Journal of Nuclear Fuel Cycle and Waste Technology

The energy band and the G-factor method were compared to determine the exposure rate from the measured spectrum using a NaI(Tl) scintillation detector. First, G-factors of a 3“ΦX3” NaI(Tl) detector mounted to a EFRD 3300, which means the environmental radiation monitor, in Korea Atomic Energy Research Institute (KAERI) were calculated for several directions of incident photons through the MCNP modeling, and the optimum G-factor applicable to that monitor was then determined by comparing the results both the energy band method and the G-factor method. The results for these spectrometric determinations were also compared with the dose rate from a HPIC radiation monitor around a EFRD 3300. The measured value at the EFRD 3300 based on a 3“ΦX3” NaI(Tl) detector was 7.7 μR/h and its difference was shown about 3 μR/h, when compared with the results from a HPIC radiation moditor. Since a HPIC is known to be able to measure cosmic rays with the relatively high energy, the difference between them was caused by cosmic rays which were not detected in a 3“ΦX3” NaI(Tl) detector.

Keywords

Energy band,G-factor,Environmental radiation monitor,NaI(Tl),Dose conversion,MCNP