ML13261A288
| 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) | |
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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 "A
-7 P.O. Box 63, Lycoming, NY 13093
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 examinations for 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 regard to the percentage of exams performed in each period.
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 3rd 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 selected for examination. Please clarify what the number shown under the column "Class 3 and Non-class Welds" represents. All other columns appear to represent total welds whereas this column appears to 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 current RI-ISI prograin with the selections of the proposed RISB 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 Safety Significance Break Failure Potential Code Weld System 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
10 FW None High 5
FW PLOCA TASCS Medium B-J 3
1 2
FW PLOCA-OC TASCS Medium B-J 12 1
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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-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
0 FW PLOCA-OC None Low B-J, CL4 8
1 4
FW None Medium 6
3 3
ICS TT,TASCS High 3
ICS PLOCA TASCS Medium B-J 4
1 0
ICS None High 5
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
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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 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
1 RCS V
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
R-I TASCS Medium 208 23
0
-ýfH None Medium 537 0
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
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 Safety Significance Break Failure Potential Code Weld System Hg oLoainDsRnCaeoy 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
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
- TASCS, High 8
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
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
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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. X1 Sysem High Low Location DMs Rank Category Count Cd aeN7 oeCs 76Sc.X WCS PLOCA None Low B-J 10 0
1 WCS PLOCA-OC None Low B-J, CL3 18 0
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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 -4 Of the welds not selected for future examinations in the RIS B program, have previous examinations of any of these welds identified service induced degradation? If so, what was the degradation mechanism 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 monitored periodically for changes, where this monitoring includes numerous facets. Please confirm that vendor issued communications such as General Electric (GE)-Hitachi Safety Communications are included as part of the reviews done for the living program aspects 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 augmented program for intergranular stress corrosion cracking (IGSCC) have been subsumed into the RI-ISI program. With respect to these Category A welds please identify the following for welds not selected for 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 piping failures (e.g., plant-specific or industry occurrences of through-wall or through-weld leakage, failure due to a new degradation mechanism or a non-postulated mechanism)." The operating experience reported on 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 intergranular stress 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 Category A welds in its current submittal that are not scheduled for inspection that conform to the similar attributes (vibratory fatigue, IGSCC, dead leg, branch connection, etc.) of the failed weld described in the LER. The licensee is requested to provide an explanation why it was not selected for examination in the risk-informed ISI program.
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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