COMPUTATIONAL SUBSTANTIATION OF ″МАSTER″ REACTOR SAFETY
Safety of the ″Master″ reactor plant in conditions of blocking flow section of a technological channel in the form of a Field’s tube is considered. The possibility of cooling a separate technological channel in the passive mode, considering heat-conducting zirconium matrix, is evaluated. It is noted that the project of the power unit with the ″Master″ reactor with 30 MW power has all the prerequisites for a successful application. General description of the power unit is presented. The mathematical formulation of the problem is formulated. Temperatures in fuel assembly with averaged properties and zirconium matrix (E-110 alloy) are described by differential equations of thermal conductivity with appropriate initial and boundary conditions. Temperatures in external and internal channels of the Field’s tube are calculated using a lumped parameters model and depend only on time. The mathematical formulation also includes an equation for determination of the flow rate of the coolant in the natural circulation circuit. Temperatures in assembly and zirconium matrix are determined by the tridiagonal matrix algorithm. System of equations for determination of temperatures in channels is solved analytically in a quasi-stationary approximation using the Laplace transformation. The developed mathematical model is implemented in the form of TK computer code. Calculations showed that the fuel temperature remains relatively low, and there is no melting of fuel elements.