ML20210J443
| ML20210J443 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 09/09/1986 |
| From: | Tucker H DUKE POWER CO. |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8610010149 | |
| Download: ML20210J443 (2) | |
Text
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DUKE POWER GOMPANY P.O. BOX 33189 CHARLOTTE, N.C. 28242 h
HALB. TUCKER rat.zeno.u E.",U".-
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- September 9, 1986 Dr. J. Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marletta Street, NW, Suite 2900 Atlanta, Georgia 30323 Re: Catawba Nuclear Station, Unit 1 Docket No. 50-413
Dear Dr. Grace:
Pursuant to Technical Specification 3.4.9.3, Action Statement c, please find attached a Special Report concerning the automatie opening of a pressurizer power-operated relief valve.
Very truly yours, Hal B. Tucker RWO/22/slb Attachment xc: Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
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NRC Resident Inspector Catawba Nuclear Station
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7.n 8610010149 860908 PDR ADOCK 05000413
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4 Special Report Lifted Valve lhC34 (NC PORV)
Circumstances Initiating the Transient:
On August 10, 1986 during unit shutdown, the pressurizer PORV's were placed in the low pressure (L/P) mode without incident. This reduces the lift setpoint of the PORV's to 400 psig. When Reactor Coolant System temperature decreased to less than 300 degrees F, the nitrogen supply to valve INC34 (pressurizer PORV) opened (expected) and the valve opened (not expected). Reactor Coolant System pressure at this time was approximately 349 psig. Valve INC34 and its block valve were closed by the operator. The valve remained closed until the valve and its associated circuitry were checked out.
Effect of PORV on the Transient:
Reactor Coolant System pressure was approximately 349 psig throughout this event.
There was no real pressure transient for the PORV to alleviate.
Corrective Action to Prevent Recurrence:
Personnel have recalibrated the instrumentation loop associated with valve INC34.
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