Estimate of the reactivity of the VENUS-F subcritical configuration using a Monte Carlo MSM method. (September 2015)

• Record Type: Journal Article
• Authors: Lecouey, J.L.; Marie, N.; Ban, G.; Bianchini, G.; Billebaud, A.; Carta, M.; Chabod, S.; Fabrizio, V.; Kochetkov, A.; Lecolley, F.R.; Lehaut, G.; Mellier, F.; Thyébault, H.E.; Uyttenhove, W.; Van Grieken, C.; Vittiglio, G.
• Is Part Of: Annals of nuclear energy. Volume 83(2015:Sep.)
• Page Start: 65
• Page End: 75
• Publication Date: 2015-09
• Subjects: Reactivity measurement -- Rod drop -- MSM -- ASM -- Subcritical -- ADS; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2015.04.010
• Languages: English
• ISSNs: 0306-4549

Abstract

Highlights: Inverse Point Kinetics can be used for low-statistics rod drop analysis. MSM factors can be calculated with a stochastic neutron transport code. Sensitivity analysis shows that the MSM method is a robust technique. Abstract: The GUINEVERE project was launched in 2006 in order to study the feasibility of transmutation in Accelerator Driven subcritical Systems (ADS). This facility, hosted at the Belgian Nuclear Research Center SCK·CEN, couples the fast subcritical lead reactor VENUS-F with an external neutron source provided by the GENEPI-3C accelerator. In order to test on-line subcriticality monitoring techniques, an independent measurement of the reactivity of VENUS-F was achieved using the Modified Source Multiplication Method (MSM). The unknown reactivity of the subcritical configuration of interest was determined by comparing detector count rates driven by an external neutron source in this configuration with those obtained in a slightly subcritical configuration whose reactivity was determined by rod drop experiments. To account for spatial effects, MSM correction factors were calculated for all the detectors using the Monte Carlo neutron transport code MCNP. The corrected reactivity values of all the detectors were found to be consistent. This led to a final estimate of −5.28 ± 0.13 $ for the reactivity of VENUS-F. The MSM factors calculated with MCNP were found to be insensitive to the assumptions made for modeling the reactor and the detectors. Thus the MSM method appears to be a robust technique for measuring large subcriticality values with good accuracy.