ML17038A552
| ML17038A552 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 02/16/2017 |
| From: | Benjamin Beasley Plant Licensing Branch II |
| To: | William Gideon Duke Energy Corp |
| Hon A, NRR/DORL/LPL2-2, 415-8480 | |
| References | |
| CAC MF8373, CAC MF8374 | |
| Download: ML17038A552 (9) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. William R. Gideon Site Vice President Brunswick Steam Electric Plant 8470 River Rd. SE (MIC BNP001)
Southport, NC 28461 February 16, 2017
SUBJECT:
BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 - RELIEF FROM THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS CODE FOR OPERATION AND MAINTENANCE FOR INSERVICE TESTING REQUIREMENTS (RELIEF REQUEST VRR-06) (CAC NOS. MF8373 AND MF8374)
Dear Mr. Gideon:
By letter dated August 29, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML16252A220), supplemented by e-mail dated January 24, 2017 (ADAMS Accession No. ML17024A331), Duke Energy Progress, LLC (the licensee) requested U.S. Nuclear Regulatory Commission (NRC) approval of Relief Request (RR) VRR-06 for the fourth 10-year interval inservice testing (IST) program at the Brunswick Steam Electric Plant (Brunswick), Units 1 and 2. The licensee's RR VRR-06 addresses the testing frequency for pumps and valves, as required by the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) for inservice testing.
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(2), the licensee requested to use the proposed alternative Code Case OMN-20 in RR VRR-06 on the basis that it provides reasonable assurance that the components are operationally ready and that compliance with the ASME OM Code requirements would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety.
The NRC staff has reviewed the subject request and concludes, as set forth in the enclosed safety evaluation, that for Alternative Request VRR-06 (use Code Case OMN-20), the proposed alternative provides reasonable assurance that the affected components are operationally ready, and complying with the ASME OM Code requirements would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety.
Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2).
Therefore, the NRC staff authorizes Alternative Request VRR-06 for the Brunswick, Units 1 and 2, current and future 10-year IST program intervals until Code Case OMN-20 is incorporated in 10 CFR 50.55a. All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject request remain applicable.
If you have any questions, please contact the Project Manager, Andrew Hon, at 301-415-8480 or Andrew.Hon@nrc.gov.
Docket Nos. 50-325 and 50-324
Enclosure:
Safety Evaluation cc w/encl: Distribution via Listserv Sincerely, Benjamin G. Beasley, Chief Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ALTERNATIVE REQUEST NO. VRR-06 TO USE CODE CASE OMN-20 FOR THE FOURTH 10-YEAR INSERVICE TESTING INTERVAL BRUNSWICK STEAM ELECTRIC PLANT, UNITS NOS. 1 AND 2 DUKE ENERGY PROGRESS, INC (DUKE ENERGY).
DOCKET NOS. 50-325 AND 50-324 (CAC NO. MF8373 AND 8374)
1.0 INTRODUCTION
By letter dated August 29, 2016 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML16252A220), Duke Energy Progress, LLC (Duke Energy, or the licensee) submitted a request for relief to the U.S. Nuclear Regulatory Commission (NRC),
proposing alternatives to certain requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) for the current inservice testing (IST) program at Brunswick Steam Electric Plant (Brunswick), Units 1 and 2.
In the same letter, the licensee also requested a correspondent change to affected technical specification pages which is being reviewed as a separate licensing amendment request.
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(2), the licensee requested to use the proposed alternative Code Case OMN-20 in Relief Request (RR) VRR-061 on the basis that it provides reasonable assurance that the components are operationally ready and that compliance with the ASME OM Code requirements would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety.
2.0 REGULATORY EVALUATION
The regulations in 10 CFR 50.55a(f), "lnservice testing requirements," require, in part, that the IST of certain ASME Code Class 1, 2, and 3 components must meet the requirements of the ASME OM Code and applicable addenda, except where alternatives have been authorized by the NRC pursuant to 10 CFR 50.55a(z)(1) or 10 CFR 50.55a(z)(2).
The regulations in 10 CFR 50.55a(z), state, in part, that alternatives to the requirements of 10 CFR 50.55a(f) may be authorized by the NRC if the licensee demonstrates that: (1) the proposed alternative provides an acceptable level of quality and safety, or (2) compliance with the specified requirements would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety.
1 The licensee designated this number in a follow up email (ADAMS Accession No. ML17024A331)
Enclosure Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request, and the NRC to authorize, the alternative proposed by the licensee.
3.0 TECHNICAL EVALUATION
3.1 Licensee's Alternative Request VRR-06 for the Use of Code Case OMN-20 3.1.1 Applicable Code Requirements This request applies to the frequency specifications of the ASME OM Code. The frequencies for tests given in the ASME OM Code include the following, but do not include a tolerance band:
ISTA-3120, "lnservice Test Interval," (a) states, "The frequency for inservice testing shall be in accordance with the requirements of Section IST."
ISTB-3400, "Frequency of lnservice Tests," states, "An inservice test shall be run on each pump as specified in Table ISTB-3400-1."
Table ISTB-3400-1, "lnservice Test Frequency," notes that Group A and Group B pump tests are to be conducted quarterly, and comprehensive pump tests are to be conducted biennially.
ISTC-3510, "Exercising Test Frequency," states, "Active Category A, Category B, and Category C check valves shall be exercised nominally every 3 months, except as provided by ISTC-3520, ISTC-3540, ISTC-3550, ISTC-3570, ISTC-5221, and ISTC-5222. Power-operated valves shall be exercise tested once per fuel cycle."
ISTC-3540, "Manual Valves," states, "Manual valves shall be full-stroke exercised at least once every 2 years, except where adverse conditions may require the valve to be tested more frequently to ensure operational readiness. Any increased testing frequency shall be specified by the Owner. The valve shall exhibit the required change of obturator position."
ISTC-3630, "Leakage Rate for Other Than Containment Isolation Valves," (a) "Frequency,"
states, "Tests shall be conducted at least once every 2 years."
ISTC-3700, "Position Verification Testing," states, in part, "Valves with remote position indicators shall be observed locally at least once every 2 years to verify that valve operation is accurately indicated."
ISTC-5221,"Valve Obturator Movement," (c)(3), states, "At least one valve from each group shall be disassembled and examined at each refueling outage; all valves in each group shall be disassembled and examined at least once every 8 years."
Mandatory Appendix I, "lnservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants," 1-1320, "Test Frequencies, Class 1 Pressure Relief Valves," (a), "5-Year Test Interval," states, in part, "Class 1 pressure relief valves shall be tested at least once every 5 years, starting with initial electric power generation."
Mandatory Appendix I, 1-1330, "Test Frequency, Class 1 Nonreclosing Pressure Relief Devices,"
states, "Class 1 nonreclosing pressure relief devices shall be replaced every 5 years unless historical data indicates a requirement for more frequent replacement."
Mandatory Appendix I, 1-1340, "Test Frequency, Class 1 Pressure Relief Valves That Are Used for Thermal Relief Application," states, "Tests shall be performed in accordance with 1-1320, Test Frequencies, Class 1 Pressure Relief Valves."
Mandatory Appendix I, 1-1350, "Test Frequency, Classes 2 and 3 Pressure Relief Valves," (a),
"10-Year Test Interval," states, in part, "Class 2 and 3 pressure relief valves, with the exception of PWR main steam safety valves, shall be tested every 1 O years, starting with initial electric power generation."
Mandatory Appendix I, 1-1360, "Test Frequency, Classes 2 and 3 Nonreclosing Pressure Relief Devices," states, "Classes 2 and 3 non-reclosing pressure relief devices shall be replaced every 5 years, unless historical data indicates a requirement for more frequent replacement."
Mandatory Appendix I, 1-1370, "Test Frequency, Classes 2 and 3 Primary Containment Vacuum Relief Valves," states, "(a) Tests shall be performed on all Classes 2 and 3 containment vacuum relief valves at each refueling outage or every 2 years, whichever is sooner, unless historical data requires more frequent testing. (b) Leak tests shall be performed on all Classes 2 and 3 containment vacuum relief valves at a frequency designated by the Owner in accordance with Table ISTC-3500-1."
Mandatory Appendix I, 1-1380, 'Test Frequency, Classes 2 and 3 Vacuum Relief Valves, Except for Primary Containment Vacuum Relief Valves," states, "All Classes 2 and 3 vacuum relief valves shall be tested every 2 years, unless performance data suggest the need for a more appropriate test interval."
Mandatory Appendix I, 1-1390, "Test Frequency, Classes 2 and 3 Pressure Relief Devices That Are Used for Thermal Relief Application," states, "Tests shall be performed on all Classes 2 and 3 relief devices used in thermal relief application every 10 years, unless performance data indicate more frequent testing is necessary. In lieu of tests the Owner may replace the relief devices at a frequency of every 10 years, unless performance data indicate more frequent replacements are necessary."
Mandatory Appendix 11, "Check Valve Condition Monitoring Program," 11-4000, "Condition-Monitoring Activities," (a), "Performance Improvement Activities," (1 ), states, in part, "If sufficient information is not currently available to complete the analysis required in 11-3000, or if this analysis is inconclusive, then the following activities shall be performed at sufficient intervals over an interim period of the next 5 years or two refueling outages, whichever is less, to determine the cause of failure or the maintenance patterns."
Mandatory Appendix 11, 11-4000, (b), "Optimization of Condition-Monitoring Activities," (1 )(e),
states, "Identify the interval of each activity. Interval extensions shall be limited to one fuel cycle per extension. Intervals shall not exceed the maximum intervals shown in Table 11-4000-1. All valves in a group sampling plan must be tested or examined again, before the interval can be extended again, or until the maximum interval would be exceeded. The requirements of ISTA-3120, lnservice Test Interval, do not apply."
In summary ASME OM Code, Division 1, Section IST, 2009 Edition through OMa-2011 Addenda, and all earlier editions and addenda, specify component (pump and valve) test frequencies based either on elapsed time periods (e.g., quarterly, 2 years, etc.) or on the occurrence of plant conditions or events (e.g., cold shutdown, refueling outage, upon detection of a sample failure, following maintenance, etc.) without any tolerance.
3.1.2
Applicable Code Edition and Addenda
The Code of Record for the Brunswick, Units 1 and 2, fourth 10-year IST program is the 2001 Edition through 2003 Addenda of the ASME OM Code. The Brunswick, Units 1 and 2, fourth 10-year IST interval ends May 10, 2018.
3.1.3 Components for Which Alternative Relief is Requested The request covers all pumps and valves contained within both Units' IST program's scope.
3.1.4 Licensee's Reason for Requesting Relief ASME OM Code Section IST establishes the IST frequency for all components within the scope of the code. The frequencies (e.g., quarterly) have always been interpreted as "nominal" frequencies (generally as defined in Table 3.2 of NUREG-1482, Revision 2 (ADAMS Accession No. ML13295A020)), and owners routinely applied the surveillance extension time period (i.e.,
grace period) contained in the plant technical specification (TS) surveillance requirements (SRs). The TSs typically allow for a less than or equal to 25 percent extension of the surveillance test interval to accommodate plant conditions that may not be suitable for conducting a TS surveillance (SR 3.0.2). However, Regulatory Issue Summary (RIS) 2012-10, "NRC Staff Position on Applying Surveillance Requirements 3.0.2 and 3.0.3 to Administrative Controls Program Tests" (ADAMS Accession No. ML12079A393), states that items related to extending the surveillance periods of the TS IST Program were inappropriately added to the TS and may not be applied.
The lack of a tolerance band on the ASME OM Code IST frequency restricts operational flexibility. The NRC recognized this potential issue in the TSs by allowing a frequency tolerance as described in TS SR 3.0.2. The lack of a similar tolerance applied to the ASME OM Code testing places an unusual hardship on the plant to adequately schedule work tasks without operational flexibility.
With the TS-required surveillance testing, some tolerance is needed to allow adjusting ASME OM Code testing intervals to suit the plant conditions and other maintenance and testing activities. This assures operational flexibility when scheduling IST that would minimize the conflicts between the need to complete the testing and plant conditions.
3.1.5 Licensee's Proposed Alternative The licensee proposed to perform IST per ASME OM Code Case OMN-20, repeated below, for determining acceptable tolerances for pump and valve test frequencies. This Code Case was approved by the ASME OM Code Standards Committee in February 2012 and subsequently published in the 2012 Edition through 2015 Edition of the ASME OM Code. The proposed alternative will be utilized for the current and future 10-year IST intervals at Brunswick, Units 1 and 2, and will apply to the various frequency specifications of the ASME OM Code for all pumps and valves contained within the IST program scope.
ASME OM Code Case OMN-20, "lnservice Test Frequency" ASME OM, Division 1, Section IST, and earlier editions and addenda of the ASME OM Code, specify component test frequencies based either on elapsed time periods (e.g., quarterly, 2 years, etc.) or on the occurrence of plant conditions or events (e.g., cold shutdown, refueling outage, upon detection of a sample failure, following maintenance, etc.).
(a)
Components whose test frequencies are based on elapsed time periods shall be tested at the frequencies specified in Section IST with a specified time period between tests as shown in the table below.
Frequency Specified Time Period Between Tests Quarterly 92 days (or everv 3 months}
Semiannually 184 days (or every 6 months)
Annually 366 days (or every year)
I x Years x calendar years where 'x' is a whole number of vears ~ 2 The specified time period between tests may be reduced or extended as follows:
(1) For periods specified as less than two years, the period may be extended by up to 25 percent for any given test.
(2) For periods specified as greater than or equal to two years, the period may be extended by up to 6 months for any given test.
(3) All periods specified may be reduced at the discretion of the Owner (i.e., there is no minimum period requirement).
Period extension is to facilitate test scheduling and considers plant operating conditions that may not be suitable for performance of the required testing (e.g., performance of the test would cause an unacceptable increase in the plant risk profile due to transient conditions or other ongoing surveillance, test, or maintenance activities). Period extensions are not intended to be used repeatedly merely as an operational convenience to extend test intervals beyond those specified.
Period extensions may also be applied to accelerated test frequencies (e.g., pumps in alert range) and other less than 2-year test frequencies not specified in the table above.
Period extensions may not be applied to the test frequency requirements specified in ASME OM Code Subsection ISTD, "Preservice and lnservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-water Reactor Nuclear Power Plants," as Subsection ISTD contains its own rules for period extensions.
(b)
Components whose test frequencies are based on the occurrence of plant conditions or events may not have their period between tests extended except as allowed by the ASME OM Code.
A similar alternative request was authorized for the Grand Gulf Nuclear Station, Unit 1, by the NRC staff in a letter dated June 16, 2016 (ADAMS Accession No. ML16160A092).
3.1.6
NRC Staff Evaluation
Historically, licensees have applied, and the NRC staff has accepted, the standard TS definitions for IST intervals (including allowable interval) extensions to ASME OM Code required testing (Reference NUREG-1482, Revision 2, Section 3.1.3). Recently, the NRC staff reconsidered the allowance of the TS testing intervals and interval extensions for IST not associated with TS SRs. As noted in RIS 2012-10, the NRC determined that programmatic test frequencies cannot be extended in accordance with TS SR 3.0.2 and SR 3.0.3. This includes all IST described in the ASME OM Code not specifically required by the TS SRs.
The lack of a tolerance band on the ASME OM Code IST frequency restricts operational flexibility. The NRC staff recognized that, just as with TS required surveillance testing, some tolerance is needed to allow adjusting ASME OM Code testing intervals to suit the plant conditions and other maintenance and testing activities. To provide operational flexibility when scheduling IST that minimizes the conflicts between the need to complete the testing and plant conditions, the NRC staff sponsored and co-authored an ASME OM Code inquiry and Code Case to modify the ASME OM Code to include TS-like test interval definitions and interval extension criteria. The resultant ASME-approved Code Case OMN-20, as shown above, was approved by the ASME Operation and Maintenance Standards Committee on February 15, 2012, with the NRC representative voting in the affirmative. Code Case OMN-20 was subsequently published in conjunction with the 2012 Edition through 2015 Edition of the ASME OM Code.
Requiring the licensee to meet the ASME OM Code requirements, without an allowance for defined frequency and frequency extensions for IST of pumps and valves, results in a hardship, without a compensating increase in the level of quality and safety. Based on the licensee's proposal to adopt the ASME-approved Code Case OMN-20 in its entirety, and prior acceptance of the similar TS test interval definitions and interval extension criteria, the NRC staff finds that implementation of the AS ME-approved OM Code Case OMN-20 provides reasonable assurance of operational readiness of pumps and valves, subject to the IST requirements of the ASME OM Code.
4.0 CONCLUSION
As set forth above, the NRC staff also determines that for Alternative Request VRR-06 (use Code Case OMN-20), the proposed alternative provides reasonable assurance that the affected components are operationally ready, and complying with the ASME OM Code requirements would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2).
Therefore, the NRC staff authorizes Alternative Request VRR-06 for the Brunswick, Units 1 and 2, current and future 10-year IST program intervals until Code Case OMN-20 is incorporated in 10 CFR 50.55a. All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject request remain applicable.
Principal Contributor: G. Bedi Date: February 16, 2017
SUBJECT:
BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 - RELIEF FROM THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS CODE FOR OPERATION AND MAINTENANCE FOR INSERVICE TESTING REQUIREMENTS (RELIEF REQUEST VRR-06) (CAC NOS. MF8373 AND MF8374)
DISTRIBUTION:
PUBLIC LPL2-2 R/F RidsACRS MailCTR Resource RidsNrrDorlLpl2-2 Resource RidsNrrEpnb Resource RidsNrrLABClayton Resource RidsNrrPMBrunswick Resource RidsRgn2MailCenter Resource GBedi, NRR JBowen, OEDO ADAMS A ccess1on N ML17038A552 o.:
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- 1 (ML17034A539)
,Y e-ma1 OFFICE NRR/DORL/LPL2-2/PM NRR/DORL/LPL2-2/LA NRR/DE/EPNB/BC* NRR/DORL/LPL2-2/BC NAME AH on BClayton DAiiey BBeasley (LRonewicz for)
(AKlett for)
DATE 02/10/17 02/10/17 01/28/17 02/16/17 OFFICIAL RECORD COPY