ML23193A783
| ML23193A783 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 07/12/2023 |
| From: | John Lamb Plant Licensing Branch II |
| To: | Lowery K, Pournaras D Southern Nuclear Operating Co |
| References | |
| L-2023-LLA-0053 | |
| Download: ML23193A783 (5) | |
Text
From:
John Lamb Sent:
Wednesday, July 12, 2023 9:23 AM To:
Pournaras, DeLisa S.; Lowery, Ken G.
Cc:
Chamberlain, Amy Christine; Michael Markley; Clinton Ashley
Subject:
For Your Action - Request for Additional Information (RAI) - Vogtle - TSTF-339 LAR (L-2023-LLA-0053)
DeLisa and Ken, By letter dated April 11, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23101A159), Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Vogtle Electric Generating Plant (Vogtle), Units 1 and 2. The proposed amendments would revise TS 2.1.1, Reactor Coolant Safety Limits, (TS) 3.3.1, Reactor Trip System (RTS) Instrumentation, TS 3.4.1, Reactor Coolant System (RCS) Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits, and TS 5.6.5, Core Operating Limits Report (COLR), to adopt most of the TS and COLR changes described in Appendix A and Appendix B of Westinghouse topical report WCAP-14483-A, to relocate several cycle-specific parameter limits from the TS to the COLR.
The amendments follow the guidance of technical specification task force (TSTF) change traveler TSTF-339-A, Revision 2. Along with the parameter relocations, the amendments also modify the Vogtle, Units 1 and 2, TS 5.6.5, to include WCAP-8745-P-A and WCAP-11397-P-A, and to revise the TS applicability for the WCAP-9272-P-A, in the list of the U.S. Nuclear Regulatory Commission (NRC) approved methodologies used to develop the cycle-specific COLR. In addition, the amendments revise an error to the TS 3.3.1 depiction of an equation.
The NRC staff reviewed the submittal dated April 11, 2023, and determined that additional information is needed to complete its review.
On June 21, 2023, the NRC staff provided draft RAI questions to SNC to make sure that the RAI is understandable, the regulatory basis is clear, to ensure there is no proprietary information, and to determine if the information was previously docketed. On July 10, 2023, a clarifying call was held between the NRC staff and SNC. On July 12, 2023, SNC stated that it would provide the RAI response within 30 days from the date of this email.
If you have any questions, you can contact me at 301-415-3100.
Sincerely, John REQUEST FOR ADDITIONAL INFORMATION (RAI)
By application dated April 11, 2023, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23101A159), Southern Nuclear Operating Company, Inc. (SNC, the licensee) requested changes to the Technical Specifications (TSs) for Renewed Facility Operating License Nos. NPF-68 and NPF-81 for Vogtle Electric Generating Plant (Vogtle), Units 1 and 2, respectively.
The proposed changes would relocate cycle-specific parameters from the TSs to the Core Operating Limits Report (COLR), a licensee-controlled document, by adopting Technical Specification Task Force (TSTF) Traveler TSTF-339, Revision 2, Relocate TS Parameters to COLR, (ML003723269).
The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the license amendment request (LAR) and determined that the NRC staff needs additional information to complete its review.
Regulatory Basis Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities, establishes the fundamental regulatory requirements.
Section 50.36 of 10 CFR, Technical specifications, details the content and information that a facility's TSs must include. Section 50.36(c) states in part, that TSs will include items in the following categories: (1) safety limits, limiting safety system settings, and limiting control settings; (2) limiting conditions for operation; (3) surveillance requirements; (4) design features; and (5) administrative controls.
The NRC provides guidance on the relocation of cycle-specific TS parameters to the COLR, to all power reactor licensees and applicants in NRC Generic Letter (GL) 88-16, Removal of Cycle-Specific Parameter Limits from Technical Specifications, (ML031200485). In GL 88-16, the NRC staff stated that license amendments are generally required every refueling outage to update the cycle-specific parameter limits in the TSs. However, there are methodologies developed for the licensee to determine these cycle-specific parameters that have been reviewed and approved by the NRC staff. As a result, the NRC staff review of proposed changes to the TSs to update these parameter limits is primarily limited to the confirmation that the updated limits were calculated by the approved methodology and consistent with the plant-specific safety analysis. The COLR was created to place the NRC-approved methodologies in the TSs and allow licensees to use these methodologies to update the parameters without requiring a change to the TSs.
The NRC staff approved Westinghouse Topical Report WCAP-14483-A, Generic Methodology for Expanded Core Operating Limits Report (ML020430092) as an acceptable method to relocate certain TS requirements to the COLR consistent with GL 88-16. The WCAP-14483-A addresses the relocation of the (1) reactor core safety limits figure (with corresponding revision to the safety limits), (2) Overtemperature T (Delta-T) and Overpower T (Delta-T) setpoint parameter values, and (3) departure from nucleate boiling (DNB) parameter limits for reactor coolant system (RCS) average temperature, RCS flow rate, and pressurizer pressure, to the COLR.
In TSTF-339, Revision 2, the NRC staff approved the incorporation of the TS changes identified in WCAP-14483-A into NUREG-1431, Volume 1, Revision 2, Standard Technical Specifications, Westinghouse Plants, June 2001 (ML011840223).
Request for Additional Information
- 1. The proposed change would relocate certain cycle-specific parameter values from the Vogtle, Units 1 and 2, TSs to the Vogtle, Units 1 and 2, COLR, by adopting NRC-approved TSTF-339. The LAR Attachment 1 provides marked-up TS pages. TS 3.3.1, Table 3.3.1-1, Note 1: Overtemperature Delta-T, contains a value for f1(AFD) that the mark-up replaced with an asterisk (*). The mark-up also indicates that the
values denoted with an asterisk (*) are specified in the COLR. The f1(AFD) value (i.e., 0, in 0% RTP) replaced by an asterisk (*) is not consistent with TSTF-339, because TSTF-339 did not consider this value to be cycle-specific. The NRC staff requests that the licensee provide a justification that this value is cycle-specific and that use of an asterisk (*) is appropriate.
- 2. The proposed change would relocate certain cycle-specific parameter values from the Vogtle, Units 1 and 2, TSs to the Vogtle, Units 1 and 2, COLR, by adopting NRC-approved TSTF-339. The LAR Attachment 1 provides marked-up TS pages. TS 3.3.1, Table 3.3.1-1, Note 1: Overtemperature Delta-T, contains a value for note (p) that the mark-up replaced with an asterisk (*). The mark-up also indicates that the values denoted with an asterisk (*) are specified in the COLR. Note (p) specifies that the compensated temperature difference shall be no more negative than 3 degrees Fahrenheit. The 3 degrees value that the LAR mark-up replaced with an asterisk
(*), indicates that it should be considered a cycle-specific value. Note (p) is Vogtle, Units 1 and 2, specific and therefore, TSTF-339 did not assess. The NRC staff requests that the licensee provide a justification for considering 3 degrees to be a cycle-specific value. As part of the response, the NRC staff requests the licensee identify the NRC-approved methodology that is referenced in the Vogtle, Units 1 and 2, TSs and is used to determine that the 3 degrees value is a cycle-specific parameter limit.
- 3. The proposed change would relocate certain cycle-specific parameter values from the Vogtle, Units 1 and 2, TSs to the Vogtle, Units 1 and 2, COLR, by adopting NRC-approved TSTF-339. The LAR Attachment 1 provides marked-up TS pages. The mark-up to TS 3.4.1 in part, changes limiting conditions for operation (LCO) 3.4.1, which currently contains limiting values for the reactor coolant system (RCS) departure from nucleate boiling (DNB) parameters for pressurizer pressure, RCS average temperature, and RCS total flow rate. For example, the current LCO specifies that pressurizer pressure is greater than or equal to a limiting value. In the proposed change, in lieu of retaining the parameters and its inequality (i.e., or )
expressions, the licensees proposed LCO mark-up removes the parameters and its inequalities and states the parameters shall be within the limits specified in the COLR [emphasis added]. The licensees deletion of individual parameters and its associated inequality is not consistent with TSTF-339. The NRC-approved TSTF-339 addressed relocating the parameter value or limit to the COLR and not the inequality expression. Therefore, the NRC staff requests that the licensee provide a justification for deleting each specified parameter and its associated inequality expression.
- 4. The proposed change would relocate certain cycle-specific parameter values from the Vogtle, Units 1 and 2, TSs to the Vogtle, Units 1 and 2, COLR, by adopting NRC-approved TSTF-339. The LAR Attachment 1 provides marked-up TS pages. The mark-up to TS 3.4.1 in part, proposed changes to the surveillance wording for three surveillance requirements (SR): SR 3.4.1.1, SR 3.4.1.2, and SR 3.4.1.4. Specifically, the change to each surveillance wording removes inequality (i.e., or ) expressions and uses the plural versus singular form of limit, that is limits versus limit. For example, the current surveillance wording is to verify that a parameter, such as pressurizer pressure, is greater than or equal to a limiting value. In lieu of specifying the inequality expression, the licensee proposed mark-up states verify the parameter is within the limits specified in the COLR [emphasis added]. The NRC-approved TSTF-339 addressed relocating the parameter value or limit to the COLR and not the
inequality expression. The licensees deletion of the inequality expression and use of limits is not consistent with TSTF-339. Therefore, the NRC staff requests that the licensee provide a justification for not having an inequality expression and for use of limits versus limit.
- 5. The LAR refers to an NRC staff approved Topical Report in several separate ways:
WCAP-14483-A, WCAP-14483-P-A, and WCAP-14483-A-P. Note, a -P would typically indicate a proprietary document (non-publicly available) and a -A would typically indicate NRC staff approval. In addition, the LAR states that TSTF-339-A Revision 2 is based on WCAP-14483-P-A; however, TSTF-339 does not refer to WCAP-14483-P-A. Furthermore, LAR Section 6, REFERENCES, Reference 1, refers to WCAP-14483-P-A, and associates it with ADAMS Accession No. ML020430092, which is a publicly available reference for WCAP-14483-A. The NRC staff requests that the license review the LAR and make any necessary corrections to consistently refer to the Topical Report, as appropriate.
Hearing Identifier:
NRR_DRMA Email Number:
2160 Mail Envelope Properties (MN2PR09MB50844101315E9F4C16101DB2FA36A)
Subject:
For Your Action - Request for Additional Information (RAI) - Vogtle - TSTF-339 LAR (L-2023-LLA-0053)
Sent Date:
7/12/2023 9:23:03 AM Received Date:
7/12/2023 9:23:00 AM From:
John Lamb Created By:
John.Lamb@nrc.gov Recipients:
"Chamberlain, Amy Christine" <ACCHAMBE@southernco.com>
Tracking Status: None "Michael Markley" <Michael.Markley@nrc.gov>
Tracking Status: None "Clinton Ashley" <Clinton.Ashley@nrc.gov>
Tracking Status: None "Pournaras, DeLisa S." <DSPOURNA@SOUTHERNCO.COM>
Tracking Status: None "Lowery, Ken G." <KGLOWERY@southernco.com>
Tracking Status: None Post Office:
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