Effect of inserted fluoride salts on criticality in the LR-0 reactor

The criticality measurements are the crucial point in design verification of all reactor concepts. The research on fluoride salts used in nuclear reactor technology has been carried out in Řež since 2002 and in the year 2006 also reactor experiments were performed. Due to the lack in the fluoride salt reactor experimental data, series of critical experiments (EROS) were performed on the LR-0 reactor during the SPHINX project. The work was focused on determination of reactivity worth and on evaluation of the calculation to experiment agreement of various nuclear data libraries in case of integral critical experiments in various core configurations. The core consisted of driver zone and different insertions with fluoride salts or graphite and their combinations. These materials were selected as they are perspective in MSR and FHR projects; discrepancies between experiment and calculations were discovered, which may be caused by nuclear data used for fluoride salts.