The Pressurized Water Reactor PWR

In most of the nuclear power plants in operation today, the heat generating unit is a pressurized water reactor 246 plants totalling about 227 GW electrical power were in operation by the end of 1994, a further 39 plants with about 39 GWe were 

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A variety of nuclear reactor designs is possible using different combinations of components and process features for different purposes (see Nuclear REACTORS, reactor types). Two versions of the lightwater reactors were favored the pressurized water reactor (PWR) and the boiling water reactor (BWR). Each requites enrichment of uranium in U. To assure safety, careful control of coolant conditions is requited (see Nuclearreactors, water CHEMISTRY OF LIGHTWATER REACTORS NuCLEAR REACTORS, SAFETY IN NUCLEAR FACILITIES). 

Pressurized vs. boiling LWRs The pressurized water reactor (PWR) transfers its energy from the fuel to an intermediate heat exchanger to generate the steam that... 

Another type of reactor is the pressurized water reactor (PWR). In a PWR, coolant water surrounding the reactor core is kept under high pressure, preventing it from boiling. This water is piped out of the reactor vessel into a second building where it is used to heat a secondary set of pipes also containing ordinary water. The water in the secondary system is allowed to boil, and the steam formed is then transferred to a turbine and generator, as in the BWR. 

The Pressurized Water Reactor (PWR) reload core optimization problem, though easily stated, is far from easily solved. The designer s task is to identify the arrangement of fresh and partially burnt fuel (fissile material) and burnable poisons (BPs) (control material) within the core which optimizes the performance of the reactor over that operating cycle (until it again requires refueling), while ensuring that various operational (safety) constraints are always satisfied. 

We illustrate the general principles of thermal reactors by a short description of the two most inqx)itant power reactor types the pressurized water reactor (PWR) and the boiling water reactor (BWR). They are further discussed in Chapter 20. 

Two types of light water reactors, namely, the boiling water reactor (BWR) and the pressurized water reactor (PWR) are in use in the United States of America. The fuel for these reactors consists of long bundles of 2-4 wt% of enriched uranium dioxide fuel pellets stacked in zirconium-alloy cladding tubes. 

The purpose of this chapter is to provide a general insight into the manufacture of fuels used in nuclear reactors. The primary focus will be on uranium dioxide (UO2) fuels for light water reactors (LWRs), including both the pressurized water reactor (PWR) and the boiling water reactor (BWR). Many of the details relating to the fuel for these reactors are also presented in Sections 1.2 and 1.3 of this handbook. Some of the information from those chapters will be repeated for clarity. 

The LWR is further classified into the pressurized water reactor (PWR) which operates at about 150 atm and 318°C with a thermal efficiency of about 34%. The other type of reactor is the boiling water reactor (BWR) which operates at 70 atm pressure and 278°C with a thermal efficiency of 33%. These reactors require fuel with enriched to about 3% to have a sufficient neutron flux for the chain reaction. The fuel, as UO2, is in the form of pellets enclosed in a zirconium alloy, Zircaloy-2. 

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... 

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