Yalina-Booster Assembly: from HEU to LEU

The YALINA facility is a unique facility which was designed as a zero power model of real ADS (Accelerator Driven System). It is intended to study ADS neutronics and kinetics of the subcritical reactors driven by external neutron sources. Accelerator-driven systems may play an important role in future nuclear fuel cycles to reduce the long-term radiotoxicity and volume of spent nuclear fuel. Successful operation of this facility is a scientific contribution from the Republic of Belarus, as well as the international community. The experimental data are used to benchmark and validate methods and computer codes for designing and licensing ADS. In this paper the investigation of spatial kinetics of the sub-critical systems with external neutron sources, validation of the experimental techniques for sub-criticality monitoring and estimation of probability of minor actinides and fission products transmutation is made for different configurations of Yalina-Booster during conversion from HEU to LEU: - 1^st configuration – with HEU fuel in the fast zone (metallic uranium of 90% enrichment by ²³⁵U and UO₂ of 36% enrichment by ²³⁵U) and uranium dioxide of 10% enrichment by ²³⁵U in thermal zone; - 2^nd one – with 36% UO₂ in fast zone and 10% in thermal zone; - 3^rd one – with 21% UO₂ in fast zone and 10% in thermal zone; - 4^th one – with 21% UO₂ in fast zone and 10% in thermal zone, differing from the 3^rd configuration by rounded shape of fast zone and annular shape of the absorber zone with permanent number of the absorbing rods. (author)