ML100760708

E-mail from D. Roberts of USNRC to Various, Regarding TMI Contamination Event - Chairman'S Talking Points

ML100760708
Person / Time
Site:	Three Mile Island
Issue date:	11/23/2009
From:	Darrell Roberts NRC Region 1
To:	Barber G, Eugene Dacus, Amy Powell, Trocine L NRC/EDO, Office of Congressional Affairs, NRC Region 1
References
FOIA/PA-2010-0118
Download: ML100760708 (2)

Text

Tiffm, Doug From: Roberts, Darrell Sent: Monday, November 23, 2009 3:40 PM To: Barber, Scott; Trocine, Leigh; Powell, Amy; Dacus, Eugene Cc: Collins, Sam; Lew, David; Clifford, James; Bellamy, Ronald; White, John; Screnci, Diane; Sheehan, Neil; Barkley, Richard; Tifft, Doug; McNamara, Nancy; Wilson, Peter

Subject:

RE: TMI Contamination Event - Chairman's Talking Points thanks, Scott.

To Scott and others, please remember to include Pete Wilson on distribution for related emails.

thanks, DJR From: Barber, Scott Sent: Monday, November 23, 2009 3:38 PM To: Trocine, Leigh; Powell, Amy; Dacus, Eugene Cc: Collins, Sam; Lew, David; Clifford, James; Bellamy, Ronald; White, John; Screnci, Diane; Sheehan, Neil; Barkley, Richard; Tifft, Doug; McNamara, Nancy; Roberts, Darrell Subject; TMI Contamination Event - Chairman's Talking Points For your review and use.

Chairman's Talking Points 02/04/2010 1:02 PM TMI Airborne Contamination Event inside Containment

" At about 4:00 p.m., on November 21, while shutdown for a refueling outage and steam generator (SG) replacement, TMI experienced alarms inside the containment due to high airborne contamination levels.

" As a precaution in response to the alarms, approximately 150 workers exited the containment. Several workers alarmed the portal monitors due to contamination levels, and were whole body counted to assess their dose. Of these workers, approximately 12 workers received doses ranging from 1.0 mrem to about 40 mrem, which was a very small fraction of the annual federal occupational exposure limit (5000 mrem/yr). It is not unusual for contamination events to occur during refueling outages and workers would be processed as they were in this event.

Exelon has attributed the cause of the contamination event to a change in air pressure inside the containmentbuilding that dislodged small irradiated particles in piping systems.

Some of these particles became airborne and were detected by containment air monitors.

One airborne monitor near the containment construction opening did show a short duration increase in activity; however, the licensee esimates that this released activity was less than 1% (0.04 mrem) of the quarterly Offsite Dose Calculation Model (ODCM) limit (7.5 mrem).

The licensee surveyed the area around the containment construction opening and did not detect any contamination in the areas that were surveyed.

" The airborne contamination returned to pre-event levels 4 to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after the initial alarms.

This event drew a significant amount of media attention, as well as attention from other federal agencies and the State of Pennsylvania. A number of Region I personnel and Headquarters personnel responded to this event over the weekend. The Resident Inspectors, Division of Reactor Safety Inspectors, and the Public Affairs Officer responded to the site to investigate the event and to address media inquires. In addition, representatives from Region I Senior Management, Division of Reactor Projects Branch 6, State Liaison Officers, and Public Affairs responded to the Regional Office to coordinate our understanding of the event and outreach activities. Exelon has issued two press releases and the NRC is in the process of issuing a press release on the event.

" There was no affect on public health and safety as a result of this event. This event did not

• result in the licensee exceeding any emergency action levels, nor were any formal event notification criteria met. The workers that were affected by this event received doses that were a small percentage of the annual occupational exposure limit. Region I is continuing to follow the licensee's evaluations for this event.

• There is a potential concern from the State of Pennsylvania about the timeliness of the licensee's notification to the State for this event. Exelon informed the NRC Resident Inspector at about 5:30 pm on November 21 that a prompt investigation was underway for radiological conditions inside the reactor building that required personnel to be removed as a precautionary measure. No additional details were provided at the time. As additional details became available, further notifications were made including informing the State at about 9:30pm and updating the NRC at about 9:45pm. Exelon submitted an event report (50.72) at 1:13 am on November 22 based on significant public interest.