ML20080F893

Proposed TOC for Thermal-Fuel Performance Topical Report 3.19.2020

ML20080F893
Person / Time
Issue date:	03/19/2020
From:	Tara Inverso Division of Fuel Management
To:
Kallan P
References
Download: ML20080F893 (2)

Text

Proposed Table of Contents

1. Introduction

2. Objectives

3. Existing Spent Fuel Storage Fuel Performance Metrics:

a. 10CFR72 Requirements

b. ISG-11 R3

c. NUREG-1567

4. Spent Fuel Storage Expert PIRT Findings:

a. Fuel Performance PIRT Results

b. Thermal Modeling PIRT Results

c. Decay Heat Modeling PIRT Results

d. Results from PIRT/Workshop on Gross Rupture Definition

e. Results from Synthesis PIRT/Workshop addressing cumulative impacts of overlapping bounding inputs, assumptions, and uncertainties for assessing fuel performance/gross rupture with thermal modeling

5. Spent Fuel Storage Fuel Performance Metrics

a. Documentation of Historical List of Metrics

b. Current 400oC Metric

c. Potential Alternative Metrics:

i. Possible Alternatives:

1. Alternate PCT

2. PCT + Stress Analysis like low burnup fuel

3. Average Rod Temperature vs. PCT

4. Average Rod Temperature on a % of the cladding vs. single point PCT

5. Cladding specific metrics for different fuels

6. Relax limits for thermal cycling (e.g. 65°C and 10 cycles)

7. Possible different CoC criteria for intact vs. undamaged fuel

8. Etc.

ii. References to basis documents

1. NUREG-2224 Dry Storage and Transportation of HBU SNF

2. NRC/ORNL HBU SNF CIRFT Test Results

3. HBU Demonstration Sibling Rod Test Program Results

4. Etc.

iii. Finalized Consensus Metric(s)

1. Regulatory basis for finalized metric(s)

2. Possible combination of different metrics for addition defense in depth, e.g. temperature and stress metrics iv. Identification of other limiting canister/cask specific metrics:

1. Resin peak temperatures

2. Shielding material peak temperatures

3. Discuss how these are different in terms of compliance as opposed to generic fuel performance metrics

6. Best Practice Evaluation Methodology to Meet the Consensus Metric(s):

a. Thermal Metrics:

i. NUREG-2152

Reference:

1. Incorporate appropriate sections of NUREG-2152 into the best practices for CFD modeling for the new or existing fuel performance metric ii. Thermal Modeling Uncertainty Discussion:

1. Use of best estimate or more accurate decay heat models

2. Realistic ambient temperature measurements vs. upper bound assumptions

3. Graded approach for mesh convergence test

4. Additional ancillary modeling assumptions/inputs (bounding vs. best estimate)

5. Impact of cumulative bounding assumptions on modeling results iii. New Additional Considerations:

1. If fuel performance metric is changed, what changes needed in thermal modeling assumptions and methodologies

2. Differences between PCT vs peak rod average vs. other thermal metrics

3. Additional areas for consideration for thermal modeling with different metrics

b. Stress Metrics:

i. Identify whether low burnup fuel stress analysis approach is a viable path for high burnup fuel stress analysis ii. Develop a generic methodology approach for vendors to use both a temperature and stress metric for fuel performance assessment

c. Other (as identified)

7. Summary

8. References