NL-07-1789, Response to NRC Request for Additional Information Regarding the Third 10-Year Interval Inservice Testing Program

Response to NRC Request for Additional Information Regarding the Third 10-Year Interval Inservice Testing Program

ML072640100
Person / Time
Site:	Vogtle
Issue date:	09/20/2007
From:	George B Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-07-1789
Download: ML072640100 (7)

Text

Southern Nuclear Operating Company, Inc.

Post Off ice Box 1295 Birmingham. Alabama 35201-1295 Tel 205.992.5000 SOUTHERNk

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COMPANY September 20, 2007 Energy to Serve Your World

Docket Nos.: 50-424 50-425 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Vogtle Electric Generating Plant Response to NRC Request for Additional Information Regarding the Third 10-Year Interval lnservice Testinq Program Ladies and Gentlemen:

On August 17, 2007, Southern Nuclear Operating Company received a facsimile containing two questions from the NRC regarding the April 16, 2007, Vogtle Electric Generating Plant Third 10-Year Interval lnservice Testing Program submittal. Enclosure 1 contains the SNC response to the NRC questions.

Enclosure 2 contains version 1.0 of proposed alternative RR-V-1 that incorporates the SNC response to the NRC questions and supersedes the proposed alternative contained in the April 16, 2007 submittal.

If you have any questions, please advise.

Sincerely, ,

Manager, Nuclear Licensing

Enclosures:

1. Request for Additional Information Response

2. Proposed Alternative RR-V-1, Version 1

U. S. Nuclear Regulatory Commission NL-07-1789 Page 2 cc: Southern Nuclear Operatina Company Mr. J. T. Gasser, Executive Vice President Mr. T. E. Tynan, Vice President - Vogtle Mr. D. H. Jones, Vice President - Engineering RType: CVC7000 U. S. Nuclear Reaulatorv Commission Dr. W. D. Travers, Regional Administrator Mr. S. P. Lingam, NRR Project Manager - Vogtle Mr. G. J. McCoy, Senior Resident Inspector - Vogtle

Vogtle Electric Generating Plant Response to NRC Request for Additional Information Regarding the Third 10-Year Interval Inservice Testing Program Enclosure 1 Request for Additional lnformation Response

Vogtle Electric Generating Plant Response to NRC Request for Additional lnformation Regarding the Third 10-Year Interval Inservice Testing Program Request for Additional lnformation - ltem RR-V-1-01 Please provide your method and measured values that determine steady-state conditions for compressible fluid tests.

SNC Response:

Further review concluded that RR-V-1 should be revised to delete all safetylrelief valves that are in compressible fluid systems. SafetylRelief valves in compressible fluid systems will be tested in accordance with Appendix I of the ASME OM Code 2001 Edition through 2003 Addenda.

Request for Additional lnformation - ltem RR-V-1-02 Safety Valves are known to have difficulty reseating properly.

In the ASME code, several options exist for determining value reseating for compressible fluid tests. Please provide your method and procedure to determine proper valve reseating prior to repeated tests.

SNC Response:

See response to RR-V-1-01.

Vogtle Electric Generating Plant Response to NRC Request for Additional Information Regarding the Third 10-Year Interval Inservice Testing Program Enclosure 2 Proposed Alternative RR-V-1, Version 1

SOUTHERN NUCLEAR OPERATING COMPANY IST PROGRAM - RELIEF REQUEST PROPOSED ALTERNATIVE IN ACCORDANCE WITH 10 CFR 50.55a(a)(3)(i)

RR-V-1, Version 1.0 PLANTIUNIT: Vogtle Electric Generating PlantlUnit 1 and 2 INTERVAL: 3"I Interval beginning June 1, 2007 and ending May 3 1,2017 COMPONENTS AFFECTED: Class 2 and 3 Safety and Relief Valves located on Water Systems CODE EDITION AND ADDENDA: ASME OM Code-2001 Edition with Addenda through OMb-2003 REQUIREMENTS: ASME OM Code, Appendix I, Section 1-8130 contains methods for set pressure testing of liquid service safetylrelief valves. Paragraph 1-8130(g) provides the requirement associated with the time between valve openings.

The requirement from this paragraph states:

A minimum of 5 min shall elapse between successive openings.

REASON FOR REQUEST: At Vogtle Electric Generating Plant (VEGP), pressure relief valves in ASME Class 2 and 3 liquid service systems are tested in accordance with the provisions of ASME OM Code, Appendix I. A minimum of two consecutive valve actuations are used to determine the set pressure of the valve. Under the provisions of Appendix I, the minimum elapsed time between valve openings is 5 minutes.

PROPOSED ALTERNATIVE AND BASIS: At VEGP, pressure relief valves in ASME Class 2 and 3 liquid service systems are set pressure tested at ambient conditions in a shop environment using water as the test medium. The test medium and the valve are brought to thermal equilibrium prior to the set pressure test.

Therefore, there are no thermal differentials that could introduce thermal imbalance or skew the accuracy of the test. Repeated valve actuations are conducted in a controlled environment under steady-state conditions.

Consequently, accurate and repeatable test results are achieved when measuring the set pressure of the liquid service system pressure relief valves with no time limit required between tests.

The omission of this hold time between valve actuations would minimize test performance and system outage times. A reduction in system outage time enhances plant safety by providing timely return of plant systems to service.

Version 1.0

SOUTHERN NUCLEAR OPERATING COMPANY IST PROGRAM - RELIEF REQUEST PROPOSED ALTERNATIVE IN ACCORDANCE WITH 10 CFR 50.55a(a)(3)(i)

RR-V-1, Version 1.0 VEGP's proposed request for relief from the provisions of ASME OM Code provides an alternative methodology for testing ASME Class 2 and 3 pressure relief valves. Alternative testing would shorten the time between valve openings from five minutes to no hold time for all liquid service system relief valves. VEGP's proposed alternative would demonstrate satisfactory repeatability and accuracy for determining set pressures of relief valves and would provide a commensurate level of quality and safety. Therefore, this proposed alternative is warranted pursuant to 10 CFR 50.55a(a)(3)(i).

DURATION: 3rd IST Interval, June 1,2007 through May 3 1,2017.

PRECEDENTS: An equivalent Relief Request was approved as RR-V-1 for the Second 10 Year IST Interval.

REFERENCES:

NRC Safety Evaluation dated September 16,2002- TAC Nos. MB55 18 and MB55 19.

STATUS: Submitted for NRC review.

Version 1.0