The Joint Project

Accelerator Driven
Transmutation Facility

Nuclear energy system can not be completed without establishing its nuclear waste management system. Although it has been addressed that the principle scenario of the waste stream in Japan is the deep land burial of high level waste (HLW), the HLW still remains as potential hazards. Accordingly, it is encouraged to pursue a way to reduce HLW to mitigate a potential load of the waste management. The accelerator driven system (ADS) has been recognized world wide as an attractive option for the nuclear transmutation of HLW. Japan Atomic Energy Research Institute has proposed an ADS concept for the nuclear transmutation of HLW. With the ADS, a hazard level of HLW is estimated to be reduced to 1/200 comparing to a case without the ADS in 500 years.

To realize ADS, we have to do various areas of fundamental researches and technical developments. They are the spallation target technology, the sub-critical reactor physics, a hybrid system operation and controls, the nuclear transmutation process, etc. Among those, the development of the material for the spallation target and the sub-critical reactor physics driven by the high-energy proton beam are the most important issue to evaluate the technical feasibility for the ADS. In order to make a breakthrough in ADS technology development, we are proposing two experimental facilities to be built under this JAERI-KEK joint project. They are (1) Accelerator Material Irradiation Facility, and (2) ADS Physics Experimental Facility. The former is aiming at evaluating soundness of the materials, which are exposed by extremely severe proton and neutron irradiation under a high temperature lead-bismuth flow. The proton beam of 600 MeV and 0.33mA (200 kW) is used. The latter facility is for researches of the basic sub-critical reactor physics, e.g., sub-criticality, reactivity, power profile, etc. and reactor power control with the beam power, with a low power proton beam of up to10 W.

We do believe that the basic experiments for ADS under the joint project will enrich our knowledge and will be the first and a great step toward a new horizon of the nuclear energy system in the 21st century.

	The author of this article, Dr. Yujiro IKEDA, is the leader of Neutronics Group of JAERI, and also is the leader of ADS Nuclear Transmutation Experimental Group under the Joint Project.