ML18248A143
| ML18248A143 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 10/11/2018 |
| From: | Peter Hearn NRC/NRO/DLSE/LB4 |
| To: | City of Dalton, GA, Georgia Power Co, MEAG Power, Oglethorpe Power Corp, Southern Nuclear Operating Co |
| HEARN P/415-1189 | |
| Shared Package | |
| ML18248A137 | List: |
| References | |
| EPID L-2018-LLA-0103, LAR 18-009 | |
| Download: ML18248A143 (5) | |
Text
SAFETY EVALUATION BY THE OFFICE OF NEW REACTORS RELATED TO AMENDMENT NOS. 146 AND 145 TO THE COMBINED LICENSE NOS. NPF-91 AND NPF-92, RESPECTIVELY SOUTHERN NUCLEAR OPERATING COMPANY, INC.
GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MEAG POWER SPVM, LLC MEAG POWER SPVJ, LLC MEAG POWER SPVP, LLC CITY OF DALTON, GEORGIA VOGTLE ELECTRIC GENERATING PLANT UNITS 3 AND 4 DOCKET NOS.52-025 AND 52-026
1.0 INTRODUCTION
By letter dated April 13, 2108 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18103A252), and supplemented by the letter dated August 10, 2018 (ADAMS Accession No. ML18222A584), the Southern Nuclear Operating Company (SNC) requested that the Nuclear Regulatory Commission (NRC or the Commission) amend Vogtle Electric Generating Plant (VEGP) Units 3 and 4, Combined License (COL) Numbers NPF-91 and NPF-92, respectively. The License Amendment Request (LAR)18-009 requested changes to COL Appendix A, Technical Specifications (TS). LAR 18-009 also requested to depart from the associated Updated Final Safety Analysis Report (UFSAR) information, which includes the plant-specific Design Control Document (DCD) Tier 2 information, with changes which conform with the requested TS changes.
The requested amendment proposes to change TS Limiting Condition for Operation (LCO) 3.5.5 to not require the Passive Residual Heat Removal Heat Exchanger (PRHR HX) to be operable in Mode 5 during vacuum fill operations. In addition, the requested amendment proposes to change Surveillance Requirement (SR) 3.5.7.1 regarding operability requirements for the In-containment Refueling Water Storage Tank (IRWST) and associated flow paths and proposes to add an additional SR 3.5.7.2 to address operability requirements that are not required during vacuum fill operations. Finally, the requested amendment proposes conforming changes to the UFSAR, Appendix 19E, Subsection 2.3.2.4.
The supplement dated August 10, 2018 provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the NRC staffs proposed no significant hazards consideration determination as published in the Federal Register on June 27, 2018 (83 FR 30199).
2.0 REGULATORY EVALUATION
The NRC staff considered the following regulatory requirements in reviewing the LAR that included the proposed changes:
Appendix D,Section VIII.B.5.a allows an applicant or licensee who references this appendix to depart from Tier 2 information, without prior NRC approval, unless the proposed departure involves a change to or departure from Tier 1 information, Tier 2* information, or the Technical Specifications, or requires a license amendment under paragraphs B.5.b or B.5.c of the section.
10 CFR Part 52, Appendix D, VIII.C.6 states that after issuance of a license, Changes to the plant-specific TS will be treated as license amendments under 10 CFR 50.90. 10 CFR 50.90 addresses the application for amendment of license, construction permit, or early site permit.
The proposed LAR requires changes in the TS, and therefore an LAR is required to be submitted for NRC approval.
The proposed changes to COL Appendix A, TS, and departure from associated UFSAR information (which includes the plant-specific DCD Tier 2 information) with changes which conform with the requested TS changes potentially effects the reference design findings for the following 10 CFR 50, Appendix A, General Design Criterion (GDC):
GDC 34, Residual heat removal. A system to remove residual heat shall be provided. The system safety function shall be to transfer fission product decay heat and other residual heat from the reactor core at a rate such that specified acceptable fuel design limits and the design conditions of the reactor coolant pressure boundary are not exceeded.
GDC 35, Emergency core cooling. A system to provide abundant emergency core cooling shall be provided. The system safety function shall be to transfer heat from the reactor core following any loss of reactor coolant at a rate such that (1) fuel and clad damage that could interfere with continued effective core cooling is prevented and (2) clad metal-water reaction is limited to negligible amounts.
10 CFR 50.36, TS impose limits, operating conditions, and other requirements upon reactor facility operation for the public health and safety. The TS are derived from the analyses and evaluations in the safety analysis report. In general, TS must contain: (1) safety limits and limiting safety system settings; (2) limiting conditions for operation; (3) surveillance requirements; (4) design features; and (5) administrative controls.
3.0 TECHNICAL EVALUATION
3.1 TECHNICAL EVALUATION
OF CHANGES ASSOCIATED WITH PRHR HX OPERABILITY DURING VACUUM FILL IN MODE 5 The information presented by SNC in LAR 18-0009 was evaluated by the staff for its completeness, quality, and clarity. SNC in section 2 of Enclosure 1 to LAR 18-009 provides proposed changes to modify when the PRHR HX is required to be operable in order to accommodate vacuum fill operation in Mode 5 in the following sections:
- COL Appendix A, Technical Specifications, Specification 3.5.5
- UFSAR Section 19E.2.3.2.4 SNC proposed a change to Applicability of LCO 3.5.5 to add a Note that states PRHR HX is not required to be OPERABLE in MODE 5 during reactor coolant system (RCS) vacuum fill operations. In addition, SNC proposed to revise UFSAR Subsection 19E.2.3.2.4 to note that the PRHR HX does not provide decay heat removal during RCS vacuum fill operations in Mode 5.
SNC stated that TS 3.5.5 requires that the PRHR HX be OPERABLE in MODE 5 with the RCS pressure boundary intact and pressurizer level greater than or equal to 20%. SR 3.5.5.1 requires the Surveillances of TS 3.5.4 to be met for the PRHR HX to be considered OPERABLE. In the LAR SNC states that SR 3.5.4.3 cannot be met in MODE 5 during RCS vacuum fill operations because the PRHR HX inlet line noncondensible gas volume will be out of TS limit once the pressurizer level reaches 20%. Since SR 3.5.4.3 cannot be met during vacuum fill operations in Mode 5, the PRHR HX would then be considered inoperable. With the addition of the proposed Note to LCO 3.5.5, the PRHR HX is not required to be OPERABLE during RCS vacuum fill in Mode 5. Subsequently, the Note precludes crediting PRHR HX operation in safety analyses for vacuum fill configuration in Mode 5.
Section 2 of Enclosure 1 to LAR 18-009 states In MODE 5, vacuum fill configuration, the PRHR HX is not credited in the safety analysis to remove decay heat. In order to establish a finding that the supporting safety analysis is acceptable, clarification regarding the referenced safety analysis was requested from SNC through a Request for Additional Information (RAI). In response to the RAI, See Vogtle Electric Generating Plant Units 3 and 4, Supplement to the Request for License Amendment (LAR-18-009S1): Technical Specification Changes to Support Operability During Mode 5 Vacuum Fill Operations, Enclosure 4, Response to NRC Request for Additional Information, (ADAMS Accession No. ML14100A135) (Reference [2]), SNC confirmed that the referenced safety analysis is the same analysis audited by the staff in support of LAR 17-027 and documented in the staff audit summary. See Audit Summary for Vogtle Electric Generating Plant Units 3 and 4 License Amendment Request 17-027: Reactor Coolant System Vacuum Fill and ITAAC for Containment Floodup, March 15, 2018 (ADAMS Accession No. ML18074A142) (Reference [7]). As documented in the audit summary and RAI response, the analysis was performed conservatively for vacuum fill configuration in Mode 5. The LAR 17-027 Safety Evaluation, (Reference [8]) and RAI response confirms, in the analysis, the core region remains covered with a two-phase mixture. Based on the response, the NRC staff finds the analysis to be acceptable. Based on staffs review of LAR 18-009 and the analysis summary presented in the RAI, which confirms that the PRHR heat exchanger is not credited in the safety analysis for vacuum fill configuration in Mode 5, the staff finds the proposed changes to TS LCO 3.5.5 acceptable.
In conclusion, the staff reviewed the proposed changes to UFSAR Section 19E.2.3.2.4 and determined that the modifications accurately reflect the changes to TS LCO 3.5.5. Based on the accurate implementation of proposed changes to TS LCO 3.5.5, the staff finds the changes to UFSAR Section 19E.2.3.2.4 acceptable. NRC staff find that with the proposed changes, the design continues to meet GDC 34.
3.2 TECHNICAL EVALUATION
OF CHANGES ASSOCIATED WITH IRWST OPERABILITY DURING VACUUM FILL IN MODE 5 Section 2 of Enclosure 1 to LAR 18-009 provides proposed changes to revise TS 3.5.7 to invoke all SRs of TS 3.5.6 except SR 3.5.6.3 and add new SR 3.5.7.2 to invoke SR 3.5.6.3 with a Note that it is not required to be met during vacuum fill operations.
SNC stated that TS 3.5.7 requires the IRWST to be OPERABLE in MODE 5. SR 3.5.7.1 requires the SRs of TS 3.5.6 to be met for the IRWST and its flow paths to be considered OPERABLE. SR 3.5.6.3 requires the IRWST injection flow path noncondensible gas volume to be within limits. However, SR 3.5.6.3 cannot be met during RCS vacuum fill operations in MODE 5. The proposed changes to TS 3.5.7 removes the requirement for noncondensible gas volume to be within limits in the IRWST injection squib valve outlet line pipe stubs in order for the IRWST and associated flow paths to be considered operable during vacuum fill operations.
Section 2 of Enclosure 1 to LAR 18-009, SNC states that noncondensible gas may be present in the IRWST injection squib valve outlet line pipe stubs causing the gas volume to not be within limits during vacuum fill operations. SNC further explains that the noncondensible gas would not be present in the main IRWST injection line and consequently would not interrupt IRWST injection flow. The NRC staff agrees that noncondensible gas in the IRWST injection squib valve outlet line pipe stubs would not prevent the IRWST from performing its safety function because the noncondensible gas is not present in the main IRWST injection line.
The NRC staff reviewed the analysis provided in Enclosure 1 of the letter dated April 13, 2108, and finds that noncondensible gas in the IRWST injection squib valve outlet line pipe stubs would not prevent the IRWST from performing its safety function because the noncondensible gas is not present in the main IRWST injection line. Based on these findings, the NRC staff concludes that there is reasonable assurance that the requirements of GDC 35 will continue to be met. Therefore, the staff finds the proposed change acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations in 10 CFR 50.91(b)(2), the Georgia State official was notified of the proposed issuance of the amendment on August 13, 2018. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes SRs 3.5.7.1 and 3.5.7.2. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (Federal Register, 83 FR 30199, dated June 27, 2018). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The staff has concluded, based on the considerations discussed in Sections 3.1 and 3.2 that there is reasonable assurance that: (1) the health and safety of the public will not be endangered by operation in the proposed manner, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public. Therefore, the staff finds the changes proposed in this license amendment acceptable.
7.0 REFERENCES
- 1. Vogtle Electric Generating Plant Units 3 and 4, Request for License Amendment (LAR-18-009): Technical Specification Changes to Support Operability During Mode 5 Vacuum Fill Operations, April 13, 2018 (ADAMS Accession No. ML18103A252).
- 2. Vogtle Electric Generating Plant Units 3 and 4, Supplement to the Request for License Amendment (LAR-18-009S1): Technical Specification Changes to Support Operability During Mode 5 Vacuum Fill Operations, Enclosure 4, Response to NRC Request for Additional Information, August 10, 2018 (ADAMS Accession No. ML18222A584).
- 3. Combined License NPF-91 for Vogtle Electric Generating Plant Unit 3, Southern Nuclear Operating Company (ADAMS Accession No. ML14100A106).
- 4. Combined License NPF-92 for Vogtle Electric Generating Plant Unit 4, Southern Nuclear Operating Company (ADAMS Accession No. ML14100A135).
- 5. Vogtle Units 3 and 4 Updated Final Safety Analysis Report, Revision 6 and Tier 1, Revision 4, June 15, 2017 (ADAMS Accession No. ML17172A218).
- 6. AP1000 Design Control Document, Revision 19, June 13, 2011 (ADAMS Accession No. ML11171A500).
- 7. Audit Summary for Vogtle Electric Generating Plant Units 3 and 4 License Amendment Request 17-027: Reactor Coolant System Vacuum Fill and ITAAC for Containment Floodup, March 15, 2018 (ADAMS Accession No. ML18074A142).
- 8. Safety Evaluation for Vogtle Electric Generating Plant Units 3 and 4, License Amendment Request 17-027 RE: Reactor Coolant System Vacuum Fill and ITAAC for Containment Floodup, March 29, 2018 (ADAMS Accession No. ML18075A104).