ML20057F396
| ML20057F396 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 10/08/1993 |
| From: | Kofron K COMMONWEALTH EDISON CO. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| BW-93-0259, BW-93-259, NUDOCS 9310150240 | |
| Download: ML20057F396 (3) | |
Text
l Commonwealth Edison l
Br:1dwood Nuclxr Powir St tion l
Rou4 C1, B x 84 Brace.<ille, Illinois 60407 Telephone 815/458-2801 i
October 8, 1993 BW/93-0259 Mr. John B. Martin Regional Administrator l
U.
S. Nuclear' Regulatory Commission l
Region III 799' Roosevelt Road Glen Ellyn, Illinois 60137
Subject:
Braidwood Station Unit 2 Train B Diesel Generator Valid Failure Docket No..STN 50-457
References:
(a)
NUREG-1276, Technical' Specifications, l
Braidwood Station, Unit Nos. 1 and 2 (b)
July 14, 1993 K. L. Kofron letter to J.
B. Martin I
Dear Mr. Martin:
Specification 4.8.1.1.3 of reference (a) requires that all diesel generator failures, valid or non-valid, be reported to the Nuclear Regulatory Commission p'Irsuant to Specification 6.9.2 of I
l reference (a).
The enclosure addresses one valid failure of the Braidwood f
Unit 2, Train B (2B) Diesel Generator (DG) which occurred on September 28, 1993, while the 2B DG was in the " standby" condition.
The criteria to determine valid / invalid tests and failures are in accordance with Regulatory Guide 1.108, Section C.2.e.
Reference (b) is the most.ecent report addressing diesel generator failures submitted in accordance with Specification 4.8.1.1.3 of reference (a).
93101505!4O-931000
'F
~^
PDR ADDCK 05000457 D
S PDR Q
M ile
Please direct any questions regarding this submittal to Harry Pontious, Braidwood Licensing Supervisor, (815) 458-2801, extension 2511.
Very truly yours, i$,ll?'
h L.
o ron Station Manager Braidwood Nuclear Station KLK/HDP/dla Enclosure cc:
NRC. Document Control Desk Senior Resident Inspector - Braidwood R. Assa - NRR l
B.
Clayton - RIII D.
Saccomando - NLA D.
Lambert - System Engineering l
i L
t.
i 1
Braidwood Station Unit 2 Train B Diesal Generator Valid Failure September 28, 1993 On Tuesday, September 28, 1993 at 2314 hours0.0268 days <br />0.643 hours <br />0.00383 weeks <br />8.80477e-4 months <br />, annunciators 2-22-C8, IX3 2B Trouble / Fail to Start, and 2-22-D6, 125V DC Ground, alarmed simultaneously on Braidwood Unit 2 Main Control Board 2PM01J.
Annunciator 2-22-D6 reset immediately.
An Equipment Operator was dispatched to the Braidwood Unit 2, Train B (2B) Diesel Generator (DG) Room to investigate the cause of annunciator 2-22-C8 being in alarm.
Subsequent investigation revealed that fuses 27 and 29, the positive and negative legs of a control power circuit, had blown. -The'2B DG was declared inoperable and the applicable Technical Specification (TS) 3.8.1.1 Limiting Condition for Operation Action' Requirements (LCOARs) were entered.
Since annunciators 2-22-C8 and 2-22-D6 had alarmed j
simultaneously, troubleshooting was focused on the normally energized relays in the circuit.- A relay with a shorted circuit was identified as the cause of the blown fuses.
That relay was replaced with a new bench tested relay.
After fuse and relay replacement, a post-maintenance test was performed to successfully demonstrate circuit continuity.
The 2B DG was then started and loaded.to demonstrate proper operation.
The 2B DG was declared operable on September 29, 1993 at 1452 hours0.0168 days <br />0.403 hours <br />0.0024 weeks <br />5.52486e-4 months <br /> and all applicable TS 3.8.1.1 LCOARs were terminated.
There have been no previous occurrences of a shorted relay circuit on the 2B DG.
This failure of the 2B DG has been determined to be a valid failure in accordance with Regulatory Guide 1.108, Section C.2.e.
The 2B DG has been placed on an increased test frequency.
As of October 7, 1993, the 2B DG has had two valid failures and the Braidwood Unit 2, Train A (2A) DG has had two valid failures in the last 100 valid Braidwood Unit 2 DG demands.