An evaluation of design pressure for the F.B.T.R. secondary sodium heat transfer system and its components in case of a leak in steam generator

Present paper aims at analysing the thermo-hydraulic phenomenon of sodium-water or sodium-steam reaction, and consequent build up of pressures in sodium at various points of the secondary heat transfer system of F.B.T.R. This is necessary to check the design of various equipments in the system for these worst conditions. Thermo-hydraulic equations describing pressure, temperature and adiabatic growth rate of hydrogen bubble (formed as result of sodium-water reaction) are solved simultaneously with equations governing the leak rate of steam or water. A Runga Kutta method of fifth order has been used. Subsequent to a leak in super heater portion, leak rate of steam is found by ''Fano-flow'' analysis of steam flowing in the ruptured tube. On the other hand leak rate of water, in case of rupture in evaporator portion, is analysed by an inertia controlled model. Pressure/flow transients, in the rest of heat transfer loop and its components, are evaluated by the simultaneous solution of quasi-hyperbolic partial differential equations of momentum and continuity balance. Solution is effected by the method of characteristics. A computer program in FORTRAN-IV is operational for handling the above problem. (auth.)