TY - GEN
T1 - A Monte Carlo normalized diffusion method for criticality analysis of spent fuel storage lattices
AU - Ilas, Germina
AU - Rahnema, Farzad
N1 - Publisher Copyright:
© PHYSOR 2002.All right reserved.
PY - 2002
Y1 - 2002
N2 - A coupled Monte Carlo-diffusion theory model for the criticality analysis of spent fuel lattice configurations was previously presented by Rahnema et al. [1]. The model is based on two-group nodal diffusion in the context of the generalized equivalence theory (GET) [2]. The nodal parameters are determined from continuous energy Monte Carlo computations. The node-averaged diffusion coefficient is estimated by using an iterative technique. In the present paper, a new method, based on a genetic algorithm, is proposed for calculating the node-averaged diffusion coefficient to be used in the nodal diffusion model. The unknown diffusion coefficients in each group and region of the lattice cell are to be estimated such that the multiplication constant of the fine-mesh diffusion calculation at the lattice cell level matches the result obtained from the Monte Carlo simulation of that cell. Two approaches are considered for modeling the spent fuel assembly when generating the nodal parameters: one in which the assembly is homogenized, and one in which the geometry of the assembly is modeled in full detail. The method is tested on a 2-D benchmark configuration typical of a spent fuel storage rack at Savannah River Site [3]. The accuracy of the nodal model is shown to be close to that of the continuous-energy Monte Carlo technique.
AB - A coupled Monte Carlo-diffusion theory model for the criticality analysis of spent fuel lattice configurations was previously presented by Rahnema et al. [1]. The model is based on two-group nodal diffusion in the context of the generalized equivalence theory (GET) [2]. The nodal parameters are determined from continuous energy Monte Carlo computations. The node-averaged diffusion coefficient is estimated by using an iterative technique. In the present paper, a new method, based on a genetic algorithm, is proposed for calculating the node-averaged diffusion coefficient to be used in the nodal diffusion model. The unknown diffusion coefficients in each group and region of the lattice cell are to be estimated such that the multiplication constant of the fine-mesh diffusion calculation at the lattice cell level matches the result obtained from the Monte Carlo simulation of that cell. Two approaches are considered for modeling the spent fuel assembly when generating the nodal parameters: one in which the assembly is homogenized, and one in which the geometry of the assembly is modeled in full detail. The method is tested on a 2-D benchmark configuration typical of a spent fuel storage rack at Savannah River Site [3]. The accuracy of the nodal model is shown to be close to that of the continuous-energy Monte Carlo technique.
UR - http://www.scopus.com/inward/record.url?scp=85104089772&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85104089772
T3 - Proceedings of the PHYSOR 2002 - International Conference on the New Frontiers of Nuclear Technology : Reactor Physics, Safety and High-Performance Computing - The ANS 2002 RPD Topical Meeting
BT - Proceedings of the PHYSOR 2002 - International Conference on the New Frontiers of Nuclear Technology
PB - American Nuclear Society
T2 - 2002 International Conference on the New Frontiers of Nuclear Technology : Reactor Physics, Safety and High-Performance Computing, PHYSOR 2002
Y2 - 7 October 2002 through 10 October 2002
ER -
