ML19260D904
| ML19260D904 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 01/30/1980 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8002120571 | |
| Download: ML19260D904 (2) | |
Text
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SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT C 6201 s Street Box 15830. sacramento, Cahfarnia 95813; (916) 452-3211 January 30, 1980 Director of Nuclear Reactor Regulation Attention:
Mr. Robert W. Reid, Chief Operating Reactor, Branch 4 U.S. Nuclear Regulatory Comission Washington, D.C.
20555 Docket No. 50-312 Rancho Seco Nuclear Generating Station, Unit No.1
Dear Mr. Reid:
Paragraph 3.1.29(2) of the Fire Protection Safety Evaluation Report (SER) attached to License Amendment 19, dated February 28, 1978, describes the following modification for Fire Area 49, West Containment Penetration Valve Area:
" Reroute, install fire barriers or insulate conduits, etc.
associated with the high pressure injection and decay heat system."
The District requests that this caragraoh be rewritten to state the following:
" Reroute circuits and/or insulate conduits and/or trays to prevent the loss of redundant eauipment required for safe shutdown and cooldown."
The District is requesting this change since the existing para-graph requires modifications to both redundant systens and to cables that are associated with these systems which are not required for safe shutdown and cooldown.
The change in wording clarifies that the intent of the modification is to prevent the loss of both redundant systems and assure safe shutdown and cooldown.
Paragraph 3.1 of the SER requested design details for the modification in Fire Area 49 be submitted to the NRC for aporoval.
The design details are listed below.
They are based on the District's prooosed rewording for Paragraph 3.1.29(2).
DESIGN DETAILS The District will reroute the Channel B cables associated with the high pressure injection pumo out of this fire area.
The cable will be routed in fire areas where a Desian Basis Fire will not make the high pressure injection systen inoperative.3 t(C
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G 8002120 g
Mr. Reid January 30, 1980 This modification will assure for a normal plant line-up which is witn both high pressure injection cumps and the make-up pump in service, only one channel of the high pressure injection system will be in the fire area.
How-ever, if the 8 high pressure injection pump is out of service and the r'ake-up pump is ooerating as the B high pressure injection pump, both channels of the high pressure injection system are in the fire area.
However, the following assures operation of the high pressure injection system in this operation mode:
a) Horizontal separation of ten feet between the Channel A and B systems with no combustibles bridging the gap.
b)
Ionization detection in the fire area that initiates an alarm in the control room.
c) The low temoerature (2500 F) and short duration (15 minutes) for the Design Basis Fire in the area, make it improbable that 4 fire can imoact both systems.
Therefore, the District's modification assures operation of the high pressure injection system with a Design Basis Fire in this area.
For the District to meet the completion requirement stated in Table 3.1 in the SER, the District re,uests that the NRC coment and/or approve this modification by February 30, 1980.
Sincerely yours,
- lv)*)>u5. A ohn Jf Mattimoe Assistant General Manager and Chief Engineer
'950 245