ML19003A487

Safety Evaluation - Vogtle Electric Generating Plant, Units 3 and 4 (LAR 18-016)re Amendment Nos. 152 and 151, Respectively

ML19003A487
Person / Time
Site:	Vogtle
Issue date:	01/28/2019
From:	NRC/NRO/DLSE/LB2
To:	City of Dalton, GA, Georgia Power Co, MEAG Power, Oglethorpe Power Corp, Southern Nuclear Operating Co
PATEL C/415-3025
Shared Package
ML19003A479	List: ML19003A480 ML19003A481 ML19003A482 ML19003A483 ML19003A484 ML19003A485 ML19003A486 ML19003A487
References
EPID L-2018-LLA-0205, LAR 18-016
Download: ML19003A487 (7)

Text

SAFETY EVALUATION BY THE OFFICE OF NEW REACTORS RELATED TO AMENDMENT NOS. 152 AND 151 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 July 19, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18200A415), Southern Nuclear Operating Company, Inc., (SNC) requested that the U.S. Nuclear Regulatory Commission (NRC) amend the combined license (COL) for Vogtle Electric Generating Plant (VEGP), Units 3 and 4, COL Numbers NPF-91 and NPF-92, respectively. License Amendment Request (LAR)18-016 proposes changes to COL Appendix C, with corresponding changes to the associated plant-specific Design Control Document (DCD) Tier 1 information.

The requested amendment proposes changes to COL Appendix C (and plant-specific DCD Tier 1) to revise Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC) related to flow testing of low pressure makeup from the cask loading pit (CLP) to the reactor coolant system (RCS) via the normal residual heat removal system (RNS) and RNS pump testing at reduced inventory.

Pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 52.63(b)(1), SNC also requested an exemption from the provisions of 10 CFR Part 52, Appendix D, Design Certification Rule for the AP1000 Design,Section III.B, Scope and Contents. This exemption request will 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 NRC staffs review of the exemption request, as well as the LAR, is included in this safety evaluation.

2.0 REGULATORY EVALUATION

The requested amendment revises the COL and licensing basis documents related to flow testing of low pressure makeup from the CLP to the RCS via the RNS and RNS pump testing at reduced inventory.

The NRC staff considered the following regulatory requirements in reviewing the LAR that included the proposed changes:

10 CFR Part 52, Appendix D, Section VIII.A.4 states that exemptions from Tier 1 information are governed by the requirements of 10 CFR 52.63(b)(1) and 10 CFR 52.98(f). It also states that the Commission will deny such a request if the design change causes a significant reduction in plant safety otherwise provided by the design.

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, including any modification to, addition to, or deletion from the ITAAC contained in the license. Therefore, the proposed changes require a license amendment and NRC approval is required prior to making the plant-specific proposed changes in this LAR.

The proposed changes to COL Appendix C (and plant-specific DCD Tier 1) potentially affects 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.

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 generic (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.

3.1 TECHNICAL EVALUATION

OF CHANGES ASSOCIATED WITH RNS LOW PRESSURE MAKEUP FLOW TEST CHANGE The information presented by SNC in LAR 18-016 was evaluated by the staff for its completeness, quality, and clarity. Section 2 of Enclosure 1 to LAR 18-016 provides proposed changes to plant specific Tier 1 and COL Appendix C Table 2.3.6-4, Acceptance Criteria for Design Commitment 9.c. SNC proposed a change to the associated water level in the following acceptance criterion: Each RNS pump provides at least 1100 [gallon per minute] gpm net flow to the RCS when the water level above the bottom of the cask loading pit is 1 foot +/- 6 inches.

SNC states that aligning the normal RNS to the CLP with a level of 1 foot +/- 6 inches above the bottom of the CLP could result in the potential for the formation of surface vortices in the CLP and gas intrusion to the RNS pump(s) resulting in potential for pump damage and flow test failure. The proposed changes to Tier 1 and COL Appendix C Table 2.3.6-4, Acceptance Criteria for Design Commitment 9.c revises the preoperational water level at which the test is performed from 1 foot +/- 6 inches to > 10 feet and < 15 feet. Additionally, SNC identified that the acceptance criteria could be interpreted as requiring both RNS pumps to be operating simultaneously during the test. Therefore, SNC proposes to add When tested individually to the acceptance criteria.

SNC states that the key design parameter that needs to be demonstrated is that each RNS pump can individually provide a minimum of 1100 gpm flow from the CLP to the RCS.

Additionally, SNC states (1) the RNS is not required to mitigate design basis accidents, (2) its operation is not considered in Chapter 15 analysis, and (3) there is no safety function that requires operating an RNS pump until the water level is at the bottom of the CLP. The staff agrees that the proposed change does not modify the design or functional requirements of the RNS pumps and does not impact safety analyses or the ability for RNS to perform its function because the change does not impact the ability of the RNS to provide low pressure injection to RCS. Based upon the staffs review of LAR 18-016, the staff finds that design basis accident analyses, Chapter 15 accident analyses, and the ability of the RNS to perform its function of providing additional margin for core cooling are not impacted by the changes to Tier 1 and COL Appendix C Table 2.3.6-4, Acceptance Criteria for Design Commitment 9.c and are acceptable.

3.2 TECHNICAL EVALUATION

OF CHANGES ASSOCIATED WITH RNS SHUTDOWN FLOW TEST CHANGE Section 2 of Enclosure 1 to LAR 18-016 provides proposed changes to plant specific Tier 1 and COL Appendix C Table 2.3.6-4, Acceptance Criteria for ITAAC Number 2.3.06.09b.ii. SNC proposed a change to clarify the acceptance criteria: Each RNS pump provides at least 1400 gpm net flow to the RCS when the hot leg water level is at an elevation 15.5 inches +/- 2 inches above the bottom of the hot leg.

SNC states that (1) the acceptance criteria wording could be interpreted as requiring both RNS pumps to be operating simultaneously during the test and (2) operation of both RNS pumps at the same time with RCS hot leg water level at 50 percent is not advised as it imposes a risk of air entrainment due to vortexing at the common suction takeoff, which could damage the pumps. Therefore, SNC proposes to add When tested individually, to the acceptance criterion. The staff agrees that the proposed change does not modify the design or functional requirements of the RNS pumps and does not impact safety analyses or the ability for RNS to perform its function.

The staff finds that design basis accident analyses, Chapter 15 accident analyses, and the ability of the RNS to perform its function of providing additional margin for core cooling are not affected by the changes to Tier 1 and COL Appendix C Table 2.3.6-4, Acceptance Criteria for ITAAC Number 2.3.06.09b.ii because the changes merely provide clarification to the acceptance criterion. Therefore, staff finds the proposed changes acceptable.

3.3 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 relates to changes to flow testing of low pressure makeup from the CLP to the RCS via the RNS and RNS pump testing at reduced inventory. The result of this exemption would be that SNC could implement the requested modifications to Tier 1 information, with corresponding changes to COL Appendix C. 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 18-016. 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 10 CFR 50.12(a)(2)(ii). 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 flow testing of low pressure makeup from the CLP to the RCS via the RNS and RNS pump testing at reduced inventory 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 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 a change related to flow testing of low pressure makeup from the CLP to the RCS via the RNS and RNS pump testing at reduced inventory as described in the licensing basis documents, and as presented in plant-specific Tier 1 information, 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 52.7 and 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 the 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 structures, systems, and components to perform their functions or negatively impact safety.

Special circumstances are present in the particular circumstances discussed in LAR 18-016 because the application of the specified Tier 1 information is not necessary to achieve the underlying purpose of the rule. The proposed exemption would revise the ITAAC supporting the flow testing of low pressure makeup from the CLP to the RCS via the RNS and RNS pump testing at reduced inventory. This exemption requests revisions to Tier 1 that continue to demonstrate that the applicable regulatory requirements will be met. Therefore, for the above reasons, the NRC staff finds that the special circumstances required by 10 CFR 52.7 and 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. The justification provided in LAR 18-016, 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 RNS. 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. 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 proposed changes will not adversely affect safety-related equipment or a fission product barrier, and do not impact the functional capabilities of the RNS 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 January 07, 2019. 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 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 48463, published on September 25, 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 NRC staff grants SNC an exemption from Tier1 information specified by SNC.

The Commission has concluded, based on the considerations discussed in Section 3.1 and Section 3.2 and the 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 NRC 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-18-016): RNS Pump Testing ITAAC Changes, July 19, 2018 (ADAMS Accession No. ML18200A415).

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).