Ritm facility for testing fuel elements in variable power regimes in the SM-2 reactor

This paper addresses the problems originating with a change of the requirements for the operating conditions of nuclear power stations with water-cooled-water-moderated reactors (VVER) in the power generation system. In order to solve the problem of assuring that the necessary durability of the fuel elements in conditions of repeated changes of the power level at a rate of 1-6% per minute are maintained, the study of the temperature conditions and mechanism of gas release from the fuel is undertaken to create reliable methods of forecasting these characteristics in the state operating conditions. The RITM facility was developed, with a gas system for regulating the power of the fuel elements. The defining criterion for choosing a system with He-3 was the relative simplicity of controlling the thermal-neutron flux density in the cells of the irradiation facility by a change of pressure of the absorbing gas. The system is described in detail here.