ML20079B761
| ML20079B761 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 12/15/1994 |
| From: | Mcmeekin T DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9501090041 | |
| Download: ML20079B761 (3) | |
Text
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' T. C McMwaw
' DukehurCompany
^ Vicehesident
' McGuire Fxlear Generatian Department 12700Hqgers ferryRoad(MG0lW)
(704)8754800
. Huntersttilq NC28078&%S (704)8754809 Fax DtMWPOWER December 15,1994
' U. S. Nuclear Regulatory Commission ATTN: Document Control Desk '
Washington, D.C. 20555 L
Subject:
McGuire Nuclear Station, Units 1 and 2 Docket Nos. 50-369 and 50-370 NRC Inspection Report No. 50-369,370/94-08 Violation 50-369,370/94-08-01 Supplemental Reply to a Notice of Violation Gentlemen:
Attached is a supplemental response to the Notice of Violation issued May 6,1994 conceming a non-conservative unidentified reactor coolant leakage calculation. The initial response dated June 1,1994 stated the reactor coolant (NC) system Design Basis Document (DBD) would be revised by December 31,1994 to address the NC system leakage calculation and the consequences of introducing inputs from other systems into the calculation. Engineering support actitivies required during the recent 1EOC9 I
refueling outage and the ongoing 2EOC9 refueling outage, in addition to the length and complexity of the -
DBD revision, have resulted in a delay in completion of the DBD revision. The DBD revision will be completed by May 1,1995.
Should there be any questions concerning this response, contac' Randy Cross at (704) 875-4179.
Very Truly You,
. C. McMeekin Attachment xc:
(w/ attachment)
Mr. S. D. Ebneter Mr. George Max vell Regional Administrator, Region 11 NRC Senior Resident inspector U.S. Nuclear Regulatory Commission McGuire Nuclear Station 101 Marietta St., NW, Suite 2900 Atlanta, Geo;gia 30323 Mr. Victor Nerses U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation One White Flint North, Mall Stop 9H3 Washington, D. C. 20555 9501090043 941215 gDR ADOCK 05000369
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l McGuire Nuclear Station Supplemental Reply to a Notice of Violation Violation 369. 370/94-08-01 Technical Specification 3.4.6.2 requires that the unidentified leakage rate shall not exceed one gallon per minute while in Medes 1,2,3, and 4.
Contrary to the above, unidentified leakage rate exceeded the technical specification limit on at least twelve occasions during the past twelve months prior to December 7,1993 while in Modes 1, 2, 3, and 4.
This is a Severity Level IV violation (Supplement I).
Sucolemental Reoly to Violation 369. 370/94-08-01 1.
Reason for the Violation:
The reason for the violation is failure to considei the system / component interaction in the original design of the program for the reactor coolant (NC) system leakage calculation. The calculation did not recognize inputs of water from other systems to the reactor coolant system drain tank (NCDT) and pressurizer relief tank (PRT).
Failure to recognize these potential inputs and the subsequent effect on the calculation logic could have caused the calculation to be non-conservative. Since plant personnel had not been aware of these potential inputs being accounted for as identified leakage, they were unaware of potentially exceeding the 1 gpm Technical Specification limit. Because they were unawaic no actions were taken to reduce the leakage or shutdown as required by the Technical Specificat.)n.
2.
Corrective steos that have been taken and the results achieved:
a.
Systems Engineering personnel initiated PIP 0-M93-1253 to investigate the circumstances surrounding the problem and determine appropriate corrective actions.
b.
Systems Engineering personnel initiated present and past operability evaluations with regard to compliance with Technical Specification 3.4.6.2.
c.
Instrumentation and Electrical (IAE) personnel implemented Temporary Modifications 6314 and 6315 to eliminate inputs to the NCDT drain header which are not NC system related.
d.
Systems Engineering personnel verified that potential for Cold Leg Accumulator drain and drain header inputs of refueling water storage tank (FWST) water to the NCDT were removed.
e.
Operations personnel changed procedures PT/1 & 2/A/4150/01B, Reactor Coolant Leakage Calculation, to conservatively lock out the input from PRT level increases.
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a a
f.
Mechanical Nuclear Engineering determined the best way to permanently remove non-NC system related inputs from the NC system leakage caEdation. This corrective action was
- completed on July 1,1994.
3.
Correctivr_11epLthat will be taken to avoid further duLations:
l Modification Engineering personnel will include appropriate information to the Design Basis Document (DBD) for the NC system to address the NC system leakage calculation and the consequences of introducing inputs from other systems into the calculation. This corrective action will be completed by May 1,1995.
Date whndul spjapliante will tuchicycd:
4.
l McGuire Nuclear Station is now in full compliance.
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