AIEA

Interest in small and medium size reactors (SMRs) for use in non-electrical applications as well as power generation is steadily increasing among Member States. The reactors will most likely find use in such areas as sea-water desalination, district heating, oil recovery enhancement, coal gasification and methanol production. The Agency’s activities in the field of SMRs focused on providing technical support for these projects. A Technical Committee meeting on small reactors with minimized staffing and/or remote monitoring, held in Mississauga, Canada, in May, assessed the level of interest in small reactors in various countries and explored potential applications and technical approaches of common interest.

An Advisory Group meeting on the introduction of SMRs was held in Rabat, Morocco, in October to review the experience acquired by Member States during the deployment of such reactors. The meeting confirmed that there is a continuing interest in SMR deployment in North African, Middle Eastern and Far Eastern countries, that considerable operating experience has been gained (which can benefit developing countries), but that more information related to the deployment of SMRs is needed. Local participation and technology transfer were recognized as important elements in the introduction of SMRs.

The large capital costs involved in the development of improved and advanced nuclear power plant designs have led to many national and international co-operative efforts. The Agency’s role in this context is to serve as a forum for information exchange on national programmes, scientific and technical issues. In one such international co-operative research activity, the Agency collected and systematized a database of thermophysical properties for a broad spectrum of light and heavy water reactor materials over a wide temperature range. The establishment of such a consistent set of information provides an international source of data for independent examination of the performance and safety of various advanced reactor designs.

A Technical Committee meeting on the design, development and testing of safety systems for advanced water cooled reactors was convened in Piacenza, Italy, in May. The results presented at this meeting indicated that the basic designs of safety systems for large evolutionary plants are well established and have been derived from experience with existing plants.

A Technical Committee meeting on the identification of severe accidents for the design of future nuclear power plants was convened in Vienna as part of the Agency’s ongoing activities to establish design safety principles. In addition to agreeing on a consistent set of severe accident phenomena, there was consensus that internal and external events should be addressed and that the resulting design features should provide prevention and mitigation, with priority given to preventive measures.

At the final Research Co-ordination meeting for a CRP on acoustic signal processing for the detection of boiling or sodium water reaction in liquid metal fast reactors (LMFRs), held in Obninsk, the Russian Federation in July, it was reported that the CRP had been able to evaluate different signal processing techniques with real field data. The results were thus invaluable to the designers of acoustic leak detection systems. In the long run, this could help enhance the economics of LMFRs through better surveillance of the reactor core and steam generators. Signal processing techniques developed in this CRP for anomaly detection (i.e. boiling or leaks) can be used to detect other types of anomalies in thermomechanical equipment (such as cavitation and rattling) in fast and thermal reactors.

One of the goals of a CRP on the intercomparison of LMFR seismic analysis codes was to validate and improve the codes used for reactor core seismic analysis through benchmark exercises. At the final Research Co-ordination meeting for this CRP, which was held in Bologna, Italy, these codes were validated on the basis of an intercomparison of experimental and analytical data. It was noted that the results derived from this CRP had a broad range of applicability, since they could be used for different types of reactors.

In 1994, the Agency was requested to initiate the Options Identification Programme (OIP) with the aim of selecting a limited set of practical options for nuclear desalination demonstration facilities. The options were to be based on reactor and desalination technologies which were readily available without any further development. A working group of representatives from interested Member States and the Agency selected the following practical candidates for demonstration projects: a reverse osmosis desalination process coupled to an existing or newly built water cooled reactor of medium-size capacity, and a multi-effect distillation process coupled to a small size reactor in the 20-50 MW(e) range. Either of these options could be implemented in the relatively near future.

A Technical Committee meeting on advanced fuels with reduced actinide generation, held in Vienna in November, identified reactor/fuel combinations, including thermal reactors, fast reactors and accelerator driven systems with fuels or targets from the uranium/plutonium and thorium/uranium families in order to reduce actinide generation. This area of work is of considerable interest for alleviating the problems of plutonium build-up and long lived wastes.