Abstract: The invention relates to a control system for controlling an average temperature of a coolant at a reactor core outlet. The control system method detects an average temperature of the coolant at the reactor core outlet, compares the actual average temperature of the coolant at the reactor core outlet with a reference temperature thereby to generate an error signal, and adjusts the actual average temperature of the coolant at the reactor core outlet in response to the error signal. The invention extends to a cascade controller for a nuclear reactor, and to a nuclear power plant.

Abstract: The invention relates to a method of controlling an average temperature of a coolant at a reactor core outlet. The method includes the steps of detecting an actual average temperature of the coolant at the reactor core outlet, comparing the actual average temperature of the coolant at the reactor core outlet with a reference temperature thereby to generate an error signal, and adjusting the actual average temperature of the coolant at the reactor core outlet in response to the error signal. The invention extends to a nuclear reactor outlet temperature control system 10, to a cascade controller for a nuclear reactor, and to a nuclear power plant.

Abstract: A nuclear power plant which includes a closed loop power generation circuit making use of helium as the working fluid. The plant further includes a helium inventory control system which includes a plurality of helium storage tanks whereby helium can be fed into or removed from the power generation circuit. Each helium storage tank is provided with a heat sink so that the tank has a relatively high thermal inertia which in turn restricts the temperature variation within the storage tank as a result of the introduction of helium into and/or the withdrawal of helium from the storage tank. This permits the optimization of the design of the storage tanks.

Abstract: A method of regulating the power generated in a nuclear power plant which includes the step of regulating the flow of helium through the reactor. To this end, the power plant includes a closed loop power generation circuit having at least one compressor and a recirculation circuit whereby helium can be recirculated around the compressor. By regulating the flow of helium around the recirculation circuit using suitable valves the flow of helium through the reactor and hence the power generated can be regulated. The plant includes a helium inventory control system whereby the inventory of helium in the power generation circuit can be varied thereby varying the power generated in the circuit.