ML20028D130
| ML20028D130 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 01/12/1983 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| REF-SSINS-6820, REF-SSINS-SSINS-6 IEB-80-04, IEB-80-4, TAC-46855, NUDOCS 8301170125 | |
| Download: ML20028D130 (1) | |
Text
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esuun SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 s street, Box 15830, Sacramento, California 95813; (916) 452-3211 January 12, 1983 DIRECTOR OF NUCLEAR REACTOR REGULATION ATTENTION JOHN F STOLZ CHIEF OPERATING REACTORS BRANCH 4 V S NUCLEAR REGULATORY COMMISSION WASHINGTON D C 20555 DOCKET 50-312 RANCHO SECO NUCLEAR GENERATING STATION UNIT N0 1 IE BULLETIN 80 MAIN STEAM LINE BREAK WITH CONTINUED FEEDWATER ADDITION Your letter dated November 3,1982, provided your review of our responses to IE Bulletin 80-04. Based on this review, you requested additional information for the current Emergency Feedwater System and upgraded Emergency Feedwater System (EFIC).
For our current Emergency Feedwater System you stated that the Auxiliary Feedwater (AFW) pumps are not protected from runout and that we should demonstrate that the pumps will not be damaged by runout or describe the interim measures that will be taken to prevent runout.
In our response to IE Bulletin 80-04 dated May 28, 1982, we said we were unable to provide information concerning damage to the AFW pumps at runout without an extensive test program, and since we are implementing our EFIC system, we feel this effort is not justified.
You stated that the present FSAR analysis does not bound the EFIC system for a Main Steam Line Break (MSLB).
For an MSLB the EFIC system will simply eliminate operator actions and make them automatic while not changing the system response.
Thus, the analysis for the containment pressure and reactivity increase given in the FSAR is bounding for the EFIC system.
You also stated that in the EFIC system design, the AFW pumps are not protected against runout during a double steam generator blowdown. With EFIC, only short periods of runout would be possible even at low pressures in the steam generators since the AFW control valves will start to close as steam generator level reaches its set point (less than three minutes). With this short period (less than three minutes), where runout is possible, we do not feel that this is sufficient to require additional controls or testing.
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A John Mattimoe s301170125 830112 General Manager DR ADOCK 05000 AN ELECTRlt SYSTEM SERVING MORE THAN 600.000 IN THE HEART Of CAltf0RNiA
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