ML19338D562
| ML19338D562 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 09/16/1980 |
| From: | Morisi A BOSTON EDISON CO. |
| To: | Ippolito T Office of Nuclear Reactor Regulation |
| References | |
| 80-223, NUDOCS 8009230453 | |
| Download: ML19338D562 (2) | |
Text
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p BOSTON EOISON COMPANY Or en*6 Omcas eco Bov6 stow Statte Bosvow. Mas 5ACMUSETTS o2199 f
Septemis-16, 1980
- 4. viema monts:
na ucra m:cLaanorsaarzons saronr zaram:wr BECo. Ltr. #80-223 Mr. '1homas A. Ippolito, Chief Operating Reactors Branch #2 Division of Licensing Cffice of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D. C.
20555 License No. DPR-35 Docket No. 50-293 i
Effect of a DC Power Supply Failure On ECCS Performance Ref. a) GE letter to NRC, "DC Power Source Failure For BWR/3 and 4" dated 11-1-7$
Dear Sir:
In response to your letter dated April 25, 1980, Boston Edison Company hereby 1
confirms that the Reference a) analysis regarding minimum ECCS equipment avail-ability with a DC power supply failure, is conservative with respect to the system availability combinations at Pilgrim Nuclear Power. Station. The Ref. a) generic study considered the worst case plant for each type of break for both "LPCI mode" and "non-LPCI mode" plants. Pilgrim Station belongs to' the category of plants which h ve retained LPCI loop selection Icgic (Non-LPCI mcde plants) and therefore has the following equipment and support systems available for all breaks:
- 1 The power for these systems is supplied by buses "A" and "B".
+ 2 LPCI + ADS is available regardless of which DC power supply is lost and additionalk, HPCI will be available on loss of bus "A", and RCIC will be avail-able on loss of bus "B".
The minimum ECCS components available in the event of a single failure to a DC bus are listed below:
ADS System C/7 5
SV-203-3A; SV-203-3b; SV-203-3C; SV-203-4B; Logic For All
/ b
T03 TON El'l CN COMPANY P
4 Mr. Thomas A. Ippolito, Chief September 16, 1980 Page 2 CS System P-215A Associated ekt, bkr. A507 plus logic "A" or P-215B Associated ekt, bkr. A607 plus logic "B" LPCI System P-203A Associated ekt, bkr. A-503 plus logic "A" P-203C Associated ekt. bkr. A-506 plus logic "A" or P-203B Associated ekt, bkr. A603 plus logic "B" P-203D Associated ekt, bkr. A606 plus Logic "B" Since the above listed equipment is located outside containment, equipment availability is independent of the location of the break and unaffected by water spillage.
We believe this information provides you with an adequate level of assurance that the systems combinations assumed in the generic analysis (Ref, a)) are conservative for Pilgrim Station; however, should you have any further questions or concerns, please do not hesitate to contact us.
Very truly yours.
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