ML19257B007
| ML19257B007 | |
| Person / Time | |
|---|---|
| Issue date: | 04/24/1979 |
| From: | Rosa F Office of Nuclear Reactor Regulation |
| To: | Grilli S MCGRAW-EDISON CO. |
| References | |
| REF-GTECI-A-30, REF-GTECI-EL, TASK-A-30, TASK-OR NUDOCS 8001150064 | |
| Download: ML19257B007 (2) | |
Text
S. Hacusa
,IO N
UNITED STATES NUCLEAR REGULATORY COMMISSION y
g s
.g wAsmuorou o.c.20sss e
\\****'*/
APR 0 41979 Power Systems Division McGraw-Edison Company General Offices Post Office Box 440 Canonsburg, PA 15317 Attn: Sandra L. Grilli, Planning Analyst
Subject:
Adequacy of Safety Related D.C. Power Supplies in Nuclear Power Plants Reference McGraw-Edison Company Letter to Director, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission
Dear Ms. Grilli:
As requested in the above reference Enclosures 1 through 3 are submitted to you for information. The basis for the request was an article in The Energy Daily regarding the WASH-1400 report as it pertained to staff decisions on D.C. batteries., NUREG-0305, addresses the basic issue which was identified by Mr. E. P. Epler, Consultant to the ACRS. Mr. Epler postulated the loss of one redundant D.C. power supply and the consequent loss of all off-site and on-site A.C. power and the remaining emergency D.C.
power supply. The loss of all power for an extended period of time would compromise reactor core cooling.
It is concluded in Enclosure 1 that a safety concern does not exist because of the D.C. power system reliability and the low likelihood of occurrence of the postulated multiple failures.
However, as outlined in Enclosure 1, the staff con-cluded that a quantitative reliability assessment of the D.C. power systems should be perfonned and any needed changes in procedures or design implemented.
Accordingly, a Task Action Plan (TAP-A30) was initiated by the Power Systems Branch, Division of Systems Safety (DSS), to resolve this issue.
Because of manpower limitations in DSS, the responsibility for comple-tion of this task has been transferred to the Probabilistic Analysis 1750 194 8 0 0115 0 O b f
APR 2 41973 S. L. Grilli
-c-Staff. The present status of this task is summarized in Enclosure 2, which also includes the latest revision of TAP A-30. As outlined in, completion of the task is seneduled for October,1979. provides DSS comments and recommendations on the latest revision of TAP A-30.
Should you require additional information, please contact me or R.
Fitzpatrick, telephone (301) 492-7276.
Sincerely, Faust Rosa, Chief Power Systems Branch Division of Systems Safety
Enclosures:
- 1. NUREG-0305 (NTIS PB 269 338) - Technical Report on D.C. Power Supplies in Nuclear Power Plants, July 1977
- 2. NRC Memorandum from A. R. Buhl to R. J.
Mattson dated March 9,1979 - Revision to Task Action Plan (TAP) A-30
- 3. NRC Memorandum from R. J. Mattson to A. R.
Buhl, dated March 28, 1979 - Revisions to A-30 1750 195