Abstract:
In this study utilized nuclear core –like environment of real nuclear core by Monte Carlo simulator MCNP5. The object of this study is determine the optimal moderator for fast neutron which act to slow down for fast neutron to thermal region, and determine theoptimal absorber (control material) for neutron to control for nuclear chain reaction in the reactor.
Utilize the light water H2O and heavy water D2O as moderator materials in cubic shape 90 cm3 and around the moderator there is reflector carbon 14C to prevents the leakage for neutrons outside the nuclear core, its thickness equal 10cm3, then after select the optimal moderator will use with absorber materials to examine the optimal absorber,utilize control rods which length is 80cm and diameter is 1cm, Those materials are cadmium (Cd), silver (Ag), &Boron carbide (BC4).
After study appears the optimal moderator for fast neutron is heavy water (D2O) than light water H2O. And found theoptimal absorber than others.