Heavy-Water Reactors

Herein reactors are described in their most prominent appHcation, that of electric power. Eive distinctly different reactors, ie, pressurized water reactors, boiling water reactors, heavy water reactors, graphite reactors, and fast breeder reactors, are emphasized. A variety of other appHcations and types of reactors also exist. Whereas space does not permit identification of all of the reactors that have been built over the years, each contributed experience of processes and knowledge about the performance of materials, components, and systems. 

The main technological uses for UO2 are found in the nuclear fuel cycle as the principal component for light and heavy water reactor fuels. Uranium dioxide is also a starting material for the synthesis of UF [10049-14-6] 6 (both critical for the production of pure uranium metal and... 

There are various types of nuclear power reactors, including boiling water reactors (BWR) and pressurized water reactors (PLWR or LWR), which are both light-water reactor (LWR) designs and are cooled and moderated by water. There also are pressurized heavy-water reactor (PHWR or HWR) designs. 

M10. Matzner, B., Experimental performance evaluation of proposed fuel elements for the steam generating heavy water reactor, NOR-1643, Columbia Univ. (1964). 

Heavy water reactors (HWR), 27 582-585 safety features in, 27 583 Heck reaction, ionic liquids in, 26 889-890 Hectoral, 25 793... 

Pressurized filters, 11 324 Pressurized heavy water reactors (PHWRs), 24 758... 

McIntyre, Hugh C., "Natural Uranium Heavy-Water Reactors, Sci. Am. (1975) (4), 17-27. 

Because early Canadian reactors used heavy water, and because it is also fundamentally the most efficient moderator, Canada naturally adopted the heavy water reactor for the development of a nuclear power system. By using heavy water both as moderator and as coolant, and by refuelling with the reactor at power, it was possible to develop the CANDU system to operate efficiently and economically with natural uranium fuel. This in turn resulted in the simplest possible fuel cycle. 

HELP HEU HFO HFR HLW HREE HRL HT HTGR HWR Hydrological evaluation of landfill performance Highly enriched uranium Hydrous ferrous oxide or ferric hydroxide Hot fractured-rock High-level nuclear waste Heavy rare earth elements (Gd-Lu) Hard rock laboratory High temperature High-temperature gas-cooled reactor Heavy water reactor... 

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... 

In order, the following types of nuclearfission reactors are described in this section (1) light water reactors, (a) pressurized water reactors, (b) boiling-water reactors (2) high-temperature gas-cooled reactors (3) heavy water reactors and (4) fast breeder reactors. Military reactors are not described. 

Principal advantages of heavy-water reactors are (l)more efficient absorption of the energy released in the reactor, (2) greater fuel bum-up and, therefore, fuel economy, and (3) refueling can take place while the reactor is in service. 

Fig. 27. Comparison of heavy water reactor (a) with light water...

Light water reactors (LWRs) and heavy water reactors (HWRs) have been successfully used for electric power generation throughout the world with good operating and... 

Pressurized heavy-water reactor (PHWR) % 5 UO2 pellets (natural U) Zircaloy DnO D2O 280- 310 8 11 700 -800 8-10... 

Radioactive waste treatment applications have been reported [3-9] for the laundry wastes from nuclear power plants and mixed laboratory wastes. Another interesting application of reverse osmosis process is in decontamination of boric acid wastes from pressurized heavy water reactors (PHWRs), which allows for the recovery of boric acid, by using the fact that the latter is relatively undissociated and hence wdl pass with water through the membrane while most of the radioactivity is retained [10]. Reverse osmosis was evaluated for treating fuel storage pool water, and for low-level liquid effluents from reprocessing plants. 

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