Study on application of superconducting transition edge sensor to internal dose assessment for decommissioning of Fukushima-Daiichi Nuclear Power Station

Takasaki, Koji  

In the decommissioning of Fukushima-Daiichi Nuclear Power Station, many radiation workers sometimes must work in contaminated areas with alpha and beta nuclide dust. In preparation for the future expansion of the scale of fuel debris removal, it is necessary to periodically check that there is no intake of alpha nuclides to ensure the safety of workers, and if radioactive materials are inhaled, to promptly evaluate the internal dose. Currently, the intake of alpha-nuclides such as plutonium is evaluated by measurement using a lung counter or bioassays, but the evaluation accuracy of the intake of alpha-nuclides in the body is not sufficient due to the difficulty of alpha-ray measurement. Therefore, we are studying the application of a superconducting transition edge sensor (TES)-type microcalorimeter, which is capable of nondestructive measurement with high resolution, to lung monitoring and analysis of bioassay samples to speed up and improve the internal dose assessment of plutonium.