ML091190582

E-mail from J. Richmond of USNRC to D. Roberts, S. Pindale and J. Heinly, Regarding Oc Reactor Cavity Leakage

ML091190582
Person / Time
Site:	Oyster Creek
Issue date:	11/08/2008
From:	Richmond J Engineering Region 1 Branch 1
To:	Justin Heinly, Stephen Pindale, Darrell Roberts Reactor Projects Branch 2, Division of Reactor Safety I, Engineering Region 1 Branch 2
References
FOIA/PA-2009-0070
Download: ML091190582 (3)

Text

Sý;rah Rich From: John Richmond Sent: Saturday, November 08, 2008 1:03 PM To: Darrell Roberts; Stephen Pindale; Justin Heinly Cc: Richard Conte; Ronald Bellamy; Neil Sheehan; Diane Screnci; David Pelton

Subject:

RE: OC Reactor Cavity Leakage The simple answer is that there should not be any water leakage into a sand bed, at this leakage rate.Additional Opportunities to verify "No Water" include --1) On-going repairs in Bays 11 and 3, with no water noted.2) Re-inspection of Bays 3, 7, 15, and 19 (extent of condition for Bay-1 1) were scheduled for Saturday.3) The sand bed drain line water collection bottles are checked daily, and have remained empty. I don't know whether they've checking the bottles more often than daily From: Darrell Roberts Sent: Friday, November 07, 2008 6:31 PM To: John Richmond; Stephen Pindale; Justin Heinly Cc: Richard Conte; Ronald Bellamy; Neil Sheehan; Diane Screnci; David Pelton

Subject:

RE: OC Reactor Cavity Leakage John, Can we conclude from the current leakrate (<12 gpm) or their visual observations

(?) that there has been no water intrusion into the drywell sand bed regions as a result of the loose strippable coating?DJRJR From: John Richmond 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 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. Theof 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 2 Received:

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with mapi; Sat, 8 Nov 2008 13:02:52 -0500 Content-Type:

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binary From: John Richmond <John.Richmond@nrc.gov>

To: Darrell Roberts <Darrell.Roberts@nrc.gov>, Stephen Pindale<Stephen.Pindale@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>, Diane Screnci<Diane.Screnci@nrc.gov>, David Pelton <David.Pelton@nrc.gov>

Date: Sat, 8 Nov 2008 13:02:51 -0500

Subject:

RE: OC Reactor Cavity Leakage Thread-Topic:

OC Reactor Cavity Leakage Thread-Index:

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