ML101590516

Response to Request for Additional Information Relief Request No. 44

ML101590516
Person / Time
Site:	Palo Verde
Issue date:	05/27/2010
From:	Hesser J Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-06199-JHH/RAS/RJR, TAC ME2335, TAC ME2336
Download: ML101590516 (4)

Text

10 CFR 50.55a(g)(5)iii

.A Asubsidiaty of Pinnacle West Capital Corporation John H. Hesser Mail Station 7605 Palo Verde Nuclear Vice President Tel: 623-393-5553 PO Box 52034 Generating Station Nuclear Engineering Fax: 623-393-6077 Phoenix, Arizona 85072-2034 102-06199-JHH/RAS/RJR May 27, 2010 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 2 and 3 Docket No. STN 50-529 and 50-530 Response to Request for Additional Information Relief Request No. 44 (TAC Nos. ME2335 and ME2336)

By APS letter no. 102-06070, dated September 29, 2009 (Agencywide Document Access and Management System [ADAMS] Accession No. ML092810228), Arizona Public Service Company (APS), submitted Relief Request No. 44 to the NRC. The enclosure to this letter contains the response to the question provided to APS by the NRC Project Manager on March 26, 2010.

No commitments are being made to the NRC by this letter. Should you need further information regarding this response, please contact Russell A. Stroud, Licensing Section Leader, at (623) 393-5111.

Sincerely, JHH/RAS/RJR/gat

Enclosure:

Response to Request for Additional Information Relief Request No. 44 cc: E. E. Collins, Jr. NRC Region IV Regional Administrator J. R. Hall NRC NRR Project Manager L. K. Gibson NRC NRR Project Manager R. I. Treadway NRC Senior Resident Inspector for PVNGS A member of the STARS (Strategic Teaming and Resource Sharing) Alliance 04f\or Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• San Onofre a South Texas 9 Wolf Creek

ENCLOSURE Response to Request for Additional Information Relief Request No. 44

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION RELIEF REQUEST No. 44 By letter dated September 29, 2009, Arizona Public Service Company (APS) submitted Relief Request No. 44, pursuant to paragraph 50.55a(a)(3)(ii) of Title 10 of The Code of FederalRegulations (10 CFR). RR No. 44 proposed to defer certain visual examinations required by the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, Table IWB-2500-1, Examination Categories B-N-2 and B-N-3 for the Palo Verde Nuclear Generating Station, Units 2 and 3 (Palo Verde 2 and 3). The visual exams for which relief is requested are for reactor internals components, including the interior attachments beyond the beltline region and the core support structure. APS has specifically requested to defer these visual examinations until the years 2027 for Palo Verde 2 and 2028 for Palo Verde 3.

On March 26, 2010, the Nuclear Regulatory Commission (NRC) requested the following additional information:

NRC Question APS stated in RR No. 44 that the visual examinations for these components were last performed in 2008 for Palo Verde 2, and in 2009 for Palo Verde 3, with "acceptable results." Please discuss whether any relevant indications were found during these examinations. If any indications were found during these examinations, please describe how these indications were evaluated and dispositioned, in accordance with ASME Code,Section XI requirements.

APS Response:

Unit 2 The B-N-2 and B-N-3 visual examination performed during the 2008, 2R14 outage identified two relevant indications: loose debris on the core barrel support ledge keyway, and a dent on the core barrel key at the 180 degree location with a similar indication of raised metal on the corresponding keyway. Both of these indications were determined to be acceptable in accordance with ASME Section XI, IWB-3520.2, Visual Examination, VT-3. However, APS took the following actions to resolve the conditions.

1. APS tried to remove the debris, however, it was adhered tight to the surface.

The resolution was to 'leave in place' as this debris appeared to be in the crevice area of the keyway and would not interfere with the core barrel seating correctly.

2. The dent area appeared to have raised metal. To prevent the raised metal from affecting the core barrel positioning, the area was hand filed. The raised metal was very loosely adhered and fell off when worked. Above this material was a streak that indicated rubbing occurred along the key during the last installation.

When the hand rework was performed on this area, it was evident that there was Page 1

Response to RAI Relief Request No. 44 essentially no raised metal along its entire length. The result was what appeared to be raised metal was superficial and accepted. During the re-insertion of the core barrel, no changes in the seating measurements were noted.

Unit 3 The B-N-2 and B-N-3 visual examinations performed during the 2009, 3R14 outage were acceptable with no relevant indications. However, on the Reactor Vessel Core Support Structure, Component B13.70, scale build up was noted around the surveillance capsule holes around the flange. The condition of the scale build up was evaluated by APS Engineering and determined to be staining and not a scale build up.

Therefore, the Core Support Structure did not require corrective action to meet the requirements of ASME Section Xl, IWB-3520.2, Inservice Visual Examinations, VT-3.

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