RAW packaging and transportation practice

International safety standards have been developed for the transport of all forms of radioactive material [62] and are issued in the form of ‘transport regulations’. These ‘regulations’ have been adopted within all the regula­tions for transport of hazardous materials by all modes (land, air and sea) and are recognised and adopted in the national regulations of most coun­tries. As with all other facilities and activities associated with RAW manage­ment and contaminated environments, the radiation safety requirements are those set down in the international Basic Safety Standards [38].

The objective of the regulations is to establish requirements that must be satisfied to ensure safety and to protect persons, property and the environ­ment from the effects of radiation in the transport of radioactive material. This protection is achieved by requiring: (a) containment of the radioactive contents; (b) control of external radiation levels; (c) prevention of critical­ity; and (d) prevention of damage caused by heat. The regulations are satis­fied firstly by applying a graded approach to content limitations for packages and conveyances and to performance standards applied to package designs, depending upon the hazard of the radioactive contents. Secondly, they are satisfied by imposing requirements on the design and operation of packages and on the maintenance of packagings, including consideration of the nature of the radioactive contents. Finally, they are satisfied by requiring adminis­trative controls, including, where appropriate, approval by competent authorities. Confidence in this regard is achieved through the adoption of appropriate management systems involving quality assurance and compli­ance assurance programmes. The regulations are based on a classification of radioactive materials to be transported in a system of increasing hazard potential. The type of package and its testing are correspondingly higher as the hazard potential increases, with prescriptive testing and defined per­formance criteria for each category of package.

At the lower hazard level, low specific activity (LSA) material and surface contaminated objects (SCO) are defined quantitatively in the transport regulations. These materials can be transported in so-called ‘industrial pack­ages’ (IP) of types 1, 2 and 3, which must be designed and tested according to the specifications set in the regulations. The next generic class of materi­als is referred to as Type A and a schedule of radionuclide specific activity limits is provided in the regulations. Materials falling within these limita­tions can be transported in Type A packages for which design and testing requirements are prescribed in the regulations. The packages are designed to maintain their integrity during normal conditions of transport, providing the necessary shielding and containment, but are not expected to withstand severe transport accidents, the limitation on radioactive content ensuring that any consequences would not be severe. IP and Type A packages must conform to these design and testing requirements but do not require com­petent authority approval nor is notification required for international ship­ments of these package types. For transporting quantities of radioactive material greater than the limits for Type A packages and fissile material requires the use of Type B and C packages. These packages are designed to transport higher activity radioactive and fissile material and have to be designed with high integrity in terms of both shielding and containment features, which must be able to withstand the impacts of the most severe transport accident. Again, design and testing requirements are specified in the regulations, the latter including drop, puncture, crush and fire tests, representing the conditions that could be encountered in severe accidents, with Type C having to undergo impact testing simulating an aircraft acci­dent in order to qualify for transporting high activity radioactive material by air. Type B and C containers require competent authority approval, both from the country of origin for Type B and also from the countries en route during the shipment.

There is no direct correlation between RAW classes and transport cat­egories, as the classification is based on long-term safety (primarily dis­posal) consideration. Nevertheless, in general, low activity waste — generally VLLW from, for example, lightly contaminated building rubble from decom­missioning activities — would fall in the category of LSA for transport purposes, LLW and ILW would be/could be LSA, Type A or Type B and HLW would be transported as Type B material.

3.5 Conclusion

Significant progress can be observed in the development of internationally agreed standards on the management of RAW, radiation safety and trans­port safety in recent years. The role of each country is to implement these standards in the most efficient and appropriate manner, taking into account the specific characteristics and conditions of existing RAW or anticipated future arisings. One of the main challenges is for operators and regulators to apply a graded approach based on the existing and potential risks to the public and the environment and at the same time providing confidence in the demonstration of adequate levels of safety.

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