ML20031F885
| ML20031F885 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 10/14/1981 |
| From: | Walbridge W SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| GL-81-14, TAC-43663, NUDOCS 8110200515 | |
| Download: ML20031F885 (2) | |
Text
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O suun SACRAMENTO MUNICIPAL UTILITY DISTRICT O 5201 s street, Box 15830, sacramento, California 95813; (916) 452 3211
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October 14, 1981
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DIRECTOR OF NUCLEAR REACTOR REGULATION ATTENTION DARRELL G EISENHUT DIRECTOR C.
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DIVISION OF LICENSING 3\\'9' D '/
U S NUCLEAR REGULATORY COMMISSION
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xw WASHINGTON D C 20555 DOCKET 50-312 RANCHO SEC0 NUCLEAR GENERATING STATION UNIT N0 1 SEISMIC QUALIFICATION 0F AUXILIARY FEEDWATER SYSTEM GENERIC LETTER N0 81-la The purpose of this letter is to supplement our July 17, 1981 response to your February 10, 1981 Generic Letter No. 81-14. The supplemental informa-tion included in this letter contains a brief description of the Auxiliary Feedwater System, a statement of how the system operates during loss of offsite power, and FSAR references where more information can be found on the basis for seismic qualification of specific components in the Auxiliary Feedwater System.
The Auxiliary Feedwater System at Rancho Seco consists of two 100% capacity pumps. Each of the pumps has the capability to provide auxiliary feedwater flow to either of the two steam generators. One of the pumps is motor driven and the other is driven by either a motor or turbine drive connected in tandem. Power for the motor drives can be provided from the emergency diesel generators.
Steam supply for the turbine drive is provided from connections on the main steam lines. The auxiliary feedwater pumps take suction from a Seismic Category 1 condensate storage tank.
When offsite power is available, the motor drives for the auxiliary feedwater pumps are automatically initiated, powered from their respective vital buses.
When offsite power is not available, emergency feedwater is provided by the turbine driven auxiliary feedwater pump. The motor drives are available as backup through manual initiation, powered from their respective diesel generator buses. Manual initiation of the motor drives when offsite power is not avail-i able is specifically covered in the auxiliary feedwater system operating pe'e-dures.
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s DARRELL G EISENHUT October 14, 1981 I
l The FSAR provides a description of the methodologies and the acceptance criteria i
used to support the conclusion that all components and structures supporting the i
Auxiliary Feedwate' System are seismically qualified. This description includes seismic analysi!
.. hods employed, seismic inputs, load combinations, and allowable stresses. The t -se below lists the Auxiliary Feedwater System components and the appropriate sections ]f the FSAR.
Component FSAR Sectio g 1.
Pumps, pipes & valves.
Appendix SA, Appeniix 58, Ques-tion No. 5A.69, Question 5A.64.
.2.
Electrical components and equipment.
Question No. 5A.69, Question 7A.20, Question 8A.7, and Ques-tion 7A.11.
3.
Structures and water supply.
Appendix 58.
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l We hope this information provides the necessary backup information to' our previous response.
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Wm. C..Walbridge
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oworn to and subscribed before me this /cf m eff', PATiiiCIA K. gel %ER 5~
t o:Am s..n cAutomA day of October,1981.
g; f 47 'OP4 Omst IN NW v.cuvuao ccerns My Commessen Empres ikvember 22.1983.. *.
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