ML20209J408
| ML20209J408 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 04/24/1987 |
| From: | Nobles L TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 87-03, 87-3, NUDOCS 8705040278 | |
| Download: ML20209J408 (3) | |
Text
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TENNESSEE VALLEY AUTHORITY Sequoyah Iluclear Plant Post Office Box 2000 Soddy-Daisy, Tennessee 37379 April 24, 1987 U. S. Nuclear Regulatory Conunission Document Control Desk Washington, DC 20555 Gentlemen:
TENNESSEE VALLEY AUTHORITY - SEQUOYAH NUCLEAR PLANT UNIT 1 - DOCKET NO.
50-327 - FACILITY OPERATING LICENSE DPR SPECIAL REPORT 87-03 The enclosed speelal report provides details concerning meteorological instrumentation being inoperable for longer than seven days. This event is reported in accordance with action statement (a) of Limiting Condition for Operation 3.3.3.4.
j Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Nobles Acting Plant Manager Enclosure ce f.Enclosura):
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 Atlanta, Georgia 30339 NRC Inspector, Sequoyah Nuclear Plant 8705040278 870424 PDR ADOCK 05000327 S
PDR Wili An Equal Opportunity Employer i
we 4,
SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 SPECIAL REPORT 87-03 On April 9, 1987, with units 1 and 2 in mode 5 (0 percent power, 0 psig.
112 degrees F and 0 percent power, 275 psig, 120 degrees F, respectively),
the meteorological instrumentation was declared inoperable on three different occasions. The meteorological data is compiled at the meteorological tower located approximately one-half mile southeast of the plant.
It is then transmitted to the plant's auxiliary instrument room via telephone lines. At 0100 EST on April 9, 1987, the meteorological instrumentation was declared inoperable because the recorders were not functioning properly. Limiting Condition for Operation (LCO) 3 3.3.4 was entered and complied with until 0755 EST when the instrumentation was returned to an operable status. Again at 1120 EST, the instrumentation was declared inoperable when the recorders failed to operate properly, and LCO 3.3.3.4 was entered. It was returned to service at 1320 EST, and the LCO was exited. At 1513 EST, the meteorological instrumentation was declared inoperable on a third occasion because once again, the recorders were not functioning. This time the LCO was entered and remained in effect until the root cause of the problem was determined and corrected. The LCO was exited at 1550 EST on Apell 22, 1987. Thus, the meteorological instrumentation was inoperable for approximately 12 days. The action statement for LCO 3.3.3.4 requires a special report to be submitted if meteorological instrumentation is inoperable longer than seven days.
CAUSE OF EVENT This event was caused by a component failure.
Investigation determined that there was no problem with the meteorological tower computer or the instrumentation in the auxiliary instrument room or the control room. Work Request (WR) B223601 was written to check the telephone line which transmits the meteorological data from the meteorological tower to the plant. It was determined a bad cable in the telephone line was creating a bad connection and producing inconsistent signals. Once the wiring was repaired and a postmaintenance test run, the meteorological instrumentation was returned to an operable status.
ANALYSIS OF EVENT This special report is being reported under the requirements of action statement (a) of LCO 3.3.3.4.
The meteorological instrumentation was inoperable for 12 days. The meteorological tower equipment measures wind direction, wind speed, and air temperature. These parameters are used to determine plume conditions in the event of an unexpected radioactive release to the atmosphere. With both units in mode 5, it is unlikely that an accident would have occurred which would have produced a radioactive release. No unexpected releases occurred during the timeframe the meteorological instrumentation was
inoperable. The health and safety of the public was not endangered by this event. Had the plant been in a different operating condition, the significance of this event would not have changed since the meteorological data is used to monitor an accident. It is not used to assist in mitigating the accident. Also, the meteorological information could have been obtained from the meteorological tower since the computer was operable during this event.
CORRECTIVE ACTION WR B223601 wss written to check the telephone line which transmits the meteorological data from the meteorological tower to the plant. It was discovered that there was a bad cable in the telephone line. This was repaired..and the meteorological instrumentation was returned to service.
No further corrective action is necessary to resolve this event.
ADDITIONAL INFORMATION There have been no previous occurrences of the meteorological instrumentation being out of service for longer than seven days.
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