Commonly Used Nuclear Energy Units and Abbreviations Prefixes and Numerical Values Basic Unit Measured Pico, Property 10 barn cross section curie radioactivity dase rate radiation dose electron volt energy gram mass meter length rad (radiation absorbed dose) radiation roentgen rem (roentgen Mero me 10 10 ub uuci; uC i; pyc ~c 1 mb Nege 10 10 b mCi; Ci; mec mR/hr; K11¢ c kCis Mc keV MeV R/hr; mr/hr sor/hr, rem/hr mg g kg mm m km urad mrad rad radiation dose uk; ur mR; mr Rs r eV yug ug equivalent man) dase radiation prem mrem rem rep (roentgen equivalent physical) radiation dose urep mrep rep us ms S second time ton (TNT equivalent) device energy watt power Ltww yw 489 mw MCI ke W KT MT kw Mw