ML13333A468

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Responds to NRC 800102 Show Cause Order Re NUREG-0578 & 800104 Request Re Power Reliability.Seeks Aid in Preparing Response.Forwards Analysis of Reliability Impacts Resulting from Facility TMI Backfit Outage. W/O Encl
ML13333A468
Person / Time
Site: San Onofre Southern California Edison icon.png
Issue date: 01/14/1980
From: Dietch R
SOUTHERN CALIFORNIA EDISON CO.
To: Harold Denton
Office of Nuclear Reactor Regulation
References
TAC-44652, NUDOCS 8001160542
Download: ML13333A468 (3)


Text

9 Southern California Edison Company P. 0. BOX BOO 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 January 14, 1980 C

Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D. C. 20555 IX

Dear Mr. Denton:

Subject:

Docket No. 50-206 San Onofre Nuclear Generating Station Unit 1 Your letter of January 2, 1980 forwarded a Show Cause Order regarding the implementation of Lessons Learned Short Term requirements at San Onofre Unit 1.

That Order indicated that San Onofre Unit 1 should be shut down by January 31, 1980 for the purpose of implementing specified requirements, except those for which necessary equipment was shown to be unavailable, unless shutdown would severely impact the power system reliability in the Pacific Northwest as determined by the Western Systems Coordinating Council.

Your letter of January 4, 1980 requested the submittal of specific power reliability information if we were to seek an extension of the implementation of the requirements specified in the Order. The purpose of this letter is to:

(1) provide the reliability information identified in your January 4, 1980 letter, (2) identify what we believe that power system reliability information requires in terms of the timing of shutdown of San Onofre Unit 1 and (3) request NRC cooperation in the preparation and consummation of a stipulation in response to the Order forwarded by your January 2, 1980 letter.

This letter should not be interpreted as a response pursuant to 10 CFR §2.202 to the Show Cause Order.

Enclosure A to this letter, entitled "Analysis of Reliability Impacts Resulting From San Onofre Unit 1 TMI Backfit Outage," presents information identified in the enclosure to your letter of January 4, 1980.

Enclosure A indicates that in order to avoid system reliability problems and based on specified assumptions, San Onofre Unit 1 should be shut down no sooner than March 1, 1980 and should be shut down for the Cycle 8 refueling no later than April 1, 1980. Further, Enclosure A recommends that, based on the uncertainty in these specified assumptions, the San Onofre Unit 1 shutdown should be scheduled for March 15, 1980.

8001160 5-2

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-2 Enclosure B to this letter is a letter dated January 14, 1980 from Mr. James L. Mulloy, Chairman, Western Systems Coordinating Council (WSCC) to Mr. M. D. Whyte, Manager of Electric System Planning For Southern California Edison Company. Enclosure B represents WSCC's concurrence in the recommended shutdown date of March 15, 1980 as identified in Enclosure A to this letter.

Enclosure C to this letter is a document entitled "Information Concerning Equipment Availability for Implementation of Lessons Learned Short Term Requirements at San Onofre Unit 1."

Enclosure C indicates that, presently, there are no equipment availability problems which preclude our implementing the Lessons Learned Short Term Requirements specified in the Order forwarded by your January 2, 1980 letter with the exception of one element of the requirements for Lessons Learned Item 2.1.4, Containment Isolation Provisions for PWRs and BWRs (all other elements of the containment isolation modifications can be implemented).

This equipment availability problem was identified in our letter of December 14, 1979 and has been discussed with representatives of the Regulatory Staff.

As of January 31, 1980, all but four* of the Lessons Learned Short Term requirements specified in the Order forwarded by your January 2, 1980 letter will be implemented. A unit shutdown is required to complete implementation of these four requirements. The information presented in Enclosure A to this letter indicates that, based on specified assumptions, San Onofre Unit 1 should not be shutdown earlier than March 1, 1980 nor later than April 1, 1980.

Such assumptions include:

(1) the return to operation of the Rancho Seco Nuclear Power Plant which is now scheduled for March 1, 1980, (2) the achievement of minimum fuel burnup for San Onofre Unit 1 consistent with the existing Cycle 8 safety analyses, which based on an assumed 90% capacity factor between now and shutdown is estimated to be March 1, 1980, and (3) the duration of the Cycle 8 refueling outage which is now estimated to be ten weeks. These matters cannot be predicted with absolute confidence at this time. It is nevertheless important for system operation and refueling planning purposes to firmly schedule the San Onofre Unit 1 outage.

  • Lessons Learned Item 2.1.1, Emergency Power Supply Requirements for the Pressurizer Heaters, Power-Operated Relief and Block Valves, and Pressurizer Level Indicators in PWRs.

Lessons Learned Item 2.1.3.a, Direct Indication of Power-Operated Relief Valve and Safety Valve Position for PWRs and BWRs Lessons Learned Item 2.1.4, Containment Isolation Provisions for PWRs and BWRs Lessons Learned Item 2.1.7.b, Auxiliary Feedwater Flow Indication to Steam Generators for PWRs

-3 We have therefore concluded that, in response to the Order forwarded by your January 2, 1980 letter, the San Onofre Unit 1 refueling outage should be scheduled to commence as soon as is possible given system reliability constraints and that the Lessons Learned Short Term requirements identified in the Order forwarded by your January 2, 1980 letter, not already implemented by January 31, 1980 be implemented at that time. As discussed in the Recommendation of Enclosure A to this letter, we believe that a reliable estimation of that earliest date is March 15, 1980. It is our proposal that the San Onofre Unit 1 shutdown be scheduled for March 15, 1980.

All Lessons Learned Short Term requirements identified in the Order can be implemented during such an outage except one element of modifications to the containment isolation provisions as discussed in Enclosure C (all other elements of the containment isolation modifications can and will be implemented). We propose the preparation and consummation of a stipulation to this effect in response to the Order forwarded by your January 2, 1980 letter. As discussed with representatives of the Regulatory Staff, we are prepared to meet and discuss this matter with you at your earliest convenience.

Sincerely, R. Dietch Vice President Nuclear Engineering and Operations Enclosures cc:

Mr. Richard Weiner, Director Division of Power Supply and Reliability U.S. Department of Energy 2000 M. Street, NW.

Washington, D. C. 20461