ML20235Q962
| ML20235Q962 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/23/1989 |
| From: | Shawn Smith TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 89-03, 89-3, NUDOCS 8903030092 | |
| Download: ML20235Q962 (3) | |
Text
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-TENNESSEE VALLEY AUTHORITY -
Sequoyah Nuclear Plant
'i Post Office Box 2000 Soddy-Daisy, Tennessec -37379
. February 23, 1989 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 z
l Gentlemen:
TENNESSEE VALLEY AUTHORITY - SEQUJYAt NUCLEAR PLANT UNIT 2 - DOCKET NO.
.50-328 - FACILITY OPERATING LICENtv LPR SPECIAL' REPORT 89-03 The enclosed special' report provides details concerning fire detectors inoperable for greater than 14 days. This event is reported in accordance with action statement (b) of Limiting Conditions For Operation 3.3.3.8.
Very truly yours, TENNESSEE VALLEY AUTHORITY
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-Plant Manager I
Enclosure cc-(Enclosure):
J._ Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Commission Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323 Records Center Institute of Nuclear Power Operations Suite 1500 1100 Circle 75 Parkway
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Atlanta, Georgia 30339 1
NRC Inspector, Sequoyah Nuclear Plant i
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An Equal Opportunity Employer
M SEQUOYAH NUCLZAR PLANT UNIT 2 SPECIAL REPORT 89-03 DESCRIPTION OF EVENT on February 7,1989, with unit 1 in mode 1 (100 percent power 2235 psis, 578 degrees F), and unit 2 in mode 6 (0 percent power, O psig, 80 degrees F),
fire detectors for fire zones 134, 135, 142, 143, 144, and 145 (Auxiliary i
Building, 714 foot elevation, colunn line Al-A15 and Q to U) were i
inoperable. Unit 2 is currently in a refueling outage and # 2 replacing the "B" component cooling water heat exchanger. Replacement of the "B" component cooling water heat exchanger (Workplan No. 12742) involved
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intensive welding and grinding.
The work area was located in the above specified fire zones. To prevent spurious actuation of fire suppression system and spurious fire alarms in the main control room (distraction to the operators) which could occur due to the smoke produced by the welding activity, the fire detectors of the fire zones were removed from service, i
Technical specifications (TSs) require that the fire detectors be operable l
whenever, 'ny equipment that the detector protects is required to be l
operabic. Two other component cooling water heat exchangers are also, locate 6 in these fire zones, one of which is required operable for unit 1 operation. Thus, the detectors were required operable. The action statement of Limiting Condition for Operation (LCO) 3.3.3.8 was entered at 2149 EST on January 24, 1989, and a continuous firewatch was established in accordance with the action statement. On February 17, 1989 when welding activities associated with the "B" component cooling water heat exchanger were reduced and the potential for spurious actuation of smoke detectors no
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longer existed, the smoke detectors were' returned to service at 1725 EST.
Thus, the detectors were inoperable for approximately 24 days. The action of LCO 3.3.3.8 requires submittal of a special report if the detectors are inoperable for longer than 14 days.
CAUSE OF EVENT The replacement of "B" component cooling water heat exchanger was not completed within 14 days due to the complexity of the work involved. To prevent spurious actuation of the fire suppression system and spurious fire alarms in the main control room (distraction to the operators), it was decided to leave the fire detectors inoperable until the smoke produced by j
the welding activities was reduced.
ANALYSIS OF EVENT This special report is being submitted as required by the action statement (b) of LCO 3.3.3.8.
The fire detectors were inoperable for approximately 24 days. The fire l
suppression system in the affected areas were operabic and would be manually i
actuated by the operators in case of a fire being detected by the continuous firewatch.
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.Thus, f! a Wire had indeed initiated in~the ares protected by these
' detectors,' the mitigating effects of. the. fire protection system would not
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- have been lessened by the inoperable detectors.
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- C'ORRECTIVE dCTION aq A continuous firewatch was established and was maintained until the smoke e
. detectors"were declared. operable at 1725 EST on February 17, 1989.
No.
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further action'is required-
.a ADDITIONAL INFORMATION.
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None.
COMMITMENTS-
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