Computational study into the experimental capabilities of the MTRR SCW reactor

Two stages of the MTRR-SCW reactor operation are planned: a test stage and a research stage. This paper considers the research stage of the MTRR-SCW experimental reactor operation, the purpose of which is to investigate current and advanced light-water reactors. The MTRR-SCW driver-type core provides a fast neutron spectrum with the possibility for the local warmup in ampoule devices and independent loop channels. Irradiation channels will be installed in the core center and periphery, as well as instead of the reactor’s changeable reflector cartridges. The MTRR-SCW irradiation channels and independent loops will provide ample opportunities both for undertaking a research on effects from neutron irradiation of different materials, and for testing a variety of fuel assembly designs and operating conditions (temperature, pressure, neutron spectrum), as well as for investigating transients and emergency processes. The MTRR-SCW channels can be used to irradiate different types of fuel, and structural and absorbing materials with different coolant inlet temperatures (from 250 to 450 °C) and, consequently, its inlet density (from 800 to 100 kg/m 3 respectively), providing different neutron spectrum options for the experimental fuel assembly in a range from thermal to fast spectrum. The MTRR-SCW allows experiments to increase power and simulate emergency processes, including reactivity accidents (RIA). The strong primary and safeguard vessels of the independent loop channels also make it possible to simulate loss-of-pressure emergencies of the LB LOCA and SB LOCA types. The peripheral independent loop channel will allow undertaking experiments for simulation of alternative reactor concepts with reactors with SKD coolant parameters, such as a single-circuit concept with the pseudophase transition in the core (VVER-SKD-1700), and with natural coolant circulation in the core (SKDI). In addition, the peripheral channel allows accelerated irradiation of fuel rods used in current VVER reactors, taking into account the reproduction of the ratio between damaging dose and burnup rates.