Principle of NPP Operation
A nuclear reactor is a facility intended for organizing and maintenance a controlled nuclear chain reaction of some heavy nuclears fission in the result of which nuclear energy is released, and further transformed into heat energy subsequently using by external electrical consumer.
Principle NPP double-loop circuit
1 – reactor;
2 – steam generator;
3, 6 – high and low presure parts of turbine;
4 – separator;
5 – steam superheater;
7 – generating uni;
8 – condenser;
9 – condenser pump;
10 – circulating pump;
11 – low pressure regenerating system;
12 – deaerator;
13 – feeding pump;
14 – high pressure regenerating system;
15 – main circulating pump (MCP);
In the nuclear reactor intranuclear energy is transformed into heat energy which is transmitted with coolant through pipelines of the Primary Coolant Circuit to a steam generator and there from the heating area the heat is transmitted to an actuating medium. The cooled coolant by means of the main circulating pump (MCP) is transmitted to the reactor again and the circuit is locked. As the actuating medium they use ordinary water which is generated into steam. The steam through the pipelines of the working circuit is directed to a turbine generator where sequentially heat energy is transformed into mechanical energy, and the mechanical energy is transformed into electric energy.
Waste steam is condensed in condenser and pumped by pumps through the low pressure regenerative system. Further, by means of feed pumps the water after coming through the high pressure regenerative system is coming again into a steam generator.
This is the principle circuit in so called two-circuit NPP which are most common currently. Depending on a nuclear reactor type there are single-circuit, two-circuit, and three-circuit nuclear power units.