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.