What is the difference between fission energy for nuclear power and fission energy for bombs?
In commercial nuclear fuel, the U235 isotope is only slightly enriched. In naturally occurring uranium, U235 is at a level of about 0.7%. It is enriched to 5% or less for use in commercial power stations. Additionally, absorbers are used in power stations to assure a slow rate of fission and to assure decreasing fission rates with increasing temperature. In nuclear bombs, the uranium is highly enriched in U235 — to 90% or greater — to provide a very high fission rate.
