Optimization of array CeBr3 scintillation detection device for water on-line radioactivity measurement system

Abstract

BackgroundWith the vigorous development of the nuclear industry and the widespread application of nuclear technology, the radioactivity of inland water has become one of the key objects of radiation environmental monitoring. CeBr3 scintillation detector is one of candidates for water on-line radioactivity measurement system, but its detection efficiency is not high enough.PurposeThis study aims to improve the detection efficiency of the water on-line radioactivity measurement system by optimization of array CeBr3 detector layout, and reduce the detection limit.MethodsFirstly, calculate the optimal number of detectors in the system according to the minimum detectable activity concentration formula was calculated. Then, the Monte Carlo method was used to simulate the number and arrangement of ⌀45 mm×50 mm CeBr3 array detectors to obtain optimized arrangement of detectors. Finally, the water on-line radioactivity measurement system with optimized layout of array CeBr3 detectors was applied to continuous monitoring of the water bodIES of a river basin in Sichuan province.ResultsThe simulation results show that the three CeBr3 detectors placed in triangular arrangement and close to each other achieve a minimum detectable activity concentration of 0.1 Bq·L-1 for 137Cs radioactive source, meeting the design standard of system detection limit.ConclusionsThe monitoring results show that the system can effectively monitor the variations of radioactivity concentration of total α/β and 238U, 232Th and 40K in the water.

Keywords

• water radioactivity
• array cebr3 detectors
• detection efficiency
• monte carlo simulation