AECM-88-217, Special Rept 88-004:on 881021,containment Ventilation Exhaust Accident Range Radiation Monitor Removed from Svc. Erratic Readings Observed During Surveillance.Caused by Damaged Cable Assembly.Channel 2 Tube Replaced

Special Rept 88-004:on 881021,containment Ventilation Exhaust Accident Range Radiation Monitor Removed from Svc. Erratic Readings Observed During Surveillance.Caused by Damaged Cable Assembly.Channel 2 Tube Replaced

ML20205P344
Person / Time
Site:	Grand Gulf
Issue date:	11/04/1988
From:	Cesare J SYSTEM ENERGY RESOURCES, INC.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
88-004, 88-4, AECM-88-0217, AECM-88-217, NUDOCS 8811080083
Download: ML20205P344 (2)

Text

,

. 4 NESOUSES,WC.

XattG cvxx h gg November 4, 1988 U. S. Nuclear Regulatory Comission Mail Station P1-137 Washington, D. C. 20555 Attention: Document Control Desk Gentlemen:

SUBJECT:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Special Report 88-004 Inoperability of Accident Monitor Exceeds 72 Hours AECM-88/0217 A containment ventilation exhaust accident range radiation monitor was removed from service on October 21, 1988 at 0815 to perform a surveillance as required by Technical Specification Table 4.3.7.5-1. Erratic readings were observed during the surveillance. Investigations revealed a damaged cable assembly. The cable assembly was replaced. In addition, it was noticed that the Channel 3 detector tube was decreasing in sensitivity; therefore, the Channel 3 detector tube was also replaced.

During the monitor retest, the background channel (Channel 2) failed.

This problem was investigated and the Channel 2 detector tube was determined to be defective. The Channel 2 tube was replaced and the monitor retested satisfactorily. The monitor was restored to service on November 3 at 1530.

This Special Repert is being submitted pursuant to Action 81 of Technical Specification Table 3.3.7.5-1 since the instrur.ent channel was inoperable longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The preplanned alternate rethod of monitoring per Action 81 is to utilize the Eberline Sping monitoring system per procedure 08-S-04-220.

The normal effluent monitoring instrumentation was functional during this time period.

Yours truly, ,

$10hEf:c $NN1,6 FDC s 47 JGC:rg cc: (See next pagri >

o m Cx88 n0,01 1 mm _. s. - , +

4

)

o +

AECM-88/0217

- Page 2 cc: Mr. T. H. Cloninger Mr. R. B. McGehee l

Mr. N. S. Reynolds

Mr. H. L. Thomas l

Mr. H. O. Christensen Mr. Malcolm L. Ernst '

Acting Regional Administrator U. S. Nuclear Regulatory Comission Region II 101 Marietta St., N. W., Suite 2900 Atlanta, Georgia 30323 Mr. L. L. Kintner, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Comission Mail Stop 14B20 We.shington, D.C. 20555 i

.A s

l 012AECM88110401 - 2 O

Text

,

. 4 NESOUSES,WC.

XattG cvxx h gg November 4, 1988 U. S. Nuclear Regulatory Comission Mail Station P1-137 Washington, D. C. 20555 Attention: Document Control Desk Gentlemen:

SUBJECT:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Special Report 88-004 Inoperability of Accident Monitor Exceeds 72 Hours AECM-88/0217 A containment ventilation exhaust accident range radiation monitor was removed from service on October 21, 1988 at 0815 to perform a surveillance as required by Technical Specification Table 4.3.7.5-1. Erratic readings were observed during the surveillance. Investigations revealed a damaged cable assembly. The cable assembly was replaced. In addition, it was noticed that the Channel 3 detector tube was decreasing in sensitivity; therefore, the Channel 3 detector tube was also replaced.

During the monitor retest, the background channel (Channel 2) failed.

This problem was investigated and the Channel 2 detector tube was determined to be defective. The Channel 2 tube was replaced and the monitor retested satisfactorily. The monitor was restored to service on November 3 at 1530.

This Special Repert is being submitted pursuant to Action 81 of Technical Specification Table 3.3.7.5-1 since the instrur.ent channel was inoperable longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The preplanned alternate rethod of monitoring per Action 81 is to utilize the Eberline Sping monitoring system per procedure 08-S-04-220.

The normal effluent monitoring instrumentation was functional during this time period.

Yours truly, ,

$10hEf:c $NN1,6 FDC s 47 JGC:rg cc: (See next pagri >

o m Cx88 n0,01 1 mm _. s. - , +

4

)

o +

AECM-88/0217

- Page 2 cc: Mr. T. H. Cloninger Mr. R. B. McGehee l

Mr. N. S. Reynolds

Mr. H. L. Thomas l

Mr. H. O. Christensen Mr. Malcolm L. Ernst '

Acting Regional Administrator U. S. Nuclear Regulatory Comission Region II 101 Marietta St., N. W., Suite 2900 Atlanta, Georgia 30323 Mr. L. L. Kintner, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Comission Mail Stop 14B20 We.shington, D.C. 20555 i

.A s

l 012AECM88110401 - 2 O