ML20080F975

Rirp I-20-01 Rev. 3.19.2020

ML20080F975
Person / Time
Issue date:	03/19/2020
From:	Tara Inverso Division of Fuel Management
To:
Kallan P
References
Download: ML20080F975 (2)

Text

USED FUEL STORAGE AND TRANSPORTATION ISSUE RESOLUTION PLAN Issue Number: I-20-01 Performance Margins Recommendation: IV-3 (Cat 1)

Rev. 2.26.2020

Title:

Develop industry Best Practices guide for thermal modeling I. Summary of Resolution Plan Industry and NRC will interact in public meetings and workshops as well as through letters to achieve the following:

• Identify the current issues for industry with the implementation of the current best practices guidance

• Using the identified recommendations from the Thermal Modeling and Decay Heat PIRTs (Recommendation IV-1), create guidance for an informed approach, including (for example):

o greater flexibilities with more accurate decay heat models o realistic ambient temperature measurements vs. upper bound assumptions o graded approach for mesh convergence (currently costly GCI needed by all vendors) o pave the way to using alternative fuel performance metrics such as:

Use of stress analysis + peak clad temperature Average rod temperature vs. peak clad temperature

• Implement the guidance into a Topical Report.

• Submit the Topical Report to NRC for approval and endorsement (Note this action will accomplish Recommendation IV-2)

II. Proposed Actions and Due Dates ACTION RESPONSIBLE PARTY DUE DATE

1. Complete initial revision of RIRP NEI March 19, 2020

2. Review and discuss guidance to be developed NEI & NRC March 25-26, 2020 at workshop

3. Gross Rupture Definition PIRT/Workshop NEI/EPRI & NRC TBD

4. Synthesis PIRT/Workshop of the Cumulative Impacts of Overlapping Bounding Inputs, NEI/EPRI & NRC TBD Assumptions, and Uncertainties

5. Workshop on Alternative Fuel Performance NEI/EPRI & NRC TBD Metric(s) to Ensure no Gross Ruptures

6. Thermal Modeling/Stress Analysis Approach to NEI/EPRI & NRC TBD Meet Alternative Fuel Performance Metrics

7. Develop draft Topical Report for thermal NEI TBD modeling and performance metrics

8. Review draft Topical Report in follow-on public NEI & NRC TBD workshop

9. Revise TR based on workshop alignment NEI TBD

10. Submit TR following revision and review NEI TBD

11. NRC provides letter affirming applicability of NRC TBD TR

12. NRC initiate review, approval, and NRC endorsement of Topical Report (i.e.

implementation of Recommendation IV-2) 13.

Enclosure 2

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Enclosure 2