Naturally-occurring Isotopes of Uranium
The main naturally-occurring isotopes, which have to be considered in the fuel cycle of all commercial light water reactors, are:
- 238U. 238U belongs to the group of fertile isotopes.
- 235U. 235U belongs to the group of fissile isotopes. 235U is the only existing fissile nucleus from naturally occurring isotopes, and therefore it is a highly strategic material.
- 234U. 234U belongs to the group of fertile isotopes.
Artificial Isotopes of Uranium
The main artificial isotopes, which have to be considered in the fuel cycle of all commercial light water reactors, are:
- 233U. 233U belongs to the group of fissile isotopes. It is produced by radiative neutron capture in nuclear reactors containing thorium fuel. 2
- 236U. 236U is neither a fissile isotope nor a fertile isotope. 236U is fissionable only by fast neutrons. Isotope 236U is formed in a nuclear reactor from fissile isotope 235U.
- 232U. 232U belongs to the group of fertile isotopes. 232U is a side product in the thorium fuel cycle, and also this isotope is a decay product of 236Pu in the uranium fuel.
Cross-sections of Naturally-occurring Isotopes
Source: JANIS (Java-based Nuclear Data Information Software); The JEFF-3.1.1 Nuclear Data Library
Uranium 238. Comparison of total fission cross-section and cross-section for radiative capture.
Uranium 235. Comparison of total fission cross-section and cross-section for radiative capture.
</aUranium 234. Comparison of total fission cross-section and cross-section for radiative capture.Cross-sections of Artificial Isotopes
Source: JANIS (Java-based Nuclear Data Information Software); The JEFF-3.1.1 Nuclear Data Library
Uranium 233. Comparison of total fission cross-section and cross-section for radiative capture.
Uranium 236. Comparison of total fission cross-section and cross-section for radiative capture.
Uranium 232. Comparison of total fission cross-section and cross-section for radiative capture.
Fissile / Fertile Material Cross-sections. Comparison of total fission cross-sections.