PNO-II-85-074, on 850729,employees Received Minor Contamination.Caused by Weld Leak Off RCS Letdown Line.Flow Rate Reduced & Path Opened to Maintain Water Control. Employees Decontaminated at Plant

PNO-II-85-074:on 850729,employees Received Minor Contamination.Caused by Weld Leak Off RCS Letdown Line.Flow Rate Reduced & Path Opened to Maintain Water Control. Employees Decontaminated at Plant

ML20133K925
Person / Time
Site:	Sequoyah
Issue date:	07/30/1985
From:	Ignatonis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-85-074, PNO-II-85-74, NUDOCS 8508120423
Download: ML20133K925 (2)

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' July 30, 1985 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-85-74 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verifi-cation or evaluation, and is basically all that is known by the Region II staff on this

'date.

FACILITY: Tennessee Valley Authority Licensee Emergency Classification:

Sequoyah Unit 2 X Notification of Unusual Event Docket No. 50-328' Alert Soddy-Daisy, Tennessee Site Area Emergency General Emergency Not Applicable

SUBJECT:

MINOR CONTAMINATION OF EMPLOYEES FROM LEAKING PRIMARY COOLANT SAMP The licensee declared an Unusual Event on July 29 at 11:57 p.m. (EDT) when a leak of approximately 15 gallons per minute developed through a weld area of a 3/4-inch sample line which branches off the reactor coolant system letdown line, inside the auxiliary building.

Particulate monitoring high radiation alarms activated, and the auxiliary building was isolated as its gas treatment system was being activated.

The leaking sample line, located between the letdown heat exchanger and a three-wayThe diverter valve, was secured by isolation of the normal charging and letdown system.

reactor coolant pump seal injection flow rate was reduced, and the excess letdown path was opened to maintain water inventory control.

Eleven electricians and technicians working in the vicinity of the leak received some skin and protective clothing contamination. One person had face contamination of 100,000 disintegrations per minute. The others had less. All were successfully decontaminated at the plant. Whole body counts detected no identifiable body burdens. There were no injuries.

There was no radioactive release to the environment outside the auxiliary building.

Media interest occurred following the licensee's announcement of the event on its automated telephone call-in recording service.

The State of Tennessee has been informed.

Both units continued to operate at 100 percent power.

The NRC received initial notification of this event by telephone from the licensee to the headquarters incident response center at 12:15 a.m. (EDT) on July 30.

This information is current as of 12 noon (EST) on July 30.

A. Ignatonis, 242-5563 D. Verrelli, 242-5526 Cortact: .-

DISTRIBUTION:

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