Enrichment level for a bomb is 90 percent--meaning the ratio of uranium-238 to
uranium-235 has switched from 993:7 to 1:7.
6, 1945, where "Little Boy", a 9,000-pound
uranium-235 atomic bomb was dropped on Hiroshima.
In nature, uranium is found as uranium-238 (99.2739 to 99.2752%),
uranium-235 (0.7198 to 0.7202%) and a very small amount of uranium-234 (0.0050 to 0.0059%).
Both light-water reactors and CANDUs breed a lot of their own fuel but it's not enough to replace the
uranium-235 that is used up in the reaction; they are therefore classified as "burner" reactors.
This potential energy stored in an explosive material may be: Chemical energy, such as nitroglycerin or grain dust; Pressurized gas, such as a gas cylinder or aerosol can; Nuclear energy, such as in the fissile isotopes
uranium-235 and plutonium-239.
Any of the forms of radiation given off by
uranium-235 (the isotope used for energy generation) and its decay products, including uranium split in a nuclear reactor or in spent fuel, can rip through a cell and damage any component of that cell, including the DNA, carrier of the cell's genetic information.
Main interested parties know the
uranium-235 isotope is a few years from depletion."
The main elements of the JPA are requirements that Iran freeze, in effect, its production of enriched uranium containing up to 5%
uranium-235 during this period by converting the material to a uranium compound unsuitable for further enrichment; refrain from producing enriched uranium hexafluoride containing 20% uranium-235--the form of enriched uranium in Iran's stockpile that has caused the most concern; halt key elements of its heavy-water reactor and uranium enrichment facilities; and provide the International Atomic Energy Agency (IAEA) with additional information about its nuclear program, as well as access to some nuclear-related facilities which are not covered by Iran's IAEA safeguards agreement.
"Little Boy" contained 64 kilograms of
uranium-235. (11) The process to separate the uranium isotopes during World War II was accomplished through gaseous diffusion, an extensive process that required nearly one-seventh of the electrical power in the United States at the time.
The other 0.7 percent of mined uranium is
uranium-235, which makes excellent fuel.
Nuclear energy is released by two physical processes: 'fission' (splitting) of certain 'fissile' heavy elements (
uranium-235, plutonium-239) and 'fusion' (joining together) of certain light elements (hydrogen-2 or deuterium, hydrogen-3 or tritium, lithium-6.