Simple harmonic moves

The transport of radioactive materials is becoming increasingly international. As this happens, there is a corresponding increase in the importance of maintaining consistency and predictability in the interpretation and application of international regulations to ensure safety through compliance and to facilitate efficient operations. Regulations do not have a beneficial impact on safety until they are properly implemented at the operating level. Differences in interpretation and implementation can jeopardise safety and lead to confusion, duplication of effort, delays in obtaining approvals and inefficiencies in both industrial transport organisations and national authorities.

For the transport of radioactive materials, safety is based on principles developed by the International Atomic Energy Agency (IAEA), Regulations for the Safe Transport of Radioactive Material (TS-R-1). These are then incorporated into the international modal regulations, namely: the International Maritime Dangerous Goods (IMDG) code for sea transport and the International Civil Aviation Organization (ICAO) technical instructions for air transport; the regional modal regulations, namely the International Carriage of Dangerous Goods by Road (ADR) and the International Carriage of Dangerous Goods by Rail (RID) for road and rail transport in Europe; and, finally, implemented through the regulations specific to a particular country.

This is a complex and protracted process. Harmonisation issues are encountered at every stage; some are of more consequence than others and they vary from region to region. Recent experience of operating under the latest TS-R-1 regulations are summarised below.

HARMONISATION ISSUES

Schedules for introduction of new regulations

The implementation of the TS-R-1 regulations for sea, air, road and rail transport by the modal organisations did not take place simultaneously and for some time both old and new regulations were in operation.

Rationalisation of implementation of regulations

In some countries different regulatory bodies deal specifically with the various modes of transport (road, rail, sea and air). This can lead to complexities such as different document structures and wording and also different adoption dates for the various modes. The regulatory body may also involve several different authorities and in such cases it is important to have clearly defined responsibilities to prevent errors and to avoid unnecessary duplication or conflicting requirements being placed on the operator.

Interpretation of regulations

During the implementation of the IAEA regulations, additional requirements – which were not specifically in the regulations – could be brought into the consideration of package approval. The certification of packages should be constrained to issues for which there are regulatory requirements.

Validation of package designs

An issue which can complicate international shipments is where a package design is approved in the country of origin, and also in some other countries, but is validated in another under a special arrangement. The certification of the package in the various countries through which it could be transported is not then consistent.

Re-validation of approved packages

At present, there often are considerable time intervals between the renewal of a package certificate in one country and the relevant re-validation in a foreign country during which time transports cannot take place.

Classification and labelling of packages

The marking of packages with a UN number and a proper shipping name is now a requirement of the IAEA TS-R-1 regulations. Complications have arisen in implementing these requirements for international transports because some packages have different certificates in different countries, as noted above. This can cause problems at international borders where markings may need to be duplicated or changed.

Sequencing of tests

The IAEA regulations specify tests to demonstrate the ability of high duty packages to withstand accident conditions of transport. The regulations specify that the order in which the specimen is subjected to the drops shall be such that, on completion, it shall have suffered such damage as will lead to the maximum damage in the thermal test which follows. Different competent authorities may have varying views on what constitute the most damaging orientations of the specimen under test, and the sequence of tests. These differences could cause serious delays in obtaining validation of new package designs and wasteful duplication of effort by transport organisations and competent authorities.

Criticality safety analyses

National authorities carry out independent reviews of the criticality safety of packages containing fissile materials but the underlying assumptions that are used in the calculations can differ, and the outcome is that the requirements for implementation of the regulations are not uniform. A single design may require preparation of multiple criticality analyses to obtain base approval and foreign validations (for example, packages for the transport of nuclear fuel elements). When several competent authorities are involved, the resolution of these issues to validate a package design can be time consuming and expensive.

Air transport

The IAEA regulations, TS-R-1, address air transport of fissile material. However, the regulations fall short of providing an unambiguous statement of the intent; namely, to preclude prompt criticality excursions following an air crash.

Limits for fissile materials on ships

For shipments of fissile nuclear materials by sea carriers under non-exclusive use (where the nuclear fuel cycle material forms only a part of the total cargo) the logic of the regulations is not clear and appears to be inconsistent. For example, a physical barrier (a bulk head) is required between groups of packages stored in a cargo space below deck but only a 6m separation for storage on deck.

PROPOSALS FOR IMPROVEMENT

Harmonisation issues are a consideration for all the organisations involved in the implementation chain. Some actions that would help to alleviate them are suggested below.

Industrial transport organisations

Harmonisation issues have a major impact at the implementation stage by the transport industry, particularly in the preparation of safety cases to obtain licences for transport packages. The industrial organisations involved could help in this regard by developing a system to ensure more structured, systematic and consistent procedures for the compilation, submission and approval of safety cases and agreeing reporting schedules and target dates.

IAEA regulations

It is generally recognised that the IAEA regulations are soundly based and have been very successful in ensuring the safety of radioactive material transport. However, implementation could be improved by avoiding ambiguities, improving the style and ease of use of the regulations, and providing comprehensive guidance documents to coincide with their publication. The current practice of revising the regulations on a two-year cycle raises implementation problems in practice and may not be justified since nuclear fuel cycle transport is more highly regulated than other dangerous goods and has an excellent safety record. An alternative would be to begin with a review of industry experience with the current regulations to identify the issues that have arisen together with possible improvements. Only where changes to the regulations appear to be necessary would the revision process need to be started.

Modal organisations

The various modal organisations base their requirements on the IAEA regulations but decide the extent to which transition periods should be allowed when the regulations are changed. This topic would be appropriate for further consideration by the modal organisations collectively.

National authorities

This is where most of the harmonisation issues arise and some of the main issues that need to be addressed include: expiry dates on certificates, which are not always consistent and can vary from country to country; varying interpretations of the IAEA regulations; and independent reviews carried out by the various national competent authorities using their own particular assessment methods requiring much time and effort and thereby causing delays.

STRATEGY FOR HARMONY

Regulations only have a beneficial impact on safety when they are fully and properly implemented at the operating level. Harmonisation issues that impede efficient and timely implementation can occur at each stage of the complex and protracted implementation process. These are likely to take on greater prominence in the light of the increased frequency of regulation review.

It is important, therefore, that all the stakeholders in the international transport of nuclear materials – industrial organisations, the IAEA, the modal organisations and the national competent authorities – should seek to develop further a strategy to ensure that regulations are implemented in a consistent, efficient and predictable fashion.

To facilitate this uniformity, industry, through the World Nuclear Transport Institute, encourages enhanced dialogue with key stakeholders, both individually and collectively. This in turn can enhance safety while at the same time reducing delays, duplication of effort and inefficiencies for all concerned.

Lorne Green, World Nuclear Transport Institute, 7 Old Park Lane, London W1K 1QR, UK