Reactivity monitoring of the accelerator driven VENUS-F subcritical reactor with the “current-to-flux” method

N. Marie (1) , J.L. Lecouey (1) , G. Lehaut (1) , T. Chevret (1) , A. Billebaud (2) , S. Chabod (2) , X. Doligez (3) , A. Kochetkov , A. Krása , F.R. Lecolley (1) , F. Mellier (4) , W. Uyttenhove , G. Vittiglio , J. Wagemans

1 LPCC - Laboratoire de physique corpusculaire de Caen
2 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
3 IPNO - Institut de Physique Nucléaire d'Orsay
4 CEA Cadarache

In this article, we evaluate the quality and robustness of a method envisaged for the on-line monitoring of the subcriticality of an ADS, called the ‘‘current-to flux” (CTF) method. For this evaluation, we performed a dedicated experiment at the GUINEVERE facility. It is hosted at the SCK-CEN and consists of the subcritical VENUS-F reactor coupled to a continuous external neutron source provided by the GENEPI-3C accelerator. During this experiment, the reactor control rods were moved in various patterns, and the subsequent dynamical evolutions of the reactor reactivity were monitored using nine fission chambers (FCs). The space-energy effects that bias the reactivity values are corrected using a procedure based on simulations computed with the Monte Carlo neutron transport code MCNP. We investigate the precision of this correction procedure by comparison with a reactivity value extracted with the beam interruption technique and we demonstrate its insensitivity to the simplifications made on the VENUS-F reactor modeling and to a simulation key parameter such as the boron carbide density filling the control rods.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

N. Marie, J.L. Lecouey, G. Lehaut, T. Chevret, A. Billebaud, et al.. Reactivity monitoring of the accelerator driven VENUS-F subcritical reactor with the “current-to-flux” method. Annals of Nuclear Energy, 2019, 128, pp.12-23. ⟨10.1016/j.anucene.2018.12.033⟩. ⟨hal-01975522⟩