ML052220679

Containment Coatings Work Scope 2EOC21

ML052220679
Person / Time
Site:	Oconee
Issue date:	08/08/2005
From:	Duke Energy Corp
To:	Office of Nuclear Reactor Regulation
Shared Package
ML052220649	List: ML052220673 ML052220679
References
Download: ML052220679 (14)

Text

Containment Coatings Work Scope 2EOC21 Oconee Nuclear Station August 8, 2005 1 Enclosure 2

ONS Containment Coatings Work Scope - 2EOC21 Introduction Dave Baxter Objectives Dave Baxter Recent Experience on Unit 2 Andy Wells Unit 2s Current Condition Andy Wells 2EOC21 Containment Coating Plans Andy Wells Basis For 2EOC21 Plans Andy Wells Conclusions Dave Baxter Questions / Wrap Up All 2

ONS Containment Coatings Work Scope - 2EOC21 Introduction Duke Participants

• Dave Baxter Oconee Engineering Manager

• Steve Capps Mechanical/Civil Engineering Manager

• Larry Nicholson Safety Assurance Manager

• Andy Wells Civil Engineering Supervisor

• Graham Davenport Regulatory Compliance Manager

• Mel Arey Material, Piping, & Seismic Engineering Supervisor

• Brant Elrod Senior Civil Engineer

• Mike Cromer Maintenance Civil Job Sponsor

• Russ Oakley Regulatory Compliance Lead

• Jon Cavallo Coating Consultant 3

ONS Containment Coatings Work Scope - 2EOC21 Objectives Outline 2EOC21 outage containment coatings work plan Explain basis for planned work scope Receive feedback/answer questions from NRC 4

ONS Containment Coatings Work Scope - 2EOC21 Recent Experience on Unit 2 Coating inspection at beginning of 2EOC20 (Spring 2004) identified a higher than expected amount of coating degradation.

Initiated a detailed effort to quantify level of degradation. As-found amount estimated to be approximately 4000 ft2.

Majority of increased delamination was on the Liner Plate in accessible areas - above 3rd and 4th floor grating levels (below Polar Crane Ring Girder).

Action was taken during 2EOC20 to abate approximately 2750 ft2 of delaminated coatings.

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ONS Containment Coatings Work Scope - 2EOC21 Recent Experience on Unit 2 An area of approximately 2000 ft2 above the 3rd floor was stripped to base metal and recoated utilizing a newly purchased sealed asbestos/lead vacuum system.

Approximately 1450 ft2 of delaminated coatings remained at end of 2EOC20 (post-ILRT).

NRC resident inspection of containment coatings following maintenance activities during 2EOC20 resulted in no findings as documented in Inspection Report 2004-003.

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ONS Containment Coatings Work Scope - 2EOC21 Unit 2s Current Condition On-line entry performed on 5/31/05 determined the following:

Delaminated Coating Delaminated Coating Estimated During Documented in Final 5/31/2005 Power 2EOC20 Coating Entry (See Note Inspection Report below)

Total - Accessible 940 ft2 250 ft2 Total - Inaccessible 1410 ft2 1207 ft2 Combined Total 2350 ft2 1457 ft2 Note -- An additional Unit 2 power entry is currently scheduled in August to verify no significant changes have occurred since 5/31/05 power entry.

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ONS Containment Coatings Work Scope - 2EOC21 Containment Coatings Plans Inspect containment coatings at beginning of outage per ONS Coatings Maintenance Program.

Remove majority of degraded coatings in accessible areas (approximately 750 ft2.) This includes Liner Plate from 4th floor to duct and accessible portion of Polar Crane & Polar Crane Ring Girder.

Abate and reconstitute approximately 25% of 4th floor Liner Plate below duct (approx. 6000 ft2).

Abate and reconstitute (with qualified coating system) one Core Flood Tank and Reactor Coolant Pump Motor to reduce quantity of unqualified coatings (approximately 1400 ft2).

Evaluate degraded coatings in inaccessible areas (Dome), but no removal planned. 8

ONS Containment Coatings Work Scope - 2EOC21 Basis For 2EOC21 Plans Installation of Bigge platform during 2EOC21 to remove delaminated coatings in Dome area is not warranted for the following reasons:

Minimal change has occurred in the inaccessible areas degradation amounts between 2EOC20 and 2EOC21. No significant changes from current amounts are expected in Cycle 22.

Current work plans address areas where majority of increased delamination occurred.

Reconstituted area on Liner Plate above the 4th floor significantly reduces potential for continued delamination in that area.

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ONS Containment Coatings Work Scope - 2EOC21 Basis For 2EOC21 Plans Current plans will leave approximately 1600 ft2 of degraded coating at end of 2EOC21. Total Service Level 1 coating surface area inside containment exceeds 250,000 ft2. Amount degraded is less than 1% of the total.

Actions taken by current work plan will meet GL 98-04 commitment to minimize degraded coatings that could detach during a LOCA.

2EOC21 work plan is consistent with the recent Bulletin 2003-01 RAI response.

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ONS Containment Coatings Work Scope - 2EOC21 Basis For 2EOC21 Plans Projected amount of delaminated coatings remaining at end of 2EOC21 is only slightly larger than at the end of 2EOC20 (1457 ft2). Total potential coating debris at the end of 2EOC21 will be less than that at the end of 2EOC20.

The amount of degraded coating in the inaccessible areas is minimal. Therefore, the nuclear safety benefit does not warrant the expense nor risk to personnel to remove these degraded coatings.

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ONS Containment Coatings Work Scope - 2EOC21 Conclusions Areas where majority of delamination has occurred since 2EOC20 are being addressed.

Significant area of degraded coating is being replaced on the Liner Plate.

Amount of unqualified coatings is being reduced.

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ONS Containment Coatings Work Scope - 2EOC21 Conclusions Use of Bigge platform is not justified by marginal improvement in overall risk.

Though not directly part of the coatings plan or program, ONS plans for 2EOC21 include installation of new sump strainer. (Approximately 5000 ft2 surface area.)

2EOC21 Containment coating work plans are comprehensive and meet regulatory commitments.

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ONS Containment Coatings Work Scope - 2EOC21 Questions / Wrap-Up Questions?

Action Items Concluding Comments 14