Here are entered works on uranium in which the proportion of the fissile isotope U-235 has been increased to a level defined by safety regulations, currently 20%.
found:U.S. Dept. of Energy. Office of Nonproliferation and National Security. Office of Emergency Management. Nuclear terms handbook, 1996:p. 32 (Uranium that is enriched in uranium-235 to above 20%, usually 90% or greater)
found:Uranium Institute glossary of nuclear terms web site, Oct. 5, 1999(Uranium in which the proportion of the fissile isotope U-235 has been increased from the naturally occurring 0.71% to a high level, normally taken to be at least 90% for weapons purposes, but defined as anything over 20% for regulatory and safeguards purposes)
General Notes
Here are entered works on uranium in which the proportion of the fissile isotope U-235 has been increased to a level defined by safety regulations, currently 20%.