The Boiling Water Reactor BWR

Roesmer, J. Minimizing core deposits and radiation flelds by coordinated Li/B chemistry. Proc. 3. BNES Conf. Water Chemistry of Nuclear Reactor Systems, Bournemouth 1983, Vol. 1, pp. 29-36 

Sicherheitstechnische Auslegung von Druckwasserreaktor-Kraftwerken. in Bohn, T. (editor) Handbuchreihe Energie, Band 10, Kemkraftwerke, p. 2—59, Verlag TUV Rheinland, Koln, 1986 

(a) Fuel assemblies for light-water reactors, in Ullmann s Encyclopedia of Industrial Chemistry, Volume A17 Nuclear Technology, p. 732-738 (1991) 

Wunderlich, F., Eberle, R., Gartner, M., Gross, H. Brennstabe von Leichtwasserreaktoren. Auslegung und Betriebsverhalten. KTG-Seminar Band 5, Verlag TUV Rheinland, Koln, 1990 

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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). 

For example, one of the earliest types of nuclear reactors is the boiling water reactor (BWR) in which the reactor core is surrounded by ordinary water. As the reactor operates, the water is heated, begins to boil, and changes to steam. The steam produced is piped out of the reactor vessel and delivered (usually) to a turbine and generator, where electrical power is produced. 

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. 

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. 

Development of the boiling water reactor (BWR) was carried out by the ANL. Following the operation of several experimental reactors in Idaho, the experimental BWR (EBWR) was constructed in Illinois. The EBWR was the first BWR power plant to be built. The plant was initially operated at 5 Megawatts electric (MWe) and 20 Megawatts thermal (MWt). The reactor was operated from 1957 to 1967 at power levels up to 100 MWt. 

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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