ML13305A829
| ML13305A829 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/13/1985 |
| From: | Knighton G Office of Nuclear Reactor Regulation |
| To: | Baskin K, Holcombe J San Diego Gas & Electric Co, Southern California Edison Co |
| Shared Package | |
| ML13305A830 | List: |
| References | |
| GL-83-028 NUDOCS 8601030148 | |
| Download: ML13305A829 (6) | |
Text
DEC 13 1985 Docket Nos.:
50-361 and 50-362 Mr. Kenneth P. Baskin Mr. James C. Holcombe Vice President Vice President -
Power Supply Southern Carolina Edison Company San Diego Gas & Electric Company 2244 Walnut Grove Avenue 101 Ash Street Post Office Box 800 Post Office Box 1831 Rosemead, California 91770 San Diego, California 92112 Gentlemen:
Subject:
RAI and SE relating to Generic Letter 83-28, Generic Application of the Salem ATWS Event By Generic Letter 83-28, dated July 8, 1983, you were requested to respond to certain generic concerns that developed from the investigation into the failure of scram circuit breakers at Salem Nuclear Power Plant, Unit 1.
These concerns are categorized into four areas: (1) Post Trip Review; (2)
Equipment Classification and Vendor Interface; (3) Post-Maintenance Testing; and (4) Reactor Trip System Reliability Improvements. Your response to these four areas of Generic Letter 83-28 was provided by letter dated November 29, 1983.
By letter dated May 8, 1985, the staff requested additional information regarding several items addressed in your November 29, 1983 letter. In the May 8, 1985 letter the staff also issued a Safety Evaluation which closed out Item 1.1 of GL 83-28 for San Onofre 2 and 3. By letter dated October 2, 1985, you responded to the staff's May 8, 1985 letter.
One purpose of this letter is to request additional information regarding GL 83-28 Items 3.2.3, 4.2.1 and 4.2.2 (see Enclosure 1 and 2).
Another purpose is to transmit the staff's safety evaluation for Items 1.2, 3.1.1, 3.1.2, 3.2.1, 3.2.2, and 4.1 (see Enclosures 3 through 6).
The enclosed safety evaluations find that you have acceptably addressed these items.
This completes the staff's action for these items.
Sincerely, George W. Knighton, Director PWR Project Directorate No. 7 Division of PWR Licensing-B
Enclosures:
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Mr. Kenneth P. Baskin San Onofre Nuclear Generating Station Southern California Edison Company Units 2 and 3 cc:
Mr. James C. Holcombe Mr. Hans Kaspar, Executive Director Vice President - Power Supply Marine Review Committee, Inc.
San Diego Gas & Electric Company 531 Encinitas Boulevard, Suite 105 101 Ash Street Encinitas, California 92024 Post Office Box 1831 San Diego, California 92112 Charles R. Kocher, Esq.
Mr. Mark Medford James A. Beoletto, Esq.
Southern California Edison Company Southern California Edison Company 2244 Walnut Grove Avenue 2244 Walnut Grove Avenue P. 0. Box 800 P. 0. Box 800 Rosemead, California 91770 Rosemead, California 91770 Dr. L. Bernath Manager, Nuclear Department Orrick, Herrington & Sutcliffe San Diego Gas & Electric Company ATTN: David R. Pigott, Esq.
P. 0. Box 1831 600 Montgomery Street San Diego, California 92112 San Francisco, California 94111 Richard J. Wharton, Esq.
University of San Diego School of Alan R. Watts, Esq.
Law Rourke & Woodruff Environmental Law Clinic Suite 1020 San Diego, California 92110 1055 North Main Street Santa Ana, California, 92701 Charles E. McClung, Jr., Esq.
Attorney at Law Mr. V. C. Hall 24012 Calle de la Plaza/Suite 330 Combustion Engineering, Inc.
Laguna Hills, California 92653 1000 Prospect Hill Road Windsor, Connecticut 06095 Regional Administrator, Region V U.S. Nuclear Regulatory Commission Mr. S. McClusky 1450 Maria Lane/Suite 210 Bechtel Power Corporation Walnut Creek, California 94596 P. 0. Box 60860, Terminal Annex Los Angeles, California 90060 Resident Inspector, San Onofre NPS c/o U. S. Nuclear Regulatory Commission Mr. C. B. Brinkman Post Office Box 4329 Combustion Engineering, Inc.
San Clemente, California 92672 7910 Woodmont Avenue Bethesda, Maryland 20814 Mr. Dennis F. Kirsh U.S. Nuclear Regulatory Commission RRegion V
1450 Maria Lane, Suite 210 Walnut Creek, California 94596 SAN ONOFRE UNITS 2 AND 3 REQUEST FOR ADDITIONAL INFORMATION GL 83-28, ITEM 3.2.3 Review of your responses to GL 83-28 dated November 19, 1983 and October 2, 1985 has indicated that Item 3.2.3 has not been adequately addressed in these responses.
Your November 29, 1983 letter identifies one post-maintenance test requirement in the existing Technical Specifications which is perceived to degrade rather than enhance safety. However, no mention is made of whether or not you have made a systematic review of all Technical Specifications to find all such safety degrading requirements. Consequently, we request that you either conduct such a review or state that such a review was conducted prior to issuance of the November 29, 1983 letter, thereby providing assurance that the identified safety degrading post-maintenance test requirement is the only such requirement in the San Onofre 2 and 3 Technical Specifications.
.nclosure 2
SAN ONOFRE UNITS 2 AND 3 REQUEST FOR ADDITIONAL INFORMATION GL 83-28, ITEMS 4.2.1 AND 4.2.2, TASK A6814 INTRODUCTION Southern California Edison Company, the licensee for San Onofre Units 2 and 3, submitted their response to Generic Letter 83-28 on November 29, 1983. That response has been reviewed with respect to Items 4.2.1 and 4.2.2 of the Generic Letter. The licensee's response was not sufficiently detailed to permit an evaluation of the adequacy of the periodic maintenance and trending programs for the breakers. The following additional information is required to evaluate compliance with Items 4.2.1 and 4.2.2.
- 1. Item 4.2.1 - Periodic Maintenance Program for Reactor Trip Breakers.
1.1 Criteria for Evaluating Compliance with Item 4.2.1 The San Onofre Units 2 and 3 Reactor Trip Systems utilize General Electric AK-2A circuit breakers. The primary criteria for an acceptable maintenance program for this breaker are contained in Maintenance Instruction GEI-50299EI*, "Power Circuit Breakers, Types AK-2/2A-15, AK-2/3/2A/3A-25, AKU-2/3/2A/3A-25," and Service Advice 9.3S and 9.20, by General Electric. The NRC Staff, Equipment Qualification Branch, has reviewed these items and endorsed the maintenance program they describe. More specifically, the criteria used to evaluate compliance include those items in the General Electric instructions and advisories that relate to the safety function of the breaker, supplemented by those measures that must be taken to accumulate data for trending. The acceptable maintenance activity interval is six months.
1.2 Issues Relating to Item 4.2.1 The licensee response identifies the San Onofre Units 1 and 2 procedures which define the Reactor Trip Breaker periodic maintenance program, and states that they were developed in accordance with supplier recommendations and IE Bulletin 79-09 with supplements. The referenced procedures were not included with the supplements.
The San Onofre Units 2 and 3 periodic maintenance program for the reactor trip breakers should include, on a six month basis:
1
- 1. Verification of breaker cleanliness and insulation structure; all foreign materials, such as paint, dust, or oil, should be removed to prevent electrical breakdown between points of different potential;
- 2. Verification of breaker physical condition, including wiring insulation and termination, all retaining rings, pole bases, arc quencher, stationary and movable contacts, and tightness of nuts and bolts;
- 3. Verification of proper manual operation of the breaker, including checks for excessive friction, trip bar freedom, latch engagement, operating mechanism alignment and freedom, and undervoltage trip (UVT) device armature freedom;
- 4. Verification of the optimum freedom of the armature as specified in General Electric Service Advice 175-9.3S, item #51;
- 5. Verification of proper trip latch engagement as specified in Service Advice 175-9.3S, item #S2;
- 6. Verification of undervoltage pick-up setting, as specified in Service Advice 175-9.3S, item #S3, and dropout voltage;
- 7. Verification that the trip torque required on the trip shaft is less than 1.5 pound-inches, as specified in Service Advice 175-9.3S, Item #S4; "Before" and "After" maintenance torque values should be recorded;
- 8.
Verification of positive-tripping by checking the adjustment between the UVT device and trip paddle as specified in Service Advice 175-9.3S, item #S5;
- 9. Verification of proper trip -response time as specified in Service Advice 175-9.3S, item #S6;
- 10.
Lubrication of trip shaft and latch roller bearings with Mobil 28 lubricant;
- 11.
Shunt Trip Attachment (STA) operation verification;
- 12.
Examination and cleaning of breaker enclosure;
- 13.
Functional test of the breaker prior to returning it to service.
The licensee is to confirm that the periodic-maintenance program includes these 13 items at the specified interval or commit to their inclusion and provide a date by which they will be included.
2
- 2. Item 4.2.2 -
Trending of Reactor Trip Breaker Parameters to Forecast Degradation of Operability.
2.1 Criteria for Evaluating Compliance with Items 4.2.2 Four parameters have been identified as trendable and are included in the criteria for evaluation. These are (1) undervoltage trip attachment dropout voltage, (2) trip torque, (3) breaker response time for undervoltage trip, and (4) breaker insulation resistance.
2.2 Issues Relating to Item 4.2.2 The licensee submittal states that the licensee measures and trends breaker undervoltage device and shunt trip device independent actuation, trip time and trip torque. It is not clear whether the trip time is for a shunt or undervoltage trip.
The licensee is to commit to inclusion of breaker response time and dropout voltage for undervoltage trip and breaker insulation resistance as trending parameters. The licensee should also identify the organization which will perform trend analysis, how often the analysis will be performed and how the information derived from the analysis will be used to affect periodic maintenance.
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