Speaker
Description
The importance of environmental radiation monitoring has increased since the nuclear accidents of the Fukushima nuclear power plant. Naturally occurring radioactive materials (NORM) also require radiation safety management to protect the public according to the protective guidelines against radiation in the natural environment developed by the Nuclear Safety and Security Commission (NSSC) in Korea. The spectrometric determination of the dose rate using scintillation detectors is a very useful method with respect estimating the ambient dose rate and the nuclide contribution to the ambient dose rate. The dose conversion from a measured energy spectrum for counts obtained using a gamma-ray spectrometer can be achieved from a G-factor, which means the theoretical detector response function, to make a spectrometric determination of the dose rate. The dose rate spectroscopy [1-3] was first introduced to make spectrometric determination more effective, that is, to get more information from one measurement, such as the ambient dose rate as well as an individual dose rate and its radioactivity for detected gamma nuclides. To expand its application to the environment, a 2”x2” LaBr3(Ce) scintillation detector within the environmental radiation monitor (ERM) was used to perform real-time monitoring of the dose rate and radioactivity for detected gamma nuclides around an ERM. After the preparation of dose rate spectroscopy of the used LaBr3(Ce) detector, which means the theoretical calculation of factors dedicated to the ERM to simultaneously estimate the dose rate and radioactivity from the measured energy spectrum, the ambient dose rate as well as the individual dose rate and its radioactivity for detected gamma nuclides were then calculated with only one measurement using the ERM during 15 minutes. The results were experimentally verified by an intercomparison of the in situ gamma-ray spectrometry results obtained by a portable HPGe detector and the analysis of samples taken around the ERM. The results showed that the dose rate spectroscopy using an ERM based on an 2”x2” LaBr3(Ce) scintillation detector could be applied to remotely monitor three variables in real-time around an ERM.
