Study on measurement of spatial dose rates from simulated products made from recycled metal below clearance levels arising from dismantling of nuclear facilities (Contract research)

Okamoto, Akiko ; Kitami, Yasuo*; Ando, Yoshiaki*; Nakamura, Hisashi; Saito, Kimiaki  ; Nakashima, Mikio

In order to contribute to safety assessment of recycling products made from dismantling metal wastes, metal ingots containing Co were produced and spatial dose rates from the ingots were evaluated by gamma-ray measurement and calculation. Stripping operations were made using detector response functions calculated by Monte Carlo program to derive spatial dose rates from measured gamma-ray spectra. In the computer simulation, Monte Carlo and point kernel calculation codes were used. Agreement between measured and calculated values was satisfactory in spite of an extremely low concentration of Co in the ingots and a complicated geometric condition between detector and samples.