ML100780504
| ML100780504 | |
| Person / Time | |
|---|---|
| Site: | Three Mile Island  |
| Issue date: | 11/23/2009 |
| From: | Michael Brown NRC/NRR/DIRS/IOEB |
| To: | David Garmon-Candelaria NRC/NRR/DIRS/IOEB |
| References | |
| FOIA/PA-2010-0118 | |
| Download: ML100780504 (3) | |
Text
Cartwright, William From: Brown, Michael Sent: Monday, November 23, 2009 12:12 PM To: Garmon-Candelaria, David; Beltz, Terry; Bernardo, Robert; Boyle, Patrick; Chapman, Travis; Craffey, Ryan; DeMarshall, Joseph; Dority, Dayna; Gaslevic, James; Giantelli, Joseph; Goldfeiz,,Eliezer; Gray, Kathy; Haskell, Russell; Ibarrola, Sherlyn; Jardaneh, Mahmoud; Jennings, Jason; Kauffman, John; King, Mark; Kleeh, Edmund; LaVera, Ronald; Le, Hien; Pannier, Stephen; Reisifard, Mehdi; Robles, Jesse; Scully, Derek; Sigmon, Rebecca; Tabatabai, Omid; Thomas, Eric; Thorp, John; Vaughn, Stephen; Webb, Michael; Wegner, Mary; Brown, Michael
Subject:
Region I Morning Call Notes for Monday, November 23, 2009 INFORMATION SENSITIVITY CAUTION -- This e-mail contains preliminary, pre-decisional information and notes gathered in the Region Morning Call discussions. It is restricted to NRC internal use only by Clearinghouse screening meeting participants and is NOT to be distributed further nor used for management decisions. Information from these notes that has been screened by the team may appear in the daily IOEB OpE Screening Summary e-mail, which can be subscribed to by anyone in NRC via the "Reactor OpE Information Gateway" link on the NRR home webpage.
Event Notifications: One (1)
EN 45514 -TMI - RADIATION RELEASE. IN CONTAINMENT ASSOCIATED WITH STEAM GENERATOR REMOVAL (Recommend Screen Out)
"This event is being reported via the ENS to the NRC Operations Center within four hours after notifications were made to the Pennsylvania Emergency Management Agency and local counties for an event of potential public interest. This notification was made at 22:45 on November 21, 2009, after the occurrence of an event related to the safety and health of onsite personnel for which a press release has been made. The press release was made following the event of potential public interest notifications. This report is being made under 10 CFR 72.75(b)(2).
"At approximately 16:00 on Saturday November 21, 2009, low levels of radiation activity were measured on radiation monitors installed in the TMI-1 reactor building. Personnel were directed to immediately leave the reactor building until the source of the activity could be identified. Surveys directly outside of the reactor building construction opening indicated a slight increase in activity. Levels have returned to normal. No contamination was identified outside of the reactor building. Approximately 150 workers were monitored for exposure to the radiation activity. No worker approached or exceeded any exposure limits. The sources of the activity are believed to be from maintenance tasks related to cutting lines in preparation for removal of the 'B' Steam Generator."
The licensee is still investigating the cause of the event but indicated that the radiation release is no longer in progress. Containment Ventilation is established to provide an inflow into containment to the extent possible (considering the openings in containment).
The licensee contacted state and local authorities and the Pennsylvania Emergency Management Agency (PEMA). The licensee notified the NRC Resident Inspector. The licensee has also issued a press release.
Preliminary Notifications: None Region I Morning Call Notes:
EN 45514 - TMI - RADIATION RELEASE IN CONTAINMENT ASSOCIATED WITH STEAM GENERATOR REMOVAL I I .
1
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 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. It is 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 inpector 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. (Recommend Screen Out at this time, send to TRGs for Containment; Jerome Bettle, Health Physics; Steven Garry, Human Performance; Michael Boggi, Dose Assessment; Mark Blumberg and Public Affairs: Scott Burnell)
!Outside of Scope S-.-----.-z 4..
- Outide f Scope INFORMATION SENSITIVITY CAUTION -- This e-mail contains preliminary, pre-decisional information and notes gathered in the Region Morning Call discussions. It is restricted to NRC internal use only by Clearinghouse screening meeting participants and is NOT to be distributed further nor used for management decisions. Information from these notes that has been screened by the team may appear in the daily IOEB OpE Screening Summary e-mail, which can be subscribed to by anyone in NRC via the "Reactor OpE Information Gateway" link on the NRR home webpage.
Mike Brown Reactor Systems Engineer NRR/DIRS/IOEB email michael.brown@nrc.gov
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