Abstract
The steam generator tube rupture (SGTR) accident greatly threatens the safe operation of lead-cooled fast reactor. The pressure wave propagation, the water/vapor-lead interaction and core cavitation effect constitute the most hazardous effects of the SGTR accident. In this paper, the multiphase flow model, the shock wave propagation model and the equation of state for lead, water and vapor are established to study the pressure changes at the initial stage of the SGTR accident. To verify the correctness of the pressure wave models, the transient responses experiment of pressurized water at various temperatures to decompression are simulated by fluent software. Based on the SGTR accident of medium-power modular lead-cooled fast reactor (M2LFR-1000) taking a straight tube heat exchanger design, the pressure changes of the lead and water are analyzed. It is found that the tube bundles greatly inhibit the propagation of pressure waves. Within 0.1ms after the rupture accident, the water pressure near the break continued to decrease, and the lead pressure increased sharply in a short time and then decreased. After 0.3ms, the pressures of lead and water reach stability. These studies provide the initial conditions and reference for the structural response of SGTR accident.
