Results of Verification and Validation of the Oxid Module of the Euclid/V2 Integral Code in Part of Physicochemical Models of Processes in a Lead Coolant

Models of physicochemical processes in a lead coolant, which can be used as part of the CFD code to justify the coolant technology, and as part of an integral code to describe the state of the reactor plant at the time of the start of the simulated dynamic regime are presented. The described models are integrated into the OXID module of the EUCLID/V2 integral code developed at the Institute for Problems of Safe Development of Nuclear Power Engineering, Russian Academy of Sciences. The OXID module makes it possible to calculate, on the basis of a two-layer model, the growth of an oxide film in a lead coolant on the surface of a metal that is in contact with liquid lead, the crystallization of dissolved oxides on the channel walls, the formation of lead oxide particles (nucleation) in a coolant flow, the coagulation of solid oxide particles in a lead coolant, the deposition of oxide particles on the channel walls, the crystallization of dissolved oxides on particles and dissolution of oxide particles in the lead coolant, and the transfer of formed impurities in the coolant. A system of relationships and equations is given that allows modeling of these processes as part of a software module. By integrating this module into the EUCLID/V2 code, it is possible to carry out connected calculations of physical and chemical processes in a lead coolant, which are typical for various operating conditions of a BREST-OD-300 reactor plant. To demonstrate the performance of the implemented models, the results of verification based on analytical tests and validation based on experimental data on the growth of an oxide film on the surface of stainless steel at different concentrations of oxygen in lead, obtained at the AO SRC RF-IPPE on the CM-2 circulation stand, are presented. The validation made it possible to estimate the errors in the calculation of individual parameters important for safety.