ML20044C167
| ML20044C167 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 03/11/1993 |
| From: | Cruse C BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9303180230 | |
| Download: ML20044C167 (2) | |
Text
A BALTIMORE GAS AND ELECTRIC CALVERT CLIFFS NUCLEAR POWER PLANT l
1650 CALVERT CLIFFS PARKWAY
- LUSBY. MARYLAND 20657-4702 CHARLES H CRUSE PLAtJT GENERAL MANAGER CALVERT CLIFFS March 11,1993 f
U. S. Nuclear Regulatory Commission Washington,DC 20555 A'ITENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit No. 2; Docket No. 50-318 Wide Rance Noble Gas Effluent Radiation Monitor - Special Report Gentlemen:
The attached Special Report is submitted in accordance with Calvert Cliffs Unit 2 Technical Specification 3.3.3.1.
Should you have any further questions regarding this matter, we will be pleased to discuss them =ith you.
Very truly yours,
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,N' yy 4t
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CIIC/WDM!bjd Attachment 1
cc:
D. A Brune, Esquire J. E. Silberg, Esquire R. A Capra, NRC D. G. Mcdonald, Jr., NRC T. T. Martin, NRC P. R. Wilson, NRC h[.
R. I. McLean, DNR J. H. Walter, PSC
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ATTACIIMENT (1)
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UNIT 2 WIDE. RANGE NOBLE GAS EFFLUENT RADIATION MONITOR SPECIAL REPORT We submit this Special Report concerning an inoperable Wide Range Noble Gas Effluent Radiation Monitor (WRNGM) on the Main Vent Stack as required by Technical Specification 3.3.3.1, Table 3.34,1 tem 2.b.i.
ACTION TAKEN On February 11,19(>3, the Unit 2 Wide-Range Noble Gas Monitor was removed from senice at approximately 1145 when the automatic eight-hour check scurce failed. During the performance of troubleshooting, the preamplifier board was found to have failed. The board was replaced on February 17. Suncillance Test Procedure M-564-2 was performed as a post-maintenance test.
During performance of M-5M-2, the voltage of one of the Mid-Range power supplies was found to be below specification. The power supply was replaced on February 18. The monitor was subsequently satisfactorily retested and returned to an operable status on February 22 at approximately 1415.
EFFECT ON OPERATION Unit 2 Technical Specification 3.3.3.1 ACTION statement (30) was entered when the WRNGM was removed from senice. In accordance with this ACTION statement and our radioactive gas release procedure (CP-213), the Main Vent Radiation Monitor was used as the alternate preplanned Main Vent Stack monitor for discharge flow-stream effluents. The WRNGM inoperability did not affect Unit 2 operation.
CAUSE OF INOPERAllILITY The cause of the inoperability was a failed preamplifier board. The board will be returned to the vendor for determination of the failure mode. The power supply replacement was a result of an "as-found" condition discovered during Surveillance Test Procedure M-564-2. The low voltage is attributable to drift cominonly associated with age.
PLANS AND SCIIEDULES FOR RESTORING TIIE SYSTEM TO OPERAllLE The Wide-Range Noble Gas Monitor was restored to OPERABLE status on February 22,1993 at approximately 1415. It was out of senice for a total of 11 days.