Neutronics experiments for ITER at JAERI/FNS

A series of fusion neutronics experiments has been performed at the Fusion Neutronics Source facility at Japan Atomic Energy Research Institute as ITE R EDA R&D tasks to find ways of dealing with various nuclear problems origi nating from 14 MeV neutrons in ITER. Recently three groups of experiments w ere carried out: (1) straight duct streaming experiments, (2) decay heat ex periments, and (3) development of a fusion power monitor utilizing activati on of water. The straight duct streaming experiments suggest that the calcu lation accuracy for straight duct streaming analyses in ITER nuclear design s is +/-40%. The decay heat experiments show that the accuracy of the decay heat calculation is within 10% for copper and type 316 stainless steel, wh ile it is similar to 30% for tungsten. It is demonstrated that a fusion pow er monitor utilizing activation of water is applicable to ITER.