ML20153G194

Forwards RAI Re 960529 Request to Modify Licenses for Plant, Units 2 & 3.Proposed Mod Would Revise Acceptance Criteria for Agastat Time Delay Relays Used in Esg Load Sequence for Diesel Generators

ML20153G194
Person / Time
Site:	San Onofre
Issue date:	09/23/1998
From:	Clifford J NRC (Affiliation Not Assigned)
To:	Ray H SOUTHERN CALIFORNIA EDISON CO.
References
TAC-M95865, TAC-M95866, NUDOCS 9809290389
Download: ML20153G194 (4)

Text

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a September.23, 1998 4

Mr. Harold B. Ray Executive Vice President Southem Califomia Edison Company San Onofre Nuclear Generating Station P. O. Box 128 San Clemente, Califomia 92674-0128

SUBJECT:

REQUEST F' OR ADDITIONAL INFORMATION FOR LOAD SEQUENCER TIME DELAY RELAY AMENDMENT (TAC NOS. M95865 AND M95866)

Dear Mr. Ray:

In a letter dated May 29,1996, Southem Califomia Edison (SCE) submitted a request to modity

' the licenses for San Onofre Nuclear Generating Station (SONGS) Units 2 and 3. The proposed modification would revise the acceptance criteria for the Agastat time delay relays used in the engineered safety features (ESF) load sequencer for the diesel generators.

The staff has reviewed your license amendment request. To assist the staff in completing its review, we request that you provide the iaformation identified in the enclosure.

Please call me at (301) 415-1352 if you have any questions.

Sincerely,

~0riginal Signed By James W. Clifford, Senior Project Manager Project Directorate IV-2 Division of Reactor Projects lil/IV Office of Nuclear Reactor Regulation

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Docket Nos. 50-361 DISTRIBUTION. '/

and 50-362 Docket File. OGC PUBLIC ACRS

Enclosure:

Request for Additional PDIV-2 R/F DKirsch, RIV WCFO g

Information EAdensam TPGwynn, RIV WBateman - JCalvo cc w/ encl: See next page JClifford OChopra EPeyton DOCUMENT NAME: SO95865.RAI OFC PDIV-2/PM PDIV-2/LA NAME JClifford - $Peyto DATE 9//3 98 QRi498 OFFICIAL RECORD COPY

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Mr. Harold B. Ray ' September 23, 1998

-cc w/enci:

Mr. R. W. Krieger,Vice President Resident inspector / San Onofre NPS l .Southem Califomia Edison Company clo U.S. Nuclear Regulatory Commission I

l. San Onofre Nuclear Generating Station Post Office Box 4329 l l

' P. O. Box 128 San Clemente, Califomia 92674 I San Clemente, Califomia 92674-0128 l

. Mayor Chairman, Board of Supervisors City of San Clemente l County of San Diego 100 Avenida Presidio )

1600 Pacific Highway, Room 335 San Clemente, California 92672 San Diego, California 92101 Mr. Dwight E. Nunn, Vice President y Alan R. Watts, Esq. Southem California Edison Company ,

L Woodruff, Spradlin & Smart San Onofre Nuclear Generating Station

.701 S. Parker St. No. 7000 P.O. Box 128 l - Orange, California 92668-4702 San Clemente, California 92674-0128 l Mr. Sherwin Harris Resource Project Manager Public Utilities Department City of Riverside .

3900 Main Street Riverside, Califomia 92522  ;

Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavilion 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Mr. Paul Schneringer ,

San Onofre Liaison San Diego Gas & Electric Company P.O. Box 1831 -

San Diego, Califomia 92112-4150 Mr. Steve Hsu '

Radiologic Health Branch State Department of Health Services Post Office Box 942732 Sacramento,'Califomia 94234 i

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O REQUEST FOR ADDITIONAL INFORMATION DIESEL GENERATOR LOAD SEQUENCER TIME DELAY RELAYS SOUTHERN CALIFORNIA EDISON COMPANY. ET AL.

SAN ONOFRE NUCLEAR GENERATING STATION. UNITS 2 AND 3 DOCKET NOS. 50-381 AND 50-362

1. What is the actual repeat accuracy of the Agastat time delay relays used to sequence engineered safety features loads at San Onofre Units 1 and 2, based on operational data collected since initiallicensing? This should include a description of how the repeat accuracy was determined. As a minimum, state:

(a) the total population of relays tested; (b) summarize the number of relays discovered during surveillance testing at each unit that were out of calibration by more than +/- 10 percent of the relay setpoint; (c) when the failures were observed; and (d) any pattems or trends, or lack thereof, noted in the relay operational data.

Your response to this question should be sufficiently detailed to justify the extent of relief required, and whether or not a valid acceptance criteria exists.

2. Discuss how the Agastat relays are calibrated and how the required surveillance testing of these relays is currently performed. Discuss what, if any, changes in the calibration or surveillance testing will be made if the staff approves this amendment request. This discussion should be sufficiently detailed to clearly describe how the current sequencing acceptance criteria impacts plant operations, and how the proposed licensing amendment will eliminate any unnecessary impact without affecting safety.

3. Discuss the current process used to identify, track, and replace problem Agastat relays.

Include a discussion of what, if any, changes will be made to this process if the sequencing acceptance criteria are relaxed. Describe the controls that will be in place to ensure that problem relays (e.g., bad relays that might pass a relaxed sequencing acceptance criteria) are not left in service. ,

4. Discuss all the options that were considered to resolve the Agastat relay issues raised by the NRC in inspection Report 50-331/95-04 and 50-362/95-04. Discuss the objectives used to evaluate these possible solutions and why requesting a change to the sequencing acceptance criteria was the chosen solution.

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5. Prov;de a list of assumptions used in the diesel generator loading analysis provided to the NRC to support a relexation of the sequencing acceptance criteria. Discuss how the data used in the analysis was collected and verified. Discuss the results of any benchmark tests performed to validate the accuracy of the computer loading analysis and to d;termine the sensitivity of the analysis results to changes in the input data. This discussion should fully describe how much reliance was placed on the results of the l l loading analysis provided in support of the proposed license amendment.  !

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