Activities on Experimental Substantiation of SFR Safety in Accidents with Sodium Boiling

The information about experimental researches of emergency processes accompanied by sodium coolant boiling in the core of a sodium-cooled fast reactor (SFR) which are scheduled to be carried out in the SSC RF-IPPE, is presented in the paper. The description of an upgraded experimental facility AR-1 where tests with modeling of sodium boiling will be carried out is given, and its basic characteristics are presented. The purposes of experimental investigations aimed at acquisition of the experimental data necessary for verification of the computational codes developed for the analysis of severe beyond design basis accidents similar to the ULOF accident are reported, and basic modes that are planned to be studied at the AR-1 are also described: a) a flow mode of two-phase sodium coolant within a sodium plenum located over the SFR core that makes an appreciable influence on dynamics of the ULOF accident, b) modes of sodium boiling within fuel pin bundle under conditions of both forced and natural coolant circulation, c) sodium boiling modes occurring due to events caused by fuel subassembly cross-section blockage, d) modes of sodium boiling in parallel channels under natural primary sodium coolant circulation conditions. (author)