Method of bringing nuclear power plant to fractional electric load conditions

The invention provides a method of bringing a nuclear power plant to fractional electric load conditions, the plant comprising at least one high temperature nuclear reactor and at least one low temperature breeder reactor, whereby a reduction in the amount of heat being transferred from the nuclear reactors to the turbine working substance will bring about an increase in the terminal capacity of the breeding reactor rather than a decrease, which, in turn, will result in a higher rate of breeding new fuel