ML120330329

Relief Request VRR4 Regarding Pressurizer Safety Valve Test Frequency

ML120330329
Person / Time
Site:	Beaver Valley
Issue date:	02/07/2012
From:	George Wilson Plant Licensing Branch 1
To:	Harden P FirstEnergy Nuclear Operating Co
Morgan N, NRR/DORL, 415-1016
References
TAC ME5752
Download: ML120330329 (7)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-Cl001 February 7,2012 Mr. Paul A. Harden Site Vice President FirstEnergy Nuclear Operating Company Beaver Valley Power Station Mail Stop A-BV-SEB1 P.O. Box 4, Route 168 Shippingport, PA 15077

SUBJECT:

BEAVER VALLEY POWER STATION, UNIT NOS. 1 AND 2 - RELIEF REQUEST VRR4 REGARDING PRESSURIZER SAFETY VALVE TEST FREQUENCY (TAC NO. ME5752)

Dear Mr. Harden:

By letter dated February 21, 2011, as supplemented by letter dated September 14, 2011, FirstEnergy Nuclear Operating Company (the licensee) submitted Relief Request VRR4 to the Nuclear Regulatory Commission (NRC) for relief from Appendix I, Paragraph 1-1320(a) of the American Society of Mechanical Engineers Code for Operation and Maintenance of Nuclear Power Plants (ASME OM Code) requirements at Beaver Valley Power Station, Unit NO.2 (BVPS- 2).

Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(a)(3)(i),

the licensee requested to use the proposed alternative on the basis that the alternative provides an acceptable level of quality and safety.

The NRC staff has reviewed the licensee's proposed alternative to use a test frequency, in accordance with ASME OM Code Case OMN-17, to perform relief valve testing on pressurizer safety valves 2RCS*RV551A, 2RCS*RV551 B, and 2RCS*RV551 C and concludes that the proposed alternative in Relief Request VRR4 provides an acceptable level of quality and safety.

Therefore, pursuant to 10 CFR 50.55a(a)(3)(i), the NRC staff authorizes the proposed alternative for the remainder of the BVPS-2 third 10-year inservice testing interval.

All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject request for relief remain applicable.

P. Harden -2 If you have any questions, please contact the Beaver Valley Project Manager, Nadiyah Morgan, at (301) 415-1016.

Sincerely, Ge rge W* on, Chief Plan . ensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-412

Enclosure:

As stated cc w/encl: Distribution via Listserv

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST VRR4 REGARDING PRESSURIZER SAFETY VALVE TEST FREQUENCY FIRSTENERGY NUCLEAR OPERATING COMPANY FIRSTENERGY NUCLEAR GENERATION CORP.

OHIO EDISON COMPANY THE TOLEDO EDISON COMPANY BEAVER VALLEY POWER STATION, UNIT NO.2 DOCKET NO. 50-412

1.0 INTRODUCTION

By letter dated February 21,2011 (Agencywide Document Access and Management System (ADAMS) Accession No. IVIL 110560014), as supplemented by letter dated September 14, 2011 (ADAMS Accession No. ML11262A045), FirstEnergy Nuclear Operating Company (the licensee) requested relief from the requirements of Appendix I, Paragraph 1-1320{a) of the American Society of Mechanical Engineers Code for Operation and Maintenance of Nuclear Power Plants (ASME OM Code) for an alternative test frequency to perform relief valve testing on pressurizer safety valves 2RCS*RV551A, 2RCS*RV55'1 B, and 2RCS*RV551C at Beaver Valley Power Station, Unit No.2 (BVPS- 2).

Specifically, pursuant to Title 10 of the Code of Federal Regulations (1 0 CFR) 50.55a(a)(3)(i),

the licensee requested to use the proposed alternative on the basis that the alternative provides an acceptable level of quality and safety.

2.0 REGULATORY EVALUATION

10 CFR 50.55a(f), "Inservice testing requirements," requires, in part, that 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 pursuant to paragraphs (a)(3)(i) or (a)(3)(ii). Paragraph (a){3) of 10 CFR 50.55a states that alternatives to the requirements of paragraph (g) may be used, when authorized by the Nuclear Regulatory Commission (NRC), if (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. 10 CFR 50.55a allows the NRC to authorize alternatives to ASME OM Code requirements upon making necessary findings. The NRC staff reviewed and evaluated the licensee's request pursuant to 10 CFR 50.55a(a){3)(i).

Enclosure

-2

3.0 TECHNICAL EVALUATION

3.1 Licensees Relief Request System/Component Affected 2RCS*RV551A, Pressurizer Safety Valve 2RCS*RV551 B, Pressurizer Safety Valve 2RCS*RV551 C, Pressurizer Safety Valve Applicable Code Requirements The 2001 Edition of the ASME OM Code with Addenda through OMb-2003 is the Code of Record for BVPS-2 third 10-year inservice testing (1ST) program interval.

Appendix I, Paragraph 1-1320, "Test Frequencies, Class 1 Pressure Relief Valves,"

subparagraph (a), "5- Year Test Interval, "states, 'Class 1 pressure relief valves shall be tested at least once every 5 years, starting with initial electric power generation. No maximum limit is specified for the number of valves to be tested within each interval; however, a minimum of 20%

of the valves from each valve group shall be tested within any 24-month interval. This 20%

shall consist of valves that have not been tested during the current 5-year interval, if they exist.

The test interval for any individual valve shall not exceed 5 years:'

ASME OM Code Case OMN-17, Alternate Rules for Testing ASME Class 1 Pressure Relief/Safety Valves"from the 2009 Edition of ASME OM Code, allows a 6-year test interval plus an additional 6-month grace period coinciding with a refueling outage, in order to accommodate extended shutdown periods.

In summary, the licensee notes the following in its February 21,2011, and September 14, 2011, submittal:

Licensee's Basis for Request BVPS-2 has three pressurizer safety valves installed to protect the reactor coolant system from overpressure. Since BVPS-2 operates on an 18-month fuel cycle, one valve can be tested each refueling outage such that each valve is tested over a 4 Y2 year period. In order to avoid outage delays due to valve testing, a pressurizer safety valve is replaced during each refueling outage with a spare valve that has been tested. The removed valve is refurbished and tested for installation during the following refueling outage. In order to ensure the spare replacement valve does not exceed the 5-year test interval limit from test to test. it must be tested within 6 months prior to installation. Extending the maximum test interval to 6 years with a 6-month grace period would allow BVPS-2 to continue to rotate in a spare pressurizer safety valve without the need to test the spare valve within 6 months of installation.

Licensees Proposed Alternative and Basis for Use As an alternative to the ASME OM Code-2001 Edition, Appendix I, Paragraph 1-1320(a) test interval for pressurizer relief valve testing, of at least once every 5 years, the licensee proposes to test pressurizer safety valves at least once every 6 years plus a 6-month grace period, if

-3 required, in accordance with the periodicity and other requirements of ASME OM Code Case OMN-17. Code Case OMN-17 provisions will not be applied to a valve until the valve is disassembled and inspected as described in paragraph (e) of Code Case OMN-17.

Paragraph (d) of Code Case OMN-17 requires disassembly and inspection of each valve after as-found set pressure testing is performed in order to verify that parts are free of defects resulting from time related degradation or service induced wear. Paragraph (e) of Code Case OMN-17 requires each valve to be disassembled and inspected in accordance with Paragraph (d) prior to the start of the 72-month test interval.

When the proposed alternative is applied to a valve, the valve will be disassembled and inspected, after as-found set pressure testing is performed in accordance with Code Case OMN-17 paragraphs (d) and (e). The initial inspection and ongoing inspections will verify that valve parts are free of defects resulting from time-related degradation or service-induced wear.

These inspections will provide additional assurance that the pressurizer safety valves will perform their intended function.

The longer test interval will eliminate the need for a valve test within 6 months of installation during each refueling outage. Eliminating the test, will in turn, remove the risk of any return shipping damage to the valve from the offsite testing facility and reduce wear on metal valve seats due to steam testing.

The as-found set-pressure acceptance criteria is plus or minus 3 percent of valve nameplate set pressure in accordance with Paragraph 1-1320(c)(1) of ASME OM Code-2001 Edition, Appendix I for the purpose of determining the need to test additional valves. The as-found set-pressure acceptance criteria is plus 1.6 percent or minus 3 percent of valve nameplate set pressure in accordance with BVPS Technical Specification (TS) Limiting Condition for Operability 3.4.10 for the purpose of determining pressurizer safety valve operability. Since 1989, 18 as-found set pressure tests have been performed for the four Crosby Model HB-86-BP pressurizer safety valves (including the spare valve). These tests have been performed at an offsite test facility using saturated steam. The majority of the tests were performed after the valve was installed for three operating cycles. As-found tests were within plus or minus 3 percent of the valve set pressure with the exception of valve 2RCS*RV551 C, which lifted low (minus 5.6 percent) in 1989 due to excessive seat leakage. BPVS TS Surveillance Requirement 3.4.10.1 requires that following testing, lift settings shall be within plus or minus 1 percent. For 12 of the 18 tests, the valves were found within the as-left tolerance of plus or minus 1 percent. These test results show limited time-related degradation or set point drift and demonstrate that it is acceptable to extend the test interval from 4 % years (three fuel cycles) to 6 years with a 6-month grace period (four fuel cycles).

The ability to detect degradation and ensure the operational readiness of the pressurizer safety valves to perform their intended function is assured based on the valve test history and by performing the required inspection and testing initially and at the proposed alternative frequency. Therefore, test and inspection of the valves in accordance with the proposed alternative demonstrates an acceptable level of quality and safety.

- 4 3.2 NRC Staff's Evaluation ASME OM Code, Mandatory Appendix I does not require that safety relief valves (SRVs) be disassembled and inspected prior to the start of the S-year test interval. The ASME Code Case OMN-17 was published in the 2009 Edition of OM Code. ASME Code Case OMN-17 allows extension of the test interval for SRVs from S to 6 years plus a 6-month grace period. The code case imposes a special maintenance requirement to disassemble and inspect each SRV to verify that parts are free from defects resulting from time-related degradation or maintenance induced wear prior to the start of the extended test interval.

The licensee has provided test data to show that the subject valves have historically exhibited very limited susceptibility to time related degradation or set point drift. They have also committed to implement a disassembly and inspection program in conjunction with the extended test interval, as required by ASME OM Code Case OMN-17, in order to detect and control defects resulting from time-related degradation or service-induced wear going forward.

Based on the historical performance of the set point testing of BVPS-2 pressurizer safety valves and the licensee's meeting the requirements of ASME Code base OMN-17 to disassemble and inspect the SRVs prior to use, the NRC staff finds that implementation of the ASME OM Code Case, OMN-17, for the testing of the designated pressurizer safety valves, in lieu of the requirements of ASME OM Code 2001 Edition with Addenda through OMb-2003, Mandatory Appendix I, Section 1-1320 of OM Code, provides an acceptable level of quality and safety.

4.0 CONCLUSION

As set forth above, the NRC staff concludes that the proposed alternative in Relief Request VRR4 provides an acceptable level of quality and safety. Therefore, pursuant to 10 CFR SO.SSa(a)(3)(i), the NRC staff authorizes the proposed alternative for the remainder of the BVPS-2 third 10-year 1ST interval.

All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject request for relief remain applicable.

Principal Contributor: J. Billerbeck Date: February 7, 2012

ML120330329 *See email dated November 18 , 2011 OFFICE LPL 1-1/PM LPL 1-'l/LA DE/EPTB/BC LPL 1-1/BC NAME NMorgan SLittle AMcMurtray* GWilson DATE 2/2/12 2/2/12 11/18/2011 2/7/12