LR-N17-0102, Response to Request for Additional Information Regarding Relief Request SC-14R-171, Use of Code Cases N-695-1 and N-696-1

Response to Request for Additional Information Regarding Relief Request SC-14R-171, Use of Code Cases N-695-1 and N-696-1

ML17156A804
Person / Time
Site:	Salem
Issue date:	06/05/2017
From:	Mannai D Public Service Enterprise Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LR-N17-0102
Download: ML17156A804 (13)

Text

PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, New ,J!lmey 08038-0236 PSECI NudearLJl:

10 CFR 50.55a LR-N17-0102 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Salem Generating Station Units 1 and 2 Renewed Facility Operating License Nos. DPR-70 and DPR-75 NRC Docket Nos. 50-272 and 50-311

Subject:

Response to Request for Additional Information Regarding Relief Request SC-14R-171, Use of Code Cases N-695-1 and N-696-1

Reference:

1. PSEG Letter to NRC, "Request for Use of American Society of Mechanical Engineers (ASME) Code Cases N-695-1 and N-696-1,"

dated March 1, 2017 (ADAMS Accession No. ML17060A477)

2. NRC Letter to PSEG, "Salem Generating Station, Unit Nos. 1 and 2-Request for Additional Information Regarding Relief Request SC-14R-171, Use of Code Cases N-695-1 and N-696-1 (CAC Nos. MF9348 and MF9349)," dated May 8, 2107 (ADAMS Accession No. ML17115A403)

In the Reference 1 letter, PSEG Nuclear LLC (PSEG) requested relief in accordance with 10 CFR 50.55a, "Codes and standards." In the Reference 2 letter, the U.S.

Nuclear Regulatory Commission (NRC) staff provided PSEG a Request for Additional

_Information (RAI)Jo support the NRC staff's review oUbe proposed relief request.-

The requested information is provided in Attachment 1. Attachment 2 provides a revision to the Reference 1 relief request with changes marked by revision bars.

There are no regulatory commitments contained in this letter.

JUN Qli 2017

\

LR-N17-0102 10 CFR 50.55a Page 2 Should you have any questions concerning this matter, please contact Mr. Brian Thomas at 856-339-2022.

Sincerely, Da eff!:;-

Senior Director, Regulatory Operations PSEG Nuclear LLC Attachments:

1. Response to Request for Additional Information

2. 10 CFR 50.55a Relief Request SC-14R-171 - Revised cc: Administrator, Region I, NRC NRC Senior Resident Inspector, Salem R. Ennis, Project Manager, Salem, USNRC P. Mulligan, Chief, NJBNE L. Marabella, Corporate Commitment Tracking Coordinator T. Cachaza, Salem Commitment Tracking Coordinator

LR-N17-01 02 Attachment 1 Response to Request for Additional Information

LRN17-0102 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING RELIEF REQUEST SC-14R-171 USE OF CODE CASES N-695-1 AND N-696-1 SALEM NUCLEAR GENERATING STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-272 AND 50-311 By letter dated March 1, 2017, PSEG Nuclear LLC (PSEG or the licensee) submitted Relief Request SC-14R-171 for Salem Nuclear Generating Station (Salem), Unit Nos. 1 and 2. The request would authorize the use of alternatives to the depth sizing requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code),Section XI, Appendix VIII, Supplements 2 and 10, as modified by Code Case N-695, "Qualification Requirements for Dissimilar Metal Piping Welds," and Code Case N-696, "Qualification Requirements for Mandatory Appendix V III Piping Examinations Conducted From the Inside Surface." Specifically, the licensee proposed to use the alternative inner diameter flaw depth sizing root mean square error criteria in ASME Code Cases N-695-1, "Qualification Requirements for Dissimilar Metal Piping Welds," and N-696-1, "Qualification Requirements for Mandatory Appendix VIII Piping Examinations Conducted from the Inside Surface," for performance demonstration of the ultrasonic testing at Salem, Unit Nos. 1 and 2.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the application and, based upon this review, determined that the following additional information is needed to complete the review:

1. The March 1, 2017, submittal proposes to use the procedures in ASME Code Cases N-695-1 and 696-1 as an alternative to the root mean square error criteria of Code Cases N-695 and N-696. The NRC staff notes that in the 2015 ASME Code, "Code Cases, Nuclear Components," the Applicability Index for Section XI Cases has limited the use of Code Cases N-695 and N-696 to the 2003 Addenda, or earlier editions and addenda of the Code.

Given that Code Cases N-695 and N-696 are not applicable -for Salem's current code ofrecord (2004 Edition wlfh no addenda), it is not clear to the NRG staff 1

that regulatory authority exists under Title 10 of the Code of Federal Regulations 50.55a(z) to authorize the proposed alternative. However, the NRC staff notes that Code Cases N-695 and N-696 provide alternatives to ASME Code,Section XI, Appendix VIII, Supplements 2, 10, and/or 14, and that regulatory authority does exist to authorize the use of N-695-1 and N-696-1 as an alternative to the ASME Code,Section XI, Appendix VIII, requirements.

Please revise the request to reflect this issue or provide justification as to why modifying the request is not required.

Page 1 of 2

LR-N17-0102 PSEG Response:

Attachment 2 contains a revised request for relief stating that PSEG is requesting relief from ASME Section XI, Appendix VIII, Supplements 2 and 10. Changes to the original relief request are identified by revision bars in Attachment 2.

2. The NRC staff notes that the tables in Section 1 of the March 1, 2017, submittal list all eight (four hot leg and four cold leg ) reactor pressure vessel nozzle to safe end dissimilar metal welds for each unit, and four reactor pressure vessel safe end to pipe austenitic welds for each unit.

In addition to the dissimilar metal welds, does this relief request also include all eight ( four hot leg and four cold leg ) reactor pressure vessel safe end to pipe austenitic welds for each unit? Please explain.

PSEG Response:

The eight cold leg safe end austenitic welds ( four on each Salem unit) are not included in the request for relief. The eight cold leg safe end welds contain austenitic stainless steel safe ends which are welded to cast austenitic stainless steel ( CASS ) elbows. These eight welds have limited examination coverage due to the CASS elbow ultrasonic properties; therefore, these eight welds are not currently scheduled for examination during the fourth lnservice Inspection 10 year intervals.

Page 2 of 2

LR-N17-0102 Attachment 2 10 CFR 50.55a Relief Request SC-14R-171 - Revised LR-N17-0102 Salem Generating Station Units 1 and 2 Renewed Facility Operating License Nos. DPR-70 and DPR-75 NRC Docket Nos. 50-272 and 50-311 10 CFR 50.55a Request SC-14R-171 Hardship in Accordance with 10 CFR 50.55a(z)(2)

Hardship without a Compensating Increase in Quality and Safety

1. ASME Code Component(s) Affected Code Class: 1 Examination Category: Code Case N-770-1 and R-A Item Number: Inspection Items B, D, E and R1.20

Description:

Reactor Pressure Vessel (RPV)

Nozzle to Safe End Alloy 600 Welds and Safe End to Stainless Steel Pipe welds:

Unit 1 Welds ASME ASME Nominal Component ID Category Item Description Thickness 27.5-RC-1110-5 N-770-1 D NOZZLE TO SAFE-END (RPV-CL) 2.5in 27.5-RC-1120-5 N-770-1 D NOZZLE TO SAFE-END (RPV-CL) 2.5in 27.5-RC-1130-5 N-770-1 D NOZZLE TO SAFE-END (RPV-CL) 2.5in 27.5-RC-1140-5 N-770-1 D NOZZLE TO SAFE-END (RPV-CL) 2.5in 29-RC-1110-1 N-770-1 D NOZZLE TO SAFE-END (RPV-HL) 2.5in 29-RC-1120-1 N-770-1 D NOZZLE TO SAFE-END (RPV-HL) 2.5in 29-RC-1130-1 N-770-1 D NOZZLE TO SAFE-END (RPV-HL) 2.5in 29-RC-1140-1 N-770-1 E NOZZLE TO SAFE-END (RPV-HL) 2.5in 29-RC-1110-2 R-A R1.20 SAFE-END TO PIPE 2.5in 29-RC-1120-2 R-A R1.20 SAFE-END TO PIPE 2.5in 29-RC-1130-2 R-A R1.20 SAFE-END TO PIPE 2.5in 29-RC-1140-2 R-A R1.20 SAFE-END TO PIPE 2.5in Page 1 of 7 LR-N17-0102 Unit 2 Welds*

ASME ASME Nominal Component ID Category Item Description Thickness 27.5-RC-1210-5 N-770-1 B NOZZLE TO SAFE-END (RPV-CL) 2.5in 27.5-RC-1220-5 N-770-1 B NOZZLE TO SAFE-END (RPV-CL) 2.5in 27.5-RC-1 230-5 N-770-1 B NOZZLE TO SAFE-END (RPV-CL) 2.5in 27.5-RC-1240-5 N-770-1 B NOZZLE TO SAFE-END (RPV-CL) 2.5in 29-RC-1 21 0-1 N-770-1 D NOZZLE TO SAFE-END (RPV-HL) 2.5in 29-RC-1220-1 N-770-1 D NOZZLE TO SAFE-END (RPV-HL) 2.5in 29-RC-1 230-1 N-770-1 D NOZZLE TO SAFE-END (RPV-HL) 2.5in 29-RC-1 240-1 N-770-1 D NOZZLE TO SAFE-END (RPV-HL) 2.5in 29-RC-121 0-2 R-A R1.20 SAFE-END TO PIPE 2.5in 29-RC-1220-2 R-A R1.20 SAFE-END TO PIPE 2.5in 29-RC-1230-2 R-A R1 .20 *SAFE-END TO PIPE 2.5in 29-RC-1 240-2 R-A R1 .20 SAFE-END TO PIPE 2.5in

2. Applicable Code Edition and Addenda

The American Society for Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section XI, "Rules for lnservice Inspection and Testing of Components of Light-Water Cooled Plants," Code* of record for Salem Units 1 and 2 lnservice Inspection (lSI) Fourth Intervals is the 2004 Edition with no Addenda.

The Salem Unit 1 Fourth lSI Interval began on May 20, 2011, and is scheduled to end on December 31, 2020, and the Salem Unit 2 Fourth lSI Interval began on November 27, 2013, and is scheduled to end on December 31, 2021.

3. Applicable Code Requirement

Code Case N-770-1 as referenced in 10 CFR 50.55a (g)(6)(ii)(F) stipulates ultrasonic examination of dissimilar metal welds fabricated fromAIIoy-82/182-material. These requirements apply to the Salem Unit 1 and Unit 2 reactor pressure vessel (RPV) nozzle to safe-end welds and Risk-Informed Examination Category R-A, Item R1.20 (formerly Code Category 8-J, 89.11) for the associated RPV safe-end to piping welds that are fabricated with stainless steel weld material.

All of the specified ultrasonic examinations (UT) are to be conducted per Appendix VIII Supplements 2 (wrought austenitic welds) and 10 (dissimilar metal welds). Supplement 2 paragraph 3.2(b) states, "The RMS error of the flaw depths estimated by ultrasonics, as compared with the true depths, shall Page 2 of 7 LR-N17-0102 not exceed 0.125 in. (3 mm)," Supplement 10 paragraph 3.3(c) states, "Examination procedures, equipment, and personnel are qualified for depth sizing when the RMS error of the flaw depth measurements, as compared to the true flaw depths, do not exceed 0.125 in. (3 mm)."

4. Reason for Request PSEG is requesting to utilize Code Cases N-695-1 and N-696-1 which requires a 0.250 in. root mean square error (RMSE) depth sizing accuracy whereas the requirements in Supplements 2 and 10 require a 0.125 in. RMSE depth sizing accuracy. To date, although examination vendors have qualified for detection and length sizing in accordance with the ASME Section XI Appendix V III requirements for examinations from the inside diameter (10),

the vendors have not met the established RMSE of 0.125 in. for depth sizing despite numerous attempts. Consequently, relief from the Supplement 2 and 10 specified 0.125 in. RMSE depth sizing accuracy requirements is necessary to support evaluation of findings from examinations when conducted from the inside surface. This relief is being requested in accordance with 10 CFR 50.55a(z)(2) as a hardship without a compensating increase in quality and safety.

Most recent UT examinations of the RPV nozzle to safe-end dissimilar metal and safe-end to pipe welds have been performed from the outside surface (OD) of the piping at Salem Unit 1 and Unit 2. Access to the 00 of these welds is inside a "sandbox" which was installed during original plant construction after all welding was completed. Although these examinations can be performed from the OD of the RPV nozzles, these inspection activities would result in the unnecessary personnel radiation exposure for the personnel performing these examinations without a compensating increase in quality or safety as discussed below as compared to performing these examinations from the inside surface (10) of the piping. Therefore Salem station has changed the examination for the welds identified in this relief request from performing the inspection from the 00 to performing them from the ID to minimize personnel radiation exposure.

Based upon a review of dose records for similar RPV Cold leg nozzle to safe-end weld volumetric UT examinations (Code Case N-770-1 item B welds) performed from the OD for the most recent lnservice inspections at Salem Unit 2, the dose exposure to personnel performing the NDE of 4 RPV Cold Leg weld UT examinations was approximately 3.5 REM. This is a conservative estimate of the personnel exposure since it does include any additional dose received by supporting organizations (i.e., maintenance, radiation protection). Performing the examinations from the ID during refueling outages also reduces the overall exposure of the weld examinations since this examination technique is performed remotely and does not require personnel to access the exterior 'sandbox' area of the RPV.

Page 3 of 7 LR-N17-0102 PSEG believes that volumetric UT examination of all noted 24 welds (12 per unit) from the OD surface would create a hardship in that personnel would unnecessarily receive additional radiation exposure, in the order of over 21 REM without an increase in quality or safety as discussed above.

5. Proposed Alternative and Basis for Use 10 CFR 50.55a(z)states:

Alternatives to codes and standards requirements. Alternatives to the requirements of paragraphs (b) through (h) of this section or portions thereof may be used when authorized by the Director, Office of Nuclear Reactor Regulation, or Director, Office of New Reactors, as appropriate. A proposed alternative must be submitted and authorized prior to implementation. The applicant or licensee must demonstrate that:

(1) Acceptable level of quality and safety. The proposed alternative would provide an acceptable level of quality and safety; or (2) 1-/ardship without a compensating increase in quality and safety.

Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

This relief is being requested in accordance with 10 CFR 50.55a(z)(2) as a hardship without a compensating increase in quality and safety .

As discussed in section 4, Salem station has changed the examination for the welds identified in this relief request from performing the examinations from the OD to performing them from the ID to minimize personnel radiation exposure.

To date, although examination vendors have qualified for detection and length sizing in accordance with the ASME Section_ XI AppendixYIILrequirere n nts for examinations from the ID, the vendors have not met the established RMSE of 0.125 in. for depth sizing despite numerous attempts. Consequently, relief from the Supplement 2 and 10 specified 0 .125 in. RMSE depth sizing accuracy requirements is necessary to support evaluation of findings from examinations when conducted from the ID.

PSEG is requesting to utilize Code Cases N-695-1 and N-696-1. Paragraph 3.3(d) of Code Case N-695-1 states:

Page 4 of 7 LR-N17-0102 For qualifications from the inside-surface, examination procedures, equipment, and personnel are qualified for depth sizing if the RMS error of the flaw depth measurements, as compared to the true flaw depths, does not exceed 0.125 in (3mm) for piping less than 2.1 in. (54 mm) in thickness, or 0.250 in. (6mm) for piping 2.1 in. (54 mm) or greater in thickness.

Paragraph 3.3(c) of Code Case N-695-1 states:

Supplement 2 examination procedures, equipment, and personnel are qualified for depth-sizing if the RMS error of the flaw depth measurements as compared to the true flaw depths, does not exceed 0.125 in. (3mm) for piping less than 2.1 in (54 mm) in thickness, or 0.250 in. (6mm) for piping 2.1 in. (54 mm) or greater in thickness, when they are combined with a successful Supplement 10 qualification.

All welds included in this request were most recently UT examined from the OD with an Appendix VIII qualified detection process and length sizing in the previous refueling outages. Greater than 90 percent coverage of the required examination areas was achieved in all cases. Prior examination history when examinations were performed from ID confirms that the inside surface profiles of the welds included in this request are suitable for ultrasonic examination.

The Salem Unit 1 and Unit 2 RPV nozzle to safe-end and safe-end to piping welds will be examined from the ID using personnel, procedures and equipment qualified by demonstration in all aspects. PSEG proposes to use a vendor qualified for ID detection and length sizing per Appendix VIII as applicable to the welds included in this request. Depth sizing qualification will meet the requirements of ASME Code Cases N-695-1 and N-696-1.

In the approval of the precedent relief requests listed in Section 7 of this attachment, the NRC safety evaluations identified the need for special treatment of flaws connected to the inside surface and are measured to be more than 50 percent through the wall thickness.

_ lf a reportable flaw is detectedan _ jned tp be ID surtace_con_necied

_ d determ _ _

during examination of the welds in accordance with this relief request, PSEG will provide a flaw evaluation including the measured flaw size as determined by ultrasonic examination for NRC review. Eddy current testing will be used to determine if flaws are surface connected. Additional data including details of the impracticable surrounding ID surface contour in the region of the flaw and percentage of the examination area where ultrasonic testing (UT) probe lift-off is evident, if any, will be included.

Indications requiring depth sizing during examination of welds in accordance with this relief request will be treated as discussed below:

Page 5 of 7 LR-N17-0102

• Flaws detected and measured as less than 50 percent through-wall will be sized in accordance the personnel, procedures and equipment qualified to meet the requirements of ASME Code Cases N-695-1 and N-696-1

• For flaws detected and measured as 50 percent through-wall depth or greater and to remain in service without mitigation or repair, PSEG will submit flaw evaluation(s) for review and approval prior to reactor startup. The flaw evaluation will include:

1. Information concerning the mechanism that caused the flaw.

2. Information concerning the inside surface roughness and/or profile of the region surrounding the flaw in the examined piping weld.

3. Information concerning areas where UT probe lift-off is observed, if any.

All other ASME Code,Section XI requirements for which relief was not specifically requested apply including the third party review by the Authorized Nuclear lnservice Inspector.

6. Duration of Proposed Alternative The duration of the request for proposed alternative for Salem Unit 1 is through the end of the fourth interval currently scheduled to end on 12/31/2020; and for Salem Unit 2, the duration is through the end of the fourth interval currently scheduled to end on 12/31/2021.

7. Precedents Similar relief requests have been previously approved for relief from the 0.125 RMSE requirement for the following plants:

(1) NRC letter to Entergy letter, "Arkansas Nuclear One, Unit 1 -Relief Request No. AN01-ISI-025, Relief from Amerian Society of Mechanical EngineersSection XI Table IWB-2500-1 Requirements (CAC No.

MF7625)," dated August 29, 2016 (ADAMS Accession No. ML16237A082)

(2) NRC Letter to Pacific Gas and Electric Company, "Diablo Canyon Power Plant, Unit No. 2 - lnservice Inspection Program Relief Request NDE RCS-SE-2R19, Associated with the Use of Alternate Sizing Qualification Criteria Through a Protective Clad Layer (CAC No. MF5348)," dated November 4, 2015 (ADAMS Accession No. ML15299A034)

Page 6 of 7 LR-N17-0102 (3) NRC Letter to Duke Energy Carolinas, "Catawba Nuclear Station, Unit 1:

Proposed Relief Request 14-CN-003, American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (ASME Code), Code Case N-695 (CAC NO. MF5447)," dated October 26, 2015 (ADAMS Accession No. ML15286A326)

8. Reference

1) Regulatory Guide 1.147, "lnservice Inspection Code Case Acceptability, ASME Section XI, Division 1," Revision 17 dated August 2014.

2) Code Case N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities,Section XI, Division 1" .

3 ) Code Case N-695-1, "Qualification Requirements for Dissimilar Metal Welds,Section XI, Division 1," approved December 31, 2014

4) Code Case N-696-1, "Qualification Requirements for Mandatory Appendix VIII Piping Examinations Conducted From the Inside Surface,Section XI, Division 1 ," approved May 7, 2014.

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