온라인 삼중수소 방사능 연속모니터링 측정시스템 개발 및 분석 최적화 기법 개발

Abstract

In this study, a liquid scintillation spectrometer was developed for online continuous monitoringof tritium nuclides in water. The device consists of two photoelectron multiplier tubes (PMT), a simultaneouscounting circuit, and a signal processing unit including a multi-channel analyzer (MCA). As a method to verifythe performance of the equipment developed in this study, samples were prepared using a standard source, and thespectrum of tritium was measured to evaluate the detector characteristics such as efficiency, background (BKG), andminimum detectable activity (MDA). To evaluate the effect of pretreatment on tritium radioactivity measurementresults, the MDA of water (seawater and groundwater) samples before and after pretreatment was calculated andcompared. The results of the evaluation confirmed the satisfaction of the reference values of the Nuclear SafetyCommission᾽s “Discharge Control Standard in Drainage Water” and the World Health Organization᾽s (WHO) “TritiumRadioactivity Concentration for Drinking Water Standards”. The liquid scintillation spectrometer developed in thisstudy, with or without pretreatment, confirmed detection performance equivalent to 1/100th of the discharge controlstandard for drainage water (40,000 Bq L-1) and the WHO᾽s drinking water standard for tritium radioactivity (10,000Bq L-1).