AIEA

An International Symposium on Storage of Spent Fuel from Power Reactors, was held in Vienna from 9-13 November 1998. The Symposium was organised by the International Atomic Energy Agency in co-operation with the OECD Nuclear Energy Agency. Over one hundred twenty five participants from 35 countries and 4 international organisations attended the Symposium. The country participants represented utilities, industry, licensing authorities, national research organisations and consulting engineers.

The meeting gave an opportunity to exchange information on the state-of-the-art and prospects of spent fuel storage, to discuss the world-wide situation and the major factors influencing the national policies in this field and to identify the most important directions that national efforts and international co-operation in this area should take.

It is noted that there continues to be worldwide growth in the generation of electricity power using nuclear energy as its source. It is further noted that the rate of growth of nuclear energy generation has essentially levelled off in Europe and North America while it has increased significantly in Asia. Although these trends have some impact on spent fuel management, including storage, the world-wide spent fuel production rate continues at about 10,800 t HM/yr.

There are three major categories for classifying spent fuel management policies and practices. These include a closed-fuel cycle which involves reprocessing of spent nuclear fuel, a once-through fuel cycle which ends with the disposal of the spent nuclear fuel, and a “wait and see” approach. One can view the decision to either reprocess or dispose as two ends of a spectrum of options. It should be noted, however, that countries which originally choose the reprocessing option envisage the final disposal of high burnup and MOX spent fuel. The “wait and see” strategy should not be viewed as avoiding a decision, but as a means of evaluating the possible options and maintaining the retrievability of the spent fuel. Some countries reported on considerable progress in the final conditioning of spent fuel for disposal in geological formations.

Dominant messages at the Symposium were that the primary spent fuel management solution for the next decades will be interim storage, the duration time of interim storage will become longer than earlier anticipated and the storage facilities will have to be designed for receiving spent fuel from advanced fuel cycle practices (i.e. high burnup and MOX spent fuel).

It was noted that the handling and storage of spent fuel is a mature technology and meets the stringent safety requirements applicable in the different countries. However, it is performed in a flexible and dynamic way, continuously adapting to changes in nuclear policy and progress in technology. Changes affect, for example, the transportability of spent fuel, application of burnup credit and utilization of advanced fuel types.

Wet storage remains dominant, even as the use of dry storage concepts increase. Wet storage is essential for cooling newly-discharged fuel, and will continue to be the method of storage used in connection with reprocessing. The industry has an extensive experience base in wet storage with an excellent performance record. Dry storage is being used increasingly, as more and more long-term storage of spent nuclear fuel is done. Dry storage may prove to be a cost-effective activity and can easily accommodate multipurpose systems (e.g., storage/transport, storage/transport/disposal).

Agency initiatives that were mentioned included:

• To assist Central and East European Countries with problems related to the storage of spent fuel and establishing adequate spent fuel storage facilities;
• To continue the exchange of information, data and experience (from licensing to operation) on spent fuel storage technologies and public acceptance matters; and,
• To organise peer reviews in the subject of spent fuel storage and management upon request of Member States.
• To continue discussions on regional spent fuel storage for which countries with small nuclear programmes demonstrated interest.

The current policies and attitudes across the world have made extended interim storage a real necessity in the nuclear power business. This is being addressed adequately by utilities, industry and licensing authorities alike, so that storage of spent fuel will continue to be safely managed.