Transport of radioactive material (RAM) is based on a revised international safety code: the IAEA Regulations for the Safe Transport of Radioactive Material (TS-R-1, which replaced SS6 in January). These regulations are implemented through legal actions in each IAEA member state, and cover all modes of transport – sea, air, road and rail. International organisations and agreements police the adoption of the IAEA recommendations in international and national law, and authorities in each country fulfil this task if it is not covered by these organisations.
The process of implementing the IAEA transport regulations involves many jurisdictions and represents a large number of interfaces, each of which can be a source of potential discontinuity. For the introduction of TS-R-1 to be harmonious, transition to the new regime should be simultaneous for all modes of transport, but this is not possible. There are different dates when TS-R-1 comes into force for different modes of transport, and there are varying transition periods where both old and new regulations can be used.
The situation is further complicated by discrepancies between the dangerous goods transport regulations for RAM and national atomic law. In some countries, exemption quantities of material can be freely released that are radioactive from a physics point of view, but non-radioactive from a legal point of view. But unconditional transportation of this material will not be allowed because it is still RAM and therefore has to be transported under the provisions of the transport regulations. This situation can be reversed when national regulation does not follow the new exemption levels of TS-R-1.
Furthermore, the format of the recent edition of the UN Orange Book for model regulations has been revised, and its different presentation makes it hard to compare it with TS-R-1.
International time schedules
There are timing questions arising from the first introduction of TS-R-1 and the introduction of the revisions according to the new two-year revision cycle.
The schedule poses an additional problem because the modal regulations allow for transport either according to the old SS6 or the new TS-R-1. The overall transition period will now be at least one year (in most European coutries).
The process of adopting the regulations by national law in different countries will not reflect the time schedule of the major modal regulations. There are transitional periods for a number of countries, where national regulation is guided by agreements or organisations but will be determined by national legislation. The actual process of embodying IAEA transport regulations may differ significantly from those already mentioned. For example, in the USA, TS-R-1 will be incorporated into 10 CFR Part 71, probably from 2003. The adoption process is quicker for most European countries because of their commitment to ADR and RID. So in Europe the adoption process closely follows the line of the modal regulations outlined in the table below and within one year the transition to TS-R-1 will be completed.
It is clearly not satisfactory to have a certain way of safety assessment in one country, which requires more explanations and calculations or testing in another.
The validation of certificates, which is mandatory for a Type B (U)-F package but not for a Type B(U) package, is treated differently in different countries. The original idea for validation of F-packages was the individual way of criticality assessment in different countries. In other words, all other conditions for the qualification as Type B could be untouched. The reality of validation is different from this original intent. Some authorities prove almost the entire safety report a second time. This leads to long validation times, misunderstandings arising from language problems, and additional safety assessments or calculations. These problems arose under the well-established SS6 regime, so there is concern about the potential for a number of new fields of disharmony between the authorities of different countries when the new regulations come into force. This will become more complex with a revision cycle of two years.
Problem areas
Four examples will serve to show the type of problems that will arise while the transition to TS-R-1 is not-fully harmonised.
Transport between regulated countries changing modes from or to TS-R-1/SS6 mode.
There are some key points to be considered when transporting from an area with one kind of regulation to another. They are illustrated in the table above.
Package design approval
The transitional arrangements for packages, licensed under different revisions of the IAEA transport regulations largely follow the precept that there was no need for an immediate change of the regulations following their adoption, but that changes aimed at a long-term improvement of safety in transport were justified. Previously each revision allowed for the continued use of packages made under the previous two revisions.
Under TS-R-1, package approval certificates will have an expiry date after which new criteria may have to be met for subsequent approval. The IAEA have acknowledged that, with the development of a two-year revision cycle, the existing procedures may not be able to sustain multiple overlapping sets of regulations. A more stable basis for transition is currently being developed.
TS-R-1 states that existing package designs can be used, provided that the following conditions are met:
•Quality assurance.
•Activity limits and materials restrictions of the new regulations only.
•Air transport of fissile material (Type C package) according to TS-R-1 only.
However, the final decision rests with the authorities and some countries may not accept older package designs.
New dose quantities in radiation protection
At the beginning of the last decade, the ICRP and the ICRU built a new system of dose quantities for radiation protection purposes. The key quantity for transport issues is the new ambient dose equivalent H*(10) and the corresponding dose rate.
This quantity was, via the IAEA Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, introduced into transport regulations as TS-R-1 refers to in its definitions of the Basic Safety Standards. But the new dose quantities are not numerically equal to the old ones. The difference for photon radiation in a certain energy range can reach up to a factor of 1.5 and the same is true for neutron radiation of certain energies.
One of the general provisions for transport is the compliance with dose rate limits. A measurement of the new dose quantities in radiation protection could result, when transporting the same contents of radioactive material, in dose rates above the limits that could be interpreted as a violation of the regulation. This situation is probable for packages which have been designed up to the dose rate limits for the maximum possible content.
Harmonisation between the authorities in charge of radiation protection and those in charge of transport regulation, as well as between countries, is clearly required.
Radiation protection programmes
In paragraph 301 of TS-R-1 there is a requirement for a radiation protection programme (RPP):
“A RPP shall be established for the transport of radioactive material…Programme documents shall be available, on request, for inspection by the competent authority.”
Although such programmes are familiar to companies that already work in the nuclear field, for those companies that do not the situation is different. They will now need trained people, measurement equipment and software. This is an added burden to these often smaller companies, and there is concern about the potential disincentive to companies willing to transport RAM. As these smaller companies have no experience with RPP, standardised solutions need to be prepared in order to minimise the additional burden and to maintain their engagement in nuclear transportation.