ML022400239

Relief, Code Relief Request from Section XI, the Pump and Valve Inservice Testing Program Regarding Inclusion of Additional Excess Flow Check Valves

ML022400239
Person / Time
Site:	Pilgrim
Issue date:	09/17/2002
From:	Andersen J NRC/NRR/DLPM/LPD1
To:	Bellamy M Entergy Nuclear Generation Co
Wall, S. NRR/DLPM 415-2855
References
TAC MB5122
Download: ML022400239 (10)

Text

September 17, 2002 Mr. Mike Bellamy Site Vice President Entergy Nuclear Generation Company Pilgrim Nuclear Power Station 600 Rocky Hill Road Plymouth, MA 02360

SUBJECT:

PILGRIM NUCLEAR POWER STATION - RELIEF REQUEST FROM SECTION XI, PUMP AND VALVE INSERVICE TESTING PROGRAM REGARDING INCLUSION OF ADDITIONAL EXCESS FLOW CHECK VALVES (TAC NO. MB5122)

Dear Mr. Bellamy:

By letter dated February 2, 2001, as supplemented on March 22, 2001, Entergy Nuclear Generation Company (ENGC) submitted valve relief request RV-44 for Pilgrim Nuclear Power Station (Pilgrim). ENGC requested relief for excess flow check valves (EFCVs), manufactured by Chemequip, from the American Society of Mechanical Engineers (ASME) Code-required tests every refueling outage, and from the biennial requirements of verifying valve position. The U.S. Nuclear Regulatory Commission (NRC) staff authorized relief request RV-44 as an acceptable alternative to the inservice testing (IST) requirements of Section XI of the ASME Code by letter dated May 2, 2001.

The March 22, 2001, supplemental letter, in part, withdrew six Chemequip EFCVs from relief request RV-44 when it was identified that upstream flow restricting orifices were not present in the lines served by the subject valves and, as a result, the basis for the relief request was not met. During refueling outage 13 (RFO 13), ENGC installed orifices in the instrument lines served by these EFCVs. Subsequently, by letter dated May 7, 2002, ENGC submitted an amendment to relief request RV-44 for Pilgrim requesting authorization to include these six additional EFCVs.

Based on the information provided, the NRC staff concludes that the proposed relief request is an acceptable alternative to the pump and valve IST requirements of Section XI of the ASME Boiler and Pressure Vessel Code for the additional EFCVs. Therefore, your request for relief is authorized for the remainder of the term of the current operating license, pursuant to 10 CFR 50.55a(a)(3)(i) on the basis that the alternative provides an acceptable level of quality and safety.

M. Bellamy If you should have any questions, please contact Travis Tate at 301-415-8474. This completes the NRC staffs action on TAC No. MB5122.

Sincerely,

/RA/

James W. Andersen, Acting Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-293

Enclosure:

Safety Evaluation cc w/encl: See next page

M. Bellamy If you should have any questions, please contact Travis Tate at 301-415-8474. This completes the NRC staffs action on TAC No. MB5122.

Sincerely,

/RA/

James W. Andersen, Acting Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-293

Enclosure:

Safety Evaluation cc w/encl: See next page DISTRIBUTION:

PUBLIC PDI-2 R/F SRichards JAndersen TTate TClark ACRS BPlatchek, RI DTerao MRubin SWall GHill (2)

OGC ACCESSION NUMBER: ML022400239 *See previous concurrence OFFICE PDI-2/PM PDI-2/PM PDI-2/LA EMEB/SC* SPSB/SC* OGC* PDI-2/SC(A)

NAME SWall RPulsifer for TClark DTerao MRubin RHoefling JAndersen TTate DATE 9/16/02 9/16/02 9/16/02 9/4/02 9/6/02 9/16/02 9/17/02 Official Record Copy

Pilgrim Nuclear Power Station cc:

Resident Inspector Mr. C. Stephen Brennion U. S. Nuclear Regulatory Commission Licensing Superintendent Pilgrim Nuclear Power Station Pilgrim Nuclear Power Station Post Office Box 867 600 Rocky Hill Road Plymouth, MA 02360 Plymouth, MA 02360-5599 Chairman, Board of Selectmen Mr. Jack Alexander 11 Lincoln Street Manager, Reg. Relations and Plymouth, MA 02360 Quality Assurance Pilgrim Nuclear Power Station Chairman, Duxbury Board of Selectmen 600 Rocky Hill Road Town Hall Plymouth, MA 02360-5599 878 Tremont Street Duxbury, MA 02332 Mr. David F. Tarantino Nuclear Information Manager Office of the Commissioner Pilgrim Nuclear Power Station Massachusetts Department of 600 Rocky Hill Road Environmental Protection Plymouth, MA 02360-5599 One Winter Street Boston, MA 02108 Ms. Jane Perlov Secretary of Public Safety Office of the Attorney General Executive Office of Public Safety One Ashburton Place One Ashburton Place 20th Floor Boston, MA 02108 Boston, MA 02108 Mr. Stephen J. McGrail, Director Dr. Robert M. Hallisey, Director Attn: James Muckerheide Radiation Control Program Massachusetts Emergency Management Commonwealth of Massachusetts Agency Executive Offices of Health and 400 Worcester Road Human Services Framingham, MA 01702-5399 174 Portland Street Boston, MA 02114 Chairman Nuclear Matters Committee Regional Administrator, Region I Town Hall U. S. Nuclear Regulatory Commission 11 Lincoln Street 475 Allendale Road Plymouth, MA 02360 King of Prussia, PA 19406 Mr. William D. Meinert John M. Fulton Nuclear Engineer Assistant General Counsel Massachusetts Municipal Wholesale Pilgrim Nuclear Power Station Electric Company 600 Rocky Hill Road P.O. Box 426 Plymouth, MA 02360-5599 Ludlow, MA 01056-0426

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST FOR INCLUSION OF ADDITIONAL EXCESS FLOW CHECK VALVES PILGRIM NUCLEAR POWER STATION ENTERGY NUCLEAR GENERATION COMPANY DOCKET NO. 50-293

1.0 INTRODUCTION

By letter dated May 7, 2002, as part of a submittal of proposed alternatives to the requirements of Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a, Entergy Nuclear Generation Company (ENGC) submitted a request to include six additional excess flow check valves (EFCVs) to relief request RV-44 for Pilgrim Nuclear Power Station (Pilgrim).

2.0 BACKGROUND

It is required by 10 CFR 50.55a that licensees perform inservice testing (IST) of certain American Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 pumps and valves in accordance with Section XI of the ASME Boiler and Pressure Vessel Code (the Code) and applicable addenda, except where alternatives have been authorized or relief has been requested by the licensee and granted by the Commission pursuant to Sections (a)(3)(i),

(a)(3)(ii), or (f)(6)(i) of 10 CFR 50.55a. In proposing alternatives or requesting relief, the licensee must demonstrate that: (1) the proposed alternatives provide an acceptable level of quality and safety; (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety; or (3) conformance is impractical for its facility. The regulations in 10 CFR 50.55a authorize the Commission to approve alternatives and to grant relief from ASME Code requirements upon making the necessary findings.

The 1989 Edition of the ASME Code is the applicable Code of Record for the third 10-year interval IST program at Pilgrim. Subsection IWV of the 1989 Edition, which gives the requirements for IST of valves, references Part 10 of the American National Standards Institute (ANSI)/ASME Operations and Maintenance Standards (OM-10) as the rules for IST of valves.

OM-10 replaces specific requirements in previous editions of Section XI, Subsection IWV, of the ASME Code. By letter dated February 2, 2001, as supplemented on March 22, 2001, ENGC submitted valve relief request RV-44 for Pilgrim. ENGC requested relief for EFCVs, manufactured by Chemequip, from the ASME Code-required tests every refueling outage, and from the biennial requirements of verifying valve position. The U.S. Nuclear Regulatory Commission (NRC) staff authorized relief request RV-44 as an acceptable alternative to the IST requirements of Section XI of the ASME Code by letter dated May 2, 2001.

Enclosure

The March 22, 2001, supplemental letter, in part, withdrew six Chemequip EFCVs from relief request RV-44 when it was identified that upstream flow restricting orifices were not present in the lines served by the subject valves and, as a result, the basis for the relief request was not met. During refueling outage 13 (RFO 13), ENGC installed orifices in the instrument lines served by these EFCVs.

The NRC staff has reviewed and evaluated the licensees request to now include the six Chemequip EFCVs in relief request RV-44 pursuant to 10 CFR 50.55a(a)(3)(i).

3.0 EVALUATION ENGC requests that the following EFCVs (manufactured by Chemiquip) be incorporated into the approved relief request RV-44. Specifically, ENGC requests relief for these EFCVs from the ASME Code IST that is required to be performed every refueling outage as specified in OM-10 Code, Paragraph 4.3.2.2, and from the biennial requirements (Paragraph 4.1 of OM-10 Code) of verifying that the valve position is accurately indicated. The relief request allows that a representative sample (approximately 20 percent) of the affected EFCVs be tested each refueling cycle such that each EFCV will be tested at least once every 10 years (nominal).

Excess Flow Check Valves to be supplemented in Relief Request RV-44 12-CK-360 1301-15A 2301-26 12-CK-361 1301-15B 2301-220 3.1 Basis for Relief NEDO-32977-A, and the associated NRC safety evaluation, dated March 14, 2000, provides the basis for this relief. NEDO-32977-A justifies relaxing the EFCV testing frequency from the current testing of each valve once/cycle to a

~20% sample once/cycle such that each valve is tested within a 10 year interval.

NEDO-32977-A demonstrates, through operating experience, a high degree of reliability with EFCVs and the low consequences of an EFCV failure. Reliability data in the report (Tables 4-1 and 4.2) documents two EFCV failures (failure to close) at 4 participating plants (Monticello, Dresden, Vermont Yankee and Oyster Creek), for Chemiquip valves similar to those used at Pilgrim. These two failures were observed over a service time of 5426 operating years (4.75E +07 operating hours). This results in a Best Estimate Failure Rate of 4.21 E-08 per hour of operating time and an Upper Limit Failure Rate of 1.33 E-07 per hour of operating time. A review of historical test surveillance data, and a test failure component history search at Pilgrim shows zero EFCV failures (failure to close) have been observed (data from 1983 through 1999 RFO #12). In addition, there are no known EFCV failures that occurred earlier than 1983.

The instrument lines at Pilgrim have a flow restricting orifice upstream of the EFCVs to limit reactor water leakage in the event of rupture. Previous evaluations contained in Pilgrims Updated Final Safety Analysis Report (UFSAR) of such an instrument line rupture do not credit the EFCVs for isolating the rupture. Thus a failure of an EFCV, though not expected as a result of this

request, is bounded by the analysis. Based on the NEDO-32977-A and the analysis contained in Pilgrims UFSAR, the proposed alternative to the required exercise testing frequency for EFCVs prescribed by OM-10 provides a satisfactory level of quality and safety.

3.2 Alternative Testing This relief request proposes to exercise test (FC), by full-stroke to the position required to fulfill its function, a representative sample of EFCVs every refueling outage. During the exercise test, gross valve seat leakage (LXEFC) will be measured. The representative sample is based on approximately 20 percent of the valves each cycle such that each valve is tested every 10 years (nominal).

An Administrative Open Normal Position Verification (AP) will be performed on each valve following exercise and leak testing.

EFCV failures will be documented in Pilgrim's Corrective Action Program as a surveillance test failure. The failure will be evaluated and corrected. The Administrative EFCV Sample Test Program procedure will trend EFCV test failures and determine if additional testing is warranted.

The Administrative EFCV Sample Test Program procedure will also establish a minimum acceptance criteria for Chemequip EFCVs of less than or equal to 1 failure per year (2 failures per 2 years) on a 2 year rolling average. This requirement will ensure EFCV performance remains consistent with the extended test interval. Upon exceeding the criteria an evaluation will be required which will:

 require a root-cause evaluation to determine cause,

 determine the extent of conditions,

 require an evaluation of the testing interval to ensure reliability of the EFCVs, and

 produce a risk analysis of the effects of the failures on cumulative and instantaneous plant safety.

Corrective actions and performance goals will be established based on the results of the root-cause analysis.

3.3 NRC Staff Evaluation EFCVs are installed on boiling-water reactor (BWR) instrument lines to limit the release of fluid in the event of an instrument line break. Examples of EFCV installations include reactor pressure vessel level and pressure instrumentation, main steamline flow instrumentation, recirculation pump suction pressure, and reactor core isolation cooling steamline flow instrumentation. EFCVs are not required to close in response to a containment isolation signal and are not required to operate under post loss-of-coolant accident (LOCA) conditions.

The Pilgrim Technical Specifications (TS) surveillance requires the EFCVs to be tested for proper operation in accordance with the IST program. The Pilgrim IST program has deferred

the quarterly testing of these valves based on the provision of the Code that states if exercising is not practical during plant operation or cold shutdowns, it may be limited to full-stroke testing during refueling outages. Based on the Code provision above, and the Refueling Outage Justification (ROJ) number ROJ-16, EFCVs at Pilgrim are currently tested once every refueling outage (24 months). The proposed change by ENGC revises the surveillance frequency by allowing a representative sample of EFCVs to be tested every 24 months. The representative sample is based on approximately 20 percent of the EFCVs being tested each refueling outage such that each valve is tested at least once every 10 years (nominal).

ENGCs justification for the relief request is based on General Electric Nuclear Energy (GE)

Topical Report NEDO-32977-A, Excess Flow Check Valve Testing Relaxation dated June 2000. The topical report provided: (1) an estimate of steam release frequency (into the reactor building) due to a break in an instrument line concurrent with an EFCV failure to close, and (2) an assessment of the radiological consequences of such a release. The staff reviewed the GE topical report and issued its evaluation on March 14, 2000. In its evaluation, the staff agreed that the test interval could be extended up to a maximum of 10 years. In conjunction with this finding, the staff noted that each licensee that adopts the relaxed test interval program for EFCVs must have a failure feedback mechanism and corrective action program to ensure EFCV performance continues to be bounded by the topical report results. Also, each licensee is required to perform a plant-specific radiological dose assessment, EFCV failure analysis, and release frequency analysis to confirm that they are bounded by the generic analyses of the topical report.

In this safety evaluation, the staff reviewed ENGCs proposal for its applicability to GE Topical Report NEDO-32977-A and conformance with approved staff guidance regarding radiological dose assessment, EFCV failure rate and release frequency, and the proposed failure feedback mechanism and corrective action program. Based on its review, the staff concludes that the radiological consequences of an EFCV failure are sufficiently low, are acceptable, and that the alternative testing in conjunction with the corrective action plan provides a high degree of valve reliability and operability. Additionally, an orifice is installed upstream of the EFCVs to limit reactor water leakage in the event of rupture. The orifice limits leakage to a level where the integrity and functional performance of secondary containment and associated safety systems are maintained. Therefore, the staff finds that ENGCs proposed alternative test provides an acceptable level of quality and safety.

4.0 CONCLUSION

Based on the above evaluation, the NRC staff finds the proposed relaxation of the Pilgrim EFCV test frequency, which would allow a representative sample of EFCVs to be tested every 24 months, with all EFCVs being tested at least once every 10 years (nominal), to be acceptable. ENGCs proposed alternative to the Code testing requirements for the six additional Chemequip EFCVs is authorized for the remainder of the term of the current operating license pursuant to 10 CFR 50.55a(a)(3)(i) based on the alternative providing an acceptable level of quality and safety. Therefore, ENGC is authorized to supplement these six Chemequip EFCVs in relief request RV-44.

Principal Contributors: T. Tate S. Wall Date: September 17, 2002