ML21029A340
| ML21029A340 | |
| Person / Time | |
|---|---|
| Issue date: | 02/19/2021 |
| From: | Andrea Kock Division of Fuel Management |
| To: | Mccullum R Nuclear Energy Institute |
| Diaz-Sanabria Y | |
| Shared Package | |
| ML21029A339 | List: |
| References | |
| Download: ML21029A340 (7) | |
Text
R. McCullum UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 February 19, 2021 Mr. Rodney McCullum, Sr. Director Decommissioning and Used Fuel Program Nuclear Energy Institute 1201 F Street, NW, Suite 1100 Washington, DC 20004
SUBJECT:
RESPONSE TO NUCLEAR ENERGY INSTITUTE LETTER -
IMPLEMENTATION OF THE RECOMMENDATIONS OF INDUSTRYS NOVEMBER 8, 2019 WHITE PAPER, DEFINING SPENT FUEL PERFORMANCE MARGINS, DATED JANUARY 14, 2021
Dear Mr. McCullum,
Thank you for your letter dated January 14, 2021 (Agencywide Documents Access and Management System [ADAMS] Accession No. ML21025A355), in which the Nuclear Energy Institute (NEI) provided its perspectives on the status of activities pertaining to recommended enhancements to the licensing framework for spent nuclear fuel (SNF) dry storage systems. In your previous letter dated November 8, 2019 (ADAMS Accession No. ML19318D970), NEI submitted a White Paper (ADAMS Accession No. ML19318D971) framing sixteen topical areas of specific interest to NEI and provided recommendations for each aimed at improving effectiveness and efficiency of the SNF dry storage licensing framework. These recommendations built on and accelerated initiatives that were already underway by the NRC staff (or staff) to transform the spent fuel licensing process in a manner that continues to ensure safety.
We agree that substantial progress has been made in transforming the spent fuel licensing process since the November 8, 2019 NEIs letter. Over the course of the last fifteen months, the NRC staff has held nine public workshops on NEIs recommendations. During these workshops, the staff and its stakeholders developed a common understanding of the recommendations, aligned on the actions and path forward, and set priorities and a roadmap to define the specific products for each recommendation. In addition, during the workshops, the staff sought NEI and other stakeholder feedback on draft regulatory products and approaches which will address 14 of the 16 NEIs recommendations. These efforts will result in transformational enhancements to the SNF storage licensing framework which will continue the NRCs mission of ensuring public health and safety. Leadership by the staff with support and engagement by NEI, the industry, and other stakeholders facilitated a healthy discussion of the recommendations and contributed to the significant successes that have been achieved in just over a years time.
I have reviewed your perspectives on the status of the sixteen recommendations and largely agree with NEIs characterization of the progress to date. I have included as an enclosure to this letter the table you provided in your January 14, 2021, letter with additional perspectives.
R. McCullum 2
As we look towards the remainder of 2021, in keeping with the NRCs principles of good regulation, I believe it is in the interests of the NRC, the industry, and the public to continue to engage in public workshops on the topics outlined in the NEI white paper. Consistent with the enclosed table, we recommend a workshop in the near future to align on priorities and goals for 2021, focusing on the recommendations where action has not been taken. Considering this, I support your proposal to continue with periodic public meetings to continue to make progress in this area and to provide NEI, the industry, and the public the opportunity to provide input and perspectives on the NRCs SNF licensing framework.
Please contact me, Christopher Regan, or Yoira Diaz-Sanabria of my staff if you have any questions.
Sincerely,
/RA/
Andrea L. Kock, Director Division of Fuel Management Office of Nuclear Materials Safety and Safeguards Andrea L.
Kock Digitally signed by Andrea L. Kock Date: 2021.02.19 16:38:58 -05'00'
R. McCullum 3
RESPONSE TO NUCLEAR ENERGY INSTITUTE LETTER - IMPLEMENTATION OF THE RECOMMENDATIONS OF INDUSTRYS NOVEMBER 8, 2019 WHITE PAPER, DEFINING SPENT FUEL PERFORMANCE MARGINS, DATED JANUARY 14, 2021 DATED: February 19, 2021 DISTRIBUTION:
JLubinski, NMSS RLewis, NMSS JMcKirgan, NMSS/DFM/STLB TBoyce, NMSS/DFM/MSB RChang, NMSS/DFM/NARAB TLiu, NMSS/DFM/STLB ADAMS Package Accession Number: ML21029A339
- via e-mail OFC NMSS/DFM NMSS/DFM NMSS/DFM NAME YDiaz-Sanabria CRegan AKock DATE 2/18/2021 2/18/2021 2/19/2021 OFFICIAL RECORD COPY
Enclosure Tables 1 through 3 provide a listing of the sixteen recommendations transmitted to the NRC in NEIs November 8, 2019 white paper. The information presented in the summary, results, and path forward columns is taken directly from NEIs January 14, 2021 letter. The column labeled NRC Comments was added with the specific goal of documenting the NRCs views on the status of activities related to NEIs white paper.
Table 1 - Actions that can be taken by industry within existing regulations Rec. #
Summary Results Path Forward NRC Staff Comments III-1 Utilize more realistic source terms COMPLETE
- NRC endorsement of NEI 12-04 (9/22/20) provides industry with improved flexibility
- Action completed per Table 2 will provide additional flexibility Industry to build more realistic source terms into analyses as appropriate.
The NRC agrees with the results and path forward. In addition to the NRCs endorsement of NEI-12-04, the NRC staff developed a Method of Evaluation approach whereby a more performance-based review of shielding analyses would be completed, and more realistic source terms could be used by applicants as a representative source for the shielding calculations.
III-2 Do not apply uncertainty penalty on top of conservative source term COMPLETE
- NRC endorsement of NEI 12-04 (9/22/20) provides improved flexibility
- Actions completed per Table 2 will provide additional flexibility Industry to reduce reliance on uncertainty penalties as appropriate.
This recommendation applies to the dry storage system users when selecting allowable fuel to be stored within a certified dry storage system. The NRC agrees with the results and path forward. The amount of certainty needed to establish that the burnup records are accurate is determined at the reactor site and is not regulated by the NRC. The NRC therefore does not require an additional level of margin associated with burnup within its reviews for compliance with 72.236(d).
IV-3 Develop and document industry consensus thermal modeling practices COMPLETE
- Thermal Modeling, Decay Heat Monitoring, and Fuel Performance PIRTS have been completed
- Industry proposed new safety objective (5/13/20),
NRC letter (6/1/20) agreed with approach, gross rupture PIRT process underway to define new safety objective that includes realistic and actionable fuel integrity metrics Industry to apply, in future license and Certificate of Compliance (CoC) applications, the insights documented in the PIRTS and letters.
The NRC agrees with the results.
While we agree with the path forward, additional discussion may be warranted regarding how the results of the Phenomena Identification and Ranking Table (PIRT) reports could be utilized.
We previously communicated in workshops, that a submittal for endorsement may be appropriate for broad applicability, consistency, and transparency (e.g., topical report, industry guidance, etc.)
VI-1 Adopt and extend graded approach CoC precedent (Per RIRP I 01)
COMPLETE
- NRC approved Orano pilot graded approach CoC (9/14/20)
- NRC and industry aligned on future use of the graded approach (12/17/20 workshop)
Industry to use the graded approach in future license and CoC applications.
The NRC agrees that significant progress has been made in completion of the graded approach pilot.The NRC staff is open to further discussion with the industry on how best to facilitate use of the graded approach. The staff also is looking to evaluate the lessons
learned from the pilot, including working with the pilots applicant, to assess if and what additional guidance may be necessary. The NRC staffs method of evaluation approach for shielding reviews is the first extension of the graded approach and the NRC staff is open to extending the graded approach concept to other technical areas.
Table 2 - Actions that can be taken by NRC within existing regulations Rec. #
Summary Results Path Forward NRC Staff Comments II-1 Graded Approach Review Process for CoC applications and amendments COMPLETE SUBJECT TO CLARIFICATION:
- NRC letter (1/24/20) defined licensing process expectations for more risk informed reviews
- NRC developed a risk tool to enable a graded review process (12/17/20 workshop)
After clarifying how regulatory transparency will be achieved in staffs use of this tool, NRC to implement this tool in its licensing reviews.
The NRC agrees with the results.
As for path forward, the NRC developed a risk tool to enhance its safety focus during a CoC application review and will begin piloting this tool in February/March timeframe. The NRC is committed to transparency and has made the tool publicly available (ADAMS Accession Number ML20350B659).
The NRC is also evaluating how best to engage with an applicant on the results of the risk tool and agrees this should be a topic for a near term future workshop.
III-3 Less detailed reviews when conservatism is demonstrated COMPLETE SUBJECT TO CLARIFICATION
- The NRC licensing process implementations and risk tool (per Rec. # II-1) effectively addresses this recommendation as well After clarifying how regulatory transparency will be achieved in staffs use of this tool, NRC to implement this tool in its licensing reviews.
The NRC agrees with the results and as for path forward is evaluating how best to engage with an applicant on the results of the risk tool and agrees this should be a topic for a near term future workshop.
IV-3 NRC recognition of PIRT results in licensing reviews SUBSTANTIAL ACTION TAKEN
- Industry recommended (7/28/20 workshop) that this be addressed in NRC graded review process per II-1 above
- Thermal Modeling, Decay Heat Monitoring, and Fuel Performance PIRTS have been completed and gross rupture PIRT is underway NRC to consider PIRTS as appropriate in its licensing reviews.
The NRC agrees with the results.
As for path forward, additional discussion may be warranted on the use of PIRT reports. We previously communicated in workshops, that a submittal for endorsement may be appropriate for broad applicability, consistency, and transparency (e.g., topical report, industry guidance, etc.)
Table 3 - Actions to be addressed through NRC/Industry Dialogue Rec. #
Summary Results Path Forward NRC Staff Comments IV-1 NRC and industry to conduct thermal modeling PIRT COMPLETE
- Thermal Modeling, Decay Heat Monitoring, and Fuel Performance PIRTs completed Industry to apply the results of the PIRTS in future CoC applications and NRC to apply the The NRC agrees with the results.
As for path forward, additional discussion may be warranted. We previously communicated in workshops, that a submittal for
results of the PIRTS in future licensing reviews.
endorsement may be appropriate for broad applicability, consistency, and transparency (e.g., topical report, industry guidance, etc.)
IV-4 Replace 400C cliff edge metric for thermal modeling SUBSTANTIAL ACTION TAKEN
- As documented in the 5/13/20 and 6/1/20 letters referenced in Rec. IV-3 above, this will be accomplished by building on the combined results of the three completed PIRTS (IV-1 above) and the ongoing gross rupture PIRT (Rec. IV-5 below)
Industry and NRC to re-evaluate this limit after completion of the gross rupture PIRT.
The NRC agrees with the results and path forward. The NRC is currently participating in the EPRI led PIRT on gross rupture.
IV-5 Develop graded approach to thermal modeling (reinterpret gross rupture)
SUBSTANTIAL ACTION TAKEN
- NRC has agreed (6/1/20 letter) to engage in an ongoing PIRT to address this recommendation. PIRT is ongoing.
Industry and NRC to engage on the development of this approach after completion of the gross rupture PIRT.
The NRC agrees with the results and path forward. The NRC is currently participating in the EPRI led PIRT on gross rupture.
V-1 Revise Sect. 6.4 of NUREG-1536 to allow representative vs.
bounding dose rates and credit for design analysis SUBSTANTIAL ACTION TAKEN
- The new review process NRC has developed per III-3 is specific to radiation dose/shielding and will enable this approach NRC to reflect new approach in NUREG.
The NRC agrees with the results and generally supports the path forward. In addition to the risk tool referenced, the NRC staff developed a method of evaluation approach to shielding analyses which would result in a more performance-based review and would facilitate the use of representative dose rates. NRC is evaluating how this approach can be applied to other technical areas and will incorporate this approach into NRC guidance.
V-2 Revise Chapter 6 of NUREG-2215 based on experience SUBSTANTIAL ACTION TAKEN
- Industry completed NRC requested Operating Experience evaluation and presented results to NRC in 12/16 public meeting
- Risk tool being developed per II-1 will help enable NRC to revise Chapter 6 of the NUREG as appropriate to reflect lessons learned (including experience with application of the risk tool)
The NRC agrees with the results and the path forward. After review of the industry proposed topical report for the implementation of the Method of Evaluation expected in FY 2021, NRC staff will begin planning for updates to NUREG-2215 (Standard Review Plan for Spent Fuel Dry Storage Systems and Facilities).
VI-2 Align licensing approaches for fuel qualification information SUBSTANTIAL ACTION TAKEN
- NRC approved graded approach to CoC amendments/applications per V-1
- Holtec has committed to submit to NRC a Shielding Method of Evaluation topical report that will substantially improve the manner in which fuel qualification information is addressed Holtec to submit and NRC to review, under the fee waiver granted for activities related to the White Paper.
The NRC agrees with results and path forward. The NRC will need to evaluate whether the current fee waiver extends to Holtecs future topical report if a fee waiver is submitted.
VII-1 Align licensing approaches for criticality safety NO ACTION IN 2020
- Industry and NRC have agreed to planning dialogue to initiate needed actions NRC and Industry to engage in further dialogue in 2021.
The NRC agrees with the result and path forward. NRC proposing a planning public workshop in the near-future.
VII-2 Develop more realistic modeling of fuel configuration NO ACTION IN 2020
- Industry and NRC have agreed to planning dialogue to initiate needed actions NRC and Industry to engage in further dialogue in 2021.
The NRC agrees with the result and path forward. NRC proposing a planning public workshop in the near-future.
VII-3 Redefine gross rupture NRC has agreed (6/1/20 letter) to engage in a PIRT that will begin in October and be complete by January 2021 to directly address this recommendation NRC and Industry to develop new definition upon completion of the gross rupture PIRT.
While no characterization of the results was provided in NEIs letter, the NRC believes, consistent with Rec. IV-4 and IV-5, that substantial action has been taken through EPRIs gross rupture PIRT and agrees with the path forward. The current schedule is to complete this work in summer 2021.