ML101230496

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E-mail from HOO Hoc to M. Ralph of USNRC FW: Update on the TMI Event Int'L Interest - So Consider an INES Rating
ML101230496
Person / Time
Site: Three Mile Island  Constellation icon.png
Issue date: 02/23/2010
From:
- No Known Affiliation
To: Melissa Ralph
Office of Nuclear Security and Incident Response
References
FOIA/PA-2010-0118
Download: ML101230496 (3)


Text

Ralph, Melissa From: HOO Hoc Sent: Tuesday, February 23, 2010 8:11 AM To: Ralph, Melissa

Subject:

FW: Update on the TMI event int'l interest- so consider an INES rating Importance: High Here is the Cyndi Jones e-mail traffic that I believe you are referring to.

Nothing in here that needs bracketing. Free to release.


Original Message----

From: Jones, Cynthia Sent: Monday, November 23, 2009 10:21 AM To: HOO Hoc; Gott, William

Subject:

Fw: Update on the TMI event int'l interest- so consider an INES rating Importance: High I meant to cc you on this as well-Cyndi Cynthia G. Jones, Ph.D.

Sr. Technical Advisor for Nuclear Security, NRC/NSIR Sent from blackberry


Original Message -----

From: Jones, Cynthia To: Sigmon, Rebecca Cc: Dean, Bill; Wiggins, Jim; Leeds, Eric; Ross-Lee, MaryJane; Thorp, John Sent: Mon Nov 23 09:38:45 2009

Subject:

Re: Update on the TMI event int'l interest- so consider an INES rating Thx Rebecca Based on what you have given me it based on exposures its a level 0 (NRC does not have dose constraints). If you gather more info from the licensee I agree with you it could rise to a Level 1. I think it would be a good idea for'NRR mgmt to decide to issue an ERF for this as a Level 1 or 0 just to help alleviate the concerns of the int'l community (I have had inquiries from Bulgaria, IAEA, Germany and the UK on this so far).

Look forward to hearing what NRR decides to do. And remind the mgmt that this would be a good example of expaining the safety signifiance of the event via INES- esp for your international counterparts who are wondering what the INES rating would be. But try to issue a provisional ERF within a day to make NRC's point.

Cyndi Cynthia G. Jones, Ph.D.

Sr. Technical Advisor for Nuclear Security, NRC/NSIR Sent from blackberry


Original Message From: Sigmon, Rebecca To: Jones, Cynthia Cc: Ross-Lee, MaryJane; Rini, Brett; Thorp, John; Thomas, Eric; Brown, Michael N,

Sent: Mon Nov 23 08:14:05 2009

Subject:

Update on the TMI event Below is the latest update I have from Region I. Highest dose appears to be 38 mrem with about 20 people showing excess exposure - I'd call it a nominal Level 0 that could possibly be considered for upgrade to Level' 1 based on the number of people involved. I don't see any indication that the criteria for consideration of a Level 2 under radiological barriers and controls were tripped. The reactor is currently defueled so there were' still a substantial number of safety layers in place to prevent the maximum possible release (though pending determination of the cause a Level 1 under Defense in Depth might be warranted).

As far as submission to NEWS based on significant public interest, I can float the idea on the NRR end; more' information as to the cause will hopefully be available in the next couple of hours.

Rebecca Sigmon Reactor Systems Engineer NRR/DIRS/IOEB Operating Experience Branch (301) 415-4018 Rebecca. Sigmon@nrc.gov


Original Message----

From: Bamford, Peter Sent: Monday, November 23, 2009 5:49 AM To: NRRDIRSIOEB Distribution

Subject:

FW: Update on the TM1 event This is information available as of Sunday evening(l1/22). I'll send an update Mon AM sometime around 0800.

Peter Bamford NRR/DORL/LPL 1-2 Limerick & TMI-1 Project Manager 301-415-2833


Original Message -----

From: Bamford, Peter Sent: Sunday, November 22, 2009 7:09 PM To: Chernoff, Harold Cc: Nelson, Robert; Guitter, Joseph

Subject:

FW: Update on the TMI event Harold, I participated in a conference call today (Sunday 11/22) at 4:30 PM sponsored by the Region at which they provided an update to this weekend's activities at TMI-1. Here is a summary:

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. Of the 151, about 20 people have potentially received doses greater than 10 mR. Two workers initially haven calculated doses of 183 and 202 mR. However the region feels that these estimates may be in error and are being re-evaluated. The next highest dose to a worker was 38 mR. The region appeared confident the the 38 mR person would end up 2

being the highest exposure for this event. No site worker left the site with external contamination. Airborne contamination levels inside containment have been restored to pre-event levels and cleanup of 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 ODCM limit.

This event has generated a significant amount of media interest. Regional OPA and state liason officers have taken inquiries from multiple radio, print media and TV stations. They have performed a media briefing at TMI at 2 PM today and have conducted an interview with CNN. Good Morning America is also interested and requested an interview with the Chariman tomorrow (Monday) morning. The region offered them Sam Collins or possibly the EDO representing the NRC. (The Chariman's office and the acting DEDO were represented on the 4:30 pm call today.) GMA said they may decide to interview just an Exelon manager (possibly Bill Noll the Site VP) ifthey cannot get the Chariman. The GMA interview was left to be decided after the phone call. If it occurs, it sounded to me that it would likely take place in a Philadelphia studio with Sam representing the NRC.

The region feels the local reporting has been balanced and factual with no fear-mongering.

The PA governor's office has been notified and they understand this is a low level event. They apparently have some concerns about notification timeliness. The PA state was notified about 9:30 PM last night (event time was 4 PM). Based on the PA state notification, an event report was filed with the HOO (event number 45514). This event was far below levels that would warrant an unusual event declaration.

Activities for the remainder of the evening were to sort out the GMA interview and respond to further media requests (regional OPA lead). The rest of the regional activities are going to stand down at this time.

I'll update you in the morning after the 0730 call.

Pete 3