ML25343A144
| ML25343A144 | |
| Person / Time | |
|---|---|
| Site: | 07109373 |
| Issue date: | 12/19/2025 |
| From: | Storage and Transportation Licensing Branch |
| To: | |
| Shared Package | |
| ML25343A142 | List: |
| References | |
| EPID L-2025-LLA-0002 | |
| Download: ML25343A144 (0) | |
Text
Enclosure 1 Request for Supplemental Information and Observation for the Model No. HI-STAR 190 Package Docket No. 71-9373 Non-Proprietary This request for supplemental information identifies information needed by the staff in connection with its acceptance review of the Holtec International Model No. HI-STAR 190 package.
Chapter 3: Thermal Evaluation RSI 3-1.
Provide bounding thermal analysis files for normal conditions of transport (NCT).
The bounding thermal analysis files were not provided to support the proposed changes Nos. 1-3, 5-7, and 13.
This information is needed to demonstrate compliance with Title 10 of the Code of Federal Regulations (10 CFR) Section 71.71.
RSI 3-2.
Provide tables in safety analysis report (SAR) section 3.I.3 for moderate and high burnup vacuum drying peak cladding temperature (PCT), cyclic drying time limits, and time-to-boil time limits.
There are proposed new fuel package types in this amendment that will undergo moisture removal operations. Tables analogous to SAR tables 3.3.10, MPC Cavity Drying Limits, {See proprietary enclosure}
Similarly, tables for each fuel type with time-to-boil time limits that are analogous to SAR table 3.3.14, Maximum Permissible Time Duration for Flooded MPC-37 Loaded with 15X15I Short Fuel, have not been provided.
This information is needed to demonstrate compliance with 10 CFR 71.33.
Obs 3-1.
Clarify the apparent difference between the SAR tables 3.I.2.2, HI-STAR 190 MSC Materials Temperature Limits, and 3.I.2.4, Basket Temperature Limits for Candidate Heat Load Patterns, basket temperature limits.
SAR table 3.I.2.2 describes two values, one for NCT and one for short-term and accident temperature limits, for the fuel basket temperature limits. However, SAR table 3.I.2.4 describes many temperature limits as a function of basket type, zone, and basket elevation. It is not clear what conditions the temperature limits in SAR table 3.I.2.4 apply to (normal, accident, or both). The staff notes that SAR section 3.I.3.9 describes that all component temperatures shall remain below the limits specified in tables 3.I.2.2 and 3.I.2.4 for the pattern to be considered acceptable.
This information is needed to demonstrate compliance with 10 CFR 71.33, 71.71, and 71.73.
Obs 3-2.
Clarify whether there are (or not) other temperatures in addition to the SAR table 3.I.2.4 basket temperature limits used to support the structural analysis.
2 The use of SAR table 3.I.2.4 has been briefly described in SAR section 3.I.2.2 to indicate that the basket temperature limits that are a function of fuel basket type, basket zone, and basket elevation are used to support structural stress analysis.
However, it is not clear whether other calculated component temperatures based on a candidate heat load pattern are also used to support the structural analysis.
This information is needed to demonstrate compliance with 10 CFR 71.33.
Obs 3-3.
{See proprietary enclosure}
Obs 3-4.
Clarify the validity of the governing fuel basket / multipurpose cask (MPC) in SAR section 3.I.3.3, Screening calculations to ascertain governing fuel package.
SAR section 3.I.3.3 describes how the bounding fuel basket / MPC is determined. However, SAR section 3.I.3.3 states, The principal results of the analysis, which is the maximum computed fuel temperatures and cavity pressure, are tabulated in Table 3.I.3.2. The results support the conclusion that the highest temperatures are obtained in the MPC-37CBS Fuel Package. {See proprietary enclosure} while SAR table 3.I.1.2 reports the maximum normal operating pressure to be 93.8 psig, and 96.6 psig with 3 percent rods rupture.
This information is needed to demonstrate compliance with 10 CFR 71.33.
Obs 3-5.
Provide an overall framework or break down more clearly the SAR section 3.I.3.9, Evaluation of candidate heat load pattern.
Clearly provide a framework in SAR section 3.I.3.9 that shows the input, thermal methodology, and acceptance criteria.
This information is needed to demonstrate compliance with 10 CFR 71.71(c)(1) and 71.73(c)(4).
Obs 3-6.
Provide justification that the physics modeled in the transportation design, specifically for fluid flow (convective heat transfer), remains valid for any proposed decay heat pattern or total decay heat value.
SAR section 3.I.3.9, Evaluation of candidate heat load patterns, does not include justification for expanding the use of the thermal models to higher total or per assembly decay heats, or in other words, to develop alternate total or per assembly decay heat limits that are higher than those that have been previously approved. Justification should be provided because the proposed total decay heat is greater than some of the total decay heat values that have been approved. The flow regimes (laminar, transitional turbulent) should remain valid for any selected heat load pattern.
This information is needed to demonstrate compliance with 10 CFR 71.33, 71.71(c)(1) and 71.73(c)(4).
3 Obs 3-7.
{See proprietary enclosure}
Obs 3-8.
Provide a brief justification that the maximum temperature for the monolithic shield cylinder (MSC) during the thermal hypothetical accident conditions (HAC) will remain below its maximum allowable temperature limits.
The MSC is a new component that provides gamma and neutron shielding for the HI-STAR 190 MSC package. A justification that the MSC maximum temperature during the thermal HAC will remain below its maximum allowable temperature limits was not provided in SAR section 3.I.4.
This information is needed to demonstrate compliance with 10 CFR 71.73.
Chapter 7: Operating Procedures Evaluation RSI 7-1.
Include a report in chapter 7.I operating procedures that serves to document each candidate heat loading pattern.
The candidate heat loading pattern is the input to the method described in SAR section 3.I.3.9, where the documented temperature and pressure results need to meet the acceptance criteria also in SAR section 3.I.3.9. The candidate heat loading pattern and temperature and pressure results should be documented in a report listed in chapter 7.I. A response that documents an example of a report (proprietary) for the HI-STORM 100 Amd. 18 was provided in Docket No. 72-1014 by letter dated September 8, 2023, in Agencywide Documents Access Management System Accession No. ML23251A250.
This information is needed to demonstrate compliance with 10 CFR 71.71(c)(1),
71.73(c)(4), 71.87(a)(f) and (k).
Editorial Comments 1.
Clarify or revise the following in the SAR:
In SAR table 3.I.2.4, Basket Temperature Limits for Candidate Heat Load Patterns, Note 1: Zones are defined in figures 3.I.2.2 through 3.I.2.10 - however, the figures in the SAR only go through figure 3.I.2.8.
The operating pressure, Pop, is not used in the equations in SAR section 3.I.3.10.
{See proprietary enclosure}
Remove the duplicate time-to-boil scenario in SAR table 3.I.3.5 or clarify the difference between the two scenarios.
In SAR section 3.I.4 for thermal evaluation under HAC, HI-STAR 190 MSC is evaluated under 10CFR71 mandated sequence of hypothetical accidents for a transport package similar.
In SAR table 8.I.1.10A, Emissivity of Finished Metamic-HT Panels, change p to.