ML20094G928
| ML20094G928 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 02/27/1992 |
| From: | Denton R BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9203050100 | |
| Download: ML20094G928 (2) | |
Text
o 13 ALTIMORE e
OAS AND ELECTRIC CHARLES CENTER
- P.O. BOX 1475
- BALTIMORE, MARYL AND 21203 1475 n t DEN 1oN cat ti wts February 27,1992 U. S. Nuclea' Regulaton Commission Washington. DC 20555 ATTENTION:
Document Centrol Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit No.1; Docket No. 50 317 Wide Rance Noble Gas Effluent Radiation hionitor Special Report Gentlemen:
The attached Special Report is submitted in 'accordance with Calvert Cliffs Unit 1 Technical Specification 3.3.3.1.
Should you have any further questions regarding this matter, we will be pleased to discuss them with you.
truly yours, f'{
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&%P kED/REIVbjd Attachment cc:
D. A. Brune, Esquire J. E. Silberg. Esquire R. A. Capra, NRC D. G. hicDonald, Jr., NRC T. T. Af artin, NRC P. R. Wilson, NRC R. I. hiclean, DNR J. II. Walter, PSC 9203050100 920227 hDR ADOCK 05000317 I
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O A'ITACilh1ENT (1)
WIDE RANGE NOlli.E GAS EITI tfENT R ADIATION MONITOR -
SPECI Al, REPORT We submit this Special Report concerning an inoperable Wide Range Noble Gas Efnuent Radiation Monitor on the Main Vent Stack as required by Technical Specification 3.3.3.1 Table 3.3-6, item 2.b.i.
IIACKGROUND The Unit I Wide Range Noble Gas Radiation Monitor (WRNGM) 1 RIC 5415, was removed from senice on Luary 28,1992 at 0350 because of noise spikes on the low Range Channel. Grab sam 31cs and readings on Main Vent Ellluent Radiation Monitor 1 RI 5415 confirmed that no unp anned release was made.
After the initial channel. noise problem was diswvered, other symptoms were found. These included:
intermittent pump failures of the mid/high pump and midrange detector failures. Trouble. hooting revealed a degraded pre amp power supply, a broken pre-amp c<mncetor wire, and an erratic input / output board. The channel noise was corrected by replacement of the pre amp power supply, and pre-amp board.
The detector failures were corrected by pre amp board replacement.
Intermittent pump failures will be prevented by prefilter replacement; dirty filters can cause low sample flow rates. The multiple failures complicated and lengthened troubleshooting efforts. The WRNGM was returned to senice on February 4,1992 at 1715.
EITECT ON OPERATION Unit 1 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 efuuents. The WRNGM inoperabi:ity did not affect Unit 1 operation.
PLANS AND SCIIEDUI.ES The WRNGM was returned to senice on February 4,1992 -- a total of 8 days after it was removed from senice.
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