| 摘要 |
PROBLEM TO BE SOLVED: To measure subcriticality of nuclear fuel material contained even in a large container.SOLUTION: A subcriticality measuring device 20 which is contained in a storage container 1 which measures effective multiplication factor of nuclear fuel material system composed of a nuclear fuel material and medium includes: a hollow tube 6 which is placed in the storage container 1 and removes a medium; a neutron source 2 which is placed outside of the storage container 1, is arranged near end of hollow tube 6, and provides a neutron to the nuclear fuel material system in storage container 1 through the hollow tube 6; one or more neutron detectors 4 which detect the neutron from the nuclear fuel material system in the storage container 1; and an effective multiplication factor calculation part 11 which calculates an effective multiplication factor based on output from the neutron detector 4. |
