ABSTRACT
The scattering of neutron collision inside a reactor depends on the geometry of the reactor, the diffusion coefficient and the absorption coefficient. In general, these parameters are not crisp (exact) and hence we may get an uncertain neutron diffusion equation. In this chapter, the uncertain neutron diffusion equation for a bare square homogeneous reactor is discussed. The uncertain governing differential equation is modelled by a modified fuzzy finite element method (FFEM). Using the modified FFEM, the obtained eigenvalues and effective multiplication factors are studied. The corresponding results are compared with the classical finite element method (FEM) in special cases and various uncertain results are explained.
