ML13330A299

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Forwards Response to NUREG-0737,Item II.K.3.17 Re ECCS Equipment Outages.Also Forwards Analysis of Probability of Toxic Gas Hazard for San Onofre Nuclear Generating Station as Result of Truck Accidents Near Plant
ML13330A299
Person / Time
Site: San Onofre  Southern California Edison icon.png
Issue date: 04/20/1981
From: Baskin K
Southern California Edison Co
To: Crutchfield D
Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, TAC-44128, TASK-2.K.3.17, TASK-TM NUDOCS 8104270213
Download: ML13330A299 (3)


Text

Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE

ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN April 20, 1981 TELEPHONE MANAGER OF NUCLEAR ENGINEERING, (213) 572-1401 SAFETY, AND LICENSING Director, Office of Nuclear Reactor Regulation N C 1981 Attention:

D. M. Crutchfield, Chief REG Operating Reactors Branch No. 5 1

on Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C.

20555 Gentlemen:

Subject:

Docket No. 50-206 Clarification of TMI Action Plan Requirements San Onofre Nuclear Generating Station Unit 1 Your letter dated October 31, 1980 forwarded NUREG-0737 containing all TMI-related items approved for implementation by the Commission at that time. You requested that we provide confirmation that the implementation dates for all items contained in NUREG-0737 will be met or propose revised dates with justification for delay and planned compensating safety actions during the interim. Our April 13, 1981 letter indicated that information required by Action Plan Item II.K.3.17, ECCS outages would be provided by April 20, 1981.

Submitted herewith is the report entitled "ECCS Outages".

The enclosed report covers outages of ECCS equipment from January 1, 1976 through December 31, 1980 and provides the outage date, component(s) involved, cause of the outage, corrective action taken and the duration of the outage.

The maintenance records for this period did not always contain detailed information as to the reason for work being done, what exactly was done and the duration of the work. In those cases, a "not available" notation is listed. It should also be noted that under certain circumstances, the duration is not an accurate indicator of the length of time the equipment was out of service, e.g., work done during refueling outages might have been extended longer than would have been the case if that work were critical path.

10 4 2 0 91-3

Mr. D. M. Crutchfield

-2 The enclosed report contains approximately 264 entries. Of these:

1) Approximately 30% are routine outages, such as calibration and tests, preventative maintenance, etc.
2) Approximately 20% are nonrecurring in nature. These include outages required to modify equipment in order to enhance its performance, increase reliability, human error, etc.
3) Approximately 20% are associated with the diesel/generator system installed during the 1976-1977 refueling outage. It is not uncommon or unexpected that new systems will experience equipment malfunctions during the initial period of operation. A review of the diesel/generator system outages indicates that most outages occurred during the first one to two years of operation and have decreased in frequency since that time.
4) Approximately 30% are generally random failures of components. In light of the large number of components under consideration and the degree of redundancy of equipment, this is not considered to be excessive.

Based on the review of the attached information, no changes in plant procedures or Technical Specifications are warranted.

Also submitted herewith is a report, "Analysis of the Probability of a Toxic Gas Hazard for the San Onofre Nuclear Generating Station as a Result of Truck Accidents Near the Plant."

This report was prepared and submitted on the San Onofre Units 2 and 3 docket (50-361 and 50-362). As stated in our April 13, 1981 letter, the new control room habitability system for Unit 1 will provide protection for the control room operators for toxic chemicals identified in the Safety Evaluation Report (SER) for Units 2 and 3 (to be issued in May, 1981).

Because of the proximity of the three units and the fact that no effects of terrain or site specific structures were used in the analysis, the results of this analysis is applicable to Unit 1 and forms the basis for using the Units 2 and 3 SER for Unit 1.

If you have any questions or desire further information, please contact me.

Mr. D. M. Crutchfield

-3 Subscribed on this

_.0 day of 1981.

By__ _ _ _ _ _ _ _

K. P. Baskin Manager of Nuclear Engineering, Safety, and Licensing Subscribed and s orn to before me this OFMIALMSAL pofA day of s,

,19.

AGNES CRABTREE 1981.

NOTARY PUBLIC - CALIFORNIA PRINCIPAL OFFICE IN LOS ANGELES COUNTY my COfmlSSion Exi. Au. 2, 1982 Notary Public in and for the County of Los Angeles, State of California Enclosures (2)