ML091190578
| ML091190578 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 11/07/2008 |
| From: | Richmond J Engineering Region 1 Branch 1 |
| To: | Justin Heinly, Stephen Pindale, Richmond J Reactor Projects Branch 2, Engineering Region 1 Branch 1, Engineering Region 1 Branch 2 |
| References | |
| FOIA/PA-2009-0070 | |
| Download: ML091190578 (5) | |
Text
Sarah Rich From:
John Richmond, \\R,1 Sent:
Friday, November 07, 2008 6:14 PM To:
Stephen Pindale; John Richmond; Justin Heinly Cc:
Richard Conte; Ronald Bellamy; Neil Sheehan; Darrell Roberts; Diane Screnci; David Pelton
Subject:
OC Reactor Cavity Leakage Attachments:
5 0C Rx Cavity Trough Drain Detail.jpg; 3 0C Drywell X-section.jpg; 4 0C Rx Cavity Detail.jpg OC Operations identified that large portions of the reactor cavity "strippable coating" is coming loose, and is taking actions to mitigate the problem. This is also an FME issue for the reactor vessel, fuel, and internals.
Beside radcon control, the strippable coating is also used to limit cavity leakage, which had been a problem in the past, resulting in water intrusion into the drywell sand bed regions. Cavity leakage is collected in the cavity concrete trough, which has a 2 inch drain line to the reactor building sump (see attached drawings). Cavity leakage had been monitored once daily, and had been approximately ZERO. Last night (Nov 6) the leakage rate took a step change, and has since been running about 4 to 5 gpm. Since last night, OC is monitoring the leakage rate every 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. I checked the logs this morning and at midday. OC has an engineering action plan to take additional contingency actions, based on specific leakage rate values (we haven't seen the plan yet). OC has an administrative limit of 12 gpm, based on a calculation which predicts no water overflow onto the drywell shell should occur at leakage rates of 12 or less gpm (the calculation is believed to have some margin).
License Renewal Commitments
- 1) Apply a "strippable coating" inside the reactor cavity liner during periods when the cavity is flooded. The purpose of the commitment is to prevent water intrusion into the gap between the drywell cement shield wall and the drywell steel shell.
- 2) Monitor cavity leakage, when the cavity is flooded.
Please continue to monitor the cavity leakage, and report any significant changes.
Thanks John Richmond
Received: from R1 CLSTRO1.nrc.gov ([148.184.99.7]) by R1 MS01.nrc.gov
([148.184.99.10]) with mapi; Fri, 7 Nov 2008 18:14:22 -0500 Content-Type: application/ms-tnef; name="winmail.dat" Content-Transfer-Encoding: binary From: John Richmond <John.Richmond@nrc.gov>
To: Stephen Pindale <Stephen.Pindale@nrc.gov>, John Richmond
<John.Richmond@nrc.gov>, Justin Heinly <Justin.Heinly@nrc.gov>
CC: Richard Conte <Richard.Conte@nrc.gov>, Ronald Bellamy
<Ronald.Bellamy@nrc.gov>, Neil Sheehan <Neil.Sheehan@nrc.gov>, Darrell Roberts <Darrell.Roberts@nrc.gov>, Diane Screnci <Diane.Screnci@nrc.gov>,
David Pelton <David.Pelton@nrc.gov>
Date: Fri, 7 Nov 2008 18:14:21 -0500
Subject:
OC Reactor Cavity Leakage Thread-Topic: OC Reactor Cavity Leakage Thread-Index: AcIBLpC6VRb6KOCCQa6rapb2h/lzhQ==
Message-ID:
<2856BC46F6A308418F033D973BBOEE72AA436328F4@R1 CLSTRO1.nrc.gov>
Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: yes X-MS-Exchange-Organization-SCL: -1 X-MS-TNEF-Correlator:
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SEE DETAIL "A7
-SEE DETAIL "B' DETAIL nC"
REACTOR CAVITY STAINLESS STEEL LINER----
CONCRETE SEE DETAIL "B's VESSEL w
DRYWELL AND REACTOR CAVITY SECTION DETAIL "A"
TOP PROTECTIVE SHIELDING STEEL UNER DRYWELL TO REACTOR CAVITY SEAL. DETAIL DETAIL 'B' OBSERVED DAMAGE.
AT LIP OF TROUGH CORRECTED IN 1988 GUSSET DRYWELL C
I REFUELING BELLOWS FIRE BARD INSULATION MATERIAL PLATE C3)
FOR CONCRETE TROUGH (2Z