ML13333A415
| ML13333A415 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/13/1979 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13333A414 | List: |
| References | |
| TASK-09-06, TASK-9-6, TASK-RR NUDOCS 7910160029 | |
| Download: ML13333A415 (2) | |
Text
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.ENCLSRE 2
UNITED STATES NUCLEAR REGULATORY COMMISSION 0
WASHINGTON, D. C. 20555 APR 13 1979 MEMORANDUM FOR:
D. Ziemann, Chief, Operating Reactors Branch #2, DOR FROM:
G. Lainas', Chief, Plant Systems Branch, DOR
SUBJECT:
SAN ONOFRE -
UNIT 1, FIRE PROTECTION ALTERNATE OFFSITE POWER SOURCE, LICENSEES LETTER OF JANUARY 15, 1979 In the subject letter, the licensee proposed to provide an alternate shutdown capability independent of certain areas where a fire could affect redundant safe shutdown equipment including the onsite power sources. The power source proposed for the alternate capability is an offsite source which is electrically independent and physically separate except for the intertie to the San Diego Gas and Electric Company's 135 Kv system. We find that dependence on offsite power alone is unacceptable and that the capability to provide power from an onsite source should be available.
The staff realizes that there are systems which could be used to achieve safe shutdown given that offsite power is available during a fire. However, the loss of offsite power is assumed for other events which do not affect systems designed to cope with the event.
The staff deems it to be a prudent conservatism to adopt the same criteria for a fire, particularly, since the fire may affect systems designed to cope with its effects. The loss of offsite power is to be assumed along with the fire without respect to mechanisms through which it can be shown to occur even though such mechanisms do exist. This will assure that at least one source of onsite power is available in the event of a loss of offsite power concurrent with the fire for whatever reason.
Therefore, the staff requests the licensee to provide design modifications which will assure that safe shutdown can be achieved and maintained using an onsite po r source.
SLainas, Chief Plant Systems Branch Division of Operating Reactors 7 91 0iZ O2 C
-2 cc:
V. Stello D. Eisenhut G. Lainas D. Ziemann R. Ferguson J. Knight A. Burger T. Wambach Fire Protection Consultants Section C, PSB L. Derderian