment for)

LReyes 

(William F. Kane for)

DATE 05/08/07 05/17/07 05/22/07 06/04/07

OFFICIAL RECORD COPY
Enclosure

Power Uprate Program Status Report

May 2007

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 June 2006

Power uprates approved since June 9, 2006, have added an additional 842 megawatts thermal

(MWt) or approximately 281 megawatts electric (MWe) to the Nation’s electric generating

capacity. This brings the total number of power uprates approved since 1977 to 113, resulting

in a combined increase of about 14,700 MWt (4,900 MWe) to the Nation’s electric generating

capacity. Table 1 provides information on these approved power uprate applications; details on

program performance versus established goals for these approved power uprates will be

discussed later in this enclosure.

Table 1 - Power Uprates Approved Since June 2006

No. Plant % Uprate MWt Application Date Approval Date Type

1 Ginna 16.8 255 07/07/2005 07/11/2006 EPU

2 Beaver Valley 1 8 211 10/04/2004 07/19/2006 EPU

3 Beaver Valley 2 8 211 10/04/2004 07/19/2006 EPU

4 Browns Ferry 1 5 165 09/22/2006 03/06/2007 SPU

Total 842

On March 6, 2007, the staff completed its review of the Browns Ferry Unit 1 SPU application

and approved the 5-percent power uprate. Browns Ferry Unit 1 was shut down in 1985, and the

licensee commenced restart of the unit in May 2007. The licensee had originally submitted

applications for EPUs for each of the three Browns Ferry units; however, because of delays in

providing the information necessary to support the review of the EPUs, the licensee

subsequently requested a two-step approach for Browns Ferry Unit 1. This approach involved,

as a first step, review and approval of a separate 5-percent SPU application to raise Unit 1 

power to the same level and operating conditions as Units 2 and 3. (The NRC approved SPUs

for Units 2 and 3 in 1998.) The second step is to submit the information needed to enable the

staff to complete its review of the three Browns Ferry EPUs.
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Power Uprate Applications Currently Under Staff Review

Power uprates currently under review could add an additional 3,091 MWt or 1,030 MWe to the

Nation’s electric generating capacity if approved, as noted in Table 2.

Table 2 - Power Uprate Applications Under Review

No. Plant % Uprate MWt Submittal

Date

Projected

Completion Date Type

1 Browns Ferry 2 15 494 06/25/2004 Fall 2007 EPU

2 Browns Ferry 3 15 494 06/25/2004 Fall 2007 EPU

3 Browns Ferry 1 15 494 06/28/2004 Fall 2007 EPU

4 Calvert Cliffs 1 1.3 37 01/31/2005 To Be Determined* MUR

5 Calvert Cliffs 2 1.3 37 01/31/2005 To Be Determined* MUR

6 Fort Calhoun 1.5 22 03/31/2005 To Be Determined* MUR

7 Hope Creek 15 501 09/18/2006 10/18/2007 EPU

8 Susquehanna 1 13 463 10/11/2006 01/05/2008 EPU

9 Susquehanna 2 13 463 10/11/2006 01/05/2008 EPU

10 Davis-Besse 1.6 45 04/12/2007 10/31/2007 MUR

11 Crystal River 3 1.6 41 04/25/2007 11/15/2007 MUR

Total 3,091

* To be determined when the NRC completes its reevaluation of the Westinghouse Crossflow ultrasonic flow meter.

Expected Power Uprate Applications

Table 3 describes intended future power uprate applications based on a survey of all licensees

conducted in April 2007.

Table 3 - Projected Future Power Uprate Applications

Fiscal

Year

Power Uprates

Expected

MUR Power

Uprates SPUs EPUs MWt MWe

2007 5 2 3 0 669 223

2008 4 3 0 1 323 108

2009 6 2 0 4 1258 419

2010 11 2 1 8 1752 584

2011 1 0 0 1 375 125

TOTAL 27 9 4 14 4,377 1,459
- 3 -

Accomplishments Since June 9, 2006

• Approved four plant-specific power uprates, specifically one SPU (Browns Ferry Unit 1)

and three EPUs (Ginna, and Beaver Valley Units 1 and 2).

• Issued acceptance review letters for the EPU applications for Hope Creek and

Susquehanna Units 1 and 2.

• Met with the Boiling Water Reactor Owners Group (BWROG) and General Electric to

discuss improvements to industry guidance on potential adverse flow effects from power

uprates.

• Met with Exelon to discuss long-term EPU operation at Dresden Units 2 and 3 and Quad

Cities Units 1 and 2.

• Completed its reevaluation of the Caldon Check and CheckPlus ultrasonic flow meters

(UFMs) that are used for MUR power uprates, and concluded that the performance of

the Caldon Check and CheckPlus UFMs is consistent with Caldon topical reports

previously approved by the NRC.

• Presented information on the Browns Ferry Unit 1 SPU application to the Advisory

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

Uprates.

• Issued the final version of NUREG-0800, "Standard Review Plan," (SRP)

Section 14.2.1, "Generic Guidelines for Extended Power Uprate Testing Programs."

• Issued updated versions of SRP Section 3.9.2, "Dynamic Testing and Analysis of

Systems, Components, and Equipment," SRP Section 3.9.5, "Reactor Pressure Vessel

Internals," and Regulatory Guide 1.20, "Comprehensive Vibration Assessment Program

for Reactor Internals During Preoperational and Initial Startup Testing," to provide

additional guidance for NRC staff reviewers and the nuclear industry on the evaluation

of potential adverse flow effects at operating plants considering power uprates.

• Provided power uprate information to support the 2007 Congressional Oversight

Hearings.

Operating Experience Related to Power Uprates

Potential Adverse Flow Effects

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

flow velocities. Plant experience has shown that the higher main steam line flow can create an

acoustic resonance in the steam lines as the flow passes over branch lines that can vary greatly

from one plant to another depending on the main steam lines routing and steam dryer vintage

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

in boiling water reactors (BWRs) with sufficient force to cause the stress in the steam dryer to

exceed the material fatigue limits. The acoustic resonance can also cause excessive vibration

that may damage steam line components, such as relief valves and piping.

In response to nuclear plant operating experience, the NRC staff has been performing more

detailed reviews and inspections of plant performance and power uprate license amendment

requests with respect to adverse flow effects on plant structures, systems, and components. 

However, the recognition of acoustic resonance as causing adverse flow effects is relatively

new to the nuclear power industry. The nuclear industry is working to achieve a full

understanding of this issue. The NRC staff has received assistance in this highly complex field
- 4 -

from technical experts at Argonne National Laboratory, Pennsylvania State University, and

McMaster University.

In response to the failure of the original steam dryers at Quad Cities Units 1 and 2 during EPU

operation, the licensee installed new steam dryers with an improved design in those units in

May 2005. The Quad Cities Unit 2 steam dryer included pressure sensors, strain gages, and

accelerometers to monitor the loads on the steam dryer during restart to EPU conditions. The

main steam lines on both units were also instrumented to monitor loads during power ascension

to EPU conditions. Following the return to EPU operation in mid-2005, the licensee discovered

significant unexpected degradation of the actuators for several electromatic relief valves (ERVs)

in the main steam lines at Quad Cities Units 1 and 2 in late December 2005 and early January

2006. To reduce the acoustic-generated pressure fluctuations and vibrations in the main steam

lines, the licensee performed modifications by installing acoustic side branches (ASBs) in the

inlet lines of the ERVs and the main steam safety valves during outages in the spring 2006. 

Following the modifications, the licensee returned the Quad Cities units to EPU operation. In

letters dated May 3 and August 2, 2006, the licensee submitted EPU startup reports for the

Quad Cities units, indicating that the ASB modifications have eliminated the severe acoustic

resonances in the main steam lines. As discussed in its EPU startup reports, the licensee

determined that with the successful performance of the ASB modifications, the pressure

fluctuations and vibrations in the Quad Cities main steam lines at full EPU operation will not

exceed the levels that were present at original licensed thermal power conditions before the

ASB modifications.

The original steam dryers in Dresden Units 2 and 3 were similar to the original Quad Cities

steam dryers, but they were subsequently modified to increase their structural capability. The

licensee initially operated the Dresden units at EPU conditions for several years without

significant damage. However, after the discovery of steam dryer damage at Dresden in 2005

and 2006, the licensee initiated plans to replace the steam dryers in the Dresden units. The

licensee replaced the Dresden Unit 3 steam dryer during the November 2006 refueling outage. 

The licensee will replace the Dresden Unit 2 steam dryer during the refueling outage scheduled

in October 2007.

On March 22, 2007, the staff held a meeting with the licensee regarding long-term EPU

operation at Quad Cities Units 1 and 2 and at Dresden Units 2 and 3. The staff did not identify

any issues associated with continuing full EPU operation at any of these units. In a followup

letter dated April 20, 2007, the licensee provided its EPU monitoring and inspection plans to

document its ongoing corrective actions and commitments.

After its detailed review of the Vermont Yankee EPU license amendment request, the NRC staff

determined that the licensee's analysis of potential adverse flow effects for EPU operation was

acceptable, with specific license conditions and a regulatory commitment for monitoring plant

instrumentation during power ascension. Following issuance of the EPU license amendment in

March 2006, the NRC staff reviewed the licensee’s analysis of plant data and the results of

plant walkdowns during power ascension to EPU conditions at Vermont Yankee. Based on

plant data, the licensee held the power ascension at specific levels to analyze the data as

necessary before achieving EPU conditions. Vermont Yankee has been operating at EPU

conditions since May 4, 2006. The licensee will conduct steam dryer inspections at Vermont

Yankee during future refueling outages in accordance with its license conditions.
- 5 -

With regard to the EPU requests for Browns Ferry Units 1, 2, and 3, the NRC staff reviewed the

steam dryer analysis submitted by the licensee in mid-2006. The licensee based its analysis on

small-scale testing without specific data from the steam dryer or main steam lines at Browns

Ferry. Given the predicted steam dryer loads, assumptions, and uncertainties, the staff

informed the licensee that the analysis did not adequately demonstrate that the steam dryer

would meet its fatigue stress limits during EPU operation. Subsequently, the licensee

requested a separate 5-percent SPU in late 2006 for Browns Ferry Unit 1 to allow the collection

of actual plant data for use in the steam dryer analysis. (Units 2 and 3 received their 5-percent

SPUs in 1998.) The licensee also installed main steam line instrumentation in Browns Ferry

Unit 2 in October 2006 and is currently analyzing the collected data. The NRC staff briefed

ACRS on the 5-percent SPU request for Browns Ferry Unit 1 in January and February 2007. 

The staff approved the 5-percent SPU on March 6, 2007. The staff anticipates completing the

EPU review for Browns Ferry after the licensee completes its analysis using the actual plant

data.

With regard to the September 18, 2006, EPU license amendment request for Hope Creek, the

staff was concerned that the calculated stresses for some steam dryer locations appeared to be

unacceptable for EPU operation. In response, by letter dated October 10, 2006, the licensee

provided an evaluation that concluded that, when conservatisms introduced in the load

assumptions are considered and estimated, the allowable stress limits of the American Society

of Mechanical Engineers Boiler and Pressure Vessel Code are met. On October 18, 2006, the

staff accepted the EPU license amendment request for its detailed technical review. The staff

has prepared requests for additional information (RAIs) on the licensee’s consideration of

potential adverse flow effects, including the steam dryer analysis, and will interact with the

licensee to resolve the RAIs.

With regard to the October 11, 2006, EPU license amendment requests for Susquehanna

Units 1 and 2, the licensee's steam dryer analysis indicated that additional evaluation was

needed for specific steam dryer components that were predicted not to meet the fatigue stress

limits under EPU conditions. During a public meeting on November 6, 2006, the licensee

indicated that it was conducting an evaluation to determine whether to modify the original steam

dryer or to install a new steam dryer with an improved design. By letter dated December 4,

2006, the licensee notified the staff that it will replace the steam dryers in Susquehanna Units 1

and 2. By letter dated December 26, 2006, the licensee subsequently provided a description of

the new steam dryers, the steam dryer stress analysis, and the plans for instrumenting one of

the steam dryers. By letter dated January 5, 2007, the staff accepted the licensee's application

and initiated its detailed evaluation, including the preparation of RAIs.

The BWROG is leading the industry response to potential adverse flow effects from power

uprate operation. On November 8, 2006, the NRC staff held a public meeting with the BWROG

and General Electric to discuss improvements to the BWROG guidance in NEDO-33159,

Revision 0, "Extended Power Uprate (EPU) Lessons Learned and Recommendations," which

focuses on potential adverse flow effects from power uprates. On May 11, 2005, the BWR

Vessel and Internals Project (BWRVIP) submitted BWRVIP-139, “BWR Vessel and Internals

Project, Steam Dryer Inspection and Flaw Evaluation Guidelines,” which is currently under staff

review. Additionally, the staff has been informed that the development of a generic steam dryer

integrated evaluation methodology is planned.
1 These goals do not include the duration of the staff's acceptance review, which the staff conducts upon

receipt of the initial application. 

- 6 -

The staff is applying lessons learned from operating experience and analysis of potential

adverse flow effects in its review of power uprate requests for currently operating nuclear power

plants and its review of design certification requests for new nuclear power plants. As part of

this effort, the staff has updated SRP Sections 3.9.2 and 3.9.5 and Regulatory Guide 1.20 to

provide additional guidance for NRC staff reviewers and the nuclear industry on the evaluation

of potential adverse flow effects at operating plants considering power uprates and at new

nuclear power plants.

Ultrasonic Flow Meter Instrumentation

Another operating experience issue relates to abnormalities in UFM instrumentation. The staff

is currently reviewing industry evaluations of a problem at plants using a UFM of the type used

for MUR power uprates. This problem has led to unexpected but small differences in powerlevel indications at some plants.

Two vendors, Caldon and Westinghouse, currently supply UFMs to nuclear power plants. The

staff is reevaluating the generic approvals previously granted for these UFMs. By letter to

Caldon dated July 5, 2006, the staff's reevaluation concluded that the performance of the

Caldon Check and CheckPlus UFMs is consistent with previous NRC reviews and therefore is

acceptable. The staff's reevaluation of the Westinghouse Crossflow UFM is ongoing. The staff

will consider issuing additional guidance for MUR power uprate applications when it completes

its reevaluation of the Westinghouse Crossflow UFM.

Program Performance versus Established Goals

The established performance goals are: 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 the goal of protecting public health and

safety is not compromised to meet these timeliness goals. Individual applications may require

more or less review time depending on the nature of the technical issues.

The timeliness goals assume that licensees’ submittals are consistent with established

guidelines, do not include other non-power-uprate related requests, do not involve new or

unanticipated significant technical issues, and that licensees respond to requests for additional

information (RAIs) within established schedules. When establishing these goals for the Office

of Nuclear Reactor Regulation (NRR) Operating Plan, the staff recognized that in some cases,

licensees’ plans for implementing power uprates exceed these timeliness goals. As a result, for

the NRR Operating Plan, the staff can meet its timeliness goals either by completing the

reviews according to the numerical goals or by completing the reviews in time to support the

licensees’ proposed implementation schedules (also known as licensees' need dates),

whichever is longer. This flexibility enables the staff to use its resources to better support other

high-priority activities.

The staff met its timeliness goals for its completed reviews of the Browns Ferry Unit 1 SPU as

well as the EPUs for Ginna and Beaver Valley Units 1 and 2. The NRC approved the Browns
- 7 -

Ferry Unit 1 SPU on March 6, 2007, which was less than 5 months after the staff accepted the

application. The Ginna EPU received approval on July 11, 2006, which was less than

11 months after the staff accepted the application. The NRC approved the EPUs for Beaver

Valley Units 1 and 2 on July 19, 2006, which was 12 months after the staff accepted the

application.

For the ongoing EPU reviews of Browns Ferry Units 1, 2, and 3, the licensee was unable to

provide its revised steam dryer analysis by the committed-to date of early April 2007; therefore,

the staff will reestablish the review schedule when the licensee provides a revised schedule for

submitting the steam dryer analysis. For the ongoing EPU reviews of Hope Creek and

Susquehanna Units 1 and 2, as a result of the staff's rigorous acceptance reviews, the

licensees expeditiously supplemented the initial applications with regard to steam dryers to

pass the staff's acceptance reviews. The staff is now conducting its detailed technical reviews

of the EPUs for Hope Creek and Susquehanna Units 1 and 2.

Regarding the ongoing Hope Creek EPU review, the staff is looking for opportunities to improve

the review process for new EPU applications with the use of audits. Hope Creek is the first new

EPU application since last year's status report. Preliminary staff views on the Hope Creek

application are that the staff needs to review the responses to the RAIs before making a final

decision on the number of audits to be conducted in some of the review areas, and audits will

not be needed in the remainder of the review areas. In addition, the staff has determined that

working-level public meetings would serve the same purpose as an audit. Therefore, the staff

will consider audits and/or working-level public meetings to improve review efficiency. 

Regarding the EPU reviews for Susquehanna Units 1 and 2, the staff only recently accepted the

application (January 2007) and also needs to progress further in that review before deciding

whether audits or working-level public meetings will improve review efficiency of those EPUs.

For the MUR power uprate reviews for Ft. Calhoun and Calvert Cliffs Units 1 and 2, the NRC

staff issued acceptance letters on May 12 and March 18, 2005, respectively. However, these

reviews did not meet the 6-month timeliness goal because subsequent to the issuance of the

acceptance letters, the staff determined that an NRC-approved methodology for feedwater flow

measurement may not be adequate based on recent operating experience. As mentioned

previously, the staff is reevaluating the generic topical report associated with these reviews (i.e.,

the Westinghouse Crossflow system).