Development of a radiation measurement system based on radiation and heat resistant materials

Abstract

Hokkaido University plays a core role for the following two projects in this tutorial paper, ① the development of diamond semiconductor devices for nuclear plants, which can survive severe accidents are described. ② the development of an elemental technology for a field-portable energy discrimination and position sensitive alpha-particle measurement system. The item ① is an effort to develop diamond semiconductor devices that can be used inside nuclear reactor containments, which require very severe demand performance in radiation and heat resistance. Although the project is in progress, a diamond field emission transistor, which stably operates at 500 degrees C, has been developed. In addition, diamond radiation detectors will soon satisfy the performance demands of operation at 300 degrees C, an accumulated dose of 5 MGy and a dynamic range of 7 digits. ② is the development of an elemental technology for a scintillator-base field-portable energy discrimination and position sensitive alpha-particle measurement system that finds alpha-particles from nuclear fuel, e.g., ²³⁸Pu, in a high gamma and beta-ray background. As a result, the developed system succeeded in identifying 0.37 Bq of Pu within 5 minutes in an environment where the existence ratio between the Pu and Radon progeny nuclei was 1:100. The foundation of these two projects is the development of environmentally resistant materials for high radiation and high temperatures.