PRELIMINARY MEASUREMENT OF PROMPT GAMMA-RAY FROM NUCLEAR MATERIAL FOR THE CLASSIFICATION OF FUEL DEBRIS AND WASTE

Abstract

A technique to simply judge the presence or absence of nuclear materials in fuel debris generated in the Fukushima Daiichi Nuclear Power Plant (1F) accident is important from the viewpoint of sorting the debris from radioactive wastes. In the case of uranium(U)-containing waste from fuel cycle facilities, the U amount may be determined by the detection of gamma-ray at 1001 keV emitted by 234mPa, a daughter nuclide of 238U (Suzuki et al., 2011). However, it has been pointed out that such gamma-ray measurement techniques cannot be used for fuel debris that contains a large number of fission products (FPs), which emit various energies of gamma-ray. In this study, we focus on the spontaneous prompt fission gamma-rays (PFGs) directly emitted from nuclear materials. PFGs exists in a higher energy region than that of FPs and can avoid the interference by them. We aim to measure PFGs in simple ways.