ML13330A032

Confirms 800410 Telcons W/Regulatory Personnel Re Implementation of Several Category a TMI Lessons Learned Task Force Requirements Described in

ML13330A032
Person / Time
Site:	San Onofre
Issue date:	04/11/1980
From:	Baskin K Southern California Edison Co
To:	Ziemann D Office of Nuclear Reactor Regulation
References
RTR-NUREG-0578, RTR-NUREG-578, TAC-44128 NUDOCS 8004220634
Download: ML13330A032 (2)

Text

Southern California Edison Company P. 0.

BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER, NUCLEAR ENGINEERING (213) 572-1401 AND LICENSING April 11, 1980 Director, Office of Nuclear Reactor-Regulation Attention* Mr. D. L. Ziemann, Chief Operating Reactors Branch No.'2 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlemen:

Subject:

Docket No. 50-206 Implementation of Category A.Lessons Learned Requirements San Onofre Nuclear Generating Station Unit 1 This letter confirms telephone discussions with members of the Regulatory staff on April 10, 1980 concerning the implementation of several Category A Lessons.Learned requirements as.described in our letter dated March 25, 1980. Specifically:

1. The subcooling meter recorder and calculational components recently installed will be upgraded to comply with the design criteria provided by the Regulatory staff during meetings held at San Onofre Unit 1 on March 10 and 11, 1980 to review the equipment, procedural and administrative changes made to,-

implement Category A Lessons Learned requirements. The subcooling meter recorder and calculational components will be upgraded as follows:

a. The range of subcooling margin display will cover inputs of 300-7000F and 15-2500 psia, b';

The most limiting temperature and pressure inputs will be automatically selected, and

c. The subcooling meter recorder and calculational components will be environmentally qualified.

In addition, a method will be examined to provide-redundant temperature inputs from each loop and.redundant pressure inputs.

80042 20 t-A

Mr. D.

April 11, 1980

2. A schedule for completing the upgrade discussed in labove cannot be established until approximately July 1, 1980. The basis for this date is that sufficient design, engineering and procurement information cannot be finalized until completion of the current refueling outage.which is expected to be June 1, 1980. We will advise you.as soon after July 1, 1980 as is practicable follow ing establishment of the completion schedule.

3. The environmental qualificationidentified for the valve position indication (limit switches and conductor seal module assemblies) for the Power Operated Relief Valves, their associated block valves and the safety valves is sufficient to envelope post-,

accident conditions at San Onofre Unit 1. The projected post accident environmental conditions were provided as an enclosure (Table 2) to our letter dated February 24, 1978 (Mr. K. P. Baskin to Mr. D. L. Ziemann;

Subject:

Environmental Qualifications of Safety-Related Electrical Equipment).

The projected post accident environmental conditions are 49.4 psig, 291 0F (vapor),

100% humidity and radiation doses ranging from 2 x 102 to 6 x 107 rads.

4. The limit switches and conductor seal module assemblies discussed in 3 above were tested in accordance with IEEE-344-1975 to a maximum of 9.52 g's in the 1 to 35 Hz range and 3 g's vertical/

3.5 g's horizontal, respectively, which is in excess of the original seismic design basis for the station. The conservatism of the original seismic design basis for the station is currently being reevaluated as part of the Systematic Evaluation' Program as discussed in our letter dated August 10, 1978 (Mr. K. P. Baskin to Mr. D. L. Ziemann; SubjectIlntegration of.Selected Backfit Modifications into the Systematic Evaluation Program).

If you have any questions concerning the above information, please contact me.

Very truly yours,