To the comparison of coolants for nuclear power plants with fast gas-cooled reactors

The effectiveness and commercial efficiency of various gas cooling schemes for fast neutron reactors using helium or carbonic acid as coolants are considered. Taking the velocity of helium to be 125 m.p.s., that of carbonic acid 40 m.p.s. and the maximum heat flow to be 2.36 x 106 wt/m2, the temperarute of the coolants at the reactor output, the thermal and electrical power of the atomic station, the specific fuel charge and other variables have been calculated for both coolants to be used in single- or double-circuit schemes. The coolant temperature at the reactor output is taken as being 500 to 700 K, the maximum temperature of the fuel-element jackets being 1000 to 1200 K. Capital costs have been considered for the alternative heat schemes discussed. It has been revealed that to increase the temperature of the gas at the reactor input above 500 K is disadvantageous, for it leads to an increase in the capital investment and worsens the operating conditions of the reactor vessel. Considering the specific capital costs, it is more advisable to use helium rather than carbonic acid, for cooling fast neutron reactors with stainless steel vessels. Under these conditions the best of all possible alternative uses of the reactor heat removed is the double-circuit scheme 'helium-steam'