TY - JOUR

T1 - Monte Carlo calculation of the effective neutron generation time

AU - Verboomen, Bernard

AU - Haeck, Wim

AU - Baeten, Peter

A2 - Malambu Mbala, Edouard

A2 - Aoust, Thierry

N1 - Score = 10

PY - 2006/7

Y1 - 2006/7

N2 - The Monte Carlo calculation of the effective (i.e. adjoint weighted) neutron generation time Λeff, especially for continuous energy simulations, is not straightforward nor standard in Monte Carlo codes. The use of the non-adjoint weighted neutron generation time Λ (standard in most Monte Carlo codes) as an approximation of the effective one can lead to a serious bias. We show here that the difference between Λeff and Λ can be more than 200% for a thermal fission system (VENUS reactor, SCK-CEN, Belgium) and more than 600% for a fast fission system (MASURCA reactor, Cadarache, France). For this, we have implemented, for the first time, in the Monte
Carlo code MCNP(X), an asymptotically exact method for the calculation of Λeff. Our method was benchmarked against measurements in MASURCA: the difference between calculated and experimental values is less than 10%.

AB - The Monte Carlo calculation of the effective (i.e. adjoint weighted) neutron generation time Λeff, especially for continuous energy simulations, is not straightforward nor standard in Monte Carlo codes. The use of the non-adjoint weighted neutron generation time Λ (standard in most Monte Carlo codes) as an approximation of the effective one can lead to a serious bias. We show here that the difference between Λeff and Λ can be more than 200% for a thermal fission system (VENUS reactor, SCK-CEN, Belgium) and more than 600% for a fast fission system (MASURCA reactor, Cadarache, France). For this, we have implemented, for the first time, in the Monte
Carlo code MCNP(X), an asymptotically exact method for the calculation of Λeff. Our method was benchmarked against measurements in MASURCA: the difference between calculated and experimental values is less than 10%.

KW - effective neutron generation time

KW - Monte Carlo

KW - reactor kinetics

KW - first-order perturbation

KW - adjoint flux

UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_32358

UR - http://knowledgecentre.sckcen.be/so2/bibref/3615

U2 - 10.1016/j.anucene.2006.05.001

DO - 10.1016/j.anucene.2006.05.001

M3 - Article

SN - 0306-4549

VL - 33

SP - 911

EP - 916

JO - Annals of nuclear energy

JF - Annals of nuclear energy

IS - 10

ER -