Feasibility Study on Passive Neutron Technique Applied to Fuel Debris Measurement at Fukushima Daiichi Nuclear Power Plan

Fukushima Daiichi Nuclear Power Plants were struck by the earthquake and tsunami on March 11, 2011 and meltdown of the reactor cores of Units 1 - 3 occurred. T he Japanese government and Tokyo Electric Power Company (TEPCO) decided decommissioning of them. For decommissioning of them , the Japanese government and TEPCO plan to recover fuel debris safely and to adequately account for the nuclear material in fuel debris . A s urvey of applicable tech nologies for the nuclear material quantification in fuel debris is currently being conducted by the Japan Atomic Energy Agency (JAEA) and the United States Department of Energy under the collaborative agreement. As one of the candidate technologies of plut onium quantification in fuel debris, the Plutonium Fuel Deve lopment Center of JAEA propose s to apply the passive neutron technique , which is widely applied to the field of material accountancy and safeguards in plutonium handing facilities. This paper provides the results of feasib ility study for the application of the passive neutron technique to fuel debris measurement.