出典:Wiktionary
出典:『Wiktionary』 (2025/12/07 22:30 UTC 版)
natural uranium (uncountable)
出典:Wikipedia
出典:『Wikipedia』 (2010/08/24 20:11 UTC 版)
Natural uranium (NU) refers to refined uranium with the same isotopic ratio as found in nature. It contains 0.7 % uranium-235, 99.3 % uranium-238, and a trace of uranium-234 by weight. In terms of the amount of radioactivity, approximately 2.2 % comes from uranium-235, 48.6 % uranium-238, and 49.2 % uranium-234.