ML13331B030
| ML13331B030 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/13/1988 |
| From: | Medford M SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8804210039 | |
| Download: ML13331B030 (7) | |
Text
ACCELERATIED DISiUTION DEMONSTRA#ON SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:8804210039 DOC.DATE: 88/04/13 NOTARIZED: NO DOCKET #
FACIL:50-206 San Onofre Nuclear Station, Unit 1, Southern Californ 05000206 AUTH.NAME AUTHOR AFFILIATION MEDFORD,M.O.
Southern California Edison Co.
RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Forwards response to NRC 871124 ltr re Proposed Change 179 to License DPR-13.
DISTRIBUTION CODE: A001D COPIES RECEIVED:LTR L ENCL 1 SIZE:
TITLE: OR Submittal:.General Distribution NOTES:License Exp date in accordance with 10CFR2,2.109.
05000206 S
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL
/
PD5 LA 1
0 PD5 PD 5
5 TRAMMELL,C 1
1A INTERNAL: ACRS 6
6 ARM/DAF/LFMB 1
0 D
NRR/DEST/ADS 7E 1
1 NRR/DEST/CEB 8H 1
1 NRR/DEST/ESB 8D 1
1 NRR/DEST/MTB 9H 1
1 NRR/DEST/RSB 8E 1
1 NRR/DOEA/TSB 11 1
1 NRR/PMAS/ILRB12 1
1 OGC 15-B-18 1
0 01 1
1 RES/DE/EIB 1
1 EXTERNAL: LPDR 1
1 NRC PDR 1
1 NSIC 1
1 R
I D
S A
D D
S TOTAL NUMBER OF COPIES REQUIRED: LTTR 27 ENCL 24
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 M. 0. MEDFORD TELEPHONE MANAGER OF NUCLEAR ENGINEERING (818) 302-1749 AND LICENSING April 13, 1988 U. S. Nuclear Regulatory Commission Attention:
Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket 50-206 RAI Relating to Proposed Change No. 179 San Onofre Nuclear Generating Station Unit 1 By letter dated November 24, 1987, the NRC provided SCE with several questions on previously submitted Proposed Change No. 179. Enclosed with this letter are responses to these questions.
If further information is required, please contact me.
Very truly yours, Enclosure cc:
J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3 8804210039 880413 PDR ADOCK 05000206 P
RESPONSE TO QUESTIONS ON PROPOSED CHANGE NO. 179 SAN ONOFRE NUCLEAR GENERATING STATION, UNIT 1 Introduction By letter dated November 24, 1987 from John 0. Bradfute, NRC, to Mr. Kenneth P. Baskin, SCE, several questions were posed regarding SCE's Proposed Change No. 179 to the plant's Technical Specifications. Briefly, that change is intended to provide a long term SIS surveillance program to supplant the interim T.S. 4.2.3 which has expired. This response first restates the NRC question and then provides an appropriate answer.
Responses
- 1. Question:
"Please clarify the statement, 'When the plant is planned to be shut down...
a Hot SIS Test shall be performed.'
Define your meaning of 'planned shutdown.'
Must the shutdown be scheduled at the beginning of the fuel cycle? Can there be a planned shutdown in response to an operational event? Will the test be performed if there is a non-emergency shutdown of the plant?"
Response: A "planned shutdown" is a shutdown that allows SCE sufficient lead time to "plan" for the test. The maximum lead time for this test for a normally "planned" outage is two weeks.
This includes such things as preparing the necessary people and obtaining the necessary equipment to perform the test. Actual lead times are likely to be on the order of three to four days.
- 2. Question:
"The SONGS-1 Inservice Testing Program contains a cold shutdown justification for exercising valves HV 851A and B. IST program requires that these valves be exercised every cold shutdown not more often than every three months.
"Discuss the impact of IST cold shutdown test frequency on the Proposed Technical Specification test."
-2
Response
The IST cold shutdown tests of valves HV 851A and B are stroke tests that are performed when the plant is in Mode 5. The IST test does not test the valve under hot differential pressure conditions. The proposed T.S. surveillance test will test the valves in Mode 3 or 4 when the plant is hot and will also simulate actual SI conditions including differential pressure decay across the valves.
The IST requirement may be satisfied by the T.S. surveillance test since it does full stroke the valves. However, the converse is not true. The IST test does not satisfy the T.S. surveillance requirement. Therefore, the IST test may be done as often as every three months (should cold shutdowns occur that often) while the T.S. surveillance test would not normally be done more frequently than the nine month interval specified in the proposed T.S.
- 3. Question: "If the measured force exceeds 10,000 lbs., the test interval is required to be reduced in direct proportion to the increased force.
"Will the plant be brought to Mode 3 and the Hot SIS test performed if there is no planned cold shutdown at the due date?"
Response
Yes.
Should the actuator force exceed 10,000 lbs., SCE considers this a situation warranting a reduced test interval.
- 4. Question:
"What is the effective lifetime of the proposed test? Over how many fuel cycles will the hot SIS test be performed?"
Response
The Proposed Change will be effective until such time as an amendment request is submitted. SCE currently plans to perform this surveillance indefinitely. Any future physical changes or additions to the Safety Injection System could, however, warrant a change.
-3
- 5. Question:
"The previously proposed Technical Specification Change (dated November 21, 1985) stated that the test would be considered satisfactory if HV 851A and B have actuated in 3 to 5 seconds.
"Why is the actuation time no longer included in the test criteria?"
Response: The 3 to 5 second criterion was included in the originally proposed T.S. change because the test would have been similar to the IST test which specifically indicates a 5 second stroke time. This time continues to be specified in the revised IST Program which was submitted to the NRC by SCE's letter dated December 28, 1987. The time requirement is not specified in the currently proposed T.S. since it has been adapted from the interim specification which also did not have a time specified.
Since the purpose of the test is to verify that long term set of the valve seat faces has not occurred, a time requirement is not necessary and the IST program requirements are adequate.
- 6. Question:
"Technical Specification 4.2.1, as presently written, implies that the trisodium phosphate additive test is to be conducted at reactor shutdown intervals not longer than the normal plant refueling intervals.
"Proposed revision states 'A test of the trisodium additive shall be conducted once every refueling "Please clarify the apparent relaxation of test frequency."
Response: The frequency of the trisodium phosphate additive testing is not intended to be changed by the proposed change. The existing specification numbered (2) does not specifically have an interval specified except that which is implied from the specification numbered (1).
The change in the format dictated that the testing interval be specifically included. In order to conform more precisely with the current T.S. wording, the proposed T.S. should be modified to read as follows:
-4 "B. Trisodium Phosphate Test (1) A test of the trisodium phosphate additive shall be conducted at reactor shutdown intervals not longer than the normal plant refueling intervals."
- 7. Question:
"Please explain the reason why the 200*F temperature restriction has been deleted from the component tests of the proposed Technical Specification."
Response
The 200*F temperature restriction has been eliminated since the modes and temperatures when these components are required to be operable are specified in T.S. 3.3, Safety Injection and Containment Spray Systems, Operating Status. The addition of Specification 4.0.1 by Amendment No. 83 requires that the surveillance requirements shall be met during the operational modes or other conditions specified for individual limiting conditions for operation unless otherwise stated in an individual Surveillance Requirement. Accordingly, the deletion of the 200*F temperature restriction does not change the effect of T.S. 4.2.1.
- 8. Question:
"Provide any failure data for pneumatic hydraulic valves which may be available from the manufacturer or other sources such as applications other than nuclear service. Provide the basis for the assumption that the failure rate of P/H valves is identical to that of MOVs or that the assumption is conservative."
Response: SCE provided the NRC with a report on proposed Safety Injection System modifications by letter dated December 22, 1986. In that report, in Section 5.4.1, the assumptions for valve failure rates were explained.
-5 The failure model of a P/H valve has been broken down into two parts (under one "or" gate), 1) failure of two redundant hydraulic dump systems to release pressurized hydraulic fluid which holds the valve in its standby position, or 2) failure of the P/H valve to travel to its safety injection position under pressure from an accumulator given operation of a hydraulic dump system. It is this second failure mode which is described as "HV FAILS TO OPEN DUE TO RANDOM CAUSES", and whose failure probability is assumed to be that of a MOV. Use of the MOV failure rate for this second type of P/H valve failure mode is conservative because a) no failure of this type could be found in a search of NPRDS data, and b) there are very few conceivable mechanisms by which a failure of this type could occur while there are many conceivable mechanisms by which a MOV could fail to operate.
GEH:9234F