Development of a Multifunctional Radiation Measurement System for the Rapid Radiological Characterization of a Decommissioned Nuclear Facility Site

摘要

In this study, a radiation measurement system with multifunctions for the rapid radiological characterization of a decommissioned nuclear facility site was developed and evaluated. The system remotely and simultaneously measures the beta and gamma radiation from the soil at a decommissioned nuclear facility site and wirelessly transmits the measurement data to the main server, which collects and analyzes the data. The radiation-measuring part of the system is composed of a sensing probe, multichannel analyzer (MCA), and laptop computer. The sensing probe is a phoswich radiation sensor (PHORS) consisting of two inorganic scintillators (NaI(Tl) and CaF 2 (Eu)), each of which simultaneously measures the count rates and energies of the beta and gamma radiation. To test the performance of the PHORS, the beta and gamma radiation from a radiation source at 0–10?cm depths (at steps of 1?cm) under a soil surface was measured. The measurements show that the radiation count rates agree well with the theoretically predicted ones; the PHORS is as good as commercial radiation detectors in providing the energy spectrum of a radionuclide. In addition, a chi-square test was conducted, and the energy resolution was evaluated. The communication part of the system consisting of a global positioning system (GPS) and long-term evolution telecommunication (LTE) modem can successfully transmit the measurement data and their location information.