Search results
Results from the WOW.Com Content Network
The BN-350 fast-neutron reactor at Aktau, Kazakhstan.It operated between 1973 and 1994. 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, on average), as opposed to slow thermal neutrons used in thermal-neutron reactors.
A fast neutron reactor uses fast neutrons, so it does not use a moderator. Moderators may absorb a lot of neutrons in a thermal reactor, and fast fission produces a higher average number of neutrons per fission, so fast reactors have better neutron economy making a plutonium breeder reactor possible.
The primary physical advantage of thorium fuel is that it uniquely makes possible a breeder reactor that runs with slow neutrons, otherwise known as a thermal breeder reactor. [6] These reactors are often considered simpler than the more traditional fast-neutron breeders. Although the thermal neutron fission cross section (σ f) of the ...
A thermal-neutron reactor is a nuclear reactor that uses slow or thermal neutrons.. ("Thermal" does not mean hot in an absolute sense, but means in thermal equilibrium with the medium it is interacting with, the reactor's fuel, moderator and structure, which is much lower energy than the fast neutrons initially produced by fission.)
A sample of thorium. Thorium-based nuclear power generation is fueled primarily by the nuclear fission of the isotope uranium-233 produced from the fertile element thorium.A thorium fuel cycle can offer several potential advantages over a uranium fuel cycle [Note 1] —including the much greater abundance of thorium found on Earth, superior physical and nuclear fuel properties, and reduced ...
Consequently, reactor operators are faced with the so-called optimal fuel reloading problem, which consists of optimizing the rearrangement of all the assemblies, the old and fresh ones, while still maximizing the reactivity of the reactor core so as to maximise fuel burn-up and minimise fuel-cycle costs.
It is not a complete fast reactor instead using mostly epithermal neutrons, which are between thermal and fast neutrons in speed. The hydrogen-moderated self-regulating nuclear power module (HPM) is a reactor design emanating from the Los Alamos National Laboratory that uses uranium hydride as fuel.
Reactors that use lead or lead-bismuth eutectic can be designed in a large range of power ratings. The Soviet union was able to operate the Alfa-class submarines with a lead-bismuth cooled intermediate-spectrum reactor moderated with beryllium from the 1960s to 1998, which had approximately 30 MW of mechanical output for 155 MW thermal power (see below).