ND-18-0879, Request for Exemption from Timing of PRA Standards

Request for Exemption from Timing of PRA Standards

ML18178A533
Person / Time
Site:	Vogtle
Issue date:	06/27/2018
From:	Sparkman W Southern Nuclear Operating Co
To:	Document Control Desk, Office of New Reactors
References
ND-18-0879
Download: ML18178A533 (14)

Text

Southern Nuclear Operating Company, Inc.

3535 Colonnade Parkway Birmingham, AL 35243 June 27, 2018 Docket Nos.: 52-025 ND-18-0879 52-026 10 CFR 50.71(h)(1) 10 CFR 50.12 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Southern Nuclear Operating Company Vogtle Electric Generating Plant Units 3 and 4 Request for Exemption from Timing of PRA Standards Ladies and Gentlemen:

In accordance with the provisions of 10 CFR 50.12, Southern Nuclear Operating Company (SNC),

as a Combined License (COL) holder under 10 CFR Part 52, hereby requests an exemption from the requirements of 10 CFR 50.71(h)(1) as applicable to Vogtle Electric Generating Plant (VEGP)

Units 3 and 4 (License Numbers NPF-91 and NPF-92, respectively). Specifically, SNC requests a partial exemption from 10 CFR 50.71(h)(1), which requires each holder of a combined license, no later than the scheduled date for initial loading of fuel, to develop a level 1 and a level 2 probabilistic risk assessment (PRA) that covers those initiating events and modes for which NRC-endorsed consensus standards on PRA exist one year prior to the scheduled date for initial loading of fuel.

The initial PRA for VEGP Units 3 and 4 is under development using Regulatory Guide 1.200, Revision 2 (RG 1.200, Rev. 2). SNC proposes a partial exemption that would modify the requirement for the initial PRA to cover those initiating events and modes for which RG 1.200, Rev. 2 endorses standards. The exemption is necessary because new consensus standards are currently scheduled to be endorsed, but shifting to new standards in the midst of the development of the initial PRA pursuant to the one-year prior requirement is not practicable and would result in undue hardship. Additionally, the timing of the forthcoming revision to RG 1.200 would not permit sufficient time to complete the initial PRA prior to fuel load. to this letter presents SNCs detailed basis for the exemption.

This letter contains no regulatory commitments. This letter has been reviewed and determined not to contain security-related information.

SNC requests NRC staff approval of the requested exemption by January 7, 2019.

Should you have any questions, please contact Mr. Ryan Henderson at (205) 992-6426.

U.S. Nuclear Regulatory Commission ND-18-0879 Page 2 of 4 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 271h of June 2018.

Respectfully submitted, Wesley . Spar Licensing Mana r Southern Nuclear Operating Company

Enclosure:

1) Vogtle Electric Generating Plant (VEGP) Units 3 and 4 - Request for Exemption from Timing of PRA Standards

U.S. Nuclear Regulatory Commission ND-18-0879 Page 3 of 4 cc:

Southern Nuclear Operating Company / Georgia Power Company Mr. S. E. Kuczynski (w/o enclosure)

Mr. D. G. Bost (w/o enclosure)

Mr. M. D. Meier (w/o enclosure)

Mr. D. H. Jones (w/o enclosure)

Mr. J. B. Klecha Mr. G. Chick Mr. D. L. McKinney (w/o enclosure)

Mr. T. W. Yelverton (w/o enclosure)

Mr. C. R. Pierce Ms. A. G. Aughtman Mr. D. L. Fulton Mr. M. J. Yox Mr. J. Tupik Mr. B. H. Whitley Ms. C. A. Gayheart Mr. W. A. Sparkman Ms. A. C. Chamberlain Ms. A. L. Pugh Mr. F. J. Redwanz Document Services RTYPE: VND.LI.L00 File AR.01.02.06 Nuclear Regulatory Commission Mr. W. Jones (w/o enclosure)

Mr. L. Burkhart (w/o enclosure)

Ms. J. Dixon-Herrity Mr. C. Patel Ms. J. M. Heisserer Mr. B. Kemker Mr. G. Khouri Ms. S. Temple Mr. F. Brown Mr. T. E. Chandler Ms. P. Braxton Mr. T. Brimfield Mr. C. J. Even Mr. A. Lerch State of Georgia Mr. R. Dunn Oglethorpe Power Corporation Mr. M. W. Price Mr. K. T. Haynes Ms. A. Whaley

U.S. Nuclear Regulatory Commission ND-18-0879 Page 4 of 4 Municipal Electric Authority of Georgia Mr. J. E. Fuller Mr. S. M. Jackson Dalton Utilities Mr. T. Bundros Westinghouse Electric Company, LLC Mr. L. Oriani (w/o enclosure)

Mr. G. Koucheravy (w/o enclosure)

Mr. M. Corletti Mr. M. L. Clyde Ms. L. Iller Mr. D. Hawkins Mr. J. Coward Other Mr. S. W. Kline, Bechtel Power Corporation Ms. L. A. Matis, Tetra Tech NUS, Inc.

Dr. W. R. Jacobs, Jr., Ph.D., GDS Associates, Inc.

Mr. S. Roetger, Georgia Public Service Commission Ms. S. W. Kernizan, Georgia Public Service Commission Mr. K. C. Greene, Troutman Sanders Mr. S. Blanton, Balch Bingham Mr. R. Grumbir, APOG Mr. S. Franzone, Florida Power & Light NDDocumentinBox@duke-energy.com, Duke Energy

Southern Nuclear Operating Company ND-18-0879 Enclosure 1 Vogtle Electric Generating Plant (VEGP) Units 3 and 4 Request for Exemption from Timing of PRA Standards (This Enclosure consists of 10 pages, including this cover page)

ND-18-0879 Request for Exemption from Timing of PRA Standards 1.0 PURPOSE In accordance with the provisions of 10 CFR 50.12, Southern Nuclear Operating Company (SNC), as a Combined License (COL) holder under 10 CFR 52, hereby requests an exemption from the requirements of 10 CFR 50.71(h)(1) as applicable to Vogtle Electric Generating Plant (VEGP) Units 3 and 4. Specifically, SNC requests a partial exemption from 10 CFR 50.71(h)(1), which requires each holder of a combined license, no later than the scheduled date for initial loading of fuel, to develop a level 1 and a level 2 probabilistic risk assessment (PRA) that covers those initiating events and modes for which NRC-endorsed consensus standards on PRA exist one year prior to the scheduled date for initial loading of fuel.

SNC proposes a partial exemption that would modify the requirement for the initial level 1 and level 2 PRA for VEGP Units 3 and 4 to cover those initiating events and modes for which Regulatory Guide 1.200, Revision 2, endorses standards.

2.0 BACKGROUND

In 2007, the Nuclear Regulatory Commission (NRC) revised its regulations to clarify the applicability of various requirements to each of the licensing processes (i.e., early site permit, standard design approval, standard design certification, combined license, and manufacturing license) by making necessary conforming amendments throughout the NRCs regulations to enhance the NRCs regulatory effectiveness and efficiency in implementing its licensing and approval processes. During the development of the Final Rule to Update 10 CFR Part 52, Licenses, Certifications, and Approvals for Nuclear Plants, various input was taken from the Public and from the Commission. Part of the input from the Commission was by way of a staff requirements memorandum (SRM) on April 11, 2007 (Reference 1) containing changes and comments to the proposed rule which were directed to be made by the staff prior to issuance of the final rule. Comment 16 in the Attachment to the SRM on SECY-06-0220 directed, in part, that rule text be added requiring combined operating license licensees to develop and maintain a level 1 and a level 2 PRA, at the time of initial operation of the reactor, covering those initiating events and modes of operation for which NRC-endorsed standards exist one year prior to initial operation. This language became 10 CFR 50.71(h)(1).

The Statement of Considerations (Reference 2) notes that the one year time period was chosen to allow time for the licensee to develop and upgrade its PRA and conduct peer review prior to the date when the PRA must be completed (i.e., by the scheduled date for initial fuel load). The scheduled fuel load date was selected because the COL holder chooses this date, and thus is in a position to determine when the one-year prior requirement comes into effect.

Regulatory Guide 1.200 (RG 1.200), An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, contains the NRC endorsement of consensus standards on PRA. Standards for initiating events and modes of operation were last endorsed by the NRC in 2009 in RG 1.200, Revision 2 (Reference 3). RG 1.200, Rev. 2 includes NRC endorsement of a consensus standard for at-power internal events, internal flood, internal fire, seismic, wind, external flood, and other external hazards (ASME/ANS RA-Sa-2009).

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ND-18-0879 Request for Exemption from Timing of PRA Standards The NRC staff and industry have continued to work together to update PRA standards and issue new standards for new initiating events and modes of operation. This includes the issuance of trial use standards and regular public meetings to discuss changes.

Endorsement of new standards is done by revision to RG 1.200. Through the regulatory guide revision and PRA standards revision processes, SNC has remained engaged in these ongoing staff activities and understands that another regulatory guide revision is scheduled to occur in May 2020.

Based on the anticipated timing of the RG 1.200 revision in relation to VEGP Unit 3 fuel load, initial PRA development is proceeding in accordance with RG 1.200, Rev. 2.

However, the next revision to RG 1.200 may take place marginally before one year prior to VEGP Unit 4 fuel load; therefore, it is possible that the initial PRA for VEGP Unit 4 could be required to cover new initiating events and modes. SNC has determined that initial development for the existing initiating events and modes will take longer than a year and that initial development of anticipated new initiating events and modes will take longer than a year. Based on a review of the scope of work that will be required to change to the proposed new standards shortly before the fuel load date, it is likely to cause a postponement of the scheduled date. It will not be practicable to shift PRA development from Rev. 2 of RG 1.200 to the newly endorsed standards during the one-year period required by 10 CFR 50.71(h)(1).

Therefore, SNC requests NRC approval to develop the initial level 1 and level 2 PRA for VEGP Units 3 and 4 to cover those initiating events and modes for which RG 1.200, Rev. 2 endorses standards.

3.0 TECHNICAL JUSTIFICATION OF ACCEPTABILITY The timeline of work required to develop a level 1 and a level 2 PRA includes identifying the inputs from the plant design information, plant operational information, plant test and maintenance procedures, and engineering aspects of the plant design (for which the level of detail continues to evolve as plant construction and design continues); using the inputs to develop the PRA models; putting the models through peer reviews; resolving Facts and Observations (F&Os); and performing plant walkdowns. It is not practicable to complete this scope of work within one year. Initial estimates by SNC, based in part on the work performed thus far since COL issuance, are that this work would take more than a year and as long as three years.

In order to complete the work in compliance with the regulation by initial loading of fuel, SNC has already begun to invest significant time and resources into the development of the level 1 and level 2 PRA to include initiating events and modes of operation included in NRC-endorsed consensus standards from RG 1.200, Rev. 2. There is a draft of all at-power models (internal events, internal flood, internal fire, seismic, and other external hazards). The at-power models are on-track for completion by the required date, with respect to the currently endorsed standards. In addition to 10 CFR 50.71(h)(1), there are license conditions and regulatory requirements which require the update of relevant risk information prior to fuel load. One such requirement is the development of a defense-in-depth shutdown model to support 10 CFR 50.65(a)(4). That effort uses qualitative methods.

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ND-18-0879 Request for Exemption from Timing of PRA Standards As part of the RG 1.200 revision process, standards have been issued for trial use. SNC considered use of the trial standards in anticipation of their endorsement. This way, should endorsement take place before one-year prior to fuel load, SNC would be better able to complete the PRA with minimal impact on the fuel load date. However, it is not practicable to work to these trial standards, as it is likely that work done to a trial standard will not ultimately meet the endorsed version of the standard (Reference 4). This would result in the need for reworksome of which may not be trivial in nature for new modes of operation. The engineering resources that would be required to accomplish this rework could be better used during the final construction and testing to accomplish work necessary to achieve fuel load. It would not be practical to reassign these resources to do significant rework to the PRA. Additionally, if the trial use standard were not approved, work could be required to force-fit the PRA models to meet the RG 1.200, Revision 2 standards and the work done on new modes of operation would result in an opportunity cost for other work to which those resources could have been applied. Depending on the significance of any of these issues, the one-year timeline prior to fuel load could be inadequate to allow resolution of the discrepancies without impacting the fuel load date.

As stated above, work has already begun on the PRA models for which RG 1.200, Revision 2 already provides NRC endorsement of consensus PRA standards. They are on track for completion by the required date. In addition, regulations require SNC to maintain and upgrade the PRA to meet future endorsed standards over the lifetime of the facility [10 CFR 50.71(h)(2) and 10 CFR 50.71(h)(3)].

In order to demonstrate SNCs concern, the following example is provided.

One of the most significant changes expected to occur in the RG 1.200, Revision 3 update is the endorsement of a low-power shutdown model standard [although it is noted that industry comments have suggested that the standard should not be endorsed in this revision (Reference 5)]. A trial use standard is currently available to the industry. Attempting to employ the low-power shutdown trial use standard is not practicable because it is likely to change before NRC endorsement. Working to a changing standard is a high-risk burden to place on a licensee because of the potential for rework, which would distract engineering resources that could be more appropriately utilized elsewhere. Instead, SNC would wait until NRC endorsement of a standard prior to use.

If the NRC issued RG 1.200, Revision 3 one year prior to Unit 3 or Unit 4 fuel load, SNC would then be required to utilize the different, and newly endorsed standards in order to comply with the regulation. Because the low-power shutdown PRA model will involve significant new investigation in order to identify relevant plant operating states and applicable operator actions, it is expected that this work will take a considerable amount of time. Initial estimates by SNC are that it could take up to three years. One year would not provide sufficient time to complete this investigation, develop the model, complete peer review, and resolve F&Os without impacting the fuel load date. This exemplifies SNCs purpose for the request.

As mentioned earlier, SNC also is developing a defense-in-depth shutdown model to support 10 CFR 50.65(a)(4). That effort uses qualitative methods and will be adequate to manage risk during shutdown conditions until regulations require Page 4 of 10

ND-18-0879 Request for Exemption from Timing of PRA Standards updates to the PRA using future endorsed standards for low power shutdown conditions.

Therefore, SNC requests NRC approval to develop the initial level 1 and level 2 PRA to cover those initiating events and modes for which RG 1.200, Rev. 2 endorses standards.

This provides adequate time to complete the PRA model updates, peer reviews, and issue resolution prior to fuel load while allowing engineering focus on important construction/testing necessary to accomplish initial fuel load safely.

4.0 JUSTIFICATION FOR EXEMPTION 10 CFR 50.12 states that the NRC may grant exemptions from the requirements of the regulations provided four conditions are met: 1) the exemption is authorized by law

[§50.12(a)(1)]; 2) the exemption will not present an undue risk to the health and safety of the public [§50.12(a)(1)]; 3) the exemption is consistent with the common defense and security [§50.12(a)(1)]; and 4) special circumstances are present [§50.12(a)(2)].

The requested exemption satisfies the criteria for granting specific exemptions, as described below.

1. This exemption is authorized by law.

The NRC has authority under 10 CFR 50.12 to grant exemptions from the requirements of NRC regulations. Specifically, 10 CFR 50.12 states that the NRC may grant exemptions from the requirements of 10 CFR Part 50 upon a proper showing.

No law exists that would preclude the changes covered by this exemption request.

Additionally, granting of the proposed exemption does not result in a violation of the Atomic Energy Act of 1954, as amended, or the Commissions regulations.

Accordingly, this requested exemption is authorized by law, as required by 10 CFR 50.12(a)(1).

2. This exemption will not present an undue risk to the health and safety of the public.

The proposed exemption from the requirements of 10 CFR 50.71(h)(1) would allow SNC to develop the initial level 1 and level 2 PRA to cover those initiating events and modes for which RG 1.200, Rev. 2 endorses standards. The proposed change in which timing of standards is required to be met does not represent any adverse impact to SNCs ability to satisfy other PRA requirements in the regulations or License. The change is needed to allow SNC a practicable amount of time to fulfill the requirement.

Risk insights from the design certification have already been incorporated into the design. Specific to low power shutdown, risk has been assessed qualitatively and will be managed in accordance with 10 CFR 50.65(a)(4).

The proposed exemption does not introduce any new industrial, chemical, or radiological hazards that would present a public health or safety risk, nor does it modify or remove any design or operational controls or safeguards intended to mitigate any existing on-site hazards. Furthermore, the proposed exemption would not allow for a new fission product release path, result in a new fission product barrier failure mode, Page 5 of 10

ND-18-0879 Request for Exemption from Timing of PRA Standards or create a new sequence of events that would result in fuel cladding failures.

Accordingly, this proposed exemption does not present an undue risk from any existing or proposed equipment or systems.

Therefore, the requested exemption from 10 CFR 50.71(h)(1) would not present an undue risk to the health and safety of the public.

3. The exemption is consistent with the common defense and security.

The proposed exemption from the requirements of 10 CFR 50.71(h)(1) would allow SNC to develop the initial level 1 and level 2 PRA to cover those initiating events and modes for which RG 1.200, Rev. 2 endorses standards. The proposed exemption does not alter the design, function, or operation of any structure or plant equipment that is necessary to maintain a safe and secure status of the plant. The proposed exemption has no impact on plant security or safeguards procedures. Risk insights from the design certification have already been incorporated into the design. Specific to low power shutdown, risk has been assessed qualitatively and will be managed in accordance with 10 CFR 50.65(a)(4).

Therefore, the requested exemption is consistent with the common defense and security.

4. Special circumstances are present.

10 CFR 50.12(a)(2) lists six special circumstances for which an exemption may be granted. Pursuant to the regulation, it is necessary for at least one of these special circumstances to be present in order for the NRC to consider granting an exemption request. Special circumstances are present as discussed below:

10 CFR 50.12(a)(2)(ii)

The requested exemption meets the special circumstances of 50.12(a)(2)(ii). That subsection defines special circumstances as when 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 proposed exemption from the requirements of 10 CFR 50.71(h)(1) would allow SNC to develop the initial level 1 and level 2 PRA to cover those initiating events and modes for which RG 1.200, Rev. 2 endorses standards. The underlying purpose of the rule is to require combined license holders to maintain and upgrade a PRA to [meet]

endorsed standards over the lifetime of the facility. (Reference 2) The proposed exemption would still require SNC to use endorsed standards, but the timing of those standards would be changed to provide a practicable amount of time to complete the initial level 1 and level 2 PRA. Regulations will continue to require SNC to maintain and upgrade the PRA to meet future endorsed standards over the lifetime of the facility

[10 CFR 50.71(h)(2) and 10 CFR 50.71(h)(3)].

Therefore, special circumstances are present, because 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.

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ND-18-0879 Request for Exemption from Timing of PRA Standards 10 CFR 50.12(a)(2)(iii)

The requested exemption meets the special circumstances of 50.12(a)(2)(iii). That subsection defines special circumstances as when Compliance would result in undue hardship or other costs that are significantly in excess of those contemplated when the regulation was adopted, or that are significantly in excess of those incurred by others similarly situated.

The proposed exemption from the requirements of 10 CFR 50.71(h)(1) would allow SNC to develop the initial level 1 and level 2 PRA to cover those initiating events and modes for which RG 1.200, Rev. 2 endorses standards. The change is needed to allow SNC a practicable amount of time to fulfill the requirement. One year does not provide practicable time to complete the scope of work and would delay fuel load until the PRA was completed. Working to trial standards presents impractical opportunity for rework.

The engineering resources that would be required to accomplish this rework could be better used during the final construction and testing to accomplish work necessary to achieve fuel load. In particular, the low power shutdown PRA, which would require significant new investigation to identify plant operating states and operator actions, could take up to three years.

Therefore, special circumstances are present, because compliance with 10 CFR 50.71(h)(1) would result in undue hardship or other costs that are significantly in excess of those contemplated when the regulation was adopted.

5.0 RISK ASSESSMENT A risk assessment was not determined to be applicable to address the acceptability of this proposal.

6.0 PRECEDENT EXEMPTIONS None.

7.0 SIGNIFICANT HAZARDS DETERMINATION AND ENVIRONMENTAL CONSIDERATION The proposed exemption has been evaluated against the criteria of 10 CFR 51.21, Criteria for and identification of licensing and regulatory actions requiring environmental assessments, and has been determined to meet the categorical exclusion criteria of 10 CFR 51.22, Criterion for categorical exclusion; identification of licensing and regulatory actions eligible for categorical exclusion or otherwise not requiring environmental review, as described below, which evaluates the change against the criteria of 10 CFR 51.22(c)(25).

The requested exemption, which seeks to change the timing of standards required by 10 CFR 50.71(h)(1), does not make any changes to the facility or operating procedures and:

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ND-18-0879 Request for Exemption from Timing of PRA Standards i) Does not involve a significant hazards consideration [10 CFR 51.22(c)(25)(i)]. The standards set forth in 10 CFR 50.92(c) were used to determine whether the requested exemption involved a significant hazards consideration:

(1) Does the proposed licensing action involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed exemption from the requirements of 10 CFR 50.71(h)(1) would allow the Licensee to develop the initial level 1 and level 2 Probabilistic Risk Assessment (PRA) to cover those initiating events and modes for which Regulatory Guide (RG) 1.200, Rev. 2 endorses standards. The requested exemption does not alter the design, function, or operation of any plant equipment.

Therefore, granting this exemption would not involve a significant increase in the probability or consequences of an accident previously evaluated.

(2) Does the proposed licensing action create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The requested exemption does not alter the design, function, or operation of any plant equipment. The requested exemption does not create any new failure mechanisms, malfunctions, or accident initiators.

Therefore, granting this exemption does not create the possibility of a new or different kind of accident from any accident previously evaluated.

(3) Does the proposed licensing action involve a significant reduction in a margin of safety?

Response: No.

A PRA is an analysis to determine the relative risk (probability) of an undesirable outcome, specifically, core damage frequency and large early release frequency.

While the PRA uses the design attributes of structures, systems, and components (SSCs), the PRA does not affect SSCs. As a result, a change to the PRA description or PRA results does not affect an SSC, SSC design function, or method of performing or controlling a design function. While the PRA uses the design attributes of SSCs, the PRA is not used to establish the design bases of an SSC nor is it used in the safety analyses. Furthermore, the requested exemption does not exceed or alter a design basis or safety limit.

Therefore, granting this exemption does not involve a significant reduction in a margin of safety.

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ND-18-0879 Request for Exemption from Timing of PRA Standards Therefore, it is concluded that the requested exemption does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding of no significant hazards consideration is justified.

ii) Does not involve a significant change in the types or significant increase in the amounts of any effluents that may be released offsite [10 CFR 51.22(c)(25)(ii)]. The requested exemption does not alter the design, function, or operation of any plant equipment. There are no changes to effluent types, plant radiological or non-radiological effluent release quantities, any effluent release path, or the functionality of any design or operational features credited with controlling the release of effluents during plant operation or construction.

Therefore, it is concluded that the proposed exemption does not involve a significant change in the types or significant increase in the amounts of any effluents that may be released offsite.

iii) Does not involve a significant increase in individual or cumulative public or occupational radiation exposure [10 CFR 51.22(c)(25)(iii)]. There are no changes to plant radiation zones, nor any change to controls required under 10 CFR Part 20 which preclude a significant increase in occupational radiation exposure.

Therefore, it is concluded that the proposed exemption does not involve a significant increase in individual or cumulative public or occupational radiation exposure.

iv) Does not involve a significant construction impact [10 CFR 51.22(c)(25)(iv)]. The requested exemption does not alter the design, function, or operation of any plant equipment. No change to the facility is being made as a result of this exemption.

Therefore, it is concluded that the proposed exemption does not involve a significant construction impact.

v) Does not involve a significant increase in the potential for or consequences from radiological accidents [10 CFR 51.22(c)(25)(v)]. The requested exemption does not alter the design, function, or operation of any plant equipment. There are no changes to plant radiation zones, nor any change to controls required under 10 CFR Part 20 which preclude a significant increase in occupational radiation exposure.

Therefore, it is concluded that the proposed exemption does not involve a significant increase in the potential for or consequences from radiological accidents.

vi) Involves reporting requirements related to the timing of NRC-endorsed consensus standards on PRA which detail the initiating events and modes that must be covered in the PRA [10 CFR 51.22(c)(25)(vi)(B)].

Accordingly, the proposed exemption meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(25). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this exemption.

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ND-18-0879 Request for Exemption from Timing of PRA Standards

8.0 CONCLUSION

The proposed exemption from the requirements of 10 CFR 50.71(h)(1) would allow SNC to develop the initial level 1 and level 2 PRA to cover those initiating events and modes for which RG 1.200, Rev. 2 endorses standards. The proposed change in the timing of when standards are required to be met does not represent any adverse impact to SNCs ability to satisfy other PRA requirements in the regulations or License. The change is needed to allow SNC a practicable amount of time to fulfill the requirement.

The exemption request meets the requirements of 10 CFR 50.12, Specific exemptions.

Specifically, the exemption request meets the criteria of 10 CFR 50.12(a)(1) in that the request is authorized by law, presents no undue risk to public health and safety, and is consistent with the common defense and security. Furthermore, approval of this request presents special circumstances and meets the eligibility requirements for categorical exclusion from requiring an environmental assessment.

9.0 REFERENCES

1. Staff Requirements Memorandum on SECY-06-0220, Final Rule to Update 10 CFR Part 52, Licenses, Certifications, & Approvals for Nuclear Power Plants, dated April 11, 2007 (ADAMS Accession Number ML071010223)

2. Licenses, Certifications, and Approvals for Nuclear Power Plants, 72 FR 49351, dated August 28, 2007

3. Regulatory Guide 1.200, Revision 2, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, dated March 2009 (ADAMS Accession Number ML090410014)

4. Memorandum from John A. Nakoski, Chief Performance and Reliability Branch, to Mary Drouin, Senior Program Manager, Meeting Between the Nuclear Regulatory Commission Staff and Stakeholders Concerning NRC Endorsement of ASME/ANS Trial Use PRA Standards and Evaluation Criteria for Multi-Module Risk, dated December 15, 2014 (ADAMS Accession Number ML14322A790)

5. Nuclear Energy Institute (NEI) presentation on Industry Input on Regulatory Guide 1.200 Changes, dated October 17, 2017 (ADAMS Accession Number ML17289A708)

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