ML091320639

Reactor Coolant Pressure Boundary Visual Inspections Proposed Alternative - N1-I3-NDE-024 and N2-I3-NDE-025

ML091320639
Person / Time
Site:	North Anna
Issue date:	05/12/2009
From:	Hartz L Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
9-253, N1-I3-NDE-024, N2-I3-NDE-025
Download: ML091320639 (7)

Text

10 CFR 50.55a VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 May 12, 2009 U.S. Nuclear Regulatory Commission Serial No.09-253 Attention: Document Control Desk NL&OS/ETS RO Washington, D.C. 20555 Docket Nos. 50-338 50-339 License Nos. NPF-4 NPF-7 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

NORTH ANNA POWER STATION UNITS 1 AND 2 REACTOR COOLANT PRESSURE BOUNDARY VISUAL INSPECTIONS PROPOSED ALTERNATIVE - N1-13-NDE-024 AND N2-13-NDE-025 Pursuant to 10 CFR 50.55a(a)(3)(i), Dominion requests approval of an alternative to the inspection requirements of footnote 1 included in 10 CFR50.55a(g)(6)(ii)(E), Reactor Coolant Pressure Boundary Visual Inspections, for North Anna Units 1 and 2. The requested alternative will permit the inspections performed during the Unit 1 fall 2007 and Unit 2 fall 2008 refueling outages on the bottom mounted instrument tubes (8MI) to be used as the initial reactor coolant pressure boundary visual inspection in place of the footnote requirement for the initial inspection to be performed at the next refueling outage after January 1,2009. Alternatives N1-13-NDE-024 and N2-13-NDE-025 are included in the attachment to this letter as well as the basis for the alternative.

The 8MI inspections performed during the fall 2007 and 2008 refueling outages for North Anna Units 1 and 2, respectively, conformed to the requirements of Code Case N-722 and met the requirements of 10 CFR50.55a(g)(6)(ii)(E). Therefore, Dominion considers the visual examinations performed during the fall 2007 refueling outage for NAPS Unit 1 and fall 2008 refueling outage for NAPS Unit 2 to provide an acceptable level of quality and safety as an alternative to performing the initial inspections in the next refueling outage after January 1,2009, as indicated in 10 CFR 50.55a(g)(6)(ii)(E).

If you should have any questions regarding this submittal, please contact Mr. Thomas Shaub at (804) 273-2763.

Sincerely,

~~ci Leslie Hartz Vice President - Nuclear Support Services

Attachment:

Proposed Alternatives - N1-13-NDE-024 and N2-13-NDE-025 Commitments made in this letter: None

Serial No.09-253 Docket Nos. 50-338/339 Alternative for BMI Baseline Inspections Page 2 of 2 cc: U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 Mr. J. E. Reasor, Jr.

Old Dominion Electric Cooperative Innsbrook Corporate Center 4201 Dominion Blvd.

Suite 300 Glen Allen, Virginia 23060 NRC Senior Resident Inspector North Anna Power Station Ms. D. N. Wright NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 0-8 H4A 11555 Rockville Pike Rockville, Maryland 20852 Mr. J. F. Stang, Jr.

NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North MaiI Stop 0-8 G9A 11555 Rockville Pike Rockville, Maryland 20852

Serial No.09-253 Docket Nos. 50-338/339 ATTACHMENT REACTOR COOLANT PRESSURE BOUNDARY VISUAL INSPECTIONS PROPOSED ALTERNATIVE N1-13-NDE-024 and N2-13-NDE-025 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

NORTH ANNA POWER STATION UNITS 1 AND 2

10 CFR 50.55a Request Number N1-13-NDE-024/N2-13-NDE-025 Alternative BMI Visual Examinations Requirement Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(i)

• • Alternative Provides Acceptable Level of Quality or Safety --

1.0 ASME Code Components Affected

Code components associated with this request are Class 1 Reactor Pressure Vessel (RPV) bottom-mounted instrument penetrations (BMI) having pressure retaining partial or full penetration welds in components fabricated with Alloy 600/82/182 material.

1.1 Category and System Details:

Code Class: Class 1 System: Reactor Pressure Vessel Examination Category: B-P Item Number: B15.80 1.2 Component Descriptions:

Reactor Vessel - RPV bottom-mounted instrument penetrations 2.0 Applicable Code Edition And Addenda North Anna Power Station Units 1 and 2 are completing their third 10-year lSI Intervals. Unit 1's third interval began on May 1, 1999 and ends on April 30, 2009 and Unit 2's third interval began on December 14, 2001 and ends on December 13, 2010. The ASME Boiler and Pressure Vessel Code (ASME Code) of record for the applicable interval is the 1989 Edition for Unit 1 and the 1995 Edition, 1996 Addenda for Unit 2.

3.0 Applicable Code Requirements 10 CFR 50.55a(g)(6)(ii)(E), Reactor coolant pressure boundary visual inspections, was recently incorporated into the 10 CFR 50.55a. The new regulations augmented the inservice inspection requirements (effective date October 10,2008).

Specifically, 10 CFR 50.55a(g)(6)(ii)(E) requires that "Alllicensees of pressurized water reactors shall augment their inservice inspection program by implementing ASME Code Case N-722 subject to the conditions specified in 10 CFR 50.55a(g)(6)(ii)(E)(2) through (4) of this section. The inspection requirements of ASME Code Case N-722 do not apply to components with pressure retaining welds fabricated with Alloy 600/82/182 materials that have been mitigated by weld overlay or stress improvement."

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10 CFR 50.55a Request Number N1-13-NDE-024/N2-13-NDE-025 Alternative 8MI Visual Examinations Requirement In addition, footnote one to 10 CFR 50.55a(g)(6)(ii)(E) states in part: "For inspections to be conducted every refueling outage and inspections conducted every other refueling outage, the initial inspection shall be performed at the next refueling outage after January 1, 2009."

4.0 Reason For Request North Anna Power Station (NAPS) Unit 1 and Unit 2 completed bare metal visual examination of RPV bottom-mounted instrument penetrations prior to the "initial inspection" indicated by 10 CFR 50.55a(g)(6)(ii)(E), which became effective October 10, 2008. NAPS Unit 1 inspections were performed during the fall 2007 refueling outage, and NAPS Unit 2 inspections were performed during the fall 2008 refueling outage. These bare metal visual inspections met the intent of ASME Code Case N-722.

Code Case N-722, "Additional Examinations for PWR Pressure Retaining Welds in Class 1 Components Fabricated with Alloy 600/82/182 Material," establishes additional requirements to the examination requirements of Table IWB-2500-1 for pressurized water reactor plants having partial or full penetration welds in Class 1 components fabricated with Alloy 600/82/182 material.

For Reactor Vessel Item Number B15.80, RPV bottom-mounted instrument penetrations, all penetrations require Visual Examination (VE) to the requirements of IWB-3522, every other refueling outage.

ASME Code Case N-722 includes specific requirements for the VE and the qualification of personnel performing the VE:

(3) The Visual Examination (VE) performed on Alloy 600/82/182 components for evidence of pressure boundary leakage and corrosion on adjacent ferritic steel components shall consist of the following:

(a) A direct VE of the bare-metal surface performed with the insulation removed. Alternatively, the VE may be performed with insulation in place using remote visual inspection equipment that provides resolution of the component metal surface equivalent to a bare-metal direct VE.

(b) The VE may be performed when the system or component is depressurized.

(c) The direct VE shall be performed at a distance not greater than 4 ft (1.2 m) from the component and with a demonstrated illumination level sufficient to allow resolution of lower case characters having a height of not greater than 0.105 in (2.7 mm).

(4) Personnel performing the VE shall be qualified as VT-2 visual examiners and shall have completed a minimum of four (4) hours of additional training in detection of borated water leakage from Alloy 600/82/182 components and the resulting boric acid corrosion of adjacent ferritic steel components.

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10 CFR 50.55a Request Number N1-13-NDE-024/N2-13-NDE-025 Alternative 8MI Visual Examinations Requirement The bottom-mounted RPV instrument penetrations examinations during the fall 2007 and fall 2008 refueling outages were performed to the enhanced Visual Examination (VE) requirements and the personnel training and qualification requirements as described in Enclosure 1, "Examiner Qualification and Resolutions Requirements."

5.0 Proposed Alternatives And Basis For Use Virginia Electric and Power Company (Dominion) considers the visual examinations performed during the fall 2007 refueling outage for NAPS Unit 1 and fall 2008 refueling outage for NAPS Unit 2 to provide an acceptable level of quality and safety as an alternative to performing the initial inspections in the next refueling outage after January 1, 2009, as indicated in 10 CFR 50.55a(g)(6)(ii)(E). Therefore, the inspection performed during the fall 2007 refueling outage for NAPS Unit 1 and fall 2008 refueling outage for NAPS Unit 2 can be considered the initial inspections to meet the 10 CFR 50.55a(g)(6)(ii)(E) footnote requirements for the performance of the initial inspection.

In accordance with ASME Code Case N-722, the bottom-mounted RPV instrument penetration examinations are required to be performed at least every other refueling outage. Therefore, the next examinations of Item No. B15.80 components (bottom-mounted RPV instrument penetration) will be performed no later than the fall 2010 refueling outage for Unit 1 and no later than the fall 2011 refueling outage for Unit 2. Dominion requests approval of this alternative pursuant to the provisions of 10 CFR 50.55a(a)(3)(i).

6.0 Duration Of Proposed Alternative The proposed alternative to the 10 CFR 50.55a(g)(6)(ii)(E) requirements is applicable for the remainder of the third 10-year inservice inspection (lSI) interval at NAPS Units 1 and 2.

7.0 Precedents None 8.0 References None 9.0 Enclosures (1) Examiner Qualification and Resolution Requirements Page 3 of 4

10 CFR 50.55a Request Number N1*13*NDE*024/N2*13*NDE*025 Alternative BMI Visual Examinations Requirement ENCLOSURE 1 Examiner Qualifications and Resolution Requirements This enclosure documents a comparison of the bare metal visual examinations performed on the reactor pressure vessel bottom mounted instrumentation (BMI) nozzles at North Anna Power Station Units 1 & 2 performed during previous outages (N1 R19 and N2R19) with the new requirements of Code Case N-722. Two areas related to examination equivalency were required to be addressed; personnel qualifications and resolution requirements.

Personnel Qualifications The examiners that performed these examinations held current VT-2 (non-alternative) and VT-3 qualifications. In addition, each of the examiners had successfully taken the Dominion Boric Acid Corrosion Control (BACC) Inspector training. The inspection team included at least one VT examiner that has also completed the Dominion BACC Evaluator training and qualification requirements.

The examiners that performed these bare metal visual examinations met the requirements of Code Case N-722 as VT-2 qualified examiners with an additional four hours of training addressing the detection of borated water leakage from Alloy 600/82/182 components and the resulting boric acid corrosion of adjacent ferritic steel components.

Based upon the additional training of the visual examiners; the bare metal visual examinations of the BMI nozzle penetrations performed during the N1 R19 and N2R19 outages are considered equivalent to the personnel qualification requirements of Code Case N-722.

Resolution Requirements The previous bare metal visual examinations were performed using a (VT-2) examination technique and required each penetration to be examined for evidence of leakage for 360 degrees around each nozzle. The bare metal visual examinations were documented in the applicable Engineering Periodic Test Procedure. These periodic test procedures specify the use of inspection equipment to be used for the inspection, which consists of a mirror, portable lights, and a visual testing examination resolution card.

Access to the BMI nozzles for the bare metal visual examination is through removable insulation panels. The bare metal visual examinations of the BMI nozzles were performed in accordance with the direct visual examination requirements of within 4 feet and sufficient illumination to resolve 0.105 inches lower case characters.

Based upon the access for the examiner to perform the bare metal visual examinations of the BMI nozzle penetrations, the equipment used to perform the examination (mirror, flashlight, 0.105 inches low case character resolution card), the previously performed bare metal visual examinations of the BMI nozzle penetration are considered equivalent to the resolution requirements of Code Case N-722.

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