NMP1L3180, Submittal of Relief Request NMP-RR-001 Concerning Nozzle-to-Vessel Weld and Inner Radii Examinations (Use of Code Case N-702)

Submittal of Relief Request NMP-RR-001 Concerning Nozzle-to-Vessel Weld and Inner Radii Examinations (Use of Code Case N-702)

ML17261A051
Person / Time
Site:	Nine Mile Point
Issue date:	09/18/2017
From:	Jim Barstow Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CAC MF9381, CAC MF9382, NMP1L3180
Download: ML17261A051 (5)

Text

Exelon Generation NMP1L3180 September 18, 2017 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Nine Mile Point Nuclear Station, Units 1 and 2 200 Exelon Way Kennett Square. PA 19348 www.exeloncorp.com 1 O CFR 50.55a Renewed Facility Operating License Nos. DPR-63 and NPF-69 NRC Docket Nos. 50-220 and 50-41 O

Subject:

Submittal of Relief Request NMP-RR-001 Concerning Nozzle-to-Vessel Weld and Inner Radii Examinations (Use of Code Case N-702)

References:

1) Letter from J. Barstow (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Submittal of Relief Request NMP-RR-001 Concerning Nozzle-to-Vessel Weld and Inner Radii Examinations (Use of Code Case N-702)," dated March 7, 2017

2) Letter from M. Marshall (U.S. Nuclear Regulatory Commission) to B. Hanson (Exelon Generation Company, LLC), "Nine Mile Point Nuclear Station, Units 1 and 2 - Request for Additional Information Regarding Relief Request to Utilize ASME Code Case N-702 (CAC Nos. MF9381 and MF9382)," dated June 27, 2017

3) Letter from J. Barstow (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "Submittal of Relief Request NMP-RR-001 Concerning Nozzle-to-Vessel Weld and Inner Radii Examinations (Use of Code Case N-702)," dated July 24, 2017

4) Letter from M. Marshall (U.S. Nuclear Regulatory Commission) to B. Hanson (Exelon Generation Company, LLC), "Nine Mile Point Nuclear Station, Units 1 and 2 - Request for Additional Information Regarding Relief Request NMP-RR-001 to Utilize ASME Code Case N-702 (CAC Nos. MF9381 and MF9382)," dated August 30, 2017 In the Reference 1 letter, Exelon Generation Company, LLC (Exelon), requested relief from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV)

Code,Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components."

Relief Request NMP-RR-001 proposed an alternative to the requirements contained in Table IWB-2500-1 concerning nozzle-to-vessel weld and nozzle inner radii examination requirements.

U.S. Nuclear Regulatory Commission Nine Mile Point Nuclear Station, Units 1 and 2 Submittal of Relief Request NMP-RR-001 Concerning Nozzle-to-Vessel Weld and Inner Radii Examinations (Use of Code Case N-702)

September 18, 2017 Page2 In the Reference 4 letter, the U.S. Nuclear Regulatory Commission requested additional information. Attached is our response to that request.

No regulatory commitments are contained in this letter. Should you have any questions concerning this letter, please contact Tom Loomis at (61 O) 765-5510.

Sincerely, Jamea:: ~

Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC

Attachment:

Response to Request for Additional Information - "NRC RAI on Nine Mile Point Unit 1 and 2 Relief Request on Nozzle Inspection," Structural Integrity Associates, Inc., Report No. 1700909.402.RO, dated September 11, 2017 cc: Regional Administrator - NRC Region I NRC Senior Resident Inspector-NMP NRC Project Manager, NRR - NMP A. L. Peterson, NYSERDA

Attachment Response to Request for Additional Information - "NRG RAI on Nine Mile Point Unit 1 and 2 Relief Request on Nozzle Inspection," Structural Integrity Associates, Inc., Report No. 1700909.402.RO, dated September 11, 2017

©Structural Integrity Associates, Inc.

September 11, 201 7 Report No. 1700909.402.RO Quality Program: l:gj Nuclear D Commercial 5215 Hellyer Ave.

Suite 210 San Jose, CA 95138-1025 Phone: 408-978-8200 Fax:

408-978-8964 1V\\W1.strucbnt.com wwong@structinlcom

Subject:

NRC RAI on Nine Mile Point Unit 1 and 2 Relief Request on Nozzle Inspection By letter dated March 7, 2017 (ML17067A056), as supplemented by letter dated July 24, 2017 (ML l 7206A I 01 ), Exelon submitted Relief Request NMP-RR-00 l for the Nine Mile Point Nuclear Station (NMP), Units 1 and 2. The Nuclear Regulatory Commission (NRC) staff has determined that the following additional information is needed to complete its review of the request, as per NRC letter from Michael L. Marshall Jr. to Bryan C. Hanson dated August 30, 2017 (ML17234A359):

Provide a justification that the PFM analyses provided in relief request NMP-RR-001 demonstrates application of ASME Code Case N-702 for Nine Mile Point Unit I, recirculation outlet nozzle, and the Nine Mile Point Unit 2, recirculation inlet nozzle, for the duration of the Nine Mile Point, Units 1 and 2 RFOLs.

Alternatively, address the following areas:

Provide a justification that demonstrates that the structural analysis of the representative nozzle geometry and the evaluation of the safety consequences of the nozzle failure in BWRVIP-108 and BWRVIP-241 apply to the plant's current licensing basis.

Provide a justification that demonstrates that the current licensing basis can be maintained when considering the stress and cycling range during the extended operating period.

Provide a justification that demonstrates that neutron tluence effects are negligible at the nozzle locations when considering the period of extended operation.

This report addresses the bounding nature of the NMP 1 N2 nozzle and the NMP 2 NI nozzle analyzed in SI Report No. 1501576.401 Rl in regards to geometry, as well as tluence and additional thermal fatigue cycles through the end of the period of extended operation.

Section 2 of BWRVIP-241 concluded that the probability of failure only needs to be checked for the recirculation inlet (N2) and recirculation outlet (N 1) nozzles. Of those two nozzle types, one

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Report No. 1700909.402.RO September 11, 2017 Page 2of2 can be determined as bounding based on the criteria set forth in the NRC safety evaluation of BWRVIP-108 (ML073600374).

For NMP 1, the tluence at all applicable (for application of ASME Code Case N-702) nozzles remain less than l.OE 17 n/cm2 through the period of extended operation. SI Report No.

1700909.401 RO determined that additional thermal fatigue cycling through the end of the period of operation had no effect on the probability of failure. Since the NMP l N2 nozzle is bounding based on the criteria set forth in the safety evaluation of BWRVIP-108, the analysis of the N2 nozzleinSIReportNo.1501576.401 Rl boundstheNMP 1 Nl nozzleandtheotherapplicable nozzles defined in the NMP submittal enclosure 1 for the application of ASME Code Case N-702 through the period of extended operation. Note: RPV feedwater nozzles and control rod drive return line nozzles are excluded as these are outside the scope of ASME Code Case N-702.

ForNMP 2, SI Report No. 1501576.401 Rl demonstrated that the analysis of the LaSalle Unit 2 Nl nozzle represents the NMP 2 Nl nozzle in geometry and material chemistry. Furthermore, the fluence value used in the LaSalle analysis bounds the maximum fluence at any applicable NMP 2 nozzle. SI Calculation No. 1501576.301 RO, concluded that the NMP 2 Nl nozzle probability of failure remains acceptable after consideration of additional thermal fatigue cycles through the period of extended operation. Since the NMP 2 Nl nozzle is bounding based on the criteria set forth in the safety evaluation of BWRVIP-108, the analysis of the N 1 nozzle in SI Report No. 1501576.401 Rl bounds the NMP 2 N2 nozzle and the other applicable nozzles defined in the NMP submittal enclosure 1 for the application of ASME Code Case N-702 through the period of extended operation. Note: RPV feedwater nozzles and control rod drive return line nozzles are excluded as these are outside the scope of ASME Code Case N-702.

Prepared by:

Wilson Wong, P.E.

Senior Engineer Reviewed by:

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Terry J. Herrmann, P.E.

Senior Associate Approved by:

Wilson Wong, P.E.

Senior Engineer 9111117 Date 9/11117 Date 9111117 Date Verified by:

S.S. Tang Associate 9/11117 Date Structural Integrity Associates, tne