ML19038A458
| ML19038A458 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  (NPF-091, NPF-092) |
| Issue date: | 02/25/2019 |
| From: | NRC/NRO/DLSE/LB2 |
| To: | City of Dalton, GA, Georgia Power Co, MEAG Power, Oglethorpe Power Corp, Southern Nuclear Operating Co |
| HEARN P/415-1189 | |
| Shared Package | |
| ML19038A450 | List: |
| References | |
| LAR 18-025, EPID L-2018-LLA-0245 | |
| Download: ML19038A458 (8) | |
Text
SAFETY EVALUATION BY THE OFFICE OF NEW REACTORS RELATED TO AMENDMENT NOS. 155 AND 154 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 August 31, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18243A459), the Southern Nuclear Operating Company (SNC) requested that the Nuclear Regulatory Commission (NRC) amend Vogtle Electric Generating Plant (VEGP) Units 3 and 4, Combined License (COL) Numbers NPF-91 and NPF-92, respectively. License Amendment Request (LAR)18-025 proposed changes to UFSAR Figure 15.3.2-1 which reflects the full power safety analysis reactor coolant system (RCS) flow coastdown curve. This LAR also proposes a change to the similar figure included in COL Appendix C Inspections, Tests, Analysis, and Acceptance Criteria (ITAAC) Number 2.1.02.08b referenced acceptance criterion as Figure 2.1.2-2 (and the corresponding plant-specific Tier 1 figure.) A change is proposed to these curves to reflect the latest coastdown curves and to revise the ITAAC-related reactor coolant pump (RCP) coastdown curve such that it is based upon the same conservative pump characteristics as those used in the safety analyses but scaled to the actual hot functional test conditions used for the preoperational testing.
Pursuant to Section 52.63(b)(1) of Title 10 of the Code of Federal Regulations (10 CFR), SNC also requested an exemption from the provisions of Title 10 of the Code of Federal Regulations (10 CFR) Part 52, Appendix D, Design Certification Rule for the AP1000 Design,Section III.B, Scope and Contents. The requested exemption would allow a departure from the corresponding portions of the certified information in Tier 1 of the generic DCD.1 In order to modify the UFSAR (the plant-specific design control document (PS-DCD)) Tier 1 information, the NRC must find the licensees exemption request included in its submittal for the LAR to be acceptable. The staffs review of the exemption request, as well as the LAR, is included in this safety evaluation.
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.A.4 to 10 CFR Part 52 states that exemptions from Tier 1 information are governed by the requirements in 10 CFR 52.63(b)(1) and 10 CFR 52.98(f). It also states that the Commission will deny such a request if it finds that the design change will result in a significant decrease in the level of safety otherwise provided by the design.
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.
The proposed change to the Tier 2 information involves a change to COL Appendix C (and the corresponding plant-specific Tier 1) ITAAC information. Therefore, NRC approval is required prior to making the change to Tier 2 information.
10 CFR 52.63(b)(1) allows the licensee who references a design certification rule to request NRC approval for an exemption from one or more elements of the certification information. The Commission may only grant such a request if it determines that the exemption will comply with the requirements of 10 CFR 52.7, which, in turn, points to the requirements listed in 10 CFR 50.12 for specific exemptions. In addition to the factors listed in 10 CFR 52.7, the Commission shall consider whether the special circumstances outweigh any decrease in safety that may result from the reduction in standardization caused by the exemption. Therefore, any exemption from the Tier 1 information certified by Appendix D to 10 CFR Part 52 must meet the requirements of 10 CFR 50.12, 52.7, and 52.63(b)(1).
10 CFR 52.98(f) requires NRC approval for any modification to, addition to, or deletion from the terms and conditions of a COL. These activities involve a change to COL Appendix C ITAAC information, with corresponding changes to the associated PS-DCD Tier 1 information.
Therefore, NRC approval is required prior to making the plant specific proposed changes in this license amendment request.
The specific NRC technical requirements applicable to LAR 18-025 are the general design criteria (GDC) in Appendix A, General Design Criteria for Nuclear Power Plants, to 10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities. In particular, these technical requirements include the following GDC:
1 While SNC describes the requested exemption as being from Section III.B of 10 CFR Part 52, Appendix D, the entirety of the exemption pertains to proposed departures from Tier 1 information in the plant-specific design control document (DCD). In the remainder of this evaluation, the NRC will refer to the exemption as an exemption from Tier 1 information to match the language of Section VIII.A.4 of 10 CFR Part 52, Appendix D, which specifically governs the granting of exemptions from Tier 1 information.
10 CFR 50, Appendix A, GDC 10, Reactor design, requires the reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to assure that specified acceptable fuel design limits (SAFDL) are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences.
10 CFR 50, Appendix A, GDC 15, Reactor coolant system design. The RCS and associated auxiliary, control, and protection systems shall be designed with sufficient margin to assure that the design conditions of the reactor coolant pressure boundary are not exceeded during any condition of normal operation, including anticipated operational occurrences.
3.0 TECHNICAL EVALUATION
3.1 TECHNICAL EVALUATION
OF THE REQUESTED CHANGES The information presented by SNC in LAR 18-025 was evaluated by the staff for its completeness, quality, and clarity. Section 2 of Enclosure 1 to LAR 18-025 provides proposed changes to plant-specific Tier 1 and COL Appendix C Figure 2.1.2-2. SNC proposed a change to the ITAAC-related Figure 2.1.2-2, which is associated with the test acceptance criterion for RCS flow coastdown, to reflect startup (hot functional) test conditions rather than safety analysis conditions.
SNC stated that at the time of the AP1000 design certification, the Tier 1 ITAAC-related Figure 2.1.2-2 and Tier 2 safety analysis Figure 15.3.2-1 were identical. SNC identified that the figures should not be identical due to the differences between the safety analysis conditions (addressed in UFSAR Subsection 15.3.2) and the hot functional test conditions (which the ITAAC-related figure should have provided). SNC further states the ITAAC-related figure should have been adjusted from the safety analysis conditions (100 percent power with a full power T) to the hot functional test conditions (hot zero power and no-load temperature).
Additionally, SNC states that the complete loss of flow (CLOF) analysis documented in UFSAR Tier 2 Subsection 15.3.2, which forms the basis for UFSAR Tier 2 Figure 15.3.2-1, is revised to incorporate design changes. SNC states the changes to the CLOF analysis do not represent a substantial change and the results remain conservative and continue to meet the acceptance criteria. Therefore, SNC is proposing to update UFSAR Tier 2 Figure 15.3.2-1 in addition to ITAAC-related Figure 2.1.2-2.
SNC states that the revised UFSAR Chapter 15 CLOF analysis RCP coastdown curve is used as the basis for hot functional test considerations but adjusted from the safety analysis conditions (100 percent power with a full power T) to the hot functional test conditions (hot zero power and no-load temperature) to reflect a revised ITAAC-related test acceptance criterion provided in revised ITAAC-related Figure 2.1.2-2. SNC states a flow coastdown calculation is documented and performed with LOFTRAN using the same pump performance parameters as those used in the revised CLOF safety analysis, but at the initial conditions of the RCP flow coastdown tests.
The staff reviewed the description of the UFSAR Tier 2 CLOF analysis and the description of the hot functional test. The staff confirms that the conditions for the CLOF analysis and the hot functional test should not be identical and therefore UFSAR Tier 2 Figure 15.3.2-1 should not be identical to ITAAC-related Figure 2.1.2-2. The staff reviewed the description of the design changes that were incorporated into the revised CLOF analysis, including the changes to UFSAR Tier 2 Figure 15.3.2-1. The staff confirms that the design changes do not represent a substantial change to UFSAR Tier 2 Figure 15.3.2-1. The staff reviewed the description of the differences between the revised CLOF analysis and the flow coastdown calculation that is documented in LAR 18-025 and performed with LOFTRAN using the same pump performance parameters as those used in the CLOF safety analysis, but at the initial conditions of the RCP flow coastdown tests. The staff confirms that the flow coastdown calculation provides a reasonable basis for revised ITAAC-related Figure 2.1.2-2. The staff observed that revised UFSAR Tier 2 Figure 15.3.2-1 is not substantially different than revised ITAAC-related Figure 2.1.2-2.
The staff finds revised UFSAR Tier 2 Figure 15.3.2-1 acceptable because the incorporated design changes do not represent a substantial change, the supporting analysis results are not significantly affected, and the analysis acceptance criteria, associated with SAFDLs and RCS pressure, continue to be met. The staff also finds revised ITAAC-related Figure 2.1.2-2 acceptable because the input conditions and basis calculation are reasonable and the figure is not substantially different than revised UFSAR Tier 2 Figure 15.3.2-1. Finally, the staff finds ITAAC-related Figure 2.1.2-2 provides the appropriate RCP coastdown test acceptance criterion and continues to meet GDCs 10 and 15 because the revised analysis demonstrates that SAFDLs and design conditions for the RCS pressure boundary are not exceeded.
3.2 EVALUATION OF EXEMPTION The regulations in Section III.B of Appendix D to 10 CFR Part 52 require a holder of a COL referencing Appendix D to 10 CFR Part 52 to incorporate by reference and comply with the requirements of Appendix D, including certified information in Tier 1 of the generic AP1000 DCD. Exemptions from Tier 1 information are governed by the change process in Section VIII.A.4 of Appendix D of 10 CFR Part 52. Because SNC has identified changes to plant-specific Tier 1 information, with corresponding changes to the associated COL Appendix C information resulting in the need for a departure, an exemption from the certified design information within plant-specific Tier 1 material is required to implement the LAR.
The Tier 1 information for which a plant-specific departure and exemption was requested is described above. The result of this exemption would be that SNC could implement modifications to Tier 1 information to the UFSAR as well as revise the RCS flow coast down curve to align the curve with the predicted results during hot functional test conditions.
Pursuant to the provisions of 10 CFR 52.63(b)(1), an exemption from elements of the design as certified in the 10 CFR Part 52, Appendix D, design certification rule is requested for the involved Tier 1 information described and justified in LAR 18-025. This exemption is a permanent exemption limited in scope to the particular Tier 1 information specified.
As stated in Section VIII.A.4 of Appendix D to 10 CFR Part 52, an exemption from Tier 1 information is governed by the requirements of 10 CFR 52.63(b)(1) and 52.98(f). Additionally,Section VIII.A.4 of Appendix D to 10 CFR Part 52 provides that the Commission will deny a request for an exemption from Tier 1 if it finds that the requested change will result in a significant decrease in the level of safety otherwise provided by the design. Pursuant to 10 CFR 52.63(b)(1), the Commission may grant exemptions from one or more elements of the certification information, so long as the criteria given in 10 CFR 52.7, which, in turn, references 10 CFR 50.12, are met and that the special circumstances, which are defined by 10 CFR 50.12(a)(2), outweigh any potential decrease in safety due to reduced standardization.
Pursuant to 10 CFR 52.7, the Commission may, upon application by any interested person or upon its own initiative, grant exemptions from the requirements of 10 CFR Part 52. As 10 CFR 52.7 further states, the Commissions consideration will be governed by 10 CFR 50.12, Specific exemptions, which states that an exemption may be granted when:
(1) the exemptions are authorized by law, will not present an undue risk to the public health and safety, and are consistent with the common defense and security; and (2) special circumstances are present. Specifically, 10 CFR 50.12(a)(2) lists six circumstances for which an exemption may be granted. It is necessary for one of these bases to be present in order for the NRC to consider granting an exemption request. SNC stated that the requested exemption meets the special circumstances of §50.12(a)(2)(ii). The requested exemption satisfies the criteria for granting specific exemptions, That subparagraph defines special circumstances as when [a]pplication of the regulation in the particular circumstances would not serve the underlying purpose of the rule or is not necessary to achieve the underlying purpose of the rule. The staffs analysis of these findings is presented below:
3.2.1 AUTHORIZED BY LAW The requested exemption would allow SNC to implement the amendment described above.
This exemption is a permanent exemption limited in scope to particular Tier 1 information.
Subsequent changes related to the test acceptance criterion for reactor coolant system flow coastdown or any other Tier 1 information would be subject to the exemption process specified in Section VIII.A.4 of Appendix D to 10 CFR Part 52 and the requirements of 10 CFR 52.63(b)(1). As stated above, 10 CFR Part 52, Appendix D,Section VIII.A.4 allows the NRC to grant exemptions from one or more elements of the Tier 1 information. The NRC staff has determined that granting of SNCs proposed exemption will not result in a violation of the Atomic Energy Act of 1954, as amended, or the Commissions regulations. Therefore, as required by 10 CFR 50.12(a)(1), the exemption is authorized by law.
3.2.2 NO UNDUE RISK TO PUBLIC HEALTH AND SAFETY As discussed above in the technical evaluation, the proposed changes comply with the NRCs substantive safety regulations. Therefore, there is no undue risk to the public health and safety.
3.2.3 CONSISTENT WITH COMMON DEFENSE AND SECURITY The proposed exemption would allow changes as described above in the technical evaluation, thereby departing from the AP1000 certified (Tier 1) design information. The change does not alter or impede the design, function, or operation of any plant structures, systems, or components associated with the facilitys physical or cyber security and, therefore, does not affect any plant equipment that is necessary to maintain a safe and secure plant status. In addition, the changes have no impact on plant security or safeguards. Therefore, as required by 10 CFR 50.12(a)(1), the staff finds that the common defense and security is not impacted by this exemption.
3.2.4 SPECIAL CIRCUMSTANCES Special circumstances, in accordance with 10 CFR 50.12(a)(2), are present, in part, whenever application of the regulation in the particular circumstances would not serve the underlying purpose of the rule or is not necessary to achieve the underlying purpose of the rule. The underlying purpose of the Tier 1 information is to ensure that a licensee will safely construct and operate a plant based on the certified information found in the AP1000 DCD, which was incorporated by reference into the VEGP Units 3 and 4 licensing basis. The proposed changes described in the above technical evaluation do not impact the ability of any SSCs to perform their functions or negatively impact safety.
Special circumstances are present in the particular circumstances discussed in LAR 18-025 because the application of the specified Tier 1 information is not necessary to achieve the underlying purpose of the rule. The proposed changes are equal or provide additional clarity to the existing requirement. The proposed changes do not affect any function or feature used for the prevention and mitigation of accidents or their safety analyses, and no safety-related SSC or function is involved. This exemption request and associated revisions to the Tier 1 information and corresponding changes to Appendix C demonstrate that the applicable regulatory requirements will continue to be met. Therefore, for the above reasons, the staff finds that the special circumstances required by 10 CFR 50.12(a)(2)(ii) for the granting of an exemption from the Tier 1 information exist.
3.2.5 SPECIAL CIRCUMSTANCES OUTWEIGH REDUCED STANDARDIZATION This exemption would allow the implementation of changes to Tier 1 information in the plant-specific DCD and corresponding changes to Appendix C that are being proposed in the LAR.
The justification provided in LAR18-025, the exemption request, and the associated licensing basis mark-ups demonstrate that there is a limited change from the standard information provided in the generic AP1000 DCD. The design functions of the system associated with this request will continue to be maintained because the associated revisions to the Tier 1 information support the design function of the RCS. Consequently, the safety impact that may result from any reduction in standardization is minimized, because the proposed design change does not result in a reduction in the level of safety. In addition, the proposed changes provide better clarity in the existing requirements because the changes to the RCS flow coastdawn reflect actual operational conditions rather than safety analysis conditions. Based on the foregoing reasons, as required by 10 CFR Part 52.63(b)(1), the staff finds that the special circumstances outweigh any decrease in safety that may result from the reduction of standardization of the AP1000 design.
3.2.6 NO SIGNIFICANT REDUCTION IN SAFETY This exemption would allow the implementation of changes discussed above. The exemption request proposes to depart from the certified design by allowing changes discussed above in the technical evaluation. The changes for consistency will not impact the functional capabilities of this system. The proposed changes will not adversely affect the ability of the RCS to perform its design functions, and the level of safety provided by the current systems and equipment therein is unchanged. Therefore, based on the foregoing reasons and as required by 10 CFR 52.7, 10 CFR 52.98(f), and 10 CFR Part 52, Appendix D,Section VIII.A.4, the staff finds that granting the exemption would not result in a significant decrease in the level of safety otherwise provided by the design.
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 December 17, 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. 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 (83 FR 53515 published on October 23, 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.
Because the exemption is necessary to allow the changes proposed in the license amendment, and because the exemption does not authorize any activities other than those proposed in the license amendment, the environmental consideration for the exemption is identical to that of the license amendment. Accordingly, the exemption meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment needs to be prepared in connection with the issuance of the exemption.
6.0 CONCLUSION
The staff has determined that pursuant to Section VIII.A.4 of Appendix D to 10 CFR Part 52, the exemption (1) is authorized by law, (2) presents no undue risk to the public health and safety, (3) is consistent with the common defense and security, (4) is a special circumstance that outweighs the reduction in standardization, and (5) does not significantly reduce the level of safety at SNCs facility. Therefore, the staff grants SNC an exemption from Tier 1 information specified by SNC.
The staff has concluded, based on the considerations discussed in Section 3.1 and the NRC staffs confirmation that the changes proposed in this LAR do not change an analysis methodology, or assumptions 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 and Exemption (LAR-18-025): Reactor Coolant System (RCS) Flow Coastdown, August 31, 2018 (ADAMS Accession No. ML18243A459).
- 2. Combined License NPF-91 for Vogtle Electric Generating Plant Unit 3, Southern Nuclear Operating Company (ADAMS Accession No. ML14100A106).
- 3. Combined License NPF-92 for Vogtle Electric Generating Plant Unit 4, Southern Nuclear Operating Company (ADAMS Accession No. ML14100A135).
- 4. Vogtle Units 3 and 4 Updated Final Safety Analysis Report, Revision 6 and Tier 1, Revision 4, June 15, 2017 (ADAMS Accession No. ML17172A218).
- 5. AP1000 Design Control Document, Revision 19, June 13, 2011 (ADAMS Accession No. ML11171A500)