ML100760470

News Flash, Update to Employees on RB Contamination Issue on 11/21/09 from Exelon Nuclear

ML100760470
Person / Time
Site:	Three Mile Island
Issue date:	11/02/2009
From:	Exelon Nuclear
To:	NRC Region 1
References
FOIA/PA-2010-0118
Download: ML100760470 (1)

Text

rhe ile Island Exekn.Nucdew Update to Employees on RB Contamination Issue on 11/21/09 Airborne contamination monitor alarms sounded inside the reactor building at about 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on Saturday 11/21/2009. Workers were immediately directed by Radiation Protection personnel to leave the area.. Significant welding, cutting, and grinding activities in the "B" D-ring were occurring at the time. The exact cause of the alarms is being evaluated.

A radiation monitor at the temporary opening cut into the reactor building wall indicated a slight increase in activity levels and then returned to normal. Other radiation monitors displayed normal readings. The temporary opening in the containment wall was constructed to allow the steam generators to be moved into and out of the reactor building.

About 150 employees who had been evacuated from the RB were evaluated for possible low-level radiation exposure. Some workers were found to have received slightly detectable levels of internal exposure. No Nuclear Regulatory Commission limits were exceeded for personnel contamination.

Many of the affected workers had to spend an extended time at the plant before they could be monitored and released to go home. This was an inconvenience for those involved and their patience is sincerely appreciated. Each case is also being evaluated for compliancewith NRC work hour limits.

No contamination was found outside of the reactor building. Radiological surveys showed that the contamination was confined to surfaces inside the containment building, primarily in the" Initial RB surveys have been performed and contamination levels in the "A" D-Ring are similar to what they were before the event and are acceptable to return to work. Contamination clean-up actions for the remainder of the reactor building are being prioritized.

A root cause team is being formed to determine why the event occurred and to develop actions to prevent recurrence.

The NRC, Pennsylvania state officials, and local elected officials were notified of the issue.