ML100780506

Executive Team Daily Brief

ML100780506
Person / Time
Site:	Three Mile Island
Issue date:	11/24/2009
From:	Office of Nuclear Reactor Regulation
To:
References
FOIA/PA-2010-0118
Download: ML100780506 (8)

Text

79 FQR-2  ? ýtSA LY EXECUTIVE TEAM DAILY BRIEF

......... ......... Tuesday, November 24, 2009 Outside of Scope 1

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[Raise threshold for presenting to ET only those ongoing plant issues of potential for shutdown due to safety concerns or that have serious violation/significant media interest potential, or ifHQ

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- From the TMI Project Manager:

- Apparent cause of the event was a change in the containment ventilation lineup in conjunction with some open RCS piping penetrations.

- Approximately 175 personnel were working in containment.

- 145 personnel could not pass the gamma sensitive personnel contamination monitoring (17 personnel had external contamination and were decontaminated; 19 were originally determined to have some measureable internal contamination, the licensee believes only 7 personnel indicate a dose greater than 10 millirem as (presented below).

Time/Date > 10mr 10,20mr 20-30mr 30-40mr maximum 1700/11/22 19 16 2 1 38.4 millirem 1600/11/23 7 5 2 0 25.7 millirem Environmental Dose Calculation:

Base on evaluation of flow rates and air samples collected, the licensee has calculated that the release on 11/21 resulted in a dose of 0.7% of annual limit of 15 mrem per year and 1.5% of the quarterly limit of 7.5 mrem per year. The total estimated dose to date from airborne releases at TMI is 0.138 mrem.

Current status of "A" SG The "A" SG is in the process of being downended (-12 hour evolution). It has been fully re-encapsulated to ensure that there is no external contamination present when it exits containment. The "A" SG could exit containment tomorrow.

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FFLTEO Informational News

References:

NRC News Electronic Newsletters Nuclear Newstand NRC News Releases EEEB Grid Report:

Grid Report

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1) EN 45514 - TMI - RADIATION RELEASE IN CONTAINMENT ASSOCIATED WITH STEAM GENERATOR REMOVAL Note: Lots of media attention to this event since it occurred at TMI.

Approximately 4 PM Saturday 11/21 TMI had an event involving loss of contamination control inside -1 4

FPRQEE1 6 1/2.U E-LY containment. At the time the reactor was defueled with a hole cut in the containment wall to support the ongoing once through steam generators (OTSG) 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 144 people were selected for detailed monitoring based on nasal smears and alarming the portal monitor readings while exiting containment. Of the 144, about 20 people have potentially received doses greater than 10 mR.

The highest dose to a worker was between 30 and 40 mR. 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 has been replaced.

At the time of the event there was a slight positive pressure in containment. This condition has been corrected and there is now a slight negative pressure in containment, The licensee has performed a release calculation for the period of time where the containment was at positive pressure and determined the maximum release was 0.04 mr. The quarterly limit for a release allowed by their ODCM is 7.5 mr.

Therefore, this release is less than 1% of the quarterly limit.

The "A"OTSG, which was in the process of being lifted when this event occurred, is still hanging vertically inside containment. Itis being deconned/encapsulated and the licensee hopes to down-end it today onto the transfer mechanism that will eventually move it out through the OTSG opening. The downending process will end up with part of the SG poking out the hole in the containment wall.

This event has generated a significant amount of media interest. Regional OPA and state liason officers have responded to inquiries from multiple radio, print media and TV stations. They performed a press release at TMI at 2 pm on Sunday, November 22.

The PA governor's office was previously notified and they understand that this is a low level event. They have some concerns about notification timeliness. The state was notified about 9:30 pm on Saturday (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.

TMI still has not determined the root cause for the event.

The Region dispatched a HP inspector and the HP inspection branch chief to the site on Sunday. In addition, the Resident inspector and one other inspector responded to the site for additional coverage. A Manual Chapter 0309 evaluation was conducted and it was determined that no reactive inspection is warranted at this time. The Region is closely following the licensee's response and will be evaluating their root cause determination once it is issued. (Send to TRGs for Containment: Jerome BettleEP: Jeffrey Temple, Health Physics: Steven Garry. Human Performance: Michael Boqqi, Dose Assessment, Mark Blumberg and Public Affairs; Scott Burnell, assicined to Mike Brown),

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