ML19323B732
| ML19323B732 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 04/25/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Bauer E PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| References | |
| NUDOCS 8005140157 | |
| Download: ML19323B732 (3) | |
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION 800514ol57 a
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E WASMNGTON. D. C.20666
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APRIL 2 5 B00 Docket Nos. 50-277 and 50-278 Mr. Edward G. Bauer, Jr.
Vice President and General Cow.3el l
Philadelphia Electric Cogany j
2301 Market Street Philadelphia, Pennsylvania 19101
Dear Mr. Bauer:
SUBJECT:
EFFECT OF A DC POWER SUPPLY FAILURE ON ECCS PERFORNANCE i
It has generally been recognized that the loss of a direct current (DC) power supply could disable seYeral emergency Core Cooling system Co@onents and thereby could result in a limiting single failure condition for some breaks. The enc.losed letter report was submitted to the NRC staff by the General Electric Cogany to provide a definitive, generic, reference analysis of the effects of DC power supply failures on ECCS conformance calculations. The NRC staff is reviewing the analysis which cocpares the peak cladding tegeratures associated with various postulated DC power supply failure (ECCS egipment availability) cases to the peak cladding teneratures for a HPCI (small break) failure and LPCI inicction valve (large break) failure cases. Since the study was based on plant design information which may have been incoglete or out-of-date, some uncer-tainty exists whether the worse ECCS system availability combinations have been identified for your operating BWRs. Accordingly, in order that we may have an adequate level of tssurance that the systems com-binations assumed in the generic analysis are conservative for Peach Bottom Units Nos. 2 and 3, we request that you confinn the conclusion of the reference study regarding the minimum ECCS equipment availability with a DC power supply failunt. Include in your response a list of the ECCS equipment that would be available for large and small (1) recirculation loop discharge breaks, and (2) recirculation loop suction breaks. The listing of equipment available should take into account not only DC power supply failure, but also loss of equipment due te water spillage.
Please provide a schedule for yc::r ra3ponse within 30 days of the receipt of this letter.
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Mr. Edward G. Bauer
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APRIL 2 5 1980 This request for generic inforration was! approved by GA0 under clearance number B-180225(579018); this clearance expires October 31, 1980.
Sincerely, Chief Operating Reactors Branch #3 Division of Operating Reactors i
Enclosure:
General Electric Conpany letter (R. E. Engel) to USNRC (P. S.
Check), "DC Power Source Failure for BWR/3 and 4," dated November 1, 1978.
cc w/ enclosure:
See next page
1 Mr. Edward G. Bauer, Jr.
APRIL 2 5 500 Philadelphia Electric Company 3
cc:
Eugene J. Bradley Philadelphia Electric Company Assistant General Counsel 2301 Market Street Philadelphia, Pennsylvania 19101 Troy B. Conner, Jr.
1747 Pennsylvania Avenue, N. W.
Washington, D. C.
20006 Raymond L. Hovis, Esquire 35 South Duke Street York, Pennsylvania 17401 Warren K. Rich, Esquire Assistant Attorney General Department of Natural Resources Annapolis, Maryland 21401 Government Publications Section State Library of Pennsylvania Education Building Coanonwealth and Walnut Streets Harrisburg, Pennsylvania 17126 M. J. Cooney, Superintendent Generation Division - Nuclear Philadelphia Electric Company 2301 Market Street Philadelphia, Pennsylvania 19101 Edward Greenman U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Peach Bottom Atomic Power Station P. O. Box 399 Delta, Pennsylvania 17314 Philadelphia Electric Company ATTN: Mr. W. T. Ullrich Peach Bottom Atomic Power Station Delta, Pennsylvania 17314
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G,E N E R AL h E LECTRIC nuCosaa suenov PaOJECTS DIVISION GENERAL ELECTRIC COMPANY,175 CURTNER AVE., SAN JOSE, CAUFORNIA 95125 MC 682, (408) 925-1153
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November 1, 1978 REE- 054-78 MFN -410-78 U.S. Nuclear Regulatory Commission Division of Operating Reactors Washington, D.C. 20555 Attention:
P.S. Check, Chief Reactor Safety Branch Operational Technology
Dear Mr. Check:
SUBJECT:
DC Power Source Failure For BWR/3 and 4 A recent concern expressed by members of your staff is the effect of a direct current (DC) power source failure on the currently approved 10CFR50.46 conformance calculations for operating BWR/3's and 4's.
The General Electric Company has conducted a study of thic concern and has documented the results in Attachment 1 to this letter. An additional concern expressed was the lack of a peak cladding temperature (PCT) versus break area curve in the small break region which could be applied to operating BWR/3's and 4's.
This concern is also covered in Attachment 1.
The sti.idy was performed with the 1977 approved model and input changes using bounding assumptions to provide a generic result applicable to all operating BWR/3's and 4's.
The results of the study show that there is an increase in PCT for small breaks; however, the PCT remains less than 1950 F.
For large breaks, the PCT was not affected. Also, the maximum average planar linear heat generation rate (MAPLHGR) is not affected for any plant.
O If you have any questions or comments, please contact R. T. Hill of my staff
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on (408) 925-3255.
I Sincerely,
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R. E. Engel, Manager p
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Operating _ Licenses I t
Safety and Licensing Operation Attachment cc:
F. D. Coffman R. H. W. Woods i
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ATTACHMENT 1 DC P0k'ER SOURCE FAILURE FOR Bb'R 3 AND 4 i
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DUPLICATE DOCUMENT Entire document previously entered into system under:
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