ML25134A045
| ML25134A045 | |
| Person / Time | |
|---|---|
| Site: | 07109385 |
| Issue date: | 08/22/2025 |
| From: | Garcia-Santos N Office of Nuclear Material Safety and Safeguards |
| To: | Maret Rose Industrial Nuclear Co |
| Shared Package | |
| ML25134A044 | List: |
| References | |
| EPID L-2024-NEW-0008, CAC 001029 | |
| Download: ML25134A045 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mike Rose QAM/ARSO Industrial Nuclear Company 14320 Wicks Blvd San Leandro, CA 94577
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE APPLICATION OF MODEL NO. IR-100ST PACKAGE, CERTIFICATE OF COMPLIANCE NO. 9385, REVISION 0 - COST ACTIVITY CODE/ENTERPRISE PROJECT IDENTIFICATION NUMBERS 001029/07109385/L-2024-NEW-0008
Dear Mr. Rose:
By letter dated August 12, 2024 [Agencywide Documents Access and Management System (ADAMS) Package Accession No. ML24295A159], as supplemented on January 24, 2025 (ML25055A138), Industrial Nuclear Company ((INC) or the applicant) requested the U.S.
Nuclear Regulatory Commission (NRC) approval to Certificate of Compliance (CoC) No. 9385, Revision 0, for the Model No. IR-100ST packaging. The staff issued staggered RAIs on May 12, 2025 (ML25132A011) and on May 20, 2025 (ML25140A931).
In connection with our review, we need the information identified in the enclosure to this letter.
To assist us in scheduling the NRC staffs review of your response, we request that you provide this information 30 calendar days from the date of this letter. Inform us at your earliest convenience, but no later than 15 calendar days from the date of this letter, if you are not able to provide the information by that time frame. If you are unable to provide a response by the time frame provided in this letter, our review may be delayed.
It is relevant to note that on May 21, 2025 (ML25142A158), you requested the staff to stop working on the application, which resulted in an approximate 3-month delay of the schedule initially communicated to you in the acceptance letter (ML25058A248). Therefore, the estimated completion date, assuming acceptable responses to requests for additional information and one round of questions, would be approximately December 2025 instead in September 2025.
Please reference Docket No. 71-9385 and CAC/EPID Nos. 001029/L-2024-NEW-0008 in future correspondence related to this request. The NRC staff is available to clarify these questions, and, if necessary, to meet and discuss your proposed responses.
In accordance with Title 10 of the Code of Federal Regulations, Section 2.390 of the NRCs Agency Rules of Practice and Procedure, a copy of this communication will be available electronically available for public inspection in the NRC Public Document Room or from the Publicly Available Records component of the NRCs ADAMS. ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
August 22, 2025
M. Rose 2
If you have any questions regarding this review, you may contact me at Norma.GarciaSantos@nrc.gov.
Sincerely, Norma Garcia Santos, Project Manager Storage and Transportation Licensing Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards Docket No.: 71-9385 Certificate No. 9385
Enclosure:
Request for Additional Information Signed by Garcia Santos, Norma on 08/22/25
Enclosure Request for Additional Information Certificate of Compliance No. 9385 Docket No. 71-9385 Revision No. 0 Model No. IR-100ST This request for additional information (RAI) identifies information needed by the U.S. Nuclear Regulatory Commission (NRC) staff (the staff) in connection with its review of the application.
The staff used NUREG-2216, Standard Review Plan for Transportation Packages for Spent Fuel and Radioactive Material: Final Report, (NUREG-2216) in its review of the application.
Each RAI describes information needed by the staff to complete its review of the application and to determine whether the applicant has demonstrated compliance with the regulatory requirements of 10 CFR Part 71.
THERMAL EVALUATION RAI-Th-1 Provide the following information:
a)
The model inputs such as thermal properties and boundary conditions (e.g., insolation) used in the ANSYS thermal model mentioned in the application.
b)
The version of ANSYS thermal model used to generate the model.
c)
Demonstration that the thermal model was appropriately converged (e.g.,
energy balances, residuals).
d)
Clarification that the thermal model accurately represents the design of the IR-100ST package by modeling package components (e.g., stainless steel housing, depleted uranium shielding, polyurethane foam).
e)
Appropriate boundary conditions including the bases for external heat transfer correlations and coefficient values as well as the radiant energy boundary conditions used in the analysis.
f)
Clarify if the design/analysis (e.g., ANSYS model generation and solution methodologies) of the Model No. IR-100ST package is performed under the NRC-approved quality assurance (QA) program.
Section 3.2.1 of the application indicated that thermal properties were not provided because package integrity was established by testing. However, section 3.3 provided package temperatures during normal conditions of transport (NCT) based on an ANSYS thermal model, which would require thermal property inputs and boundary conditions for calculations. Similarly, there was no explicit discussion that the ANSYS thermal model accurately portrayed the Model No.
IR-100ST design. The model inputs (e.g., thermal properties such as thermal
2 conductivity, boundary conditions, package components modeled) and quality assurance (QA) discussions are needed in order to make a determination that model results are representative of the package during transport conditions.
In terms of clarifications of the boundary conditions, Section 3.3.1 of the application only refers to a 12-hour average, but did not specify the insolation value (e.g., 800 watts per square meter (W/m2)) and the package surfaces absorptivity and emissivity. Also, the application did not include a discussion about the bases for external heat transfer correlations and coefficient values and for the radiant energy boundary conditions used in the analysis.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 71.35(a) and 71.41(a).
RAI-Th-2 Describe the behavior of the plastic surround and PM Tag during the fire hypothetical accident conditions (HAC) and address its impact on the fires thermal evaluation.
Section 1.1 of the application mentioned the presence of a urethane surround and plastic PM Tag. However, section 3.4 of the application did not address the behavior of the plastic surround and plastic PM Tag during the fire HAC. In addition, the evaluation did not:
1) provide details of potential exothermic reactions (e.g., combustion), such as quantifying its thermal input (e.g., thermal energy release and heat of combustion (joules per kilogram (J/kg)) associated with the plastic PM Tag and surrounds (unspecified) mass relative to the thermal input to the package from the 800 degrees Celsius (°C) fire; 2) discuss the potential impacts on the packages integrity, for example, on:
(i) shielding material (ii) special form source capsule (iii) melted plastic hindering pressure release from the housings openings that keep the package unpressurized, per section 3.1.4 of the application.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 71.43(d), 71.51(a)(2), and 71.73(c)(4).
RAI-Th-3 Provide the packages maximum surface temperature without insolation. As part of your response, explain if the package will meet the nonexclusive use temperature or the exclusive use temperature.
Section 3.3.1 of the application appears to indicate that the maximum outer package temperature (without a personnel barrier) may be 140°F (based on the battery manufacturer data sheet), which is above the 122°F non-exclusive use temperature. However, section 3.3.1 of the application also indicated that the maximum package temperature would be 100°F and, therefore, less than the
3 non-exclusive use temperature.
This information is needed in order to determine compliance with the regulatory requirements in 10 CFR 71.43(g).
RAI-Th-4 Discuss the relevant differences between the Model No. IR-100ST package and the Model No. IR-100 certified test unit package that underwent the fire HAC test and explain the impacts of the differences.
Section 3.4.1 of the application indicated that the fire HAC thermal performance of the Model No. IR-100ST package would be similar to the thermal performance of the Model No. IR100. However, there was no explicit discussion that justified the appropriateness and relevance of the Model No. IR100 package thermal results (e.g., the same construction details), considering there are differences between the two packages (e.g., presence of plastic surround, presence of power cells).
Section 3.1.4 and 3.4.3 of the application stated that gas can move freely from the internal cavity of the depleted uranium shield to the ambient such that there is no pressurization of the package during NCT and HAC. This would indicate there are openings within the package to release internal pressures. A potential pressurization was indicated in section 3.4.2 of the application, which noted that the Model No. IR100 test units polyurethane foam was consumed by the fire, thereby indicating combustion gases were released. In addition, it would appear that gaps would be small since the application noted the Model No. IR100 test units depleted uranium shield was not appreciably oxidized. There should be further information of the package vent mechanisms that ensure the IR-100ST package is not pressurized during NCT and HAC (e.g., expansion of foam and release of polyurethane combustion gases) and that the vent opening sizes are insufficient to cause oxidation of the depleted uranium and there will not be unintended effects by melting of the plastic surround that prevent venting (e.g.,
plugging vent openings).
This information is needed to determine compliance with the regulatory requirements in 10 CFR 71.35(a) and 71.51.
RAI-Th-5 Clarify that the Model No. IR-100ST package (with functioning power cells) will not be adversely affected by a -40°C ambient temperature or specify an ambient temperature restriction for transport.
Section 2.6.4 of the application mentions that discharging and charging occur during transport, which can include cold ambient conditions (e.g., -29°C, -40°C).
However, the LithiumWerks datasheet (reference noted in section 1.2.1 of the application) for the packages PM Tag power cells mentions a charging temperature range of 0°C to 60°C and a discharging temperature range of -30°C to 60°C.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 71.35(a) and 71.51.
Editorial clarification: Clarify the S-tube material(s) in drawing number IR100ST-
4 C, considering it lists titanium, but section 2.2.2 of the application mentions that the S-tube can be either titanium or zircaloy.
MATERIALS EVALUATION RAI-M-1 Update the lists of components in the Model No.IR-100ST package drawings to include component and material specifications for the following items:
a)
The pigtail assembly that must remain intact and secured to the special form radioactive source capsule to prevent an unintended displacement of the radiographic source from its required position inside the depleted uranium (DU) shield assembly during normal conditions of transport (NCT) and hypothetical accident conditions (HAC);
b)
The not-important to safety (NITS) Li-ion power cells inside the PM tag assembly that are described and referenced in section 1.2.1 of the application, considering that, for certain battery types different from those described in section 1.2.1, a thermal runaway reaction could be initiated for NCT events and common electrical faults.
The staff identified that the Model No. IR-100ST application indicates that the pigtail is a device that must remain intact and secured to the special form radioactive source capsule and the lock assembly to ensure that the radioactive source is not free to move from its safe shielded position in the middle of the S-tube inside the depleted uranium (DU) shield assembly. Therefore, the staff infers that the pigtail should be considered an important to safety (ITS) component, and as such, the material specifications for pigtail assembly should be included in the package drawings.
The staff recognizes that a thermal runaway reaction in the Li-ion batteries is expected to occur during the HAC thermal test of 10 CFR 71.73(c)(4), and such exothermic reactions are not prohibitive events for the HAC thermal test provided that the additional heat inputs into the package due to thermal runaway reaction plus organic material combustion reactions are adequately evaluated to demonstrate compliance with 10 CFR 71.51(a)(2). However, the package must meet the requirements for 10 CFR 71.43(d) for all routine operations and NCT by not undergoing significant chemical, galvanic, or other reactions under these conditions. The staff reviewed the Li-ion battery specifications and consensus standards described and referenced in section 1.2.1 of the application and confirmed that these battery specifications and associated consensus standards adequately demonstrate that the batteries will not be susceptible to thermal runaway reaction during routine operations and NCT, including common electrical faults that can occur in Li-ion batteries, such as short circuit, overcharge and over-discharge.
To ensure adequate control of the material and component specifications for the package, the NITS safety classification for the Li-ion batteries should be supported by including the battery specification cited in section 1.2.1 of the application in the drawings. Otherwise, the lack of a battery specification in the drawings could potentially be prone to misinterpretation as allowing other battery
5 types that may be susceptible to thermal runaway for routine operations and NCT.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 71.31(c) and 71.43(d).
RAI-M-2 For the HAC thermal test of 10 CFR 71.73(c)(4), address whether there is any potential for significant pressure buildup inside the stainless steel housing of the IR-100ST package during the event that could lead to a failure of the stainless steel housing welds or base metal. The staff requests that the evaluation of potential pressure buildup inside the package housing consider additional heat inputs due to exothermic reactions that are expected to occur during the HAC thermal event, including combustion of organic materials and thermal runaway in the Li-ion batteries.
If there is a significant risk of pressure buildup to cause a failure of the stainless steel housing, address the potential consequences of a failure of the stainless steel housing during the thermal test, including the potential for escape or movement of the radioactive source and the ingress of air that may lead to high temperature oxidation of the depleted uranium (DU) shield casting that could result in a deterioration of gamma shielding performance and dispersion of uranium oxide powder outside of the stainless steel housing. For any such potential consequences, demonstrate that the package can continue to meet the requirements of 10 CFR 71.51(a)(2).
The staff identified that the Model No. IR-100ST test sequence did not include HAC thermal tests, and the applicants evaluation of the Model No. IR-100ST package performance for HAC thermal test conditions relied on the results of previous HAC thermal tests performed on an IR-100 test unit for the certification of the NRC-approved Model No. IR-100 package design. The IR-100 test unit did not include the sensor/handle jacket assembly (comprised of significant combustible organic materials) and the Li-ion batteries, which are prone to thermal runaway during the HAC thermal test conditions. The application indicates that the HAC thermal test would initiate combustion of organic materials and thermal runaway in the Li-ion batteries, in addition to heat inputs from the HAC thermal test environment. Given that there was no failure in the stainless steel housing as a result of the preceding NCT and HAC drop tests of the Model No IR-100ST package, the staff needs assurance that the additional heat inputs into the package due to combustion of the new organic materials and thermal runaway in the Li-ion batteries would not cause pressurization and failure of the package body housing that could result in the package failing to meet applicable performance requirements in 10 CFR 71.51(a)(2).
This information is needed to determine compliance with the regulatory requirements in 10 CFR 71.51(a)(2).
6 STRUCTURAL EVALUATION RAI St-1 Provide the total number of locations where the weld detail applies for attachment of the support saddle (Item No. 5) to the housing base (Item No. 6) shown on the applications drawing No. IR100ST-B, Sheet 3, Revision 1, IR-100ST BODY ASSEMBLY, SAR.
The drawing No. R100ST-B, Section B-B, depicts the near side fillet weld detail for attachment of the support saddle (Item No. 5) to the housing base (Item No.
- 6) with a note in the tail that reads TYP, ITEM 5 to ITEM 6. Since the weld is shown only for the near side of the saddle, and there are two quantities of Item No. 5 (support saddle) specified in the bill of material, it is unclear the total number of locations (i.e., 2 or 4 places) where this weld detail applies.
Therefore, the applicant needs to include in the drawing the total number of locations the weld detail is to be applied.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 71.33(a)(5) and 10 CFR 71.107(a).
RAI St-2 Regarding the tie-down test:
a)
Provide the location on the package, where vertical, horizontal, and transverse loads were applied while the package was tied down with two straps as shown in Figure 2.5-1 of the application.
b)
For the tie-down test, clarify if the vertical, horizontal, and transverse loads were applied simultaneously or not. If not, provide an explanation.
c)
Clarify if the unit was tested by swapping the magnitude of test loads in the horizontal and transverse directions. If not, provide an explanation.
Section 2.5.2 of the application notes that the loads of 583.4 pound-force (lbf),
294.6 lbf, and 120.0 lbf were applied in the longitudinal, lateral, and vertical directions, respectively, as shown in Figure 2.5-1. However, it does not provide the following information of importance for structural evaluation:
1) relevant details such as the test loads locations on the package, 2) whether the loads were applied in different directions simultaneously or separately, etc.
Since there are no restrictions on how the package is oriented with respect to the direction of travel during the transport, the package evaluation for the tie-down needs to be performed for all possible orientations to ensure that the limiting forces applied on the package tie-down are considered in the direction of vehicle travel and in the transverse direction.
This information is requested to determine compliance with the regulatory requirements in 10 CFR 71.45(b).
7 RAI-St-3 Provide the temperature that the stainless steel body of the package was exposed when it was placed on a dry ice environment as noted in the Section 2.6.2 of the application.
Section 2.6.2 of the SAR notes that the IR-100ST stainless steel body was exposed to a dry ice environment (-109ºF [-40ºC]) for an extended period of time in an ice chest without detrimental effects. The staff notes that -109ºF is -78ºC and -40ºC is -40ºF. Also, Sections 2.12.1.7.2.1 and 2.12.1.7.2.2 of the application note that the measured surface temperatures of the CTU-2 package were less than -20ºF and -21ºF, respectively. Clarify what temperatures the IR-100ST body was exposed to during the cold test.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 71.71(c)(2) and 71.73(b).
RAI-St-4 Explain why a package orientation to maximize damage at the outlet port end of the package was not considered for the hypothetical accident condition (HAC) free drop and puncture tests.
The Section 2.12.1.5 of the application provides the technical basis to select a worst-case package orientation that could potentially compromise depleted uranium (DU) shield integrity and/or the special form source of the package under the free drop and puncture tests. The package drawing Nos. IR100ST-E, Revision 0, and IR100ST-F, Revision 0, depict a configuration and parts for the lock assembly and the outlet port assembly, respectively, that are attached to the package housing at the opposite ends. These drawings do not provide overall dimensions for the lock and outlet port assemblies. However, it appears, from these drawings and the package assembly drawing No. IR100ST-B, that the cantilever dimension from the housing base to the free end is greater for the outlet port assembly than that for the lock assembly, assuming these drawings are drawn to the scale. If the outlet port assembly is longer, the CG-Over-Outlet Port Assembly free end corner orientation may cause overstress conditions at the assembly welded joint to the housing base (i.e., being a weak point) under the free drop and puncture tests. Therefore, the latter conditions need to be evaluated and included in the application, otherwise the applicant needs to provide a justification for not considering this orientation.
Note that the secondary objective of the HAC free drops is to fail the stainless steel body such that a potential air pathway into the interior would form, which could potentially result in a self-sustaining oxidation reaction of the DU and hence, result in a loss of shielding.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 71.73(c)(1) and (3).