▁plut on ium ▁separation . ▁" M ost ▁important ly , ▁on ▁the ▁basis ▁of ▁additional ▁cent rif uge ▁assistance ▁from ▁the ▁A . Q . ▁Khan ▁network , ▁Iran ▁was ▁able ▁to ▁begin ▁the ▁construction ▁of ▁pilot - scale ▁and ▁industrial - scale ▁en rich ment ▁facilities ▁at ▁Nat anz ▁around ▁ 2 0 0 0 ." ▁Full ▁expos ure ▁of ▁Iran ' s ▁nuclear ▁activities ▁came ▁in ▁ 2 0 0 2 , ▁when ▁an ▁Iran ian ▁ex iled ▁opposition ▁group , ▁the ▁National ▁Council ▁of ▁Res istance ▁of ▁Iran ▁( NC RI ) ▁declared ▁the ▁Nat anz ▁project ▁in ▁August ▁of ▁that ▁year . ▁Since ▁that ▁time , ▁international ▁pressure ▁on ▁Iran ▁has ▁remained ▁steady , ▁ham per ing ▁but ▁not ▁hal ting ▁the ▁country ' s ▁nuclear ▁development . ▁Iran ▁remains ▁leg ally ▁bound ▁to ▁the ▁N PT ▁and ▁states ▁its ▁support ▁for ▁the ▁treat y . ▁ ▁There ▁are ▁various ▁estimates ▁of ▁when ▁Iran ▁might ▁be ▁able ▁to ▁produce ▁a ▁nuclear ▁weapon , ▁should ▁it ▁choose ▁to ▁do ▁so : ▁ ▁A ▁ 2 0 0 5 ▁assess ment ▁by ▁the ▁International ▁Institute ▁for ▁Str ateg ic ▁Studies ▁concluded ▁" if ▁Iran ▁threw ▁ca ution ▁to ▁the ▁wind , ▁and ▁sought ▁a ▁nuclear ▁weapon ▁cap ability ▁as ▁quickly ▁as ▁possible ▁without ▁regard ▁for ▁international ▁reaction , ▁it ▁might ▁be ▁able ▁to ▁produce ▁enough ▁HE U ▁for ▁a ▁single ▁nuclear ▁weapon ▁by ▁the ▁end ▁of ▁this ▁de cade ", ▁assuming ▁no ▁technical ▁problems . ▁The ▁report ▁con cludes ,