ML20078J643
| ML20078J643 | |
| Person / Time | |
|---|---|
| Site: | Nuclear Energy Institute |
| Issue date: | 03/18/2020 |
| From: | Tara Inverso Office of Nuclear Material Safety and Safeguards |
| To: | |
| Kallan P | |
| References | |
| N-20-01 | |
| Download: ML20078J643 (2) | |
Text
SPENT FUEL STORAGE AND TRANSPORTATION ISSUE RESOLUTION PLAN Issue Number: N-20-01 Performance Margins Recommendation: III-3 (Cat 2)
Rev. 3.18.2020 Note: This document is DRAFT and the positions noted therein are preliminary NRC staff potions. This DRAFT is being made publicly available to support discussions at a March 2020 public workshop.
Title:
Risk-informing application reviews to reflect use of conservative source terms, conservative modeling, and source term uncertainty.
I. Summary of Resolution Plan The NRC staff is evaluating an industry recommendation where, when applicants have applied conservative source terms (e.g., burnup uncertainty) and conservative modeling assumptions in applications, the NRC could risk-inform the application review. For example, if the NRCs review focused on the applicants overall methodologies in confirming safety, the review may be simplified, thus shortening the review timeline.
This recommendation is related to Recommendations III-1 and III-2 in the Nuclear Energy Institutes (NEIs) Spent Fuel Performance Margin White Paper (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19318D971). In Recommendation III-1 and III-2, industry is exploring whether applicants could apply more realistic assumptions in their source term calculations when other conservatisms are included. As part of those recommendations, the industry will develop a conservatism roadmap to demonstrate what uncertainties are currently included in models for understanding and relative ranking based on importance.
In parallel with industrys activities on Recommendations III-1 and III-2, the NRC staff plans to identify and evaluate transformative approaches and develop review guidance based on known conservatisms and appropriate level of review within the defined source terms. The guidance would also describe how the review would consider conservatisms identified in Recommendations III-1 and III-2. The guidance could also be a means of addressing Recommendations V-11 and VI-22 in NEIs white paper. This guidance will be developed based on a comprehensive examination of the parameters that are important to shielding design and the built-in conservatisms.
The NRC staff will lead this activity by taking the following actions. The NRC staff will seek and incorporate external stakeholder feedback (i.e., industry and public) as noted and at additional intervals as appropriate and identified during this activity.
- Develop alternative licensing approaches, including pros and cons of each.
- Conduct a public workshop to discuss alternatives and receive feedback from stakeholders
- Select optimal alternative o NRC decision point, with input from public and industry 1 Recommendation V-1: Revise the guidance in Section 6.4 of the proposed NUREG-2215 to 1) request typical/realistic/representative instead of bounding dose rates, consistent with the reduced safety significance of the presented results and to 2) remove or appropriately modify the discussion that implies that the dose and dose rates provided in the FSAR demonstrate that the design is sufficient to meet the regulatory dose requirements at the site boundary. This is a Category 3 recommendation which would require NRC to revise its regulatory guidance.
2 Recommendation VI-2: Align approaches in fuel qualification information for dry cask storage systems CoC (Technical Specifications) with current practices in operating reactors. This is a Category 3 recommendation as Industry and NRC will need to engage in a dialogue to determine the best way to accomplish this.
Enclosure 2
- Use public feedback and develop draft review guidance based on a balanced consideration of the level of review within the design parameters such as source term definition as conservatisms present.
- Evaluate and incorporate, as appropriate, the specific recommendations made in Recommendations III-1 and III-2 into draft review guidance.
- Pilot the approach on an appropriate application
- Conduct public meetings to inform and obtain feedback from the stakeholders, including the general public, the general licensees, and the cask vendors, on the potential changes in the regulating approach
- Conduct a public meeting(s) to present major conclusions and potential resolutions of the RIRP issues from pilot review
- Update NRC review guidance, as appropriate, and make revised guidance publicly available.
II. Proposed Actions and Due Dates ACTION RESPONSIBLE PARTY DUE DATE
- 1. Develop alternative licensing approaches, NRC June 2020 with pros and cons of each
- 2. Conduct a public workshop to discuss All July 2020 alternatives and receive feedback from stakeholders
- 3. Select optimal alternative NRC September 2020
- 4. Develop draft review criteria considering NRC December 2020 flexibility within shielding modeling (including the source terms and shielding design) and conservatisms within analysis
- 5. Await conclusions of spent fuel performance All December 2020 margins white paper Recommendations III-1 (assumption) and III-2.
- 6. Review results of Recommendations III-1 and NRC February 2021 III-2, and incorporate into draft review guidance
- 7. Conduct public meeting to present revised All April 2021 guidance
- 8. Select pilot application to apply risk-informed NRC/Industry May 2021 review method.
- 9. Gather lessons learned on pilot review NRC/Industry TBD
- 10. Conduct a public meeting to review lessons NRC TBD learn/modify approach as needed
- 11. Update NRC review guidance to incorporate NRC TBD risk insights
- 12. Hold public meeting on draft guidance NRC TBD
- 13. Finalize review guidance and utilize for NRC TBD upcoming reviews Enclosure 2