Fabrication processes and testing of the moderator for irradiating devices of BN reactors. Testing of the moderator

Abstract

Abstract The work presents the results of studies of zirconium hydride used as the moderator for irradiating devices in fast reactors. Zirconium hydride fabrication process using methods of direct saturation of the source material and powder preparation and compacting has been optimized. Hydrostatic method was used to measure density of the samples: for the samples produced by direct saturation density varies within 5.61 to 5.65 g/cm3, for compacted zirconium hydride - 5.45 to 5.55 g/cm3. Tests to evaluate hydrogen release from zirconium hydride have been conducted. It has been shown that dehydration onset temperature is (420 – 450) °C (powder compaction method) and (500 – 550) °C (direct saturation method). It has been noted that in 20 minutes of the sample heating from 500 to 900 °C, the mass fraction of the hydrogen released is 0.6 %. The results acquired confirm the data on diminished thermal stability of zirconium hydride produced by the powder method in gaseous media.