SAFETY INSTRUMENTATION FOR SODIUM-COOLED FAST-REACTOR

An outline is given of the particular safety problems of the fast reactor, and the role of instrumented protection in relation to the overall safety design of the reactor. The importance of the accident sequence arising from a fault within one sub-assembly is indicated, and the physical phenomena involved are discussed with regard to the generation of detectable signals. Several possible detection techniques for sub-assembly accidents are described, including those with detectors situated at the outlet of each sub-assembly, and also those involving whole-core parameters. The current status of these techniques is indicated, and where appropriate the steps necessary for their future application are specified. Reference is made to the way in which type of instrument would have to be combined to give a high degree of protection to the system, the actual protection required being dependent on the overall safety intentions.