ML083510740

Request for Relief from the Requirements of the ASME OM Code

ML083510740
Person / Time
Site:	Susquehanna
Issue date:	01/08/2009
From:	Mark Kowal Plant Licensing Branch 1
To:	Spence W PPL Corp
vaidya B, NRR/Dorl/lpl1-1, 415-3308
References
TAC MD9436
Download: ML083510740 (6)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. William H. Spence Executive Vice President Chief Operating Officer/Chief Nuclear Officer PPL Corporation Two North Ninth Street, GENTW16 Allentown, PA 18101-1179

SUBJECT:

SUSQUEHANNA STEAM ELECTRIC STATION, UNIT 2 - REQUEST FOR RELIEF FROM THE REQUIREMENTS OF THE ASME OM CODE (TAC NO. MD9436)

Dear Mr. Spence:

By letter dated August 5, 2008, PPL Susquehanna, LLC (the licensee) submitted a request to the U. S. Nuclear Regulatory Commission (NRC) for relief from certain American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code)/American National Standards Institute (ANSI), "Code for Operation and Maintenance of Nuclear Plants," (ASME OM Code), requirements at Susquehanna, Unit No.2.

Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a(a)(3)(i), you 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 subject request, and concludes that you have adequately addressed all of the regulatory requirements set forth in 50.55a(a)(3)(ii) and demonstrated that complying with the specified Code requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety and that the component is operationally ready. Therefore, the NRC staff authorizes licensee proposed alternatives on one-time basis, in accordance with 10 CFR 50.55a(a)(3)(ii) at Susquehanna, Unit No.2 until the completion of the April 2009 Unit 2 refueling outage.

The NRC staffs safety evaluation is enclosed.

Mark G. Kowal, Chief Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-388

Enclosure:

As stated cc w/encl: Distribution via Listserve

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RELIEF REQUEST 2RR07 THE INSERVICE TESTING PROGRAM, THIRD 10-YEAR INTERVAL PPL SUSQUEHANNA. LLC ALLEGHENY ELECTRIC COOPERATIVE INC.

SUSQUEHANNA STEAM ELECTRIC STATION, UNIT 2 DOCKET NO. 50-388

1.0 INTRODUCTION

By letter dated August 5, 2008, (Agencywide Documents Access and Management System Accession No. ML082270202), PPL Susquehanna, LLC, (the licensee), pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a(a)(3)(i), submitted Relief Request 2RR07 for the third 1O-year interval inservice testing (1ST) program at Susquehanna Steam Electric Plant, Unit 2, for relief from certain 1ST requirements of the 1998 Edition through 2000 Addenda of the American Society of Mechanical Engineers (ASI\IIE) Code for Operation and Maintenance of Nuclear Power Plants (OM Code). The relief request involves an extension to the ASME OM Code 8-year test interval for check valve disassembly and inspection in light-water reactor power plants.

2.0 REGULATORY EVALUATION

10 CFR 50.55a, requires that 1ST of certain ASME Code Class 1, 2, and 3 pumps and valves be performed at 120-month (1O-year) 1ST program intervals in accordance with the specified ASME Code and applicable addenda incorporated by reference in the regulations, except where alternatives have been authorized or relief has been requested by the licensee and granted by the U.S. Nuclear Regulatory Commission (NRC) pursuant to paragraphs (a)(3)(i),

(a)(3)(ii), or (f)(6)(i) of 10 CFR 50.55a. In accordance with 10 CFR 50.55a(f)(4)(ii), licensees are required to comply with the requirements of the latest edition and addenda of the ASME Code incorporated by reference in the regulations 12 months prior to the start of each 10 year 1ST program interval. In accordance with 10 CFR 50.55a(f)(4)(iv), 1ST of pumps and valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in 10 CFR 50.55a(b), subject to NRC approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions and addenda are met.

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 the facility. Section 50.55a authorizes the Enclosure

-2 NRC to approve alternatives and to grant relief from ASME OM Code requirements upon making necessary findings. NRC guidance contained in Generic Letter (GL) 89-04, "Guidance on Developing Acceptable Inservice Testing Programs," provides alternatives to ASME Code requirements which are acceptable. Further guidance is given in GL 89-04, Supplement 1, and NUREG-1482, Revision 1, "Guidance for Inservice Testing at Nuclear Power Plants,"

3.0 EVALUATION OF RELIEF REQUEST 2RR07 3.1 Description of Subject of Relief Request 2RR07 Pursuant to 10 CFR, Section 50.55a(a)(3)(i), the licensee requested relief from certain 1ST requirements of the 1998 Edition throuqh 2000 Addenda of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code). The relief request involves an extension to the ASME OM Code 8-year test interval for check valve disassembly and inspection in light water reactor power plants.

3.1.1 ASME Code Components Affected (as submitted)

PPL Susquehanna Unit 2, High Pressure Coolant Injection (HPCI) Turbine Exhaust to Suppression Pool Vacuum Breaker Line Check Valve, 255F076; Model number W8121381; manufacturer: Anchor Darling Valve Company.

Function This check valve is in the HPCI turbine exhaust line. It has an open safety function to prevent a vacuum relief path for the turbine exhaust line. It has a close safety function to prevent steam flow into the suppression chamber. The valve has no containment isolation function. The open and closed safety functions of the valve are currently verified by valve disassembly and examination.

3.1.2 Applicable Code Requirements [including Code Edition and Addenda] (as submitted)

American Society of Mechanical Engineers (ASME)/American National Standards Institute, "Code for Operation and Maintenance of Nuclear Power Plants" (ASME OM Code), 1998 Edition through OMb-2000 Addenda.

ISTC-5221(c)(3), "Valve Obturator Movement" "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."

3.1.3 Licensee's Proposed Alternative Check valve 255F076 will be tested on a frequency of 8 years and 1 month to correspond with the extended operating cycle in lieu of the 8-year requirement currently allowed by the ASME Code. The proposed alternative is requested as a one time extension from the 8-year

- 3 frequency specified in the ASME Code. The extension will allow disassembly and inspection during the April 2009 Unit 2 refueling outage.

3.1.4 Licensee's Basis for Relief The ASME Code, 1998 Edition through 2000 Addenda, ISTC 5221 permits disassembly and inspection of check valves when it is impractical to verify obturator movement. The Unit 2 HPCI turbine exhaust to suppression pool vacuum breaker check valve, 255F076, has no external means for exercising the valve and no external position indication. Due to the lack of installed flow or pressure indication and a lack of test connections, it is not possible to use other means to verify the open and close exercising of this check valve. Disassembly and examination of the valve is the only feasible method to verify operability.

Check valve 255F076 is grouped with similar valves as required by ISTC 5221(c)(1). This group contains four valves: 149F064, 249F063, 255F076, and 255F077. The last disassembly and examination of check valve 255F076 occurred on March 23, 2001, during a refueling outage, therefore, to comply with the 8-year Code requirement the next disassembly and examination is due by March 22, 2009, requiring a plant shutdown resulting in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The next scheduled refueling outage is scheduled to commence in early April 2009, which exceeds the 8-year Code requirement. There have been no problems identified during the previous disassembly and inspections of this valve or the other valves associated with this group. Extending the required inspection interval by 1 month for check valve 255F076 would not have an adverse impact on quality or nuclear safety.

3.2 Evaluation The NRC staff has reviewed the licensee's basis for relief to determine if it is acceptable to extend the test interval for check valve 255F076 beyond the allowable 8-year interval specified in the ASME OM Code. The test interval will be extended approximately 1 month until the April 2009 Unit 2 refuelling outage. The valve will be disassembled and inspected prior to returning Unit 2 to service.

The disassembly and inspection history for check valve 255F076 and the other 3 check valves in the group indicates satisfactory valve performance. There have been no problems identified during previous disassembly and inspection activities for any of the valves in the group. One check valve in the group has been disassembled and inspected during each of the previous refueling outages with satisfactory results. The NRC staff finds that the licensee has demonstrated that the disassembly and inspection activity along with previous inspection results provide adequate assurance that the operational readiness of the valve to perform its safety function will not be impaired during the period that the proposed alternative is authorized. Compliance with the ASME Code requirements would result in hardship or unusual difficulty without a compensating increase in quality and safety due to unnecessary challenges to safety systems, unnecessary cycling of equipment, and an unnecessary plant shutdown. Therefore, the I\IRC staff finds that the proposed alternative to extend the disassembly and inspection interval for check valve 255F076 approximately 1 month beyond the ASME OM Code 8-year requirement is acceptable.

-4

4.0 CONCLUSION

S Based on the above evaluation, the proposed alternative to disassemble and inspect check valve 255F076 on a frequency of a years and 1 month to correspond with the extended operating cycle in lieu of the a-year requirement currently allowed by the ASME Code is authorized on the basis that compliance with the Code requirements would result in hardship or unusual difficulty without a compensating increase in quality and safety. The additional time beyond that required by the ASME Code should not impair the valves operational readiness. The proposed alternative is authorized on a one time basis until the completion of the April 2009 Unit 2 refueling outage.

The NRC staff concludes that licensee has adequately addressed all of the regulatory requirements set forth in 50.55a(a)(3)(ii) and demonstrated that complying with the specified Code requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety and that the component is operationally ready.

Therefore, the NRC staff authorizes licensee proposed alternatives on one-time basis, in accordance with 10 CFR 50.55a(a)(3)(ii) at Susquehanna, Unit 1\10. 2 until the completion of the April 2009 Unit 2 refueling outage.

Principal Contributor: W. Poertner Date: Jarrnry 8, 2ffJ1

... ML083510740 OFFICE LPLI-1/PM LPLI-1/LA NRRlDCI/CPTB/BC OGC LPLI-1/BC NAME BVaidya SLittie JMcHaie LSubin MKowal DATE 12/22/08 12/22/08 12/15/08 12/24/08 1/08/09