ML20215K486

Forwards Summary of Reevaluation of Reliability of Emergency Diesel Generators in Response to Generic Ltr 84-15.Data Collected for 1982-1986 Has Been Reevaluated Using Epri/ Nuclear Safety Analysis Ctr 108 Failure Criteria

ML20215K486
Person / Time
Site:	Maine Yankee
Issue date:	05/01/1987
From:	Whittier G Maine Yankee
To:	Thadani A Office of Nuclear Reactor Regulation
References
GDW-87-113, GL-84-15, MN-87-56, NUDOCS 8705110222
Download: ML20215K486 (2)

Text

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MAME HARHEE AWMICPOWERComPARUe avaug,,j,?7?g o"a'*2, a

h (207) 623-3521 May 1, 1987 HN-87-56 GDH-87-113 Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Washington, D. C.

20555 Attention:

Mr. Ashok C. Thadani, Director PHR Project Directorate #8 Division of Licensing

References:

(a) License No. DPR-36 (Docket No. 50-309)

(b) USNRC Letter to HYAPC0 dated July 2, 1984 (Generic Letter 84-15)

(c) HYAPCo Letter to USNRC dated September 26, 1984 (HN-84-166)

Subject:

Supplemental Emergency Diesel Generator Reliability Data Gentlemen:

In response to Generic Letter 84-15 Reference (b), Maine Yankee reported in Reference (c) a summary of the emergency diesel generator reliability data.

The data for the years 1982 through 1986 have been re-evaluated using the EPRI/NSAC 108 failure criteria. He believe the EPRI/NSAC 108 criteria for determining emergency diesel generator failures to be an acceptable alternative to the criteria outlined in Regulatory Guide 1.108 position c.2.e.

Maine Yankee's re-evaluation of the emergency diesel generators has determined that they are more reliable than previously reported in Reference (c). Our re-evaluation of the reliability of the emergency diesel generators is summarized in Attachment A.

If you should have any questions, please do not hesitate to contact me.

Very truly yours, HAINE YANKFE ATO Jjb/VW, HIC POWER COMP 8705110222 870501 PDR ADOCK 05000309 G. D. Whittier, Manager P

PDR Nuclear Engineering and Licensing GDH/bjp Attachment cc: Mr. James R. Allan Mr. Pat Sears A gd, Mr. Cornelius F. Holden II 8349L-LHO i

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ATTACHMENT A EMERGENCY DIESEL GENERATOR (S) RELIABILITY DATA l

EDG-1A l

- 97.98%

l EDG-1B l=98.95%

1. OF VALID

1. OF VALID

1. OF FAILURES

1. OF VALID

1. OF VALID

1. OF FAILURES YEAR STARTS LOAD RUNS START LOAD NO COUNT

• YEAR STARTS LOAD RUNS START LOAD NO COUNT

• Start Load Start Load 1982 21 19 1

1 1

0 1982 24 24 0

0 0

0 1983 25 25 0

0 0

0 1983 19 18 0

0 0

1 1984 22 22 0

0 0

0 1984 16 16 0

0 0

0 1985 20 20 0

0 0

0 1985 24 23 0

0 0

1 1986 12 12 0

0 0

0 1986 15 15 0

0 0

0 TOTAL 100 98 1

1 1

0 TOTAL 98 96 0

1 1

1 EDG Reliability - (Start Reliability) (Load Run Reliability)

(EDGR)

(SR)

(LRR)

EDG-1A EDG-1B Start Reliability -

1. of Successful Starts 99

=.99 98

= 1.0 Total # of Valid Demands to Start 100 98

1. of Successful Load Runs 97

=.9897 95

=.9895 Load Reliability

=

Total # of Valid Demands to Load 98 96 EDGR - (SR) (LRR)

EDGR - (SR) (LRR)

EPRI / NSAC-108 Criteria EDGR = (.99) (.9897)

EDGR = (1.0) (.9895)

EDGR - 97.98%

EDGR = 98.95%

s