[3C05-07] Technologies for Dismantling, Decontamination & Evaluation 1

[3C05] Study of possibility of clearance measurement for covered cables and control panels by detection simulation

*Masakazu Namekawa¹, Taro Shimada², Seiji Takeda² (1. NAIS, 2. JAEA)

Keywords:detection simulation, clearance, covered cable, control panel, activation product, PHITS, plastic scintillation, portable Ge detector

Change of detector response according to combination of measuring time, density deference, accumulated condition and radiation source position may impact clearance determining unlike measurement of target objects made from a single material such as metal scraps. And also, it is necessary to confirm that radionuclides such as Zn-65, Sb-125 activated in the covered cables are able to be detected in measurement system. We constructed simulation models of measurement systems using plastic scintillation and portable Ge detectors, and simulation of detector response was carried out by PHITS code to evaluate possibility of clearance measurement by conventional method of measurement and evaluation. Then, measurement of clearance levels of target nuclides is possible in measurement system of covered cables bundled with about 100kg. On the other hand, in the case of measurements of control panels which have large housings without segmentation by using the portable Ge detector at once, clearance judgement may be difficult. In the case, multiple measuring with changing position of the detector is required.