ML021060775

Evaluation of Relief Request RR-12, Table RR-12-6, Rotation of Snubbers and Relief Valves (TAC Nos. MB1018 and MB1019)

ML021060775
Person / Time
Site:	Limerick
Issue date:	05/02/2002
From:	Clifford J NRC/NRR/DLPM
To:	Skolds J Exelon Generation Co, Exelon Nuclear
Gratton C, NRR/DLPM 415-1055
References
TAC MB1018, TAC MB1019
Download: ML021060775 (9)

Text

May 2, 2002 Mr. John L. Skolds, President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2, EVALUATION OF RELIEF REQUEST RR-12, TABLE RR-12-6, RE: ROTATION OF SNUBBERS AND RELIEF VALVES (TAC NOS. MB1018 AND MB1019)

Dear Mr. Skolds:

By letter dated January 9, 2001, PECO Energy Company (PECO), the then licensee, submitted proposed alternatives to the requirements of Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a, concerning the second 10-year inservice inspection (ISI) programs.

PECO was succeeded by Exelon Generation Company, LLC (EGC or the licensee), as the licensed operator of Limerick Generating Station, Units 1 and 2, on January 12, 2001. By letter dated January 30, 2001, EGC requested that the Nuclear Regulatory Commissions (NRCs) staff continue to process and disposition licensing actions previously docketed and requested by PECO.

This NRC staff safety evaluation applies to relief request (RR) RR-12, Table RR-12-6. RR-12, Tables RR-12-9 through RR-12-11, and RR-24 through RR-31 were evaluated and approved in a letter to the licensee dated September 12, 2001. RR-12, Table RR-12-7 was evaluated and approved in a letter to the licensee dated February 14, 2002. The NRC staff will provide their evaluation of the remaining relief requests from the January 9, 2001, letter under separate cover.

Subsection IWA-7000 of Section XI of the American Society of Mechanical Engineers Code (ASME Code) requires that the rotation of snubbers and relief valves be treated as an ASME Code replacement. The licensee has proposed adoption of Code Case N-508-1, Rotation of Serviced Snubbers and Pressure Relief Valves for the Purpose of Testing, which would eliminate the burdensome administrative controls and documentation required by Section XI of the ASME Code.

Based on the information provided, the NRC staff concludes that for RR-12, Table RR-12-6, the proposed alternative will provide an acceptable level of quality and safety. Therefore, the use of the proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i) for the second 10-year ISI interval. The NRC staff's safety evaluation is enclosed.

J. Skolds If you have any questions, please contact your Project Manager, Christopher Gratton, at 301-415-1055.

Sincerely,

/RA/

James W. Clifford, Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosure:

Safety Evaluation cc w/encl: See next page

J. Skolds If you have any questions, please contact your Project Manager, Christopher Gratton, at 301-415-1055.

Sincerely,

/RA/

James W. Clifford, Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosure:

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

MOBrien PUBLIC DTerao JArroyo CGratton ACRS PDI-2 R/F EThomas OGC BPlatchek, RGN-I GHill (4)

SRichards JClifford TBergman, EDO, RI Accession Number: ML021060775 *SE provided, no major changes made OFFICE PM/PDI-2 PM/PD1-2 LA/PD1-2 EMEB* OGC SC/PD1-2 NAME EThomas CGratton MOBrien DTerao SUttal JClifford DATE 4/25/02 4/26/02 4/25/02 SE dtd 04/01 /02 4/30/02 5/1/02 OFFICIAL RECORD COPY

Limerick Generating Station, Units 1 & 2 cc:

Edward J. Cullen, Jr. Library Vice President & General Counsel U.S. Nuclear Regulatory Commission Exelon Generation Company, LLC Region I 300 Exelon Way 475 Allendale Road Kennett Square, PA 19348 King of Prussia, PA 19406 Manager-Limerick Licensing Dr. Judith Johnsrud Exelon Generation Company, LLC National Energy Committee Nuclear Group Headquarters Sierra Club Correspondence Control 433 Orlando Avenue P.O. Box 160 State College, PA 16803 Kennett Square, PA 19348 Mr. Jeffrey A. Benjamin Mr. William Levis, Site Vice President Licensing - Vice President Limerick Generating Station Exelon Corporation P.O. Box 2300 1400 Opus Place, Suite 900 Sanatoga, PA 19464 Downers Grove, IL 60515 Mr. R. Braun Mr. Michael P. Gallagher Plant Manager Director-Licensing Limerick Generating Station Exelon Generation Company, LLC P.O. Box 2300 Nuclear Group Headquarters Sanatoga, PA 19464 Correspondence Control P. O. Box 160 Regional Administrator, Region I Kennett Square, PA 19348 U.S. Nuclear Regulatory Commission 475 Allendale Road Correspondence Control Desk King of Prussia, PA 19406 Exelon Generation Company, LLC 200 Exelon Way, KSA 1-N-1 Senior Resident Inspector Kennett Square, PA 19348 U.S. Nuclear Regulatory Commission Limerick Generating Station Mr. John Skolds P.O. Box 596 Chief Operating Officer Pottstown, PA 19464 Exelon Generation Company, LLC 1400 Opus Place, Suite 900 Chairman Downers Grove, IL 60515 Board of Supervisors of Limerick Township Mr. William Bohlke 646 West Ridge Pike Senior Vice President, Nuclear Services Linfield, PA 19468 Exelon Generation Company, LLC 1400 Opus Place, Suite 900 Chief-Division of Nuclear Safety Downers Grove, IL 60515 PA Dept. of Environmental Resources P.O. Box 8469 Harrisburg, PA 17105-8469

Limerick Generating Station, Units 1 & 2 cc:

Mr. John Cotton Senior Vice President, Operations Support Exelon Generation Company, LLC 1400 Opus Place, Suite 900 Downers Grove, IL 60515 Mr. Joseph Hagan Senior Vice President Mid-Atlantic Regional Operating Group Exelon Generation Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348 Ms. K. Gallogly Regulatory Assurance Manager Limerick Generating Station P.O. Box 2300 Sanatoga, PA 19464

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE INSERVICE INSPECTION PROGRAM RELIEF REQUEST RR-12-6 EXELON GENERATION COMPANY, LLC LIMERICK GENERATING STATION, UNITS 1 AND 2 DOCKET NOS. 50-352 AND 50-353

1.0 INTRODUCTION

By letter dated January 9, 2001, 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, PECO Energy Company (PECO), the then licensee, submitted inservice inspection (ISI) program Relief Request (RR) RR-12, Table RR-12-6, for Limerick Generating Station (LGS), Units 1 and 2, for American Society of Mechanical Engineers (ASME) Code, Class 1, 2, and 3, snubbers and relief valves. PECO, now Exelon Generation Company, LLC (EGC), requested authorization from the Nuclear Regulatory Commission (NRC, the Commission) to implement ASME Code Case N-508-1, Rotation of Serviced Snubbers and Pressure Relief Valves for the Purpose of Testing, at LGS Units 1 and 2. Pursuant to 10 CFR 50.55a(a)(3)(i), EGC proposed the implementation of ASME Code Case N-508-1 in lieu of the requirements in Article IWA-7000 in the 1989 Edition of the ASME Boiler and Pressure Vessel Code (ASME B&PV Code),

Section XI, which is the current ASME Code of record for LGS Units 1 and 2.

2.0 BACKGROUND

It is required by 10 CFR 50.55a that licensees perform ISI and inservice testing (IST) of certain ASME Code, Class 1, 2, and 3, components in accordance with Section XI of the ASME B&PV Code, the ASME Code for Operation and Maintenance of Nuclear Power Plants (ASME OM Code), and applicable addenda, except when alternatives are authorized or relief is requested by the licensee and granted by the Commission pursuant to 50.55a(a)(3)(i), (a)(3)(ii), or (f)(6)(i).

In proposing alternatives or requesting relief, the licensee must demonstrate that: (1) the alternatives will 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 would be 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 staff has reviewed and evaluated the licensees request and supporting information on the proposed alternative to the ASME Code requirements for LGS Units 1 and 2 pursuant to the provisions of 10 CFR 50.55a(a)(3)(i).

3.0 EVALUATION 3.1 EGCs Basis for Relief EGC requested relief from the requirements of ASME Code,Section XI, IWA-7000, when rotating serviced snubbers and pressure relief valves for the purpose of testing at LGS Units 1 and 2. The licensee proposed to use ASME Code Case N-508-1 as an alternative to the requirements of the ASME Code pursuant to 10 CFR 50.55a(a)(3)(i). This ASME Code Case is not yet approved by the staff in NRC Regulatory Guide 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1. This relief request is a result of EGCs update of their ISI program to the 1989 Edition of the ASME B&PV Code,Section XI. This update is required by 10 CFR 50.55a(g)(4)(ii). The relief request will be implemented during the second 10-year interval of the LGS Units 1 and 2 ISI program, which began on January 8, 2000.

The ASME Code,Section XI, IWA-7000, provides technical and administrative requirements that must be implemented when an item within the scope of the ASME Code is replaced.

Currently, when a snubber or relief valve is removed for the purpose of testing at LGS Units 1 and 2, the following two options are available:

(a) Maintain the system or portion of the system in a degraded condition, while complying with the applicable LGS Units 1 and 2 Technical Specification, until the removed item is tested, refurbished if required, and reinstalled, or (b) Replace the item being tested with a like item, and test the removed item at a later date.

Per ASME Code,Section XI, the rotation of snubbers and relief valves, as addressed in the second option, is required to be treated as an ASME Code replacement that must meet the requirements of IWA-7000. This entails the use of replacement programs, replacement plans, suitability evaluations, review and concurrence by the Authorized Nuclear Inservice Inspector, and maintenance of NIS-2 forms or other Section XI documentation to record the replacement.

Such controls are appropriate when items are replaced for the purpose of design changes, failures, or expiration of component life, but are considered excessive for the removal and installation of snubbers and relief valves solely for the purpose of testing.

The use of the alternative approaches (ASME Code Case N-508-1) will eliminate the burdensome administrative controls and documentation requirements associated with an ASME Code replacement for these components.

In adopting this ASME Code Case, all other aspects of the replacement, such as design, manufacture, ASME Code,Section XI, pressure testing requirements, operational limits, and setting, will be maintained. In addition, the implementation of ASME Code Case N-508-1 does not change the testing requirements provided by LGS Units 1 and 2 Technical Specifications (TSs).

3.2 NRC Staffs Evaluation EGC proposes to use ASME Code Case N-508-1, in lieu of ASME Code,Section XI, IWA-7000, for the rotation of snubbers and pressure relief valves for testing purposes at LGS Units 1 and 2.

ASME Code Case N-508-1 states that, for the purpose of testing, snubbers and relief valves may be rotated from stock and installed on components (including piping systems) within the Section XI boundary provided that the following requirements are met:

(a) Items being removed and installed shall be of the same design and construction; (b) Items being removed shall have no evidence of failure at the time of removal; (c) Items being rotated shall be removed and installed only by mechanical means; (d) Items being installed shall have previously been in service; (e) Preservice inspection and pressure tests shall be performed as required by IWA-7000; (f) The owner shall maintain a method of tracking the items to ensure traceability of ISI and IST records; (g) Use of an NIS-2 form is not required except as provided in (i) below; (h) Testing of removed snubbers and pressure relief valves, including required sample expansions, shall be performed in accordance with the Owners test program; and (i) Repair or replacement of removed items, when required, shall be performed in accordance with IWA-7000.

The implementation of ASME Code Case N-508-1 does not change the testing requirements provided by LGS Units 1 and 2 TSs. Also, in the adoption of this Code Case, all other aspects of the replacement such as design, manufacture, ASME Section XI pressure testing requirements, operational limits, and setting will be maintained.

ASME Code Case N-508-1 does not alter any Section XI requirement if a removed item requires any repair or replacement of Code parts. As required by item (i) of the ASME Code Case, repair or replacement of the removed item, when required, shall be performed in accordance with IWA-4000 for repairs and IWA-7000 for replacements. Because of this requirement, if the removed item requires repair or replacement, this activity shall be treated as a Section XI repair or replacement, and the required Section XI documentation must be prepared.

The use of ASME Code Case N-508-1 as an alternative to IWA-7000 for the rotation of snubbers and relief valves for the purpose of testing provides a reasonable reduction in the administrative requirements and documentation for this specific activity. The reduction in the administrative requirements has no effect on the ability of the snubbers or relief valves to perform their safety functions. All technical requirements are maintained in a manner that provides an acceptable level of quality and safety. Therefore, RR-12, Table RR-12-6, which adopts ASME Code Case N-508-1 for the rotation of snubbers and relief valves for the purpose of testing at LGS Units 1 and 2, is acceptable.

4.0 CONCLUSION

The NRC staff concludes that EGCs request to use ASME Code Case N-508-1 provides an acceptable level of quality and safety and is, therefore, authorized pursuant to 10 CFR 50.55a(a)(3)(i) for the second 10-year ISI interval.

Principal Contributor: J. Arroyo Date: May 2, 2002