ML18107A756

Regulatory Audit Summary License Amendment Request for Transition to Westinghouse Core Design and Safety Analyses Including Adoption of Alternative Source Term (CAC MF9307; EPID L-2017-LLA-0211)

ML18107A756
Person / Time
Site:	Wolf Creek
Issue date:	05/03/2018
From:	Balwant Singal Plant Licensing Branch IV
To:	Heflin A Wolf Creek
Singal B, NRR/DORL/LPL4-1
References
CAC MF9307, EPID L-2017-LLA-0211
Download: ML18107A756 (7)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 3, 2018 Mr. Adam C. Heflin President, Chief Executive Officer, and Chief Nuclear Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, KS 66839

SUBJECT:

WOLF CREEK GENERATING STATION, UNIT 1 - REGULATORY AUDIT

SUMMARY

REGARDING LICENSE AMENDMENT REQUEST FOR TRANSITION TO WESTINGHOUSE CORE DESIGN AND SAFETY ANALYSES INCLUDING ADOPTION OF ALTERNATIVE SOURCE TERM (CAC NO. MF9307; EPID L-2017-LLA-0211)

Dear Mr. Heflin:

By letter dated January 17, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17054C103), as supplemented by letters dated March 22, May 4, July 13, October 18, and November 14, 2017; and January 15 and January 29, 2018 (ADAMS Accession Nos. ML17088A635, ML17130A915, ML17200C939, ML17297A478, ML17325A982, ML18024A477, and ML180336024, respectively), Wolf Creek Nuclear Operating Corporation (the licensee) submitted a license amendment request for transition to Westinghouse Core Design and Safety Analyses including adoption of Alternative Source Term in accordance with Title 10 of the Code of Federal Regulations Section 50.67 for the Wolf Creek Generating Station, Unit 1.

To support its review of the license amendment request, the U.S. Nuclear Regulatory Commission staff conducted a regulatory audit at the Westinghouse facility in Rockville, Maryland from March 19, 2018, to March 20, 2018, to verify information submitted by the licensee and the supporting calculations. The regulatory audit summary is enclosed with this letter.

A. Heflin If you have any questions, please contact me at 301-415-3016 or via e-mail at Balwant.Singal@nrc.gov.

Sincerely,

~+0£,~&St Balwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-482

Enclosure:

Regulatory Audit Summary cc: Listserv

REGULATORY AUDIT

SUMMARY

FOR MARCH 19- MARCH 20. 2018, AUDIT IN SUPPORT OF THE REVIEW OF LICENSE AMENDMENT REQUEST FOR TRANSITION TO WESTINGHOUSE CORE DESIGN AND SAFETY ANALYSES INCLUDING ADOPTION OF ALTERNATIVE SOURCE TERM WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION, UNIT 1 DOCKET NO. 50-482

1.0 BACKGROUND

By letter dated January 17, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17054C103), as supplemented by letters dated March 22, May 4, July 13, October 18, and November 14, 2017; and January 15 and January 29, 2018 (ADAMS Accession Nos. ML17088A635, ML17130A915, ML17200C939, ML17297A478, ML17325A982, ML18024A477, and ML180338024, respectively), Wolf Creek Nuclear Operating Corporation (WCNOC, the licensee) submitted a license amendment request (LAR) for transition to Westinghouse Core Design and Safety Analyses including adopting an Alternative Source Term (AST) for the Wolf Creek Generating Station, Unit 1 (WCGS).

The proposed amendment would revise the WCGS Technical Specifications (TSs) to replace the existing WCNOC methodology for performing core design, non-loss-of-coolant accident (non-LOCA) and LOCA safety analyses with standard Westinghouse developed and U. S. Nuclear Regulatory Commission (NRC)-approved analysis methodology. The proposed LAR would also change the TSs to revise WCGS licensing basis by adopting the AST radiological analysis methodology in accordance with Title 10 of the Code of Federal Regulations (10 CFR) Section 50.67, "Accident source term."

The NRC staff reviewed the impact of implementing an AST on currently analyzed design-basis accidents in the WCGS licensing basis and identified the need for additional information in order to complete the review of the LAR. By letters dated January 15 and January 29, 2018, the licensee provided responses to the request for addition information (RAI). The NRC staff has performed a detailed review of the proposed TS changes and supporting calculations and determined that face-to-face interactions with the WCNOC staff can resolve complex technical issues more quickly than multiple rounds of RAls. Hence, the NRC staff determined the need for a regulatory audit to be conducted in accordance with the Office of Nuclear Reactor Regulation (NRR) Office Instruction LIC-111, "Regulatory Audits" (ADAMS Accession No. ML082900195), for the NRC staff to gain a better understanding of the licensee's calculations and other aspects of the LAR. An audit plan was issued by the NRC staff by letter dated March 8, 2018 (ADAMS Accession No. ML18066A050). The scope of the audit was primarily focused on changes to the WCGS licensing basis for adopting the AST radiological analysis methodology. In addition to examining the audit documents,

the NRC staff held discussions with the Westinghouse and WCNOC subject matter experts to better understand WCNOC's response to the RAls, provided by letters dated January 15 and January 29, 2018.

2.0 AUDIT DATES AND LOCATION The regulatory audit was held at the Westinghouse facility in Rockville, Maryland. The audit was originally planned for March 19, March 20, and March 21, 2018. However, the NRC staff was able to complete it in 2 days (March 19 and March 20, 2018).

3.0 AUDIT TEAM MEMBERS The following NRC audit team members consisted of:

• Mark Blumberg, Lead Technical Reviewer, NRR, Division of Risk Assessment (ORA), Radiation Protection and Consequences Branch (ARCB)

• Kristy Bucholtz, Technical Reviewer, NRR/DRA/ARCB (Part Time)

• Balwant Singal, Senior Project Manager, NRR, Division of Operating Reactor Licensing (DORL). Plant Licensing Branch IV (LPL4)

• Siva Lingam, Project Manager, NRR/D0RULPL4 (Part Time)

• John Hughey, Technical Reviewer, NRR/DRA, Probabilistic Risk Assessment and Human Factors Branch (APHB) (Part Time)

• Kevin Quinlan, Office of New Reactors, Division of Site and Environmental Analysis, Hydrology and Meteorology Branch, Meteorology Team (Part Time)

The following WCNOC and Westinghouse staff (in support of the licensee) participated in the audit:

• Nicole Good, Licensing Engineer, WCNOC

• Dustin Wirth, Westinghouse (WCGS Site Supervisor)

• Sean Kinnas, Containment Radiological Analysis, Westinghouse

• Alex Markivich, Radiation Engineering and Analysis, Westinghouse

• Jim Smith, Licensing Manager, Westinghouse

• Mike Watson, Project Manager, Westinghouse

4.0 DOCUMENTS AUDITED The following documents were reviewed at the Audit:

a. The radiological calculations and documents which support the LAR and the RAI responses dated January 15 and January 29, 2018.

b. The RADTRAD computer code input and output decks used to support the LAR.

5.0 AUDIT ACTIVITIES The audit consisted of the following activities:

• NRC's staff entrance briefing.

• A period in which the staff examined the documents and held discussions with WCNOC and Westinghouse participants as needed for technical understanding.

• Exit briefing for NRC to present observations in person and Westinghouse to seek clarification.

6.0 AUDIT

SUMMARY

The purpose of this regulatory audit was to determine if calculations performed by the licensee support the bases for the proposed changes to the TSs and the modifications to the design basis in accordance with 10 CFR 50.67. The area of focus during the audit was the licensee's response to RAls, by letters dated January 15 and January 29, 2018, and the calculations performed by the licensee in support of the proposed LAR (RAls were issued by the NRC staff by letter dated December 4, 2017 (ADAMS Accession No. ML17331A178)).

Results of the Audit

a. Based on the review of the RAI responses, the NRC staff indicated that the NRC staff currently does not have any followup questions for the following RAls: 1 LOAC-2, LLBA-1, LOCA-2, LOCA-4, FHA-1, FHA-4, FHA-7, SGTR-1, SGTR-4, WT-1, WT-2, CREA-2, Control Room-5, and General-1

b. Based on the clarifications provided by the licensee during the audit, the NRC staff indicated that the NRC staff currently does not have any further questions on the following RAls: 1 LLBA-3, SGTR-3, Control Room-1, Control Room-2, Control Room-6, General-3.

c. Based on the review of the calculations and discussions during the audit, the licensee indicated that it understands the NRC staff concerns and intends to supplement its previous RAI response for the following RAI questions: 1 LOCA-1, LOAC-1, LLBA-2, LLBA-4, LOCA-1, LOCA-3, FHA-2, FHA-5, FHA-6, SGTR-2, SGTR-6, LRA-1, MSLB-1, MSLB-2, WT-3, WT-4, WT-5, CREA-1, Control Room-3, Control Room-4, and General-2.

1 All RAI numbers to be preceded by ARCB1

d. The discussions could not be concluded on RAls ARCB1-LOCA-5, ARCB1-FHA-3, and ARCB1-SGTR-5. It was decided to have follow-up discussions on these RAls after the conclusion of the audit. Follow-up discussions may result in additional RAls.

7.0 EXIT BRIEFING As described in Section 6.0 of this summary, the exit discussion summarized the status of each RAI. As described in Section 6.0, either based on the RAI responses provided by the licensee by letters dated January 15 and January 29, 2018, or as a result of clarifications provided during the audit, the NRC staff currently has no followup questions for the RAls listed in 6a and 6b. The licensee intends to provide a supplemental response for RAls listed in item 6c to address the NRC staff concerns relating to the RAI responses provided earlier, and further discussions are needed to resolve the pending NRC staff concerns for RAls listed in 6d.

The licensee proposed to provide the supplemental response in two phases. The licensee proposed to provide the response to the first set of RAls (RAls not requiring additional analysis) within 30 days from the conclusion of the audit and requested for 60 to 90 days for responding to the RAls potentially requiring additional analysis. It was decided that the proposed schedule will be discussed with the DORL and DRA management before providing a final response.

ML18107A756 *via e-mail OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA NRR/DSS/STSB/BC* NRR/DRA/ARCB/BC*

NAME BSingal PBlechman VCusmano KHsueh DATE 04/19/18 04/19/18 04/25/18 04/24/18 OFFICE NRR/DRA/APHB/BC* NRO/DSEA/RHM/BC* NRR/DORL/LPL4/BC NRR/DORL/LPL4/PM NAME CFong CCook RPascarelli BSingal DATE 04/24/18 04/23/18 05/01/18 05/03/18 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 3, 2018 Mr. Adam C. Heflin President, Chief Executive Officer, and Chief Nuclear Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, KS 66839

SUBJECT:

WOLF CREEK GENERATING STATION, UNIT 1 - REGULATORY AUDIT

SUMMARY

REGARDING LICENSE AMENDMENT REQUEST FOR TRANSITION TO WESTINGHOUSE CORE DESIGN AND SAFETY ANALYSES INCLUDING ADOPTION OF ALTERNATIVE SOURCE TERM (CAC NO. MF9307; EPID L-2017-LLA-0211)

Dear Mr. Heflin:

By letter dated January 17, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17054C103), as supplemented by letters dated March 22, May 4, July 13, October 18, and November 14, 2017; and January 15 and January 29, 2018 (ADAMS Accession Nos. ML17088A635, ML17130A915, ML17200C939, ML17297A478, ML17325A982, ML18024A477, and ML180336024, respectively), Wolf Creek Nuclear Operating Corporation (the licensee) submitted a license amendment request for transition to Westinghouse Core Design and Safety Analyses including adoption of Alternative Source Term in accordance with Title 10 of the Code of Federal Regulations Section 50.67 for the Wolf Creek Generating Station, Unit 1.

To support its review of the license amendment request, the U.S. Nuclear Regulatory Commission staff conducted a regulatory audit at the Westinghouse facility in Rockville, Maryland from March 19, 2018, to March 20, 2018, to verify information submitted by the licensee and the supporting calculations. The regulatory audit summary is enclosed with this letter.

A. Heflin If you have any questions, please contact me at 301-415-3016 or via e-mail at Balwant.Singal@nrc.gov.

Sincerely,

~+0£,~&St Balwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-482

Enclosure:

Regulatory Audit Summary cc: Listserv

REGULATORY AUDIT

SUMMARY

FOR MARCH 19- MARCH 20. 2018, AUDIT IN SUPPORT OF THE REVIEW OF LICENSE AMENDMENT REQUEST FOR TRANSITION TO WESTINGHOUSE CORE DESIGN AND SAFETY ANALYSES INCLUDING ADOPTION OF ALTERNATIVE SOURCE TERM WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION, UNIT 1 DOCKET NO. 50-482

1.0 BACKGROUND

By letter dated January 17, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17054C103), as supplemented by letters dated March 22, May 4, July 13, October 18, and November 14, 2017; and January 15 and January 29, 2018 (ADAMS Accession Nos. ML17088A635, ML17130A915, ML17200C939, ML17297A478, ML17325A982, ML18024A477, and ML180338024, respectively), Wolf Creek Nuclear Operating Corporation (WCNOC, the licensee) submitted a license amendment request (LAR) for transition to Westinghouse Core Design and Safety Analyses including adopting an Alternative Source Term (AST) for the Wolf Creek Generating Station, Unit 1 (WCGS).

The proposed amendment would revise the WCGS Technical Specifications (TSs) to replace the existing WCNOC methodology for performing core design, non-loss-of-coolant accident (non-LOCA) and LOCA safety analyses with standard Westinghouse developed and U. S. Nuclear Regulatory Commission (NRC)-approved analysis methodology. The proposed LAR would also change the TSs to revise WCGS licensing basis by adopting the AST radiological analysis methodology in accordance with Title 10 of the Code of Federal Regulations (10 CFR) Section 50.67, "Accident source term."

The NRC staff reviewed the impact of implementing an AST on currently analyzed design-basis accidents in the WCGS licensing basis and identified the need for additional information in order to complete the review of the LAR. By letters dated January 15 and January 29, 2018, the licensee provided responses to the request for addition information (RAI). The NRC staff has performed a detailed review of the proposed TS changes and supporting calculations and determined that face-to-face interactions with the WCNOC staff can resolve complex technical issues more quickly than multiple rounds of RAls. Hence, the NRC staff determined the need for a regulatory audit to be conducted in accordance with the Office of Nuclear Reactor Regulation (NRR) Office Instruction LIC-111, "Regulatory Audits" (ADAMS Accession No. ML082900195), for the NRC staff to gain a better understanding of the licensee's calculations and other aspects of the LAR. An audit plan was issued by the NRC staff by letter dated March 8, 2018 (ADAMS Accession No. ML18066A050). The scope of the audit was primarily focused on changes to the WCGS licensing basis for adopting the AST radiological analysis methodology. In addition to examining the audit documents,

the NRC staff held discussions with the Westinghouse and WCNOC subject matter experts to better understand WCNOC's response to the RAls, provided by letters dated January 15 and January 29, 2018.

2.0 AUDIT DATES AND LOCATION The regulatory audit was held at the Westinghouse facility in Rockville, Maryland. The audit was originally planned for March 19, March 20, and March 21, 2018. However, the NRC staff was able to complete it in 2 days (March 19 and March 20, 2018).

3.0 AUDIT TEAM MEMBERS The following NRC audit team members consisted of:

• Mark Blumberg, Lead Technical Reviewer, NRR, Division of Risk Assessment (ORA), Radiation Protection and Consequences Branch (ARCB)

• Kristy Bucholtz, Technical Reviewer, NRR/DRA/ARCB (Part Time)

• Balwant Singal, Senior Project Manager, NRR, Division of Operating Reactor Licensing (DORL). Plant Licensing Branch IV (LPL4)

• Siva Lingam, Project Manager, NRR/D0RULPL4 (Part Time)

• John Hughey, Technical Reviewer, NRR/DRA, Probabilistic Risk Assessment and Human Factors Branch (APHB) (Part Time)

• Kevin Quinlan, Office of New Reactors, Division of Site and Environmental Analysis, Hydrology and Meteorology Branch, Meteorology Team (Part Time)

The following WCNOC and Westinghouse staff (in support of the licensee) participated in the audit:

• Nicole Good, Licensing Engineer, WCNOC

• Dustin Wirth, Westinghouse (WCGS Site Supervisor)

• Sean Kinnas, Containment Radiological Analysis, Westinghouse

• Alex Markivich, Radiation Engineering and Analysis, Westinghouse

• Jim Smith, Licensing Manager, Westinghouse

• Mike Watson, Project Manager, Westinghouse

4.0 DOCUMENTS AUDITED The following documents were reviewed at the Audit:

a. The radiological calculations and documents which support the LAR and the RAI responses dated January 15 and January 29, 2018.

b. The RADTRAD computer code input and output decks used to support the LAR.

5.0 AUDIT ACTIVITIES The audit consisted of the following activities:

• NRC's staff entrance briefing.

• A period in which the staff examined the documents and held discussions with WCNOC and Westinghouse participants as needed for technical understanding.

• Exit briefing for NRC to present observations in person and Westinghouse to seek clarification.

6.0 AUDIT

SUMMARY

The purpose of this regulatory audit was to determine if calculations performed by the licensee support the bases for the proposed changes to the TSs and the modifications to the design basis in accordance with 10 CFR 50.67. The area of focus during the audit was the licensee's response to RAls, by letters dated January 15 and January 29, 2018, and the calculations performed by the licensee in support of the proposed LAR (RAls were issued by the NRC staff by letter dated December 4, 2017 (ADAMS Accession No. ML17331A178)).

Results of the Audit

a. Based on the review of the RAI responses, the NRC staff indicated that the NRC staff currently does not have any followup questions for the following RAls: 1 LOAC-2, LLBA-1, LOCA-2, LOCA-4, FHA-1, FHA-4, FHA-7, SGTR-1, SGTR-4, WT-1, WT-2, CREA-2, Control Room-5, and General-1

b. Based on the clarifications provided by the licensee during the audit, the NRC staff indicated that the NRC staff currently does not have any further questions on the following RAls: 1 LLBA-3, SGTR-3, Control Room-1, Control Room-2, Control Room-6, General-3.

c. Based on the review of the calculations and discussions during the audit, the licensee indicated that it understands the NRC staff concerns and intends to supplement its previous RAI response for the following RAI questions: 1 LOCA-1, LOAC-1, LLBA-2, LLBA-4, LOCA-1, LOCA-3, FHA-2, FHA-5, FHA-6, SGTR-2, SGTR-6, LRA-1, MSLB-1, MSLB-2, WT-3, WT-4, WT-5, CREA-1, Control Room-3, Control Room-4, and General-2.

1 All RAI numbers to be preceded by ARCB1

d. The discussions could not be concluded on RAls ARCB1-LOCA-5, ARCB1-FHA-3, and ARCB1-SGTR-5. It was decided to have follow-up discussions on these RAls after the conclusion of the audit. Follow-up discussions may result in additional RAls.

7.0 EXIT BRIEFING As described in Section 6.0 of this summary, the exit discussion summarized the status of each RAI. As described in Section 6.0, either based on the RAI responses provided by the licensee by letters dated January 15 and January 29, 2018, or as a result of clarifications provided during the audit, the NRC staff currently has no followup questions for the RAls listed in 6a and 6b. The licensee intends to provide a supplemental response for RAls listed in item 6c to address the NRC staff concerns relating to the RAI responses provided earlier, and further discussions are needed to resolve the pending NRC staff concerns for RAls listed in 6d.

The licensee proposed to provide the supplemental response in two phases. The licensee proposed to provide the response to the first set of RAls (RAls not requiring additional analysis) within 30 days from the conclusion of the audit and requested for 60 to 90 days for responding to the RAls potentially requiring additional analysis. It was decided that the proposed schedule will be discussed with the DORL and DRA management before providing a final response.

ML18107A756 *via e-mail OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA NRR/DSS/STSB/BC* NRR/DRA/ARCB/BC*

NAME BSingal PBlechman VCusmano KHsueh DATE 04/19/18 04/19/18 04/25/18 04/24/18 OFFICE NRR/DRA/APHB/BC* NRO/DSEA/RHM/BC* NRR/DORL/LPL4/BC NRR/DORL/LPL4/PM NAME CFong CCook RPascarelli BSingal DATE 04/24/18 04/23/18 05/01/18 05/03/18