Reactivity Coefficients in BN-600 Core with Minor Actinides
Résumé
In 1999, the IAEA has initiated a Coordinated Research Project on ‘‘Updated Codes and Methods to
Reduce the Calculational Uncertainties of the LMFR Reactivity Effects.’’ Three benchmark models
representing different modifications of the BN-600 fast reactor have been sequentially established and
analyzed, including a hybrid core with highly enriched uranium oxide and MOX fuel, a full MOX core
with weapons-grade plutonium, and a MOX core with plutonium and minor actinides coming from spent
nuclear fuel. The paper describes studies for the latter MOX core model. The benchmark results include
core criticality at the beginning and end of the equilibrium fuel cycle, kinetics parameters, spatial
distributions of power, and reactivity coefficients obtained by employing different computation tools
and nuclear data. Sensitivity studies were performed to better understand in particular the influence of
variations in different nuclear data libraries on the computed results. Transient simulations were done to
investigate the consequences of employing a few different sets of power and reactivity coefficient
distributions on the system behavior. The obtained results are analyzed in the paper.