ML20009F616

Ro:On 810626,equipment Insp Revealed Steam Generator Level Transmitters 1-LT-3-148,156,164,172,174 & 175 Could Fail During Loca.Caused by Degraded Teflon Insulation.Defective Amplifiers Replaced

ML20009F616
Person / Time
Site:	Sequoyah
Issue date:	06/26/1981
From:	Ballentine J TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 8107310356
Download: ML20009F616 (1)

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,a TELECOPY TO NRC OFFICTAL COPY 1

June 26, 1981 i , gb$ll/Q U.S. Nuclear Regulatory Comission Region II D

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101 Marietta Street, NW . ej. 2-Suite 3100 JUL 3 01981 w

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Atlanta, Georgia 30303 SQRO-50-327/81067 ta s Reported under Technical Specification 6.9.1.12.1 Date of Occurrence: 06/26/81 Time of Occurrence: 1055 EDT Technical Specification Involved: 3.3.3.5 and 3.7.1.2 Conditions Prior __to Occurrence Unit in Mode 4 preparatory to heat up to Mode 3.

Identificat_ ion and__ Description of Occurrence A safety evaluation based on nonconformance report NCR SQN EEB 8118 and a related equipment inspection at the plant site identified that the following steam generator level transmitters could fail during a LOCA:

1-LT-3-148, 156, 164, 172, 174, 175. The transmitters are required to meet Technical Specifications 3.7.1.2 (Modes 1-3) and 3.3.3.5 (Modes 1-3). Since the Unit was in Mode 4, no action statement was applicable.

Apparent Cause of O_ccurrence Tefloninsulagionusedinthetransmitteramplifiersisdegradedby radiation (10 rads) such that the transmitter output is reduced.

_0ther Related Events f

The potential defect was reported to TVA by Foxboro. The resulting inspections identified the equipment containing defective amplifiers.

Corrective Action Taken or Planned The defective amplifiers were replaced with qualified amplifiers (supplied by Foxboro) prior to entry into Mode 3.

Ao N ' _ Fdaus:-

Jere M. Ballentine Plant Superintendent REGIONAL DIRECTOR Sequoyah Nuclear Plant DEPUTY y55 ECTOR R

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