Flow-Induced Accident and Transient Analyses of a Direct-Cycle, Light-Water-Cooled, Fast Breeder Reactor Operating at Supercritical Pressure
This paper deals with the safety design of a light-water-cooled fast breeder reactor operating at supercritical pressure (SCFBR) which has the advantages of high thermal efficiency and simple reactor system. A new computer code was developed and five important flow-induced events were analyzed for the 1, 245MWe SCFBR with two coolant loops.<BR>A core flow rate must be maintained for the safety of once-through type plant. Thus this reactor has two high-pressure auxiliary feedwater, four low pressure coolant injection and automatic depressurization systems.They are activated by the emergency signals of the decrease in coolant flow rate. The feedwater pumps should have fly-wheels for prolonging the coast-down time.<BR>It has been found that the peak cladding surface temperature of fuel rods does not exceed the allowable temperature under the accidents of the total loss of feedwater flow and feedwater pump shaft seizure. The minimum deterioration heat flux ratio satisfies the criterion under the transients of the loss of feedwater heating, inadvertent start of the auxiliary feedwater pump and partial loss of feedwater flow. The loss of feedwater heating causes a flow-induced transient in this reactor, because the flow rate in the downstream decreases with a decrease in coolant temperature.
- Journal of nuclear science and technology
Journal of nuclear science and technology 33(4), p.307-315, 1996-04-25
Atomic Energy Society of Japan