ML091460689
| ML091460689 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 11/17/2008 |
| From: | Neil Sheehan NRC Region 1 |
| To: | Richmond J NRC Region 1 |
| References | |
| FOIA/PA-2009-0070 | |
| Download: ML091460689 (4) | |
Text
Sarah Rich From:
Neil Sheehan Sent:
Monday, November 17, 2008 9:23 AM To:
John Richmond
Subject:
FW: DRAFT OC Preliminary Notification -rev-3 Attachments:
OC PNO-Nov-2008_Drywell_rev-3.doc Importance:
High
- John, Please include me on these.
- Thanks, Neil From: Diane Screnci Sent: Monday, November 17, 2008 8:16 AM To: Neil Sheehan
Subject:
FW: DRAFT OC Preliminary Notification -rev-3 Importance: High FYI-DIANE SCRENCI SR. PUBLIC AFFAIRS OFFICER USNRC, RI 610/337-5330 From: John Richmond Sent: Friday, November 14, 2008 8:38 PM To: Darrell Roberts; Marsha Gamberoni; Marjorie McLaughlin; Nancy McNamara; Ronald Bellamy; David Pelton; Diane Screnci; Mary Baty; Richard Barkley Cc: Doug Tifft; Michael Modes; Richard Conte; Stephen Pindale; Jeffrey Kulp; Justin Heinly; Scott Barber
Subject:
DRAFT OC Preliminary Notification -rev-3 Importance: High We plan to issue this PN Monday mid-day. I've incorporated many comments. Please review this [final] draft and provide any comments.
Thanks John Richmond 610-337-5220
Received: from R1CLSTR01.nrc.gov ([148.184.99.7]) by R1 MS01.nrc.gov
([148..184.99.10]) with mapi; Mon, 17 Nov 2008 09:23:18 -0500 Content-Type: application/ms-tnef; name="winmail.dat" Content-Transfer-Encoding: binary From: Neil Sheehan <Neil.Sheehan@nrc.gov>
To: John Richmond <John.Richmond@nrc.gov>
Importance: high Date: Mon, 17 Nov 2008 09:22:42 -0500
Subject:
FW: DRAFT OC Preliminary Notification -rev-3 Thread-Topic: DRAFT OC Preliminary Notification -rev-3 Thread-Index: AclGwtYrCHml 1 hMkR/ypqTjmYBZ+8gB881 rAAAJP68A=
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Preliminary Notification DCS No.: 05000219110XX08 Date: November XX, 2008 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-1-08-XXX Facility Licensee Emergency Classification AmerGen Energy Company, LLC Notification of Unusual Event Oyster Creek Alert Forked River, New Jersey Site Area Emergency Docket: 50-219 General Emergency, X
Not Applicable
Subject:
RESULTS OF IMPLEMENTATION OF OYSTER CREEK LICENSE RENEWAL COMMITMENTS RELATED TO THE DR-VVELL PRIMARY CONTAINMENT The NRC staff is performing an inspection of AmerGen's actions related to license renewal commitments, which were implemented during the 2008 refueling outage at the 6 yster Creek Nuclear Generating Station (OCNGS). The NRC staff completed its on-site portio"cf a multi-week inspection of AmerGen's three aging management programs associated with the drywell primary containment: Containment Metallic Liner Inseric'.Inspection; Structures Monitoring Program; and Protective Coating Monitoring and Maintennc Program. In accordance with the NRC's agreement with the State of New Jersey,a Stte Engineers observed portions of the NRC staff review. Based on the results of the NRC's *inspection activities to date, the NRC staff concluded there were no safety significant conditionswit rspectthe de containment that would prohibit plant startip.
In the mid-1 980s, GPU Nuclear (previous licensee) identified corrosion of the drywell containment steel shell in the sandced region. Initial licensee actions were not effective in arresting the corrostn% 1992, allsand was removed from the sand bed region and the accessible exterior surfaces of the
/
hell werw*cleaned and coated with epoxy. Ultrasonic test (UT) thickness measureents of the d ry.wi llhell taken in 1992 and 1996 indicated the corrosion ihad. been effectivelygrrested. This information was confirmed by UT measurements in 2006, during a refueling outag'e On Oct ober 24, 2008, OCNGS shutdown for a scheduled refueling and maintenance outage.
Outage workincluded implementation of various license renewal aging management programs.
During the 2008 refueling outage, the NRC's drywell shell inspection focused on:
- 1. Results of drywelkls"elI UT thickness measurements.
- 2.
Direct observationhqd drywell shell conditions both inside the drywell, including the floor trenches, and outside the drywell, in the sand bed regions.
- 3. Condition and integrity of the drywell shell epoxy coating, including AmerGen's activities to evaluate and repair one small broken blister (with a small rust stain) and three small unbroken blisters (initially described as surface bumps) found in Bay-1 1, during the outage.
- 4. Condition and integrity of the drywell shell moisture barrier seal between the shell and the sand bed floor, including AmerGen's activities to evaluate and repair small cracks in moisture barrier seals in multiple sand bed bays, and a small seal crack in Bay-3 which also exhibited small rust stains.
- 5. AmerGen's activities to monitor, evaluate, and mitigate water leakage from the reactor refueling cavity onto the external surface of the drywell shell and into the sand bed regions.
Preliminary Notification With respect to AmerGen's implementation of license renewal commitments, the NRC staff has concluded:
- 1. All drywell shell UT thickness measurements satisfied AmerGen's acceptance criteria and current licensing basis design requirements.
- 2. There were no identified significant conditions affecting the drywell shell structural integrity.
- 3. AmerGen's inspection of the as-found condition of the external drywell shell epoxy coating, in the sand bed regions, was acceptable. Four small blisters on the coating in Bay-1 1 were identified and repaired. AmerGen reported that some blisterng wasiexpected, and would be identified during routine visual examinations. The NRC staff wili
ýview AmerGen's cause evaluation after it is completed.
4
- 4. AmerGen's inspection of the as-found condition of the exte rnal ryell shell moisture barrier seal, between the shell and the sand bed floor, was acce~ae. Surface cracks, which did not appear to completely penetrate the seal, were ide.ntified in multiple*,bays, and were repaired. During one crack repair in Bay-3, some drywell shell surfac corrosion was also identified and repaired.
- 5. AmerGen's activities to monitor and mitigate water leakage from the reactorrefueling cavity onto the external surface of the drywell shell and into the sand bed regions are still under evaluation.
During the outage, water leakage from the'reactor refueling cavity into the cavity drain trough, as monitored in the trough's drain line, inc.ease fro*n less than 1 gallon per minute (gpm) to approximately 5 gpm. Some of the water'.i thecavity drain trough spilled into the gap between the steel shell and the concrete shield wall' Ind ultimiatyinto th eýand bed regions. AmerGen enhanced its leakage monitoring and p ied visual nspeptions to detect any water entry.
Water puddles were identifi*d in seral san be.d:as. Atete cavity was drained, AmerGen performed direct inspections of the-'and bed 1ag's and no significant adverse conditions were identified. To determiine whether ancreased 11*well shell corrosion may have occurred as a result of this leakage, AmerGen stake they will perform UT thickness measurements on the upper drywell shell durinrgthe next ing outage (2010).
AmerGen iderntified and fixed the problems found in sand bed Bay-3 and Bay-i 1, as part of their aging managaement program implementation. The drywell shell epoxy coating and the moisture barr seal, both in the,sand bed
-egion, are barrier systems used to protect the drywell shell from corrosion. The problens identifI' with these barriers had a minimal impact on the drywell steel shad the projectedshell corrosion rate remains very small, as confirmed by NRC staff review of UT data.
Based on a review of the technical information, the NRC staff determined AmerGen has provided an adequate basisto conclude the drywell primary containment is operable.
The information presented herein has been discussed with AmerGen and is current as of November 17, at xxx p.m. The State of New Jersey has been notified.
This Preliminary Notification is being issued for information only and will not be updated.
ADAMS Accession Number: ML.....................
CONTACT:
Richard J. Conte John Richmond (a.nrc.Qov
(@nrc.qov (610) 337-5183 (610) 337-5220