ML13261A288

Request to Utilize an Alternative to the Requirements of 10 CFR 50.55a(g) for Implementation of a Risk-Informed, Safety-Based Inservice Inspection Program Based on ASME Code Case N-716 - Response to Nrc.

ML13261A288
Person / Time
Site:	Nine Mile Point
Issue date:	09/06/2013
From:	Swift P Constellation Energy Nuclear Group, Nine Mile Point, EDF Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC ME9876
Download: ML13261A288 (12)

Text

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a joint venture of 0 Constellation Energy*

1. 1..D 10 NINE MILE POINT NUCLEAR STATION September 6, 2013 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION: Document Control Desk

SUBJECT:

Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License No. NPF-69 Docket No. 50-410 Request to Utilize an Alternative to the Requirements of 10 CFR 50.55a(g) for Implementation of a Risk-Informed, Safety-Based Inservice Inspection Program Based on ASME Code Case N-716 - Response to NRC Request for Additional Information (TAC No. ME9876)

REFERENCES:

(a) Letter from P. M. Swift (NMPNS) to Document Control Desk (NRC), dated October 25, 2012, Request to Utilize an Alternative to the Requirements of 10 CFR 50.55a(g) for Implementation of a Risk-Informed, Safety-Based Inservice Inspection Program Based on ASMIE Code Case N-716 (b) E-mail from B. Vaidya (NRC) to J. J. Dosa et.al. (NMPNS), dated July 15, 2013, Nine Mile Point, Unit 2 - Request to Utilize an Alternative to the Requirements of 10 CFR 50.55a(g) for Implementation of a Risk-Informed, Safety-Based Inservice Inspection Program Based on ASME Code Case N-716 (TAC No.

ME9876)

Nine Mile Point Nuclear Station, LLC (NMPNS) hereby transmits supplemental information requested by the NRC in support of a previously submitted request for alternative (No. 21SI-01 1) under the provisions of 10 CFR 50.55a(a)(3)(i). This 10 CFR 50.55a request, submitted in Reference (a), requests authorization to implement a risk-informed, safety-based inservice inspection (ISI) program for Nine Mile Point Unit 2 based on American Society of Mechanical Engineers (ASME) Code Case N-716, "Alternative Piping Classification and Examination Requirements,Section XI, Division 1." The supplemental information, provided in the Attachment to this letter, responds to the request for additional information (RAI) documented in the NRC's e-mail dated July 15, 2013 (Reference b). This letter contains no new regulatory commitments.

Nine Mile Point Nuclear Station, LLC P.O. Box 63, Lycoming, NY 13093 "A -7

Document Control Desk September 6, 2013 Page 2 Should you have any questions regarding the information in this submittal, please contact Theresa H.

Darling, acting Licensing Director, at (315) 349-5219.

Very truly yours, Paul M. Swift Manager Engineering Services PMS/JJD

Attachment:

Nine Mile Point Unit 2 - Response to NRC Request for Additional Information Regarding 10 CFR 50.55a Request Number 21SI-011 cc: Regional Administrator, Region I, NRC Project Manager, NRC Resident Inspector, NRC

ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-011 Nine Mile Point Nuclear Station, LLC September 6, 2013

ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-01 1 By letter dated October 25, 2012, Nine Mile Point Nuclear Station, LLC (NMPNS) submitted 10 CFR 50.55a request number 21SI-0 11 under the provisions of 10 CFR 50.55a(a)(3)(i). This 10 CFR 50.55a request is for implementation of a risk-informed, safety-based inservice inspection (ISI) program for Nine Mile Point Unit 2 (NMP2) based on American Society of Mechanical Engineers (ASME) Code Case N-716, "Alternative Piping Classification and Examination Requirements,Section XI, Division 1." This attachment provides supplemental information in response to the request for additional information (RAI) documented in the NRC's e--mail dated July 15, 2013. Each individual NRC request is repeated (in italics), followed by the NMPNS response.

RAI - 1 The October 25, 2012 submittal states, the ISI examinationsfor the first inspection period of the third ten-year interval were performed in accordance with your RI-ISI program based on Code Case N-578. The submission also states that the proposed RI-ISI program based on N-716 will be used to perform the remaining ISI exams for the second and third inspection periods. Please provide details of how the requirements ofI[WB-2412 will be met with regardto the percentage of exams performed in eachperiod.

Response

The risk-informed examinations performed in the first inspection period of the third ten-year interval met the inspection percentages as required by IWB-2412 (16% minimum to 50% maximum) with 18% of the examinations completed based on the population determined using the previously approved Code Case N-578. The population of risk-informed components for the second and third periods will be determined using the methodologies described in Code Case N-716.

The population of examinations required for the 10-year inspection interval, based on Code Case N-716, will be prorated for the 2nd and 3 rd inspection periods since the first period examination requirements were satisfied using Code Case N-578. At the completion of the third 10-year interval, 100% of the required risk-informed examinations will have been completed as required by IWB-2412.

RAI -2 On page 7 of the Attachment to the October 25, 2012 submittal there is a table which provides a summary of the number of welds and the welds selectedfor examination. Please clarify what the number shown under the column "Class 3 and Non-class Welds" represents. All other columns appearto represent total welds whereas this column appearsto show only HSS welds.

Response

The ASME Class 3 and Non-class Welds selected are based on High Safety Significance (HSS) as determined by the NMPNS-ASME Code case-N-716 evaluation. The evaluation revealed only 6 HSS welds from the total population of ASME Class 3 and Non-class welds. Low Safety Significant (LSS),

welds which are not in the ASME Section XI ISI program, were not included in the tables provided since they are not contained in the Section XI database.

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ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-011 RAI- 3 Please provide a Table similar to Table 5.1 of the October 25, 2012 submittal that compares the selections of the currentRI-ISI prograinwith the selections of the proposedRISB program.

Response

The table below expands upon Table 5.1 of the October 25, 2012 submittal by adding the selections from the previously approved Code Case N-578 submittal for comparison. The N-578 information is depicted in the table in rows with a gray background.

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ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-011 Table 5.1 Inspection Location Selection Comparisons between ASME Section XI and Code Case N-716 System Safety Significance Break Failure Potential Code Weld Code Case N578 Code Case N716 Sect. XI High Low Location DMs Rank Category Count ASS " LSS n/a Assume Medium C-F-2 4 0 1 CSH LOCA TASCS High 11 3 CSH " LOCA TASCS Medium B-J 11 2 3 CSH None High 6 3 CSH ' PLOCA None Low B-J 8 0 1 CSH None Low 4 0 CSH " PLOCA-OC None Low B-J 2 1 1 CSH None Medium 164 0 CSH " LSS n/a Assume Medium C-F-i, C-F-2 164 0 14 CSL TASCS High 8 2 CSL " LOCA TASCS Medium B-J 8 2 3 CSL None High 10 1 CSL " PLOCA None Low B-J 9 0 1 CSL None Medium 114 0 CSL " PLOCA-OC None Low B-J 2 1 1 CSL None Low 4 0 CSL " LSS n/a Assume Medium C-F-I, C-F-2 117 0 10 DER TASCS High 1 1 DER None Low 2 0 DER " PLOCA None Low B-J 2 1 2 FW TASCS High 8 FW " LOCA TASCS Medium B-J 31 8 10 FW None High 5 FW " PLOCA TASCS Medium B-J 3 1 2 FW IGSCC Medium I FW " PLOCA-OC TASCS Medium B-J 12 1 4 3 of9

ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-Oll Table 5.1 Inspection Location Selection Comparisons between ASME Section XI and Code Case N-716 System Safety Significance Break Failure Potential Code Weld Code Case N578 Code Case N716 Sect. XI High Low Location DMs Rank Category Count FW TASCS Medium 11 1 FW I LOCA None Low B-J 47 0 2 FW TASCS,IGSCC Medium 4 0 FW " PLOCA-OC None Low B-J, CL4 8 1 4 FW None Medium 6 0 ICS " LOCA TASCS Medium B-J 9 3 3 ICS TT,TASCS High 3 ICS " PLOCA TASCS Medium B-J 4 1 0 ICS None High 5 ICS " LOCA None Low B-J 15 2 4 ICS TTTASCS Medium 1 ICS " PLOCA None Low B-J 34 0 2 ICS None Medium 0 ICS " PLOCA-OC None Low B-I, C-F-2 11 2 4 ICS None Low 0 ICS " LSS n/a Assume Medium C-F-i, C-F-2 207 0 12 ISC " LOCA TASCS Medium B-J 6 2 1 ISC TASCS High 3 1 ISC None High 2 1 ISC TASCS Medium 3 1 ISC None Medium 11 0 ISC " LOCA None Low B-F, B-J 13 0 11 MSS None High 84 9 MSS " LOCA TASCS Medium B-J 10 3 2 MSS TASCS Medium 10 1 MSS " LOCA None Low B-J 199 13 61 MSS None Medium 238 0 MSS " PLOCA None Low B-I 14 1 7 4 of 9

ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-011 Table 5.1 Inspection Location Selection Comparisons between ASME Section Xl and Code Case N-716 System Safety Significance Break Failure Potential Code Weld Code Case N578 Code Case N716 Sect. X1 System High Low Location DMs Rank Category Count MSS None Low 8 0 MSS " PLOCA-OC None Low B-J, C-F-2 34 7 21 MSS " LSS n/a Assume Medium C-F-2 90 0 5 RCS IGSCC High 1 1 RCS V LOCA IGSCC Medium B-J I I I RCS None High 105 1 RCS " LOCA None Low B-J 105 10 26 RDS CC High I I RDS " LOCA None Low B-J 2 1 1 RDS None High 1 1 RDS None Medium 76 0 RDS " LSS n/a Assume Medium C-F-2 76 0 6 RIHR EC High 4 1 RHR TASCS High 22 6 RHR None High 77 8 RHR LOCA TASCS Medium B-J 22 6 9 RHR PLOCA-OC EC Medium B-J 4 1 2 RHR TASCS, FAC Medium 17 0 R-I TASCS Medium 208 23

• F.RR FAC Medium 3 0

-ýfH None Medium 537 0 RHR " LOCA None Low B-1 46 6 15 RHR " PLOCA None Low B-J 68 0 7 RHR " PLOCA-OC None Low B-1 24 4 4 RHR " LSS n/a Assume Medium C-F-1, C-F-2 725 0 65 RHR TASCS Low 16 0 R-HR None Low 104 0 RPV V LOCA IGSCC Medium B-F 30 1 4 30 5 of 9

ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-011 Table 5.1 System Safety Hg Significance Break oLoainDsRnCaeoy Failure Potential Code Weld ontCode Case N578 Code Case N716 Sect. XI

_____ High Low Location DMs Rank Category Coun't RPV CC, IGSCC High 21 6 R-PV None High 3 0 RPV IGSCC High 9 2 RPV None Medium 1 0 RPV 1' LOCA None Low B-F, B-J 4 0 3 SLS TASCS High 3 1 SLS None High 14 2 SLS LOCA TASCS Medium B-J 10 4 4 SLS TASCS Medium 7 1 SLS None Medium 26 0 SLS v" PLOCA None Low B-J 26 0 1 SLS PLOCA-OC None Low B-J 14 2 1 WCS TASCS High 10 0 WCS TASCS, High 8 5 IGSCC WCS IGSCC High 10 5 W.C-8 " _FAc High 4 0 WCS None High 75 4 WCS _ " LOCA TASCS,IGSCC Medium B-J 8 5 0 WC.S TASCS, FAC Medium 4 0 WCS TASCS Medium 25 3 WCS FAC Medium 2 0 WCS None Medium 15 0 WCS " LOCA IGSCC Medium B-J 10 5 4 WCS " LOCA TASCS Medium B-J 11 0 3 WCS " PLOCA-OC TASCS Medium B-J 29 5 15 wcs None Low 8 0 WCS " LOCA None Low B-J 76 2 4 6 of 9

ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-011 Table 5.1 Inspection Location Selection Comparisons between ASME Section XI and Code Case N-716 Sysem System High Low Safety Significance Location Break Rank DMsFailure Potential Category Code Count Weld Cd aeN7 Code Case N578 oeCs Code 76Sc.XSect. X1 Case N716 WCS PLOCA None Low B-J 10 0 1 WCS PLOCA-OC None Low B-J, CL3 18 0 4 7 of 9

ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-011 RAI -4 Of the welds not selectedfor future examinations in the RIS B program, have previous examinations of any of these welds identified service induced degradation? If so, what was the degradationmechanism and what was done to mitigate the degradation?

Response

No previously examined weld currently not selected for examination under RISB had indications of service induced degradation.

RAI- 5 The October 25, 2012 submittal states, the RISB Program is a living program monitoredperiodicallyfor changes, where this monitoring includes numerous facets. Please confirm that vendor issued communications such as General Electric (GE)-HitachiSafety Communications are included as part of the reviews donefor the living programaspects of the program.

Response

The RISB Program, once implemented, will include reviews of pertinent operating experience (OE) and vendor communications similar to the requirements of the currently approved N-578 program.

RAI- 6 The October 25, 2012 submittal states that, welds identified as "Category A" (resistant material) in accordance with the augmentedprogramfor intergranularstress corrosion cracking (IGSCC)have been subsumed into the RI-ISI program. With respect to these CategoryA welds please identify the following for welds not selectedfor fi4ture examinations. Section 7, Program Updates, Paragraph(d)of the ASME, Section XN, Code Case N-716, states that "The reevaluation shall determine if any changes to the examination selections need to be made, by evaluation of the following pipingfailures (e.g., plant-specific or industry occurrences of through-wall or through-weld leakage, failure due to a new degradation mechanism or a non-postulatedmechanism)." The operatingexperience reportedon August 17, 2012, in a License Event Report (LER) 50-387/2012-007-00 (Agencywide Documents Access and Management System (ADAMS) Accession Number ML12230A169), indicated that synergistic effects of vibratory fatigue (caused by flow perturbations)and intergranularstress corrosion cracking (IGSCC) caused a leakage in a chemical decontamination pipe (dead leg, branch connection) to reactor recirculation suction pump of an operating Boiling Water Reactor. The staff requests the licensee to identify any CategoryA welds in its currentsubmittal that are not scheduledfor inspection that conform to the similar attributes (vibratoryfatigue, IGSCC, dead leg, branchconnection, etc.) of the failed weld describedin the LER. The licensee is requested to provide an explanation why it was not selectedfor examination in the risk-informed ISIprogram.

Response

Based upon review of the OE described in the referenced LER, NMPNS has scheduled a one-time examination of all six NMP2 Reactor Recirculation decontamination flange welds during the spring 2014 8 of 9

ATTACHMENT NINE MILE POINT UNIT 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING 10 CFR 50.55a REQUEST NUMBER 21SI-011 refueling outage. The OE had not been incorporated into the IST program at the time of the October 25, 2012 submittal.

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