SSR-6 (Rev. 2): Regulations for the Safe Transport of Radioactive Material

At the beginning of this last month of the year 2025, just a couple of weeks before the holiday season, the 2025 Edition of the Regulations for the Safe Transport of Radioactive Material has been published by the International Atomic Energy Agency (IAEA). This is the end result of the review and subsequent revision process that formally started four years ago, on 5 November 2021, when the IAEA issued a note verbale to initiate the review of the 2018 edition of the IAEA Transport Regulations.

The Safety Standards Series development follows a structured 14-step process, known as the Safety Standards Development and Review Process (SPESS). To achieve this, the development process includes four rounds of internal review (Steps 2, 6, 10 and 1).

• Numerous changes to A1/A2 values:
  • Major revision of radionuclide limits using modern Q-system data.
  • Moved from Table 2 to Appendix I.
  • Updates for Uranium (separation of natural at secular equilibrium and purified, update of lung absorption types, new lines for enrichment up to 10% then 20%).
  • 10-year transitional period for implementation.
• Transitional arrangements (other than the 10-years transition for A1/A2 values):
  • Non-approved packages from 1985 editions prohibited after 31 December 2035.
  • New transitional provisions for packages and special form materials from 2018 edition.
• Definitions introduced for “naturally occurring radioactive material” and “naturally occurring radionuclides:
  • Added definitions for “naturally occurring radioactive material” and “naturally occurring radionuclides”.
• Deletion of definition of “confinement system”
• Two new exceptions to the requirements for the classification of fissile material:
  • Residual contamination on UF₆ cylinder surfaces.
  • Packages with very small fissile content relative to mass
• New requirement that the design of special form radioactive material shall take ageing mechanisms into account:
  • Design of special form radioactive material must consider ageing.
  • Approval applications must justify ageing considerations for all packages.
• Several paragraphs were revised to clarify how the requirements apply when different groups of low specific activity material (LSA) and surface contaminated objects (SCO) are packed/transported together.
• Several paragraphs were revised to clarify which requirements apply when freight containers are used as packaging.
• For various packages, requirements for the maximum dose rate at the surface of the package after the package has been subjected to certain tests have been relaxed:
  • The criterion was revised to specify that for packages whose maximum dose rate at its external surface is below 50 μSv/h, the allowable increase in dose rate following certain tests will be no more than 10 μSv/h.
• The requirements for an application for approval of a package were revised to require a justification of considerations of ageing mechanisms for all packages, not only those that will be used for shipment after storage:
  • New text is harmonized with a change in the 2018 Edition.
• The images and figure descriptions for the Category I-WHITE, II-YELLOW, III-YELLOW, and CSI labels were revised for alignment with the Orange Book.
• New requirements were added concerning empty large freight containers and conveyances that were used previously to transport unpackaged LSA-I or SCO-I.
• A new requirement was added for a Type B(M) package for high dose rate LSA and SCO for which the dose rate is higher than the limit specified in para. 517:
  • New requirement for Type B(M) packages containing LSA or SCO with dose rates higher than the 10 mSv/h at 3m criteria, allowing relaxation of some requirements during tests.
• Several paragraphs were revised to clarify that the requirements for “exclusive use” apply to a conveyance or a large freight container (and not to a consignment or a shipment).

“This was a long journey but, when reaching the final stop, WNTI can be proud of the final product. A significant number of our proposals have been accepted, and no proposal from Member States and International Organizations which we thought were not appropriate has been accepted. Our proposals that were accepted cover a wide range of topics. For instance:

• Adaptation of the Regulations to new transport needs, e.g.
  • New requirements for Type B(M) packages containing LSA or SCO with higher dose rates.
  • New fissile exceptions for contamination on UF₆ cylinder surface.
• Improvement of the wording of the Regulations to facilitate their correct understanding and implementation, e.g.
  • LSA and SCO when packed together.
  • Freight containers used as packaging.
  • Multiple UN numbers in one package (e.g., special form radioactive material and non-special radioactive material in the same package).
  • Application of “exclusive use” to conveyances or large freight containers, not consignments.

WNTI expresses its gratitude for Pierre’s valuable collaboration on the SSR-6 Rev. 2, his expertise and commitment being instrumental in achieving this important milestone. His careful scrutiny of every comment and knack for editorial precision was indispensable.

Special thanks are also extended to Bruno Desnoyers for his contributions at the beginning of the review process and to the Co-Chairmen of the Policy and Regulatory Working Group Steven Crane and Daniel Fisher for their leadership and support throughout.

“My first meeting at the IAEA was in 1993, more than 32 years ago. It was a Technical Meeting about LSA material. And more particularly about the criteria to classify the LSA material in the different categories. There was no conclusion at this meeting, nor in the following discussions. At the last TRANSSC meeting, in November 2025, it was agreed that further work was needed on this topic. The wheel of fortune is still turning, we still do not know who the winner will be!”

“My second meeting in the IAEA was a seminar about “Developments in the transport of radioactive waste”, held in February 1994. I presented a paper untitled “Packagings for irradiating waste: industrial experience and evolution of the Regulations”. It was about the difficulties regarding the transport of waste that meet the requirements for LSA material or SCO except the criteria regarding the dose rate of the bare material. My conclusion was: “Keep the regulations, change the minds!”, i.e. change the way the Regulations is implemented, not the Regulations themselves.”

“I must recognize that I was not very successful… Other strategies were implemented to transport this waste, and the topic was buried (with the waste…). Nevertheless, WNTI Members came back with this issue a couple of years before the latest review cycle was launched, and we started again to think about this subject with a new approach.”

“A lot of discussions within WNTI and with the competent authorities took place, the WNTI proposal was changed and rechanged several times. Now, the 2025 Edition of the Transport Regulations includes new requirement for Type B(M) packages containing LSA or SCO with higher dose rates. This was not our preferred option, but this is acceptable and provides an acceptable way to deal with this subject.”

“One of the reasons for this success is that we were able to adapt our proposal to the remarks of those who thought differently from us: we were also able to think differently! The final provisions in the Regulations are very different from our first proposal. And our first proposal was very different from our first ideas. More than 31 years after my presentation during this seminar in February 1994, the loop is closed.”

“Never give up!”

– Pierre Malésys, WNTI Consultant