Substance that can absorb large quantities of neutrons in a reactor core
"Nuclear poison" redirects here. Not to be confused with Radiation poisoning.
In applications such as nuclear reactors, a neutron poison (also called a neutron absorber or a nuclear poison) is a substance with a large neutron absorption cross-section.[1] In such applications, absorbing neutrons is normally an undesirable effect. However, neutron-absorbing materials, also called poisons, are intentionally inserted into some types of reactors in order to lower the high reactivity of their initial fresh fuel load. Some of these poisons deplete as they absorb neutrons during reactor operation, while others remain relatively constant.
The capture of neutrons by short half-life fission products is known as reactor poisoning; neutron capture by long-lived or stable fission products is called reactor slagging.[2]
^"Nuclear poison (or neutron poison)". Glossary. United States Nuclear Regulatory Commission. 7 May 2014. Archived from the original on 14 July 2014. Retrieved 4 July 2014.
^Kruglov, Arkadii (2002). The History of the Soviet Atomic Industry. Trans. by Andrei Lokhov. London: Taylor & Francis. p. 57. ISBN 0-415-26970-9. OCLC 50952983. Retrieved 4 July 2014.
as nuclear reactors, a neutronpoison (also called a neutron absorber or a nuclear poison) is a substance with a large neutron absorption cross-section...
directly into the reactor coolant. Neutronpoison solutions are water-based solutions that contain chemicals that absorb neutrons, such as common household borax...
chain reaction, control rods containing neutronpoisons and neutron moderators can change the portion of neutrons that will go on to cause more fission...
cross-section for neutron capture. In pressurized water reactors a variable concentration of boronic acid in the cooling water is used as a neutronpoison to compensate...
fission products, and (the few most absorptive) neutronpoison fission products, from thermal neutron fission of U-235 (typical of nuclear power reactors)...
sufficient length of control rod. However, without addition of a neutronpoison or active neutron-absorber, decreases in fission rate are limited in speed, because...
nuclear poisons in the reactor core. The main isotope responsible is 135Xe, mainly produced by natural decay of 135I. 135I is a weak neutron absorber...
shutdown margin is called a burnable poison. The neutron cross section, and therefore the probability of an neutron-nucleus interaction, depends on: the...
design, the operators were unaware that there was a maximal level of neutronpoison in the core). A negative void coefficient means that the reactivity...
A neutron bomb, officially defined as a type of enhanced radiation weapon (ERW), is a low-yield thermonuclear weapon designed to maximize lethal neutron...
of boric acid by neutrons in the water of the primary circuit of light-water reactor when the compound is added as a neutronpoison during refueling operations...
lower as its parent nuclide, xenon-135, is a strong neutronpoison and will have absorbed neutrons before decaying to 135 Cs in some cases), 28 kilograms...
fission product and acts as a neutronpoison in the nuclear fuel cycle. The stable fission product 149Sm is also a neutronpoison. Samarium is theoretically...
poison causes it to "burn up" or progressively transmute to non-poison isotopes, depleting this poison effect and leaving progressively more neutrons...
nuclear reactors. Indeed, because fission products are often neutronpoisons (absorbing neutrons that could be used to sustain a chain reaction), fission...
struck by a neutron of low energy. A self-sustaining thermal chain reaction can only be achieved with fissile material. The predominant neutron energy in...
uranium-235 (U-235) accounting for about 0.7%. U-238 has 146 neutrons and U-235 has 143 neutrons. Different isotopes have different behaviors. For instance...
mass numbers or are neutron-poor like 152Eu, have high cross sections for neutron capture, often high enough to be neutronpoisons. 151Eu is the beta decay...
require the presence of a neutron moderator like heavy water or high purity carbon (e.g. graphite) in the absence of neutronpoisons, which is even more unlikely...
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