Fast Reactor

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fast reactor

[¦fast rē′ak·tər]
A nuclear reactor in which most of the fissions are produced by fast neutrons, with little or no moderator to slow down the neutrons.

Fast Reactor


(also fast-breeder reactor), a nuclear reactor in which a chain fission reaction of nuclear fuel is effected by fast neutrons. High-energy neutrons produce a relatively high yield of fission neutrons. The absorption of some fast neutrons by nonfissionable isotopes followed by their conversion into fissionable isotopes (for example, 238U into 239Pu) results in the production of nuclear fuel (the formation of secondary fuel). (The conversion ratio may attain 1.6:1.) A breeding blanket surrounds the core in the reactor tank (see Figure 1). In a fast power reactor, the coolant (mainly liquid sodium) is heated in these blankets and emits heat to the working steam-water medium in the heat exchangers. If a sodium coolant is used, the reactor and steam-generating circuits are separated by an intermediate (also sodium) circuit in order to prevent radioactive sodium from entering the turbine circuit. Other means of heat removal can be used.

Figure 1. Cross section of the vessel of a fast reactor in the nuclear electric power plant in the city of Shevchenko

The breeding of nuclear fuel in a fast reactor makes it possible in principle to utilize all the existing uranium resources, including 238U, substantial quantities of which remain unused in reactors operating on thermal neutrons. A series of experimental fast reactors has been built in the USSR, and an electric power plant based on a fast reactor has been built in the city of Shevchenko (Kazakh SSR).


References in periodicals archive ?
The same year the original fast reactor was closed and in 1994 the prototype fast reactor shut, leaving Dounreay carrying out only decommissioning
Because it will lose its facility for burning the experimental fuel when it shuts down the Integral Fast Reactor work, DOE now plans to fly fuel rods to Russia for testing in one of that nation's plutonium-burning reactors.
Another feature is that the burn rate in the fast reactor consumes less than one percent of the uranium it is fed.
Improving fuel cycle design and safety characteristics of a gas cooled fast reactor.
For the ARR, MHI is proposing a loop-type fast reactor concept that uses liquid-metal sodium for the reactor coolant.
In their interim report, submitted to the Atomic Energy Commission, the Ministry of Economy, Trade and Industry, the Ministry of Education, Culture, Sports, Science and Technology and other bodies said a new fast reactor should be put into practical use around 2050 after starting the operations of the demonstration reactor in 2025.
NHS Highland confirmed a male sub- contractor working at Dounreay's prototype fast reactor was admitted to Caithness General Hospital in Wick, before being transferred to Aberdeen Royal Infirmary with "probable meningitis".
The plant, which was set up in the 1950s as the first fast reactor research programme for the UK, has been in the process of decommissioning since 1994.
In the Integral Fast Reactor, high-energy neutrons work to form a minimum amount of actinide wastes.
But in Argonne's experimental Integral Fast Reactor (IFR), "we can effectively destroy them," notes IFR project manager Yoon I.

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