ANALYSIS OF A NEUTRONIC COMPUTATIONAL MODEL FOR BOILING WATER REACTOR ASSEMBLY USING MCNP CODE

Mcnp code, based on monte carlo method, is used to design a three dimensional model for a bwr fuel assemblies at a typical operating temperature and pressure conditions. a test case was considered to compare with a benchmark problem and good agreement was found. the model is used to calculate the distribution of pin by pinpower and flux inside the assembly. the effect of axial variation of water (coolant)density and of control rods motion on the neutron flux and power distribution is analyzed.