Development of a continuous energy version of the Monte Carlo code KENO V.a

KENO V.a is a multigroup Monte Carlo code which solves the Boltzmann Transport Equation and is used extensively in the Nuclear Criticality Safety community to calculate the effective multiplication factor (k_eff) of systems containing fissile material. Due to the smaller amount of disk storage and cpu time required in calculations, multigroup approaches have been preferred over continuous energy (point) approaches in the past for solving transport problems. With the advent of high performance computers, storage and cpu limitations are less restrictive, thereby making continuous energy methods viable for transport calculations. Moreover, continuous energy methods avoid many of the assumptions and approximations inherent in multigroup methods. Since a continuous energy version of KENO V.a does not exist, the objective of the work is to develop a new version of KENO V.a which utilizes continuous energy cross sections. Currently, a point cross section library which is based on a raw continuous energy cross section library such as ENDF/B-V is not available for implementation in KENO V.a; however, point cross section libraries are available for MCNP, another widely used Monte Carlo transport code. Since MCNP cross sections are based on ENDF data and are readily available, a new version of KENO V.a named PKENO V.a has been developed which performs the random walk using MCNP cross sections. In order to utilize point cross sections, extensive modifications have been made to ΚΕΝΟ V.a. In order to test the new code, PKENO V.a was benchmarked against the multigroup version of KENO V.a, MCNP and experiment using fifty test problems. The calculated results obtained with PKENO are in agreement (i.e., within ± 2ó) with both MCNP, KENO V.a and experiment. As a result, PKENO can be used to perform Nuclear Criticality Safety Evaluations.