Denaturation (fissile materials)
Encyclopedia
Denaturation of fissile
materials suitable for nuclear weapon
s is the process of transforming them into a form that is not suitable for weapons use and can not easily be reversely transformed. For Uranium 235 this is straightforward, by mixing it with Uranium 238, but for plutonium
it is more difficult and/or less effective, because other plutonium isotope
s are either also suitable for weapons or not available and not practical to produce, while mixing with another element allows chemical separation.
The situation with Uranium-233
is more drastic. Decay of the attached Uranium-232 produces Thorium-228 with a radioactive half-life of 1.9 years and several short-lived daughter nuclides; these daughters include some very hard gamma-ray emitters like Thallium-208 and Lead-212. After approximately one single year the alpha activity of these decay products is several hundred curies per kilogram of U-233, and the gamma penetration radiation is a thousand times larger to some than from the plutonium. Aged U-233 is self-protected radiologically from diversion.
Fissile
In nuclear engineering, a fissile material is one that is capable of sustaining a chain reaction of nuclear fission. By definition, fissile materials can sustain a chain reaction with neutrons of any energy. The predominant neutron energy may be typified by either slow neutrons or fast neutrons...
materials suitable for nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
s is the process of transforming them into a form that is not suitable for weapons use and can not easily be reversely transformed. For Uranium 235 this is straightforward, by mixing it with Uranium 238, but for plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
it is more difficult and/or less effective, because other plutonium isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
s are either also suitable for weapons or not available and not practical to produce, while mixing with another element allows chemical separation.
The situation with Uranium-233
Uranium-233
Uranium-233 is a fissile isotope of uranium, bred from Thorium as part of the thorium fuel cycle. It has been used in a few nuclear reactors and has been proposed for much wider use as a nuclear fuel. It has a half-life of 160,000 years....
is more drastic. Decay of the attached Uranium-232 produces Thorium-228 with a radioactive half-life of 1.9 years and several short-lived daughter nuclides; these daughters include some very hard gamma-ray emitters like Thallium-208 and Lead-212. After approximately one single year the alpha activity of these decay products is several hundred curies per kilogram of U-233, and the gamma penetration radiation is a thousand times larger to some than from the plutonium. Aged U-233 is self-protected radiologically from diversion.