ML17262A264
| ML17262A264 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 11/30/1990 |
| From: | Mecredy R ROCHESTER GAS & ELECTRIC CORP. |
| To: | Andrea Johnson Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9012140021 | |
| Download: ML17262A264 (4) | |
Text
~ ACCELERATED DIS RIBUTION DEMONST TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
.ACCESSION NBR:9012140021 DOC.DATE: 90/11/30 NOTARIZED: NO DOCKET g
FACIL:50-244 Robert Emmet Ginna Nuclear Plant, Unit 1, Rochester G
05000244 AUTH.NAME AUTHOR AFFILIATION MECREDY,R.C.
Rochester Gas 6 Electric Corp.
RECIP.NAME RECIPIENT AFFILIATION JOHNSON,A.R.
Project Directorate I-3 R
SUBJECT:
Advises of util decision to pursue resolution of offsite power sys analyses internally.
DISTRIBUTION CODE AOOID COPIES RECEIVED LTRI ENCL 2 SIZE'ITLE:
OR Submittal:
General Distribution NOTES:License Exp date in accordance with 10CFR2,2.109(9/19/72).
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05000244 RECIPIENT ID CODE/NAME PDl-3 LA JOHNSON,A INTERNAL: NRR/DET/ECMB 9H NRR/DOEA/OTS B1 1 NRR/DST/SELB 8D NRR/DST/SRXB 8E OC/LF B
RE ILE 01 EXTERNAL: NRC PDR COPIES LTTR ENCL RECIPIENT ID CODE/NAME PD1-3 PD NRR/DET/ESGB NRR/DST 8E2 NRR/DST/SICB 7E NUDOCS-ABSTRACT OGC/HDS2 RES/DSIR/EIB NSIC COPIES LTTR ENCL D
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NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE iVASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 18 ENCL 16 D
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89 EAST AVENUE, ROCHESTER N.Y. 14649.0001 ROBERT C MECREDY Vlcc Prerldent Ginna Nudear Production TELEPHONE AREACODE 71B 546 2700 November 30, 1990 U.S. Nuclear Regulatory Commission Document Control Desk Attn:
Allen R. Johnson Project Directorate I-3 Washington, D.C.
20555
Subject:
Offsite Power System Analyses R.E.
Ginna Nuclear Power Plant Docket No. 50-244
Dear Mr. Johnson:
In RG&E's letter of September 20, 1990, regarding, information of Ginna Station's reconfigured Offsite Power System, we stated that further evaluation of the test methodology for diesel generators was being pursued.
As mentioned in that letter, the present monthly test configuration could result in certain breakers ex-ceeding their interrupting rating if a concurrent phase-to-phase fault occurred.
This postulated single failure at the time of the test could result in the loss of an equipment item being operated at that time (e.g.
a: Service Water Pump).
This could. result in a loss of redundancy, with the potential for a
required plant shutdown.
Because of the economic consequences of such an occurrence, RG&E determined -that corrective action should be investigated.
A probabilistic risk analysis was performed.
on the existing test configuration.
The results showed a probability of 1.84E-03 per year of such an occurrence.
An alternate method of testing the diesels was proposed. that would limit. the breaker short circuit duties to within their acceptance criteria.
The new method would have required a
reconfiguration of the normally operating components before and. after the testing.
A PRA analysis was performed on the proposed change which indicated an increase in the frequency of a plant transient occurrence to 2.05E-02, based on the potential for human error.
This alternative test method, will, therefore, not be pursued.
Because this is an economic issue for RG&E, rather than a safety
- concern, RG&E willpursue resolution of this issue internally.
No A-.K)i'2140021 '901130
<<PDR ADOCK 05000244 a,P, r
-Pl3C JODI r ld'
further reguests for NRC resources will be made for this aspect of our Offsite Power System modification.
Very ruly yours THM/126 Attachment Robert,C.
Mecredy xc: Mr. Allen R. Johnson (Mail Stop 14D1)
Project Directorate I-3 Washington, D.C.
20555 U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406 Ginna Senior Resident Inspector
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