Calculations of critical masses of minor actinides on the ANSI/ANS-8.15 model using the nuclear data library JENDL-3.3

Okuno, Hiroshi  ; Sato, Shohei; Kawasaki, Hiromitsu*

The critical masses of 23 minor actinides in metal and 7 minor actinides in metal-water mixtures were calculated using a combination of the Monte Carlo neutron transport code MCNP4C2 and the nuclear data library JENDL-3.3. The selected reflector conditions were bare, with a 30-cm-thick water and with a 30-cm-thick SS304. Comparisons of the calculated critical masses with the data in reference literature and those calculated using JENDL-3.2 were made. The effect of reflectors on the critical masses and the relations between the critical mass of actinide in metal and its neutron multiplication factor in the infinite media were discussed.