ML091980137

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License Renewal Commitments Inspection, Exit Meeting, Dec. 3, 2008
ML091980137
Person / Time
Site: Oyster Creek
Issue date: 12/03/2008
From:
NRC Region 1
To:
References
FOIA/PA-2009-0070
Download: ML091980137 (5)
v • d • e


Text

/ i, P e hal Informa on -- 0 laI Oyster Creek License Renewal Commitments Inspection Exit Meeting - Dec 3, 2008 G:\DRS\Engineering Branch 1\ LicRenewal\Oyster Creek\2008 Outaqe\OC LRI 2008-07 Exit Notes 12-3-08 rev-2.doc

Introductions

" NRC Region 1

" NRC HQ

  • NRC Residents
  • AmerGen

" NJ DEP (Observers)

Excellent Overall Cooperation from everybody

>>> use of the Certrec Internet Database was quite helpful Special Thanks

  • Pete Tamburro (LR Program Owner)

" Chris Hawkins (NDE Level-Ill)

  • Cal Taylor & Jhansi Kandasamy Tough Inspection Schedule & Difficult Inspection

" LR outage schedule slipped due to unexpected issues

" Some NDE UTs re-scheduled, due to unanticipated physical interference issues

" Bay 11 Coating Blisters

" Bay 3 Moisture Barrier Seal Problem

  • Cavity Leakage and Water Intrusion into 4 bays

" As a result, our inspection ran into a 2nd on-site week and a 3rd in-office week Documentation Team Report 45 days after the Exit Meeting (mid Jan)

Exec Summary of Inspection Results

" Monitoring of Sand Bed Drain Lines

  • Strippable Coating to Prevent Water Intrusion
  • For the selected samples[ (b)(5) ,
  • Sampled 9 AMPs to Verify Commitment Implementation
  • No Problems or Issues Identified, with Two/Three (??) Notable Exceptions 0 (b)(5) 1(two items) £. k
  • Perform Full Scope inspections of sand bed region every other'outage e Monitor drywell trenches every refueling outage, until trenches are restored
  • Verified 2 commitment changes were done iaw Exelon commitment management program
  • Bolting Integrity Program (commitment 12)
  • Rx Vessel Axial Weld Examination Relief.Request (commitment 48)
  • Regarding §54.21(b) Annual Updates, you intend to submit your 2008 Amendment Update by the end of the year -- ,in consultation with NRR, we consider that to be acceptable ronnalon in this record was deleted re' pudanoe with the Freedom of Intonn ft O iale ýi , Page 1 of 5

eci I in ,rmation

-- O, 6Jlal  !

Inspection Details -- Three (??)IMl(5) ssues Will be Documented Kr (1) Commitment 27, ASME Section XI, Subsection IWE, Item (2)L (b)(5)

A strippable coating will be applied to the reactor cavity liner to prevent water intrusion into the .ap 9 owIs between the drywell shield wall and the drywell shell during periods when the reactor cavity is flooded.

9 The strippable coating initially limited leakage into the cavity drain trough at < 1 gpm. On Nov 7, the leakage rate took a step change to 4 to 6.gpm. Water was subsequently identified in 4 sand bed bays.

9 This was also a previous commitment made in response to Generic Letter 87-05 (b)(5) tw (b)(5)

(2) Commitment 27, ASME Section XI, Subsection IWE, Item (3)f (b)(5)

Sand bed region drains will be monitored daily during refueling outages. I-

  • Sand bed drains were remotely monitored by checking poly bottles, attached via tygon tubing to funnels hanging below the drain lines. The drain lines were not directly observed.

Pr4-decisio al lnformati' -. Offtial U(e oP(ye Page 2 of 5

P -Decisi nalI nfor tion -- 0 /I Le/0

>>> I ~(b)(5)

(3) Commitment 27, ASME Section XI, Subsection IWE, Item (3) -4?. (b)(5)

Reactor cavity seal leakage trough drains and the drywell sand bed region drains will De monitorea tor' leakage. Periodically.

  • Drain line was found isolated during a boroscope examination to verify no line blockage.

I ANY QUESTIONS at this point Page 3 of 5 7,*e-decisioIal IInforttion -- Official U/ey%'IY

- Pr5 ecis/nal Inform ion-- Off"aal Uaiy (b)(5)

Insp ction Observations ASME IWE, Containment In-service Inspection

  • D/W Inside UT Examinations

" 41 separate 7x7 arrays and 7 separate 1x7 arrays evaluated (2058 separate UT readings)

" No on-going corrosion or trend was identified

  • No statistically significant deviations from 2006 data values

" Overall, not enough data sets to identify a corrosion trend, with any statistical certainty

" Adequate margin for the 20 year extended period

" D/W External UT Examinations in the Sand Bed Region

  • 111 separate UT readings
  • Overall, not enough data sets to identity a corrosion trend, with anystatistical certainty
  • 2008 data compared to 2006, shows a 1-2 mil decrease, well within the statistical variances
  • Adequate margin for the 20 year extended period

" Leakage Monitoring of cavity drain and sand bed drains

  • Problems as already discussed
  • Good poly bottle monitoring practices and log keeping

" Good pro-active monitoring actions during cavity flood-up (continuous Ops monitoring)

" Good compensatory actions, when strippable coating de-laminated

  • You are re-thinking action levels, based on cavity drain leakage rates a Calc and Action plan established 12 gpm Admin Limit
  • Didn't expect water intrusion at observed leakage values

" Cavity Strippable Coating e Problems as already discussed

" Done as part of Structural Monitoring Program. No issues or problems identified.

" Newly installed in 2006. Turned out to be an interference item to D/W UTs.

" Commitment for post-EPO is per ASME Sec-XI IWE. We asked whether your Structural Monitoring examination satisfied IWE requirements. You initiated an engineering action item to evaluate this question.

" Moisture Barrier Seal inside Sand Bed Bays

  • Numerous deficiencies identified in 7 of 10 bays (none in 2006). All problems were repaired.

" Moisture barrier function not impaired, no cracks or separation fully penetrated the seal

  • Surface cracks
  • Separation from shell or floor a Inadequate epoxy cure -- initial installation issue, from 1992 Protective Coating Monitoring and Maintenance Program
  • D/W Interior Service Level I Coating a Some minor issues identified. Documented results indicated a good quality inspection

" D/W Exterior Service Level II Coating, in Sand Bed Bays

  • Bay 11, one small 1/4 inch broken blister identified, with a 6" rust stain

" During initial investigation, 3 smaller unbroken blisters also found

" All 4 blisters were within a 1-2 inches square area, and all were thoroughly evaluated and fixed.

  • Good extent of condition, 4 bays re-inspected by a different level-Il

" During follow-up, you identified a 2006 video that showed the same 6" rust stain

" Estimated corrosion of - 3 mils, over a 16 year period

" No impact to DMW structural integrity, when compared to existing thickness margins P -decis**nl lnfo 7 *aion -- Off jal Us,6'-O/y Page 4 of 5

, e-Decis.10/nl Infor /ation -- i! e 0 ly Electrical Cables and Connections

  • Drywell Cable Inspections

" Good attention to detail & good questioning attitude

" Good engineering planning, prep, and participation

" Excellent cooperation between work group and engineering Inaccessible Medium Voltage Cables

  • Cable Testing - Auxiliary Transformer (bank 4)
  • Cable test done as part of transformer Doble Test

" Some industry experience suggests that large transformer characteristics can de-sensitize the test results regarding cable insulation degradation Buried Piping

  • ESW Pipe Replacement and Tie-in a FME control and pipe handling (to protect pipe coating) adequate to ensure a quality installation Structures Monitoring Program
  • Intake tunnel and expansion joints
  • Good hand-offs between night-shift and day-shift engineering One-Time Inspection Program
  • Isolation Condenser Inspection and UT below the water line

" Reviewed UT data evaluation Periodic Inspection Program

" Condensate System expansion joint inspection

" Fire barrier inspection inside a switchgear Metal Fatigue Program 9 At this point in time, not enough 'program usage to have resulted in a change to the high cumulative usage factor components List.

ANY QUESTIONS for US ire-decis'i.nal Inform on -- Off' ial nly Page 5of5

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