ML12128A294

Request for Additional Information Related to the Relief Request I3-09 for the Reactor Vessel Closure Head Nozzles Repair for the Third Inservice Inspection Program Interval

ML12128A294
Person / Time
Site:	Harris
Issue date:	05/11/2012
From:	Billoch-Colon A Plant Licensing Branch II
To:	Burton C Progress Energy Carolinas
Billoch-Colon, Araceli
References
TAC ME8523
Download: ML12128A294 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 11, 2012 Christopher L Burton, Jr., Vice President Shearon Harris Nuclear Power Plant Progress Energy Carolinas, Inc.

Post Office Box 165, Mail Code: Zone 1 New Hill, North Carolina 27562-0165

SUBJECT:

SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE RELIEF REQUEST 13-09 FOR THE REACTOR VESSEL CLOSURE HEAD NOZZLES REPAIR FOR THE THIRD INSERVICE INSPECTION PROGRAM INTERVAL (TAC NO. ME8523)

Dear Mr. Burton:

By letter to the U.S. Nuclear Regulatory Commission (NRC) dated May 3, 2012, (Agencywide Documents Access and Management System Accession No. ML12128A007), Carolina Power

& Light Company, doing business as Progress Energy Carolinas, Inc. submitted Relief Request 13R-09 for the repair of degraded reactor vessel closure head nozzle penetrations for Shearon Harris Nuclear Power Plant, Unit No.1.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on May 10, 2012, it was agreed that you would provide a response 7 days after the date of this letter.

The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3302.

Sincerely, Araceli T. Billoch Colon, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-400

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION SHEARON HARRIS NUCLEAR POWER PLANT UNIT NO.1 CAROLINA POWER & LIGHT COMPANY DOCKET NO. 50-400 By letter to the U.S. Nuclear Regulatory Commission (NRC) dated May 3, 2012, Carolina Power

& Light Company, doing business as Progress Energy Carolinas, Inc. submitted Relief Request (RR) 13R-09 for the repair of degraded reactor vessel closure head (RVCH) nozzle penetrations for Shearon Harris Nuclear Power Plant, Unit No.1. To complete its review, the NRC staff requests additional information as discussed below.

1. Page 6, Section 5.a. of the RR states that the interpass temperature will be determined by one of the following methods: (1) heat flow calculations or (2) measurement based on a test coupon. Discuss the exact measurement method that will be used and explain why that method is selected.

2. Page 8, Section 5.b. of the RR states, in part, "... For this modification, the repair weld is suitable, except for the taper transition, for ultrasonic testing (UT) examination and a final surface examination can be performed .... " Discuss the examination method(s) that will be used for the taper transition. If the answer is: No examination will be performed, discuss how the taper transition can be ensured of its structural integrity (Le., no flaws).

3. Page 8, Section 5.b. of the RR states, in part, "...Approximately 70% of the weld surface will be scanned by UT. Approximately 83% of the RVCH ferritic steel heat affected zone (HAZ) will be covered by UT. ... " Based on the aforementioned examination coverage, Figure 4 through Figure 8 provide the coverage for UT examination with the hashed lines.

a. Discuss the area 'and volume of the new weld that could not and will not be examined.

b. Discuss how the area and volume of the new weld that could not be examined can be ensured of structural integrity (Le., no flaws).

c. If 70% of the new weld surface will be scanned by UT, clarify what is the percentage of coverage for the "volume" of the weld.

4. Page 10, Section 5.d., last paragraph of the RR states that the stress on the postulated circumferential flaw has a margin of 1.43 with respect to the allowable stress and the depth of axial flaw has a margin of 3.9 with respect to the allowable flaw depth. First paragraph on page 11 states that the fatigue crack growth is acceptable.

a. Provide the final crack size (length and depth) in the axial and circumferential direction at the end of 40 years and explain why the final crack size is acceptable.

ENCLOSURE

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b. Explain how the margins on stress and flaw depth satisfy the required margins in the American Society o'F Mechanical Engineers (ASME) Code.Section XI, IW8-3600.

c. The RR states that the fracture toughness margins for flaws have been shown to be acceptable. Discuss the fracture toughness margins.

5. Page 11. Section 5.e. of the RR discusses the worst-case flaw in the J-groove weld.

a. Describe the worst-case flaw.

b. Explain why the proposed nozzle repair design configuration is considered to be acceptable for 30 years of operation after the weld repair.

6. Discuss whether all the flaws identified in Nozzles No.5, 17.38, and 63 will be removed as a result of the proposed repair. If not, justify how the nozzles with remnant flaws can be ensured of structural integrity so as not to affect the function of the control rod drive mechanism and the structural integrity of the reactor vessel head.

7. Section 6 of the RR states that the proposed repair has a design life expectancy of 14.8 effective full-power years (EFPYs). Describe in detail or submit the analysis that results in the design life of 14.8 EFPYs. Section 5.e. states that the nozzle repair design is considered to be acceptable for 30 years. Explain the discrepancy between the two different design life expentancies.

8. Discuss the mockup for the proposed repair in general and specifically for the welding and inspection qualification.

9. The RR stated that ASME Code Case N-638-1 will be implemented.

a. Clarify whether Shearon Harris, Unit 1, has already adapted ASME Code Case N-638-1 (approved by the NRC in Regulatory Guide (RG) 1.147. Rev. 15, for use with conditions) during the third 10-year Inservice Inspection interval.

b. If the answer to RAI-9.a. is: No, then clarify why ASME Code Case N-638-4 (approved by the NRC in RG 1.147. Rev. 16, for use with conditions) that has superseded the previous versions of that code case is not being used.

t1ay 11, 2012 Christopher L Burton, Jr., Vice President Shearon Harris Nuclear Power Plant Progress Energy Carolinas, Inc.

Post Office Box 165, Mail Code: Zone 1 New Hill, North Carolina 27562-0165

SUBJECT:

SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE RELIEF REQUEST 13-09 FOR THE REACTOR VESSEL CLOSURE HEAD NOZZLES REPAIR FOR THE THIRD INSERVICE INSPECTION PROGRAM INTERVAL (TAC NO. ME8523)

Dear Mr. Burton:

By letter to the U.S. Nuclear Regulatory Commission (NRC) dated May 3, 2012, (Agencywide Documents Access and Management System Accession No. ML12128A007), Carolina Power

& Light Company, doing business as Progress Energy Carolinas, Inc. submitted Relief Request 13R-09 for the repair of degraded reactor vessel closure head nozzle penetrations for Shearon Harris Nuclear Power Plant, Unit No.1.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on May 10, 2012, it was agreed that you would provide a response 7 days after the date of this letter.

The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3302.

Sincerely, IRA!

Araceli T. Billoch Colon, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-400

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION PUBLIC LPL 11-2 Reading RidsNrrDorlLpl2-2 RidsNrrPMShearonHarris JCollins, NRR ARezai RidsNrrLABClayton RidsRgn2MailCenter RidsAcrsAcnwMailCenter JTsao, NRR DAiley, NRR A DAMS Accession No. ML12128A294 *BvEmaii OFFICE LPL2-21PM LPL2*2ILA DE/EPTB* LPL2*2/BC LPL2-2/PM NAME ABiliochCol6n BClayton JTsao DBroaddus ABillochCol6n DATE 05/11/12 05/11/12 05/11/12 05/11/12 05/11/12 OFFICIAL RECORD COpy