L-86-377, Special Rept:On 860819,condenser Air Ejector High Range Noble Gas Effluent Monitor Exceeded 7 Day Outage Reportability Limitations Established in Tech Spec Table 3.5-5.Caused by Water Intrusion Into Casing of Detector

Special Rept:On 860819,condenser Air Ejector High Range Noble Gas Effluent Monitor Exceeded 7 Day Outage Reportability Limitations Established in Tech Spec Table 3.5-5.Caused by Water Intrusion Into Casing of Detector

ML20210J723
Person / Time
Site:	Turkey Point
Issue date:	09/18/1986
From:	Woody C FLORIDA POWER & LIGHT CO.
To:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
L-86-377, NUDOCS 8610010227
Download: ML20210J723 (2)

Text

P. O. BOX 14000, JUNO RE ACH, FL 33408 M6 NNb FLORIDA POWER & LIGHT COMPANY SEPTEMBER 181986 L-86-377

g. 2 6 Dr. J. Nelson Grace Regional Administrator, Region 11 U. S. Nuclear Regulatory Commission 101 Marietta St., N.W. Suite 2900 Atlanta, GA 30323

Dear Dr. Grace:

Re: Special Report Turkey Point Unit 3 Date of Event: August 19,1986 Technical Specification 6.9.3 Condenser Air Ejector High Range Noble Gas Monitor Outage -

The attached Special Report is being submitted in accordance with Technical Specification 6.9.3 to provide 30 day notification of the subject occurrence.

Very truly yours, f C. O. Woody Ag Group Vice President Nuclear Energy COW /PLP/gp Attachment cc: Harold F. Reis, Esquire c~

8610010227 860918 0 DR ADOCK 0500

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evi PLP1/001/l PEOPLE. . SERVING PEOPLE

o SPECIAL REPORT SEPTEMBER 18,1986 COtOENSER AIR EJECTOR HIGH RANGE NOBLE GAS MONITOR OUTAGE

Purpose:

On August 19, 1986, the Condenser Air Ejector High Range Noble Gas Effluent Monitor, exceeded the 7 day outoge reportability limitations established in Technical Specification Table 3.5-5. In accordance with' the reporting requirements of Technical Specifications, this special report on the outage of the Condenser Air Ejector High Range Noble Gas Effluent Monitor is generated to notify the NRC. The health and safety of the public were not offected as a result of this event.

Event:

On August 19,1986, the Condenser Air Ejector High Range Noble Gas Monitor was declared out of service due to the Channel 7 detector tube failing low during functional testing. Channel 7 covers the intermediate range. Channels 5 and 9, the low and high range, respectively, continued to function properly during the time that Channel 7 was out of service.' As Channel 5, the low range monitor, indicated radiation levels within its range during the time that Channel 7 was out of service, no need to perform radiation level measurements using on alternate method existed.

The plant did not have a spore detector on hand. A new detector was not received from the vendor until September 9. Subsequently, the detector was replaced and the monitor was calibrated. The monthly functional test was completed satisfactorily on September iI,1986.

Cause and Corrective Actions:

The cause of the Channel 7 detector failing low was water intrusion into the casing of the detector. The water is at a high temperature and the detector failed

from either shorting caused by the water, or from the high temperature of the I

water. The cause of the water intrusion is failure of the rubber 0-ring which seals the detector casing. With the 0-ring failed, steam enters the casing, then condenses within the casing. The probable cause of the rubber 0-ring failure was the high ambient temperature coincident with the presence of steam.

Replacement of the failed detector was completed on September i1, 1986.

Subsequently, the detector was calibrated and functionally tested with satisfactory results. Following the above post-maintenance testing, the detector was placed back in service.

PLPl/001/2 L