CHARACTERISTICS OF THE SIMULATED WORKPLACE NEUTRON FIELDS USING A ~(252)Cf SOURCE SURROUNDED WITH CYLINDRICAL MODERATORS

摘要

The authors established the simulated workplace neutron fields using a ~(252)Cf source surrounded with cylindrical moderators at the Japan Nuclear Cycle Development Institute (JNC), Tokai Works. The moderators are annular cylinders made of polymethyl methacrylate and steel. The neutron energy spectrum at the reference calibration point was evaluated from the calculations by MCNP-4B and the measurements by the Bonner multisphere spectrometer and the hydrogen-filled proportional counters. The calculated neutron spectra were in good agreements with the measured ones. These fields can provide the realistic neutron spectra similar to those encountered around the glove-boxes of the fabrication process of MOX (PuO_(2)-UO_(2) mixed oxide) fuel.