TY - JOUR
T1 - Monte Carlo uncertainty quantification of the effective delayed neutron fraction
AU - Iwamoto, Hiroki
AU - Stankovskiy, Alexey
AU - Fiorito, Luca
AU - Van den Eynde, Gert
N1 - Score=10
PY - 2018/4/4
Y1 - 2018/4/4
N2 - The applicability of Monte Carlo techniques, namely the Monte Carlo sensitivity method and the random-sampling method, for uncertainty quantification of the effective delayed neutron fraction βeff is investigated using the continuous-energy Monte Carlo transport code, MCNP, from the perspective of statistical convergence issues. This study focuses on the nuclear data as one of the major sources of βeff uncertainty. For validation of the calculated βeff, a critical configuration of the VENUS-F zero-power reactor was used. It is demonstrated that Chiba’s modified k-ratio method is superior to Bretscher’s prompt k-ratio method in terms of reducing the statistical uncertainty in calculating not only βeff but also its sensitivities and the uncertainty due to nuclear data. From this result and a comparison of uncertainties obtained by the Monte Carlo sensitivity method and the random-sampling method, it is shown that the Monte Carlo sensitivity method using Chiba’s modified k-ratio method is the most practical for uncertainty quantification of βeff. Finally, total βeff uncertainty due to nuclear data for the VENUS-F critical configuration is determined to be approximately 2.7% with JENDL-4.0u, which is dominated by the delayed neutron yield of U-235.
AB - The applicability of Monte Carlo techniques, namely the Monte Carlo sensitivity method and the random-sampling method, for uncertainty quantification of the effective delayed neutron fraction βeff is investigated using the continuous-energy Monte Carlo transport code, MCNP, from the perspective of statistical convergence issues. This study focuses on the nuclear data as one of the major sources of βeff uncertainty. For validation of the calculated βeff, a critical configuration of the VENUS-F zero-power reactor was used. It is demonstrated that Chiba’s modified k-ratio method is superior to Bretscher’s prompt k-ratio method in terms of reducing the statistical uncertainty in calculating not only βeff but also its sensitivities and the uncertainty due to nuclear data. From this result and a comparison of uncertainties obtained by the Monte Carlo sensitivity method and the random-sampling method, it is shown that the Monte Carlo sensitivity method using Chiba’s modified k-ratio method is the most practical for uncertainty quantification of βeff. Finally, total βeff uncertainty due to nuclear data for the VENUS-F critical configuration is determined to be approximately 2.7% with JENDL-4.0u, which is dominated by the delayed neutron yield of U-235.
KW - Effective delayed neutron fraction
KW - uncertainty quantification
KW - sensitivity
KW - bretscher's prompt k-ratio method
KW - Chiba's modified k-ratio method
KW - random-sampling method
KW - MCNP
KW - VENUS-F
UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/28873098
U2 - 10.1080/00223131.2017.1416691
DO - 10.1080/00223131.2017.1416691
M3 - Article
VL - 55
SP - 539
EP - 547
JO - Journal of Nuclear Science and Technology
JF - Journal of Nuclear Science and Technology
SN - 1881-1248
IS - 5
ER -