ML101190580

E-mail from R. Barkley of USNRC to M. Cullingford of USNRC, Regarding 11/21/2009 TMI Contamination Control Event

ML101190580
Person / Time
Site:	Three Mile Island
Issue date:	11/23/2009
From:	Barkley R NRC Region 1
To:	Cullingford M Office of Nuclear Reactor Regulation
References
FOIA/PA-2010-0118
Download: ML101190580 (2)

Text

Barber, Scott From: Barkley, Richard Sent: Monday, November 23, 2009 10:50 AM To: Cullingford, Michael Cc: Glitter, Joseph; Bellamy, Ronald; Barber, Scott

Subject:

RE: 11721/2009 TMI Contamination Control Event Mike - Thanks forthe heads up. I have been on the periphery of this issue. Ron or Scott can give you more details if needed.

I'll also forward a ,recent staff communication in this matter.

RichardS. Brkley. PE Technical Communications Assistant, Region I - ...........

__1610) 3375065 -- --

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Pleaseconsider the environment before printing this e-maiL. Thank you.

From: Cullingford, Michael Sent: Monday, November 23, 2009 10:17 AM To: Ba'rkley, Richard Cc:. Gitter, Joseph

Subject:

-FW: 11/21/2009 TMI Contamination Control Event Richard: fyi .................... mike From: Cullingford, Michael Sent: Monday, November 23, 2009 10:13 AM To: Schwartzman, Jennifer

Subject:

FW: 11/21/2009 TMI Contamination Control Event A summary of the subject TMI event as we know it today. Based on what we know, ,it is likely that this event would not even be rated on the INES scale. No operating limit was exceeded and no contamination outside the containment building has been detected.

Approximately at 4 PM Saturday 11/21 TMI had an event involving loss of contamination control inside containment. At the time the reactor was defueled With a hole cut in the containment wall to support the ongoing SG replacement outage. The licensee is, not sure at this time what activity inside containment led to the problem. Their investigation is focusing on two activities (1) "A"piping loop decontamination activities or (2) some work on a drain line on the B"SG.

At the time of the event 175 workers were inside containment. Of these workers 151 people were: selected for detailed monitoring, based on nasal smears and portal monitor readings. Ofithe 151, preliminarily,-about 19 people have potentially received doses greater than 10 mR. The highest dose to a worker was approximately 38 mR, far below the yearly NRC limit of 5000,mrem. No site worker left the site with external contamination.

_ontamination levels inside containment have been restored to pre'event levels and cleanup of ecoomnw vt VW F/Gedom of InmwnUoon AcL P ..........

-O

containment surfaces is in progress. The tarp that was covering the containment opening was contaminated on its inside surface and is in the process of being replaced.

With the open equipment hatch and the SG opening there was the potential for a release outside of containment. At the time of the event a slight positive pressure existed in containment. This has now been corrected to what it should be, ie a slightly negative pressure. Based on readings from radiation monitors present at the SG opening and the duration of the positive pressure, the estimates of release levels are still less than one percent of the quarterly limit in the licensee's offsite dose calculation manual.

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