# BACKGROUNDER Office of Public Affairs Phone: 301-415-8200 Email: opa.resource@nrc.gov 

# Power Uprates for Nuclear Plants

Introduction When the NRC issues a license for a commercial nuc lear power plant, the agency sets limits on the maximum heat output, or power level, for the reactor core. This power level play s an important role in many of the analyses that demonstrate plant safety, so the NRC’s permission is required before a plant can change its maximum power level. A “power uprate” only occurs after the NRC approves a commercial nuclear power plant’s request to increase its power. 

## Background Utilities have used power uprates since the 1970s as a wa y to generate more electri city from their nuclear plants. As of January 2008, the NRC has approved 116 uprates, resulting in a gain of approximately 15,600 MWt (megawatts thermal) or 5,200 MWe (megawatts electric) at existing plants. These uprates are listed in Table 1 at the end of this document. Collectively, th ese uprates have added generating capacity at existing plants that is equiva lent to more than five new reactors. 

## Discussion To increase the power output of a reactor, typically a u tility will refuel a reactor w ith either slightly more enriched uranium fuel or a higher percentage of new fuel. This enables the reactor to produce more thermal energy and therefore more steam, driving a tu rbine generator to produce electricity. In order to accomplish this, components such as pipes, valves, pum ps, heat exchangers, elec trical transformers and generators must be able to accommodate the conditions that would exist at the higher power level. For example, a higher power level usua lly involves higher steam and water flow through the systems used in converting the thermal power into electric power. Th ese systems must be capable of accommodating the higher flows. In some instances, licensees will modify and/or replace components in order to accommodate a higher power level. Depending on the desire d increase in power level and or iginal equipment design, this can involve major modifications to the plant such as the replacement of main turbin es. All of these factors must be analyzed by the licensee as part of their request to amend their license for the uprate. The analyses must demonstrate that the proposed new conf iguration remains safe and that measures continue to be in place to protect the heal th and safety of the public. The NRC = s technical and legal staffs review these analyses, which span many technical disciplin es and may be complex, before approving a request for a power uprate.2 

## Types of Power Uprates The design of every U.S. commercial reactor has exce ss capacity needed to potentially allow for an uprate, which can fall into one of th ree categories: 1) measurement uncerta inty recapture power uprates, 2) stretch power uprates, and 3) extended power uprates. 1) Measurement uncertainty recapture power uprates are power increases less than 2 percent of the licensed power level, and are ach ieved by implementing enhanced te chniques for calculating reactor power. This involves the use of state- of-the-art devices to more precisel y measure feedwater flow which is used to calculate reactor power. Mo re precise measurements reduce the degree of uncertainty in the power level which is used by analysts to predict the ability of th e reactor to be safely shut down under possible accident conditions. 2) Stretch power uprates are typically between 2 per cent and 7 percent, with the actual increase in power depending on a plant design’s specific operating margi n. Stretch power uprates usually involve changes to instrumentation settings but do not involve major plant modifications. 3) Extended power uprates are greater than stretch power uprates and have been approved for increases as high as 20 percent. Extended power uprates usually require significant modifications to major pieces of non-nuclear equipment such as high-pressure turbin es, condensate pumps and motors, main generators, and/or transformers. 

## Review Process Since uprates affect a reactor’s licensed power level, utilities apply for NRC permission to amend their operating license in order to implement a power uprate. The process for requesting and approving a change to a plant's power level is governed by 10 CFR 50.90 -92. These regulations are available on the agency’s Web site at: http://www.nrc.gov/reading-rm/ doc-collections/cfr/part050/ . The applications and reviews are complex and involve many areas of expe rtise in the NRC’s Offi ces of Nuclear Reactor Regulation and General Counsel. Some reviews may also involve the Office of Nuclear Regulatory Research and the Advisory Committee on Reactor Safeguards (ACRS). In evaluating a power uprate request, NRC reviews data and accident analyses submitted by a licensee to confirm that the plant can operate safely at the higher power level. Revi ews of power uprate reque sts are a high priority. The NRC uses a review standard for extended po wer uprates (RS-001, December 2003), that has been endorsed by the ACRS. The standard provides a co mprehensive process and technical guidance for reviews by the NRC staff, and provides useful info rmation to licensees cons idering applying for an extended uprate. After a licensee submits an uprate app lication, the NRC places a notice in the Federal Register to notify the public that the agency is c onsidering the application. The public has 30 days to comment on the licensee's request and 60 days to request a hearin g where the application c ould be contested. The NRC thoroughly reviews the application and any public comments, while the Atomic Safety and Licensing Board (ASLB) considers any requests for hearings. NRC technical staff comple te their review while considering and addressing any public comments , issuing a safety ev aluation and another Federal Register notice to inform the public. If the ASLB determines a hearing is required, a sepa rate legal process takes place, and NRC staff provides technical information, if needed. The safety evaluation and any hearing rulings form the basis for the NRC’s final decision on the uprate request, although the staff can authorize3 

### an uprate while a hearing is underw ay. The NRC issues a press releas e for any approved uprate, and an updated list of approved uprates is available on the NRC’s Web site at: http://www.nrc.gov/reactors/ope rating/licensing/pow er-uprates/approved-applications.html

. The NRC usually has several applicati ons for power uprates under review at any given time. The latest list of applications under review is on the NRC’s Web site at: http://www.nrc.gov/reactors/ope rating/licensing/pow er-uprates/pending-applications.html

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## Expected Uprate Applications Licensee responses to a September 2007 NRC survey indicate they plan to submit 24 power uprate applications in the next five years, including 17 extended uprates and 7 measurement uncertainty recapture uprates. If these applications are appr oved, the resulting uprates would add another 5,254 MWt (1,751 MWe) to the nation's generating capacity. Anticip ated future applications can be found in Table 3 at the end of this fact sheet, and upda tes will be on the NRC’s Web site at: http://www.nrc.gov/reactors/ope rating/licensing/pow er-uprates/expected-applications.html

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## Public Involvement The NRC welcomes public involvement in our activities as part of our strong, fair oversight of the nuclear industry. The public’s opportuni ties to participate in the power uprate arena include:

• Pre-application meetings, where licensees disc uss their uprate plans with NRC staff (some portions of these meetings may be closed to th e public to discuss proprietary information);

• Comments related to an application and requests for a hearing on the application.

• Briefings to the ACRS on the results of the staff' s review of the applicat ions (some portions of these meetings may be closed to the public to disc uss proprietary information). ACRS meeting schedules are available on the N RC’s Web site at this address: http://www.nrc.gov/readingrm/doc-collections/acrs/agenda/

. For each extended power uprate, the NRC staff typically issues a draft environmental assessment for a 30- day public comment period. The NRC st aff considers and addresses all comments before finalizing the draft environmental assessment. 

## Table 1 - Approved Power Uprates, February 2008 (TYPE – S = Stretch; E = Extended; MU = Measurement Uncertainty Recapture)

No. Plant % Uprate MWt Year Approved TYPE

1 Calvert Cliffs 1 5.5 140 1977 S 2 Calvert Cliffs 2 5.5 140 1977 S 3 Millstone 2 5 140 1979 S 4 H. B. Robinson 4.5 100 1979 S 5 Fort Calhoun 5.6 80 1980 S 6 St. Lucie 1 5.5 140 1981 S4 No. Plant % Uprate MWt Year Approved TYPE

7 St. Lucie 2 5.5 140 1985 S 8 Duane Arnold 4.1 65 1985 S 9 Salem 1 2 73 1986 S 10 North Anna 1 4.2 118 1986 S 11 North Anna 2 4.2 118 1986 S 12 Callaway 4.5 154 1988 S 13 TMI-1 1.3 33 1988 S 14 Fermi 2 4 137 1992 S 15 Vogtle 1 4.5 154 1993 S 16 Vogtle 2 4.5 154 1993 S 17 Wolf Creek 4.5 154 1993 S 18 Susquehanna 2 4.5 148 1994 S 19 Peach Bottom 2 5 165 1994 S 20 Limerick 2 5 165 1995 S 21 Susquehanna 1 4.5 148 1995 S 22 Nine Mile Point 2 4.3 144 1995 S 23 WNP-2 4.9 163 1995 S 24 Peach Bottom 3 5 165 1995 S 25 Surry 1 4.3 105 1995 S 26 Surry 2 4.3 105 1995 S 27 Hatch 1 5 122 1995 S 28 Hatch 2 5 122 1995 S 29 Limerick 1 5 165 1996 S 30 V. C. Summer 4.5 125 1996 S 31 Palo Verde 1 2 76 1996 S 32 Palo Verde 2 2 76 1996 S 33 Palo Verde 3 2 76 1996 S 34 Turkey Point 3 4.5 100 1996 S 35 Turkey Point 4 4.5 100 1996 S 36 Brunswick 1 5 122 1996 S5 No. Plant % Uprate MWt Year Approved TYPE 37 Brunswick 2 5 122 1996 S 38 Fitzpatrick 4 100 1996 S 39 Farley 1 5 138 1998 S 40 Farley 2 5 138 1998 S 41 Browns Ferry 2 5 164 1998 S 42 Browns Ferry 3 5 164 1998 S 43 Monticello 6.3 105 1998 E 44 Hatch 1 8 205 1998 E 45 Hatch 2 8 205 1998 E 46 Comanche Peak 2 1 34 1999 MU 47 LaSalle 1 5 166 2000 S 48 LaSalle 2 5 166 2000 S 49 Perry 5 178 2000 S 50 River Bend 5 145 2000 S 51 Diablo Canyon 1 2 73 2000 S 52 Watts Bar 1.4 48 2001 MU 53 Byron 1 5 170 2001 S 54 Byron 2 5 170 2001 S 55 Braidwood 1 5 170 2001 S 56 Braidwood 2 5 170 2001 S 57 Salem 1 1.4 48 2001 MU 58 Salem 2 1.4 48 2001 MU 59 San Onofre 2 1.4 48 2001 MU 60 San Onofre 3 1.4 48 2001 MU 61 Susquehanna 1 1.4 48 2001 MU 62 Susquehanna 2 1.4 48 2001 MU 63 Hope Creek 1.4 46 2001 MU 64 Beaver Valley 1 1.4 37 2001 MU 65 Beaver Valley 2 1.4 37 2001 MU 66 Shearon Harris 4.5 138 2001 S6 No. Plant % Uprate MWt Year Approved TYPE 67 Comanche Peak 1 1.4 47 2001 MU 68 Comanche Peak 2 0.4 13 2001 MU 69 Duane Arnold 15.3 248 2001 E 70 Dresden 2 17 430 2001 E 71 Dresden 3 17 430 2001 E 72 Quad Cities 1 17.8 446 2001 E 73 Quad Cities 2 17.8 446 2001 E 74 Waterford 3 1.5 51 2002 MU 75 Clinton 20 579 2002 E 76 South Texas 1 1.4 53 2002 MU 77 South Texas 2 1.4 53 2002 MU 78 ANO-2 7.5 211 2002 E 79 Sequoyah 1 1.3 44 2002 MU 80 Sequoyah 2 1.3 44 2002 MU 81 Brunswick 1 15 365 2002 E 82 Brunswick 2 15 365 2002 E 83 Grand Gulf 1.7 65 2002 MU 84 H. B. Robinson 1.7 39 2002 MU 85 Peach Bottom 2 1.62 56 2002 MU 86 Peach Bottom 3 1.62 56 2002 MU 87 Indian Point 3 1.4 42.4 2002 MU 88 Point Beach 1 1.4 21.5 2002 MU 89 Point Beach 2 1.4 21.5 2002 MU 90 Crystal River 3 0.9 24 2002 S 91 D.C. Cook 1 1.66 54 2002 MU 92 River Bend 1.7 52 2003 MU 93 D.C. Cook 2 1.66 57 2003 MU 94 Pilgrim 1.5 30 2003 MU 95 Indian Point 2 1.4 43 2003 MU 96 Kewaunee 1.4 23 2003 MU 97 Hatch 1 1.5 41 2003 MU7 No. Plant % Uprate MWt Year Approved TYPE 98 Hatch 2 1.5 41 2003 MU 99 Palo Verde 2 2.9 114 2003 S 100 Kewaunee 6.0 99 2004 S 101 Palisades 1.4 35 2004 MU 102 Indian Point 2 3.2 101.6 2004 S 103 Seabrook 5.2 176 2005 S 104 Indian Point 3 4.85 148.6 2005 S 105 Waterford 8.0 275 2005 E 106 Palo Verde 1 2.9 114 2005 S 107 Palo Verde 3 2.9 114 2005 S 108 Vermont Yankee 20 319 2006 E 109 Seabrook 107 61 2006 MU 110 Ginna 16.8 255 2006 E 111 Beaver Valley 1 8 211 2006 E 112 Beaver Valley 2 8 211 2006 E 113 Browns Ferry 1 5 165 2007 S 114 Crystal River 3 1.6 41 2007 MU 115 Susquehanna 1 13 463 2008 E 116 Susquehanna 2 13 463 2008 E 

## Table 2 - Power Uprates Un der Review, February 2008 (TYPE -- S = Stretch; E = Extended; MU = Measurement Uncertainty Recapture)

No. Plant % Uprate MWt Submittal Date Projected Completion Date Type

1 Browns Ferry 2 15 494 06/25/04 Spring 2008 E 2 Browns Ferry 3 15 494 06/25/04 Spring 2008 E 3 Browns Ferry 1 15 494 06/28/04 Spring 2008 E 4 Hope Creek 15 501 09/18/06 Spring 2008 E 5 Davis-Besse 1.6 45 04/12/07 TBD MU 6 Millstone 3 7.0 239 07/13/07 08/15/08 S 7 Comanche Peak 1 4.5 154 08/28/07 07/09/08 S 8 Comanche Peak 2 4.5 154 08/27/07 07/09/08 S 9 Vogtle 1 1.7 61 08/27/07 03/01/08 MU8 No. Plant % Uprate MWt Submittal Date Projected Completion Date Type

10 Vogtle 2 1.7 61 08/24/07 03/01/08 MU 11 Cooper 1.6 38 11/19/07 06/20/08 MU 

## Table 3 - Expected Futu re Submittals for Power Uprates, December 2007

Fiscal Year Total Uprates Expected Measurement Uncertainty Recapture

Uprates Stretch Power Uprates Extended Power Uprates Megawatts Thermal Approximate Megawatts

Electric

2008 4 2 0 2 804 268 2009 11 5 0 6 1966 655 2010 6 0 0 6 1368 456 2011 2 0 0 2 895 298 2012 1 0 0 1 221 74 TOTAL 24 7 0 17 5,254 1,751 

### Additional Information Additional information and guidance for power uprate license amendment request submittals can be found on the NRC = s Power Uprate Web page at this address: http://www.nrc.gov/reactors/opera ting/licensing/pow er-uprates.html

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February 2008