LMFBR fuel rod response in natural convection heat decay removal

This paper describes the fuel rod response in a pool type liquid metal fast breeder reactor, in shutdown natural convection heat removal. The fuel rod response is studied resorting to a finite element technique; the transient temperature and thermal stresses profiles are found.For this aim the code FENHT (Finite Element Nuclear Heat Transfer), has been developed: it is based on a one-dimensional three nodal finite element subdivion of the fuel rod and the solution of the pertinent heat transfer equations is performed by the Crank-Nicholson integration method. Although the strongly non linearities, arising from the thermal properties of the system and from the boundary conditions,the computing time is very low and the numerical solution isreached without undesiderable oscillation