PNO-III-85-046, on 850604,while Taking Sample from Vol Control Tank,Valve Packing Failed,Resulting in Release of Approx 700 Mci Xenon & Krypton Gas.Workers Evacuated,Gas Removed by Ventilation Sys & Valve Repaired

PNO-III-85-046:on 850604,while Taking Sample from Vol Control Tank,Valve Packing Failed,Resulting in Release of Approx 700 Mci Xenon & Krypton Gas.Workers Evacuated,Gas Removed by Ventilation Sys & Valve Repaired

ML20126B405
Person / Time
Site:	Byron
Issue date:	06/07/1985
From:	Greger L, Marabito R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-85-046, PNO-III-85-46, NUDOCS 8506140094
Download: ML20126B405 (1)

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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-III-85-46 Date June 7, 1985 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without veri-fication or evaluation, and is basically all that is known by the staff on this date.

Facility: Commonwealth Edison Co. Licensee Emergency Classification:

Byron Unit 1 Notification of an Unusual Event Byron, IL 61010 Alert Site Area Emergency Docket No. 50-454 General Emergency XX Not Applicable

Subject:

MEDIA INTEREST IN MINOR RADIATION RELEASE On June 4,1985, while taking a sample from the Volume Control Tank, a valve packing apparently failed, releasing approximately 700 millicuries of xenon and krypton gas to the Auxiliary Building. The licensee was alerted to the release by an increased count rate in some nearby radiation detection equipment.

As a precautionary measure, the licensee evacuated several hundred workers from the Auxiliary Building. The noble gases were removed by the ventilation system. Releases from the plant via the ventilation system were within technical specification limits. The release was not reportable.

Th3 clothing of twelve workers was contaminated with short-lived ncble gas daughters. The workers' clothing was aerated to remove the contamination,and the employees were allowed to raturn to work.

Personal dosimeters on seven of the 12 workers showed readings of 10 millirem which included exposures for the day's work. The licensee has since repaired and tested the failed valve.

R:gion III (Chicago) was first informed of this event about 2 p.m. (CDT), June 5,1985, when a r; porter from a Chicago radio station telephoned the Public Affairs Office. The r; porter's story was aired on June 7,1985. Media attention has increased steadily.

R;gion III has been monitoring the licensee's course of action. A health physics inspector is on site. The radiological health consequences of this event are not significant. Region III is interested in assuring the root cause is known.

The State of Illinois will be notified.

This information is current as of 3 p.m. (CDT), June 7, 1985.

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CONTACT: . Marabito L. eger FTS 388-5667 FTS 388-5644 DISTRIBUTION:

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