ML25132A010

Materials Staggered - Request for Additional Information, CoC No. 9385, Revision 0, Model No. IR-100ST, Radiography Camera (Docket No. 71-9385)

ML25132A010
Person / Time
Site:	07109385
Issue date:	05/12/2025
From:	Garcia-Santos N, Yeon Kim, Christopher Sydnor Storage and Transportation Licensing Branch
To:	Maret Rose Industrial Nuclear Co
Shared Package
ML25132A009	List: ML25132A010 ML25132A011
References
CAC 001029, EPID L-2024-NEW-0008
Download: ML25132A010 (1)

Text

Staggered Requests for Additional Information Model No. IR-100 ST, CoC No. 9385, Revision 0 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

Staggered Requests for Additional Information Model No. IR-100 ST, CoC No. 9385, Revision 0 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, please 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).