ML13324A838

Forwards Request for Addl Info Re 860408 Investigative Rept Concerning 851121 Water Hammer Event Including Clarification of Commitment to Open & Visually Inspect New Check Valves. Response Should Be Provided by 860430

ML13324A838
Person / Time
Site:	San Onofre
Issue date:	04/21/1986
From:	Dudley R Office of Nuclear Reactor Regulation
To:	Baskin K Southern California Edison Co
References
NUDOCS 8604240552
Download: ML13324A838 (5)

Text

APR 21 1986 Docket No.:

50-206 Mr. Kenneth P. Baskin, Vice President Nuclear Engineering Safety and Licensing Department Southern California Edison Company 2244 Walnut Grove Avenue P.O. Box 800 Rosemead, California 91770

SUBJECT:

SAN ONOFRE, UNIT 1 The April 8, 1986 Investigative Report on the San Onofre Unit 1 Water Hammer Event of November 21, 1985 has been received by the NRC and is under review. Based upon our review, several items require further information, as discussed in a telephone call on April 16, 1986.

Specific questions are provided in the enclosure to this letter. In order for the NRC review schedule to remain consistent with the current facility restart schedule, a response should be provided by April 30, 1986.

The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely, Original signid li#

George E. Leaf'f

,-Richard F. Dudley, Jr.

Project Manager PWR Project Directorate #1 cc's next page Office:

PM A PD/P Surname:

udley/im GLear Date:

86

//8686 8604240552 860421 PDR ADOCK 0500020P S

PDR

Mr. Kenneth P. Baskin San Onofre Nuclear Generating Station Southern California Edison Company Unit No. 1 cc Charles R. Kocher, Assistant Joseph 0. Ward, Chief General Counsel Radiological Health Branch James Beoletto, Esquire State Department of Health Southern California Edison Company Services Post Office Box 800 714 P Street, Office Bldg. 8 Rosemead, California 91770 Sacramento, California 95814 David R. Pigott Mr. Hans Kaspar, Executive Director Orrick, Herrington & Sutcliffe Marine Review Committee, Inc.

600 Montgomery Street 531 Encinitas Boulevard, Suite 105 San Francisco, California 94111 Encinitas, California 92024 Mr. Stephen B. Allman San Diego Gas & Electric Company P. 0. Box 1831 San Diego, California 92112 Resident Inspector/San Onofre NPS c/o U.S. NRC P. 0. Box 4329 San Clemente, California 92672 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego San Diego, California 92101 Director Energy Facilities Siting Division Energy Resources Conservation &

Development Commission 1516 -

9th Street Sacramento, California 95814 Regional Administrator, Region V U.S. Nuclear Regulatory Commission 1450 Maria Lane Walnut Creek, California 94596

00 ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION

1. What are the new locations of the 10 inch feedwater system check valves relative to the flow control valve upstream and the block valve downstream?

The Isometric Drawings previously provided only show the original locations.

2. With regard to your current IST program, it appears that at least some of the five check valves which failed can be (and have been) tested while the plant is hot. However, relief from the Code has been requested for these valves to only test during cold shutdown. What is the basis for the reduced periodicity of testing these valves in light of the code requirements and the recent failures?

3. What enhanced testing is planned for each of the new Atwood Morrill check valves, including any quantitative leak rate criteria, procedures, and how new testing taps will be utilized?

4. Please clarify your commitment with regard to opening and visually inspecting the new check valves. Specifically:

Which valves will be inspected?

)

How often will they be inspected?

If valves are noisy in operation, will inspection periodicity be increased?

-2

5. Since less than 165 gpm through the 10 inch check valves is considered to be severe service by the vendor, what additional actions do you intend to take to assure that operations within this regime (AFW flow) will not unacceptably degrade the valve.

6. Please provide the results of the full scale valve testing performed by Dr. Tullis at Utah State University.

7. How do you intend to monitor the performance of these valves during startup and operation to determine if they are tapping?

8. In Table 8 of Appendix D, provide the reason for replacement of the internals to valve DWN309.

APR 21 1986 Distribution Copies:

Docket No. 50-206 NRC PDR Local PDR TNovak, Actg Div Dir OELD EJordan BGrimes JPartlow GBagchi (EB)

ORothberg (DSRO)

GZech (IE/VPB)

EMerschoff (IE/VPB)

AChaffee (RV)

PNarbut (RV)

GLear RDudley PShuttleworth ACRS (10)

PAD1 p/f PAD1 r/f Service List