ML100780261

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E-mail from R. Nimitz of USNRC to D. Kern of USNRC, Regarding Summary of Ventilation Status
ML100780261
Person / Time
Site: Three Mile Island  Constellation icon.png
Issue date: 01/21/2010
From: Nimitz R
NRC/RGN-I/DRS/PSB2
To: Kem D
NRC/RGN-I/DRP/PB6
References
FOIA/PA-2010-0118
Download: ML100780261 (2)


Text

Brand, Javier From: Nimitz, Ronald Sent: Thursday, January 21, 2010 12:31 PM To: Kern, David Cc: Brand, Javier

Subject:

RE: summary of ventilation status next week is fine., thanks From: Kern, David Sent: Thursday, January 21, 2010 11:36 AM To: Nimitz, Ronald Cc: Brand, Javier

Subject:

RE: summary of ventilation status Hi Ron:

I got your message on phone late yesterday. We were doing a lot of containtment and other plant walkdowns in preps for restart. We haven't done our inspection activity yet, but plan to get it done (including feeders) next week. If this doesn't-work, please give me a call and I'll see if we can make some other adjustments here.

Dave.

p.s. Thanks for offering to bring the PC out with you. The week of 2/1/10 is great. This just saves some shipping money and the potential for it to get lost in the warehouse. We'll come out to bring it in from the parking lot after you get here.

From: Nimitz, Ronald Sent: Thursday, January 21, 2010 8:22 AM To: Kern, David; Brand,.Javier

Subject:

RE: summary. of ventilation status Do you folks have any input yet I can put in ??

I am actively working the report here..

ron From: Kern, David Sent: Tuesday, December 22, 2009 3:53 PM To: Nimitz, Ronald; Burket, Elise Cc: Brand, Javier

Subject:

RE: summary of ventilation status Ron's right. Javier and I will be reviewing (and documenting) 3 elements of this event.

- RB flow characterization for the period 11/12 - 11/21/09 (broken into 4 separate segments).

- TMI response to the IR regarding unplanned Co-58 release when not maintaining negative RB pressure (prior to the 11/21 event).

- Station implementation of the containment evacuation procedure on 11/21/09.

Javier said he planned to talk with Elise (possibly work together) and incorporate the work/info she had already done in early event follow-up.

Dave S

From: Nimitz, Ronald Sent: Tuesday, December 22, 2009 11:03 AM To: Burket, Elise Cc: Brand, Javier; Kern, David

Subject:

RE: summary of ventilation status I thought Javiar and Dave were going to write this up plus discuss evacuation ?

From: Burket, Elise Sent: Monday, December 21, 2009-6:20 PM To: Nimitz, Ronald Cc: Brand, Javier

Subject:

summary of ventilation status Hello Ron -

I'm at TMI this week and spoke with Javier yesterday regarding the ventilation investigation for the PCE on 11/21. I did not realize we needed to provide more information. Please see my write-up below and let me and Javier know if this is sufficient. Thanks. Elise NOTE: THIS

SUMMARY

IS

      • MAY CONTAIN SENSITIVE/ PROPRIETARY .L I I if DO NOT FORWARD ANY PORTIONS OUT OF NRC WITHOUT FIRST OBTAINING PERMISSION

,,FROM ORIGINATOR About two weeks prior to the PCE, the RB supply fans were removed from service to support heater maintenance (clearance 09500607). The exhaust fans were set-up to start if needed. On 11/18, AR994989 was written voicing concern over the inability to purge the RB and the length of the clearance which was preventing the purge occur. The AR recommends an alternate method be developed to operate purge with supplyfans not available to ensure a negative pressure in the RB during tasks that could create airborne activity. Concerns about the airflow out of the temporary access hole in containment was also expressed in the AR. Per ECR TM 06-00816, "Containment Structural Opening,' if the RB purge is unavailable, an airborne radioactivity monitor shall be established near the temporary construction opening for continuous assessment.

An AMS-4 was stationed at the opening and daily airborne samples were being taken. As stated in the AR and by a chemist, the Co & Cs concentrations increased mid-week prior to the event. At about 2200 on 11/20, the purge was operating or increase the temperature on the NDTT(nil-ductility transistion temperature)-concern components. Around 0500.on 11/21, the purge was secured based on temperature. -1430, a new permit to purge was approved. -1540 the purge was in service (2 exhaust/1 supply fan). -1600, airborne alarms are received. The supply fans are shutdown and the exhaust fans are running fully following the alarming conditions.

During a discussion with the mechanical design supervisor, it was expressed to me that more attention should have have been given to the concerns in the AR mentioned above. The Root Cause Team was made aware of the AR. Following the airborne alarms the following actions were taken to reduce an airborne release: the canvas was put down on the equipment hatch, the canvas on the contruction hole was pulled down, and actions were taken to remove the personnel monorail system in the personnel hatch.

NOTE: THIS

SUMMARY

IS

      • MAY CONTAIN SENSITIVE/ PROPRIETARY OR AL ,- ............

DO NOT FORWARD ANY PORTIONS OUTSID NRC WITHOUT FIRST OBTAINING PERMISSION F ORIGINATOR 2