ML14217A326

RAI for Relief Request N2-I4-LMT-002 Regarding Limited Examination Coverage

ML14217A326
Person / Time
Site:	North Anna
Issue date:	07/30/2014
From:	V Sreenivas Division of Operating Reactor Licensing
To:	Heacock D A Dominion Generation
References
MF3982
Download: ML14217A326 (3)

Text

1 NRR-PMDAPEm Resource From: Sreenivas, V Sent: Wednesday, July 30, 2014 5:05 PM To: 'david.heacock@dom.com' Cc: 'david.sommers@dom.com'; Pascarelli, Rober t; Tom Shaub; Rezai, Ali; Jay Leberstien (jay.leberstien@dom.com); 'Gary D Miller'

Subject:

RAI FOR RELIEF REQUEST N2-I4-LM T-002 REGARDING LIMITED EXAMINATION COVERAGE (TAC MF3982)REQUEST FOR ADDITIONAL INFORMATION RELIEF REQUEST N2-I4-LMT-002 REGARDING LIMITED EXAMINATION COVERAGE VIRGINIA ELECTRIC AND POWER COMPANY - DOMINION NORTH ANNA POWER STATION, UNIT 2 DOCKET NUMBER 50-339 By letter dated April 21, 2014 (Agencywide Document s Access and Management System (ADAMS) Accession Number ML14115A066), Virginia Electric and Power Company - Dominion (the licensee) submitted relief request (RR) N2-I4-LMT-002 for the U.S. Nuclear Regulatory Commission (NRC) review and approval. The licensee requested relief from a certain requirement of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI. The request relates to essentially 100 percent coverage of the ASME Code required examination volume for various welds. The licensee submitted RR N2-I4- LMT-002 for the North Anna Power Station, (North Anna), Unit 2. The NRC staff requests the following additional information.

1. The licensee stated in Section 6.A1, Attachment to RR N2-I4-LMT-002, that, "-The examination volumes included the weld and base materials near the inside surface of the weld joint, which are typically the highest regions of stress, and where the expected degradation sources to be manifested should they occur-"

The NRC staff reviewed the examination coverage schematic diagrams the licensee provided on pages 14, 15, and 16 of Enclosure A1-1, and was unable to confirm from the schematic diagrams whether the volume scanned by the ultrasonic testing (UT) included the weld materials and the heat affected zone (HAZ) near the inside diameter (ID) surface of the weld joint. Provide and show clearly on the schematic diagrams on pages 14, 15, and 16 the volume scanned by the UT (e.g., similar to the dashed areas depicted on the schematic diagrams on pages 22 and 23, Enclosure A1-2 to the relief request, that showed the exact volume scanned by the UT). 2. Given the reduced inspection coverage of the welds under consideration, discuss the need for compensatory measures such as plant walk downs, VT-2 examination, or leak detection systems and whether such compensatory measures have been implemented.

3. Clarify whether the 75 percent coverage of the ASME Code required examination volume obtained by the UT is accurately documented in the following Enclosures to the relief request. If no, provide correct examination coverage obtained. a. In Enclosure R1-1 to RR N2-I4-LMT-002, the ultrasonic data records on pages 50, 51, and 52 as compared to Table entitled "Coverage Summary" on page 53 appear to be inconsistent.

2(Example: Table entitled "Coverage Summary" on page 53 shows that during performance of the circumferential scanning from the downstream side of the weld in the clockwise and counter clockwise directions, 100 percent coverage of the required volume was obtained. However, no ultrasonic data were recorded to substantiate this coverage.)

b. In Enclosure R2-1 to RR N2-I4-LMT-002, the ultrasonic data records on pages 74, 75, 76, and 77 as compared to Table entitled "Coverage Summary" on page 79 appears to be inconsistent. (Example: Table entitled "Coverage Summary" on page 79 shows that during performance of the circumferential scanning from the downstream side of the weld in the clockwise and counter clockwise directions, 100 percent coverage of the required volume was obtained. However, no ultrasonic data were recorded to substantiate this coverage.)

4. The licensee stated in R1 and R2, Attachment to RR N2-I4-LMT-002, that the UT procedures, equipment, and personnel are qualified in accordance with the performance demonstration requirements of Appendix VIII,Section XI of the ASME Code. Provide the applicable supplement(s) used for the UT qualification in R1 and R2.

5. The licensee stated on page 61 and 62 in R2, Attachment to RR N2-I4-LMT-002, that, "- The UT examination identified two recordable indications: 1) The first indication evaluated as acceptable per ASME Section XI Table IWB-3514-1, and 2) The second identified as Inner Diameter Geometry. -"

(a) Discuss the history of these indications (e.g., (i) Had the above indications ever been detected during previous examinations? (ii) did the fabrication radiographs document the above indications?). (b) Comparing to the baseline data, discuss whether the indications have grown. If the indications have grown, provide the flaw growth projection for the future.

(c) Discuss whether these indications will be re-examined in the future to monitor their growth or lack of.

Please submit the response to these RAIs by September 1, 2014. If you have any questions please contact me at your earliest.

___________________________ V. Sreenivas, PH.D., C.P.M.,

Project Manager, Rm.#O8F6, LPL2-1 North Anna and Surry Power Stations, Units 1 and 2 Division of Operating Reactor Licensing-NRR (301) 415-2597, v.sreenivas@nrc.gov

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Subject:

RAI FOR RELIEF REQUEST N2-I4-LMT-002 REGARDING LIMITED EXAMINATION COVERAGE (TAC MF3982) Sent Date: 7/30/2014 5:05:26 PM Received Date: 7/30/2014 5:05:00 PM From: Sreenivas, V Created By: V.Sreenivas@nrc.gov Recipients: "'david.sommers@dom.com'" <david.sommers@dom.com> Tracking Status: None "Pascarelli, Robert" <Robert.Pascarelli@nrc.gov> Tracking Status: None "Tom Shaub" <tom.shaub@dom.com>

Tracking Status: None "Rezai, Ali" <Ali.Rezai@nrc.gov> Tracking Status: None "Jay Leberstien (jay.leberstien@dom.com)" <jay.leberstien@dom.com> Tracking Status: None

"'Gary D Miller'" <gary.d.miller@dom.com> Tracking Status: None "'david.heacock@dom.com'" <david.heacock@dom.com> Tracking Status: None

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