Consulting core surveillance system COCOSS I at KNK II

Fuel cladding defects cannot be avoided in nuclear power plant operation. In the worst case they may lead to loop contamination or to local cooling disturbance. Especially in case of the liquid metal cooled fast breeder reactor, continuation of plant operation or power set back calls for an expert who possesses comprehensive knowledge of (a) detection and location of failed subassemblies, (b) behavior of failed subassemblies, and (c) questions of safety of the plant while operated with faulty subassemblies. Since such an expert cannot be permanently available, it is intended to transfer this expert knowledge to the COCOSS 'Consulting Core Surveillance System'. This report gives a description of the status of COCOSS as operated at present at KNK II as a measuring data acquisition and evaluation system. In the final stage of implementation COCOSS - inserted in a large diagnosis system - is to make the same calculations for the reactor operator and to give him the same recommendations as he receives now from an expert commanding of an extensive knowledge in this specialized field. (orig.)