▁What ▁is ▁the ▁use ▁of ▁that ?" ▁ ▁Vice ▁President ▁of ▁the ▁At omic ▁Energy ▁Organ ization ▁of ▁Iran ▁Gh ann adi ▁fr amed ▁the ▁debate ▁as ▁a ▁human itar ian ▁issue , ▁" This ▁is ▁about ▁human ▁be ings . ▁. ▁. ▁. ▁When ▁someone ▁is ▁sick , ▁we ▁should ▁give ▁medicine ." ▁Iran ▁informed ▁the ▁International ▁At omic ▁Energy ▁Agency ▁( IA E A ) ▁that ▁fuel ▁obtained ▁from ▁Argentina ▁in ▁ 1 9 9 3 ▁would ▁run ▁out ▁by ▁the ▁end ▁of ▁ 2 0 1 0 , ▁and ▁that ▁it ▁could ▁produce ▁the ▁u ran ium ▁itself ▁or ▁buy ▁the ▁u ran ium ▁from ▁abroad . ▁ ▁In ▁February ▁ 2 0 1 0 , ▁to ▁ref uel ▁the ▁Te h ran ▁Research ▁Re actor ▁which ▁produces ▁medical ▁is ot op es , ▁Iran ▁began ▁using ▁a ▁single ▁cas cade ▁to ▁en rich ▁u ran ium ▁" up ▁to ▁ 1 9 . 8 % ", ▁to ▁match ▁the ▁previously ▁foreign ▁supplied ▁fuel . ▁ 2 0 % ▁is ▁the ▁upper ▁threshold ▁for ▁low ▁en rich ed ▁u ran ium ▁( LE U ). ▁Though ▁HE U ▁en rich ed ▁to ▁levels ▁exceed ing ▁ 2 0 % ▁is ▁considered ▁techn ically ▁us able ▁in ▁a ▁nuclear ▁explos ive ▁device , ▁this ▁route ▁is ▁much ▁less ▁des irable ▁because ▁far ▁more ▁material ▁is ▁required ▁to ▁achieve ▁a ▁sust ained ▁nuclear ▁chain ▁reaction . ▁HE U ▁en rich ed ▁to ▁ 9 0 % ▁and ▁above ▁is ▁most ▁typically ▁used