방사능 수치 오염 지도 작성을 위한 방사선 계측 시스템 연구 = Study of Radiation Mapping System for Water Contamination in Water System

다국어 초록 (Multilingual Abstract)

As nuclear industry has been developed, a various types of radiological contaminationhas occurred. After 9.11 terror in U.S.A., it has been concerned that terrorists’ active area hasbeen enlarged to use nuclear or radioactive substance. Recently, the most powerful earth-quakestroke, which triggered a massive tsunami in Japan and then Fukushima nuclear power plant reactorhas suffered from a serious accident in history. The Fukushima reactor accident has occurredan anxiety of radiation leaks and about 170,000 people have been evacuated from the accidentalarea near the nuclear power plant. For these reasons, a social chaos can be occurred if radiologicalcontamination occurs to the supply system for the drinking water. As such, the establishmentof the radiation monitoring system for the city main water system is compelling for the nationalsecurity. In this study, a feasibility test of radiation monitoring system which consists of unifiedhybrid-type radiation detectors was experimented for multi detection system by using gammarayimaging. The hybrid-type radiation sensors were fabricated with CsI(Tl) scintillators andphotodiodes. A preamplifier and amplifier was also fabricated and assembled with the sensor inthe shielding case. For the preliminary test of detection of radiological contamination in the river,multi CsI(Tl)-PIN photodiode radiation detectors and 137Cs gamma-ray source were used. TheDAQ was done by Linux based ROOT program and NI DAQ system with Labview program. Thesimulated contamination was assumed to be occurred at Gapcheon river in Daejeon city. MultiCsI(Tl)-PIN photodiode radiation detectors were positioned at the Gapcheon river side. Assumingthat the radiological contaminations flows in the river the 137Cs gamma-ray source has beenmoved and then, the contamination region was reconstructed.