Pressure boiling light water coolant

Pressure Tube Boiling Light Water Coolant, HWM Reactors... 

About 13% of the light water which is circulated over the fuel elements in the most highly rated boiling channel is converted into steam to give a turbine a stop valve pressure of 900 psig. The heavy water moderator has its own cooling and purification circuit and the light water coolant has circuits for water treatment and the detection of fuel element can failure. 

The reactor core was housed in a large vessel or tank called a calandria, which contained the heavy water moderator. The pressure tubes containing the fuel elements passed vertically through this tank. The heavy water in the calandria was not pressurised and formed a separate circuit from that of the main coolant in the pressure mbes, which was light water. The light water coolant was pumped up through the pressure tubes past the fuel elements in the tubes. The water then boiled in the core, and the steam produced was separated from the recirculating water in an external... 

All over the world, 432 nuclear power reactors are under operation and more than 36 GW of electricity could be produced as of December 31, 2001. There are several types of reactors such as boiling water reactor (BWR), pressurized water reactor (PWR), Canada deuterium uranium (CANDU), and others. In these reactors, light water is normally used not only as a coolant, but also as a moderator. On the contrary, in CANDU reactors, heavy water is taken. It is widely known that the quality control of coolant water, the so-called water chemistry, is inevitably important for keeping the integrity of the plant. 

The basic design of most nuclear reactors is similar, but several types of reactors are used throughout the world. In the United States most reactors use plain water as the coolant. Reactors using ordinary water are called light water reactors. Light water reactors can be pressurized to approximately 150 atmospheres to keep the primary coolant in the liquid phase at temperatures of approximately 300°C. The heat from the pressurized water is used to heat secondary water to generate steam. In a boiling water reactor, water in the core is allowed to boil. The steam produced powers the turbines directly. Heavy water reactors use water in... 

This section provides a comparison of power reactors built in the UK with the Soviet RBMK. But it is worth recollecting that, elsewhere in the world, other types of power reactors are in use. The most widely built reactor is the Pressurised Water Reactor (PWR) but the second is the Boiling Water Reactor (BWR), a light water reactor in which, like the RBMK, steam is generated in the core and passed to the turbines in a direct cycle. Light (i.e. ordinary) water is used as coolant and moderator. The Canadian industry has developed the CANDU series of reactors, with limited export to India, etc., which have many pressure tubes to retain the coolant, as in the British SCHWR and Soviet RBMK, but are heavy-water-cooled and moderated. 

Heat extraction Light water (ordinary water, H2O) at pressure is heated by passing over the fuel in the pressure tubes and allowed to boil the steam from the boiling coolant drives a turbine coupled to an electric generator. 

In the light-water reactor, ordinary water acts as both a moderator and a coolant. Figure 21.19 shows a pressurized-water design of this type of reactor. Water in the reactor is maintained at abont 350°C under high pressnre (150 atm) so it does not boil. The hot water is circnlated to a heat exchanger, where the heat is nsed to produce steam to run a turbine and generate electricity. 

The two light water reactors (LWRs) are the pressurized water reactor (PWR) and the boiling water reactor (BWR). The systems are similar in that both employ light water as both moderator and coolant, which necessitates the use of fuel enriched to about 2.0 %-2.5 % due to the appreciable neutron absorption of the water in the core. They are also alike in that in both cases the core is enclosed within a single large steel pressure vessel (see Fig. 7,1). The distinction between the two designs is also illustrated in the figure. In the... 

Nuclear reactor types can be classified by power output and by the peak temperatures of their coolants (Fig. XXVI-4). Light water reactors (LWRs), such as the General Electric Economic Simplified Boiling Water Reactor (ESBWR), are low temperature, high pressure reactors. 

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