Safety of research reactors - an overview

Research reactors play an important role in developing a country's nuclear energy programme and in establishing the safety basis for the related activities. Due to diversity in their design, operating power levels and utilization aspects, a slightly flexible and graded safety approach is necessary for research reactors. While the major safety aspect for research reactors are similar to that of power reactors, special attention is necessary on account of several irradiations and experiments that are carried out in these facilities. Safety of research reactors in the world has shown great improvement over the years and no accident or serious incident has been reported during last 35 years. In recent times, there is some concern about safety of ageing reactors and reactors under extended shutdown. Track record of safety of research reactors in India has been excellent. Ageing of old reactors has been managed by systematic assessments and refurbishing actions. The refurbishing outage has been also utilized for making several safety upgrades to meet present day requirements, as in the case of refurbishment of the Cirus reactor. The safety objectives for research reactors and safety aspects of design, operation and utilization of these facilities are briefly discussed in this paper. An overview of the experience with research reactor safety worldwide and ageing management and refurbishing of research reactors in India is also presented. (author)