A fast-neutron reactor (FNR) or fast-spectrum reactor or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons (carrying energies above 1 MeV or greater, on average), as opposed to slow thermal neutrons used in thermal-neutron reactors.
Such a fast reactor needs no neutron moderator, but requires fuel that is relatively rich in fissile material when compared to that required for a thermal-neutron reactor.
Around 20 land based fast reactors have been built, accumulating over 400 reactor years of operation globally. The largest of this was the Superphénix Sodium cooled fast reactor in France that was designed to deliver 1,242 MWe.
Fast reactors have been intensely studied since the 1950s, as they provide certain decisive advantages over the existing fleet of water cooled and water moderated reactors. These are:
More neutrons are produced when a fission occurs, resulting from the absorption of a fast neutron, than the comparable process with slow (thermal, or moderated) neutrons. Thus, criticality is easier to attain than with slower neutrons.
All fast reactor design built to this date use liquid metals as coolant, such as the sodium fast reactor and the lead-cooled fast reactor. As the boiling points of these metals is very high, the pressure in the reactor can be maintained at a low level, which improves safety considerably.
As temperatures in the core can also be substantially higher than in a water cooled design, such reactors have a greater thermodynamic efficiency; a larger percentage of the heat generated is turned into usable electricity.
Atoms heavier than uranium have a much greater chance of fission with a fast neutron, than with a thermal one. This means that the inventory of heavier atoms in the nuclear waste stream, for example curium, is greatly reduced, leading to a substantial lower waste management requirement.
In the GEN IV initiative, about two thirds of the proposed reactors for the future use a fast spectrum for these reasons.
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
In this course, one acquires an understanding of the basic neutronics interactions occurring in a nuclear fission reactor as well as the conditions for establishing and controlling a nuclear chain rea
The purpose of this course is to provide the necessary background to understand the effects of irradiation on pure metals and on alloys used in the nuclear industry. The relation between the radiation
This course is intended to understand the engineering design of nuclear power plants using the basic principles of reactor physics, fluid flow and heat transfer. This course includes the following: Re
Learn the basics of plasma, one of the fundamental states of matter, and the different types of models used to describe it, including fluid and kinetic.
Learn the basics of plasma, one of the fundamental states of matter, and the different types of models used to describe it, including fluid and kinetic.
Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission. Most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing and sustaining nuclear fission. The three most relevant fissile isotopes are uranium-233, uranium-235 and plutonium-239. When the unstable nuclei of these atoms are hit by a slow-moving neutron, they frequently split, creating two daughter nuclei and two or three more neutrons.
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. These reactors can be fuelled with more commonly available isotopes of uranium and thorium, such as uranium-238 or thorium-232, as opposed to the rare uranium-235 which is used in conventional reactors. These materials are called fertile materials since they can be bred into fuel by these breeder reactors. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use.
The Alfa class, Soviet designation Project 705 Lira (Лира, meaning "Lyre", NATO reporting name Alfa), was a class of nuclear-powered attack submarines in service with the Soviet Navy from 1971 into the early 1990s, with one serving later with the Russian Navy until 1996. They were among the fastest military submarines ever built, with only the prototype submarine (NATO reporting name Papa-class) exceeding them in submerged speed. The Project 705 submarines had a unique design among other submarines.
DT operations at JET gave a unique and invaluable opportunity to design, develop and test real -time controllers that will be applied in future burning plasma devices, as ITER and SPARC. Among them, the dud detector [L. Piron et al. 2019 Fusion Eng. Design ...
This article outlines the advancements made in broadening the application scope of the OpenMC neutron transport code to include thermohydraulic coupling and nuclear data uncertainty propagation. These developments primarily involve the incorporation of the ...
The sequence of codes Serpent/DYN3D has been developed by the Helmholtz-Zentrum Dresden-Rossendorf and successfully applied to core static and transient analyses of sodium-cooled fast reactors (SFRs). The successful application of the sequence to SFRs was ...