ML25272A109
| ML25272A109 | |
| Person / Time | |
|---|---|
| Site: | 07109261 |
| Issue date: | 09/15/2025 |
| From: | Christopher Markley Storage and Transportation Licensing Branch |
| To: | |
| References | |
| Download: ML25272A109 (1) | |
Text
Observations Application for the HI-STORM 100 Revision 14 Docket No 71-9261 By \
letter dated August 1, 2025, (Agencywide Documents Access and Management System
[ADAMS] Accession No. ML25213A096, you submitted an application to the U.S. Nuclear Regulatory Commission (NRC) for amendment 14 of the Holtect HI-STAR 100 certificate of compliance (CoC) No. 9261. In your application, you requested the following changes:
Changes to the SAR to update maximum burnup in the MPC-32 In conducting the acceptance review, NRC staff identified the observations below. Responses to observations are not required for staff to begin a detailed technical review. Observations are not the result of a detailed technical review and may be resolved once staff begins a detailed review.
Obs-Str-1.
Justify or revise the source of the value for the MPC-32 high burnup fuel cladding material yield stress added in Table 2.9.2 of safety analysis report (SAR) HI-951251, Application HI-STAR 100 Transportation (10CFR71), Revision 21, as well as identifying the cladding material, temperature and strain rate for which the evaluation is being performed.
The reference for the yield stress value of 600 MPa for the MPC-32 high burnup fuel cladding appears to be taken from a sample true stress-strain curve shown in SAR reference 2.9.4, PNNL-17700, PNNL Stress/Strain Correlation for Zircaloy, by Geelhood et al, dated 2008.
However, a yield stress value that corresponds to the cladding material, temperature and strain rate at which it is being evaluated is required to be cited in order to be compared to the value employed in the original analysis, as discussed in SAR section 2.9.
This information is required to satisfy the requirements of 10 CFR 71.73(c).
The following two observations are based on comparing Rev 21 to Rev 20.
Obs-Mat-1 Fuel Cladding row lists 400F limit for HBF for short term operations, a value which is less than the limit for normal operations. It is possible that the number should be 400C, which would be equal to 752F, the same as the normal conditions limit.
Obs-Mat-2 Holtite-A row lists 1105F for both short term operations and accident condition limits, whereas Rev 20 had stated this to be N/A since the analysis assumed that the Holtite would be lost during a fire accident. These two values in the table also have the same triple-dagger footnote label as the previous row, aluminum alloy 5052, a footnote that clearly refers to aluminum, not epoxy resin.