ML20236E177
| ML20236E177 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/14/1987 |
| From: | Nobles L TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8710290101 | |
| Download: ML20236E177 (2) | |
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,.o TENNESSEE VALLEY ' AUTHORITY Sequoyah Nuclear Plant USNRC-DS Po3t Office Box 2000 Soddy-Daisy, Tennessee 3737El DCI 29 A 9: 57 September 14, 1987 U. S. Nuclear Regulatory Commission Region II
.101 Marietta Street, NW Suite 2900
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Atlanta, Georgia 30323 Gentlemen:
The purpose of this telecopy is to confirm the notification to NRC of 1
conditions of noncompliance with section 3.7.11.1.a of plant technical
' specifications for Facility Operating License Nos. DPR-77 and -79, Docket l
Nos. 50-327 and -328.
This notification is required in accordance with j
action b.2.b of section 3.7.11.1 of plant technical specifications.
After further evaluation of the event, it has been determined that the 2B-B fire pump was operable and capable of mitigating the consequence of any event for which it was designed.
The design basis of the plant does not require postulation of'a tornado coincident with any other design basis event, such as fire, seismic event, and loss of coolant accident.
Therefore,-in the event of a fire, diesel generator 2B-B would have been capable of supplying emergency power to the fire pump.
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For the duration of this event, both units 1 and 2 were in cold shutdown j
(mode 5).
On September 11, 1987, at approximately 1345 EDT, the fire i
i suppression system (i.e., fire pumps) was declared inoperable as a result of all four emergency diesel generators being declared inoperable.
Before the event, diesel generators 1A-A, IB-B and 2A-A had been removed from service for maintenance activities. With both units in mode 5, only one train of diesel generatora is required. With only 28-B diesel generator operable, the appropriate action statements were being met.
At the tin.e or the event, 28-B was declared inoperabic when it'was noted that as a result of a -
modification, the train B cablec to the Auxiliary Building shutdown boards from the diesel generator were exposed.
As part of the addition of a dry waste compacting system, it was necessary to cut a hole in a pullbox manhole which contained the train B diesel generator cables. As a result of the i
opening, in the event of a tornado generated missile, the train B cables l
could have been damaged if left unprotected. Thus, upon event discovery, the train B diesel generators were dociared inoperable, and in turn, the fire pumps were declared ir. operable. With all fire pumps declared inoperable, compliance with Limiting Condition for Operation (LCO) 3.7.11.1, action b, was initiated which requires, in part, a telecopy to NRC of the event.
8710290101 870914 PDR ADOCK 05000327 PDR g
l An Equal Opportunity Employer gg
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September 14, 1987 U. S.~ Nuclear Regulatory Commission l
CORRECTIVE ACTION TAKEN OR PLANNED At the time of discovery, Limiting Condition for Operation 3.7.11.1 on fire suppression water _ system was entered.
A missile shield.for the opening in the manhole was put in place, and diesel generators 1B-B and 2B-B were e
declared operable at.0628 EDT on September 13, 1987. and 0108:EDT on September 12, 1987, respectively.
This event is being reviewed to assess any lessons learned for. inclusion into our operating' experience review program.
Very truly yours, TENNESSEE VALLEY AUTHORITY f' /f f
L L. M. Nobles Plant Manager 0656Q
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