ML26042A204
| ML26042A204 | |
| Person / Time | |
|---|---|
| Site: | 07109337 |
| Issue date: | 02/03/2026 |
| From: | Longman G Croft Associates Limited |
| To: | Kristina Banovac Office of Nuclear Material Safety and Safeguards |
| References | |
| Download: ML26042A204 (0) | |
Text
Croft Associates Ltd F4 Culham Campus Abingdon, Oxfordshire, United Kingdom OX14 3DB T:
E:
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+44 (0)1865 407740 info@croftltd.com www.croftltd.com FM 28718 - ISO9001 EMS 720456 - ISO14001 Registered in England No: 1698337 3rd February 2026 Attention: Kristina Banovac Project Manager Storage and Transportation Licensing Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards US Nuclear Regulatory Commission Washington DC 20555-0001 Docket Number: 07109337
Subject:
Request for Inclusion of Impurities in CoC No. USA/9337/B(U) for the 3979A Package
Dear Ms Banovac,
The CoC, USA/9337/B(U) Revision 5, for Croft package design No. 3979A expires on the 30th of April 2026. Croft have previously (12/16/2025) requested the timely renewal of this certificate without changes, to allow the continued use of this package and to obtain multiple validation certificates. This further request is for the inclusion of for an allowance to cover activation impurities to also be included within the CoC for all currently permitted solid content types.
Background:
The SAFKEG-LS Package is used extensively for the transport of medial radioisotopes that are used for the identification and treatment of cancer within the USA and globally.
When medical isotopes are produced, they are often encased in an aluminium capsule when placed in the reactor. Impurities/contaminants in this ampule (or in the product itself) can then lead to small quantities of other radionuclides being present in the product which are not listed on the package approval.
The quantities of impurities present are not significant, but they are above exempt limits by a small margin. In terms of the overall inventory, they are typically MBq quantities, thus do not have any significant impact on the package external dose rates or heat generation (or on the total inventory carried in Bq or A2). These impurities often have a short half-life, but delaying shipping for these to decay to exempt levels will also reduce the amount of product present - which is undesirable in terms of maximising the number of patient doses that can be produced. Enclosed is a spreadsheet showing typical levels of contaminants present provided by two users (see Bounding Contaminants-Impurties.pdf).
Request:
Thus, we request that the CoC (USA/9337/B(U)-96) to be amended for all contents types to recognise that small quantities of other radionuclides can be shipped without undermining the safety of the package.
This would be conditional on the contents continuing to meet the other contents requirements; maximum heat load, the specified mass limits as well as meeting the dose rate limits.
Croft Associates Ltd F4 Culham Campus Abingdon, Oxfordshire, United Kingdom OX14 3DB T:
E:
W:
+44 (0)1865 407740 info@croftltd.com www.croftltd.com FM 28718 - ISO9001 EMS 720456 - ISO14001 Registered in England No: 1698337 Safety Basis:
The introduction for an allowance of impurities does not reduce the safety provisions of the package on the following basis:
Radiation Levels: The shielding assessments that support the current approval are conservative,
. The impurities requested are primarily associated with the transport of
, for which the permitted contents limit is based on its heat generation not its radiation levels. Thus, the package radiation levels, excluding the impurities, will be below the transport limits. At the proposed quantities for impurities, there will be no significant increase in the package radiation levels.
Furthermore, prior to consignment the package radiation levels are confirmed before entering the public domain, giving assurance that they are at acceptable levels.
Heat Generation: The heat generation of these radionuclides, at the levels proposed is extremely low at <0.1 Watts (see enclosed Bounding Contaminants-Impurties.pdf). Thus, although these impurities are primarily associated with the transport of (for which the permitted contents limit is based on its heat generation), there will be no significant increase in the package contents heat generation.
Containment: The impurities anticipated to be carried are solid or are absorbed into the solid parent material or aluminium capsule. Thus, there will be no gas generation from the impurities that could increase the pressure within the insert or leak to loss of containment.
It is noted that the package containment design assessment assumes a MNOP of 7 bar, which is in excess of the calculated internal pressure for NCT (see SARP section 3.3.2). Therefore, the containment will remain leaktight, as demonstration through testing to a leakage rate of 10E-7 ref.cm3/s as specified in ANSI N14.5.
The recognition and acceptance that the inclusion of these impurities is not detrimental to the overall safety of the SAFKEG-LS package has been Timeline:
As this amendment makes a real impact to the users of the package and their ability to provide medical treatments, the preferred inclusion of an impurity clause would ideally be at introduced at the same time as the previously requested no-change renewal. One user have planned shipments from Canda to the USA which start at the end of April.
Therefore, inclusion before this date is desirable for them. Moreover, as various validations are required for this (and other users globally) the requested need dates for the renewal are as follow:
Week commencing 23rd February 2026: NRC to issue the new rev 6 CoA (including impurities if feasible, or as a straightforward renewal of the existing Rev 5 certificate)
Week commencing 9th March 2026: US DoT approval of NRC rev 6 CoA to IAEA SSR-6:2018 Week commencing 16th March 2026, Croft to pursue the other validations of the US DoT CoA will other competent authorities (e.g., the Canadian CNSC, Dutch ANVS and Australian ARPANSA etc). With these to be complete by 30th April at the very latest.