ML20095A374

Special Rept:On 951104,Unit 2 Main Steam Header Radiation Monitor Removed from Svc.Caused by Degraded Performance of Circuit Cards in Control Room Ratemeter.Main Steam Header Radiation Monitor Returned to Operable Status

ML20095A374
Person / Time
Site:	Calvert Cliffs
Issue date:	12/01/1995
From:	Cruse C BALTIMORE GAS & ELECTRIC CO.
To:	Martin T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 9512070093
Download: ML20095A374 (2)

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j chant Es H. CaesE Baltimore Gas and Electric Company Plant GeneralManager Calven Cliffs Nuclear Power Plant

. Calven Cliffs Nuclear Power Plant 1650 Calven Cliffs Parkway Lusby, Maryland 20657 410 586-2200 Ext.410l local 410 260-4101 Baltimore December 1,1995 U. S. Nuclear Regulatory Commission Region 1 475 Allendale Road King of Pmssia, PA 19406 ATTENTION: Mr. T. T. Martin, Administrator i

SUBJECT:

Calven Cliffs Nuclear Power Plant Unit No. 2; Docket No. 50-318 Inocerable Main Steam Header Radiation Monitor - Special Report l

The attached special report is submitted in accordance with Calvert Cliffs Unit 2 Technical Specifications 3.3.3.1 and 6.9.2. The report concerns the inoperability of Unit 2 No. 22 Main Steam Header Radiation Monitor for a period in excess of seven days.

l Should you have questions regarding this matter, we will be pleased to discuss them with you.

l Very truly yours, l

for ,

C. H. Cruse I Plant General Manager CHC/RCG/bjd Attachment l cc: Document Control Desk, NRC D. G. Mcdonald, Jr., NRC i

D. A. Brune, Esquire Resident Inspector, NRC J. E. Silberg, Esquire R. I. McLean, DNR L. B. Marsh, NRC J. H. Walter, PSC 1

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h l 9512070093 951201 I

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l PDR ADOCK 05000318 I S. . _ ~ . _ JDR.

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l ATTACHMENT (1) i UNIT 2 NO. 22 MAIN STEAM HEADER l RADIATION MONITOR - SPECI AL REPORT l We submit this Special Report concerning an inoperable Main Steam Header Radiation Monitor as I required by Technical Specification 3.3.3.1, Table 3.3-6, item 2.b.ii.

ACTION TAKEN  :

l On November 4,1995, the Unit 2 No. 22 Main Steam Header Radiation Monitor was removed from i service at approximately 1000 due to the monitor spiking into alarm intermittently. Troubleshooting determined that the Control Room ratemeter for the No. 22 Main Steam Header Radiation Monitor was sensitive to mechanical vibrations. Since the alarm setpoint is near the process signal, the slightest vibration was sufficient to cause an alarm. It was found that the functions of two circuit cards within the ratemeter had degraded. Troubleshooting was conducted throughout the week of November 4,1995 and the problem was corrected. The No. 22 Main Steam Radiation Monitor was returned to senice on November 13,1995 at approximately 1715.

EFFECT ON OPERATION Unit 2 Technical Specification 3.3.3.1 Action Statement (30) was entered when the No. 22 Main Steam  !

Header Radiation monitor was removed from service. In accordance with this Action Statement and our j Accidental Radioactivity Release Monitoring and Sampling Methods procedure (ERPIP-821), alternate sampling methods were implemented. He inoperability of the No. 22 Main Steam Header Radiation ,

Monitor did not affect Unit 2 operation.

CAUSES OF INOPERABILITY

'Ihe causes of the inoperability were the degraded performance of two circuit cards in the Control Room ratemeter.

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, PLANS AND SCHEDULES FOR RESTORING THE SYSTEM TO OPER ABLE STATUS The No. 22 Main Steam Header Radiation Monitor was returned to OPERABLE status on November 13, 1995 at approximately 1715. It was out of senice for a total of nine days.

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