The Lead-Based VENUS-F Facility: Status of the FREYA Project

The GUINEVERE project in the 6th European Framework Program (FP6) [1] aimed to check the methods for sub-criticality monitoring. To execute the project, the water-moderated thermal VENUS facility was modified into the lead fast VENUS-F facility in the period 2007-2010. To prove the reliability of the reactivity monitoring methods, first of all a critical reference configuration was assembled and characterized by measurements of criticality, power distribution, and spectral indexes. These experiments were communicated for benchmarking at ISRD-14 [2]. The Monte Carlo MCNP 5-1.60 code with the JEFF 3.1.2 data library is used to perform simulations of the VENUS-F core, in particular to obtain Calculated-to-Experimental ratios (C/E) for fission rates and spectral indices. A sensitivity study is performed focusing on the impact of global and local parameters on C/E. In most cases C/E is close to unity within the uncertainties. Only a few exceptions were found, e. g. for the F28/F25 spectral index [3]. In order to investigate the discrepancies, a new measurement campaign with the same critical configuration was included in the currently ongoing FREYA project in FP7 [4]. The facility status, experimental plans, and the sensitivity study are presented in this paper.