▁non - tok am ak ▁systems , ▁such ▁as ▁Robert ▁B uss ard ▁and ▁Eric ▁L erner , ▁have ▁been ▁critical ▁of ▁I TER ▁for ▁diver ting ▁fund ing ▁from ▁what ▁they ▁believe ▁could ▁be ▁a ▁potentially ▁more ▁vi able ▁and / or ▁cost - effect ive ▁path ▁to ▁fusion ▁power , ▁such ▁as ▁the ▁pol yw ell ▁re actor ▁though ▁the ▁latter ▁was ▁ultimately ▁found ▁to ▁be ▁in fe as ible . ▁Many ▁critics ▁acc use ▁I TER ▁research ers ▁of ▁being ▁unw illing ▁to ▁face ▁up ▁to ▁the ▁technical ▁and ▁economic ▁potential ▁problems ▁pos ed ▁by ▁to k am ak ▁fusion ▁schemes . ▁The ▁expected ▁cost ▁of ▁I TER ▁has ▁ris en ▁from ▁US $ 5 ▁billion ▁to ▁US $ 2 0 ▁billion , ▁and ▁the ▁tim eline ▁for ▁operation ▁at ▁full ▁power ▁was ▁moved ▁from ▁the ▁original ▁estimate ▁of ▁ 2 0 1 6 ▁to ▁ 2 0 2 7 ▁. ▁ ▁A ▁French ▁association ▁including ▁about ▁ 7 0 0 ▁anti - n uc lear ▁groups , ▁Sort ir ▁du ▁nu cl é aire ▁( Get ▁Out ▁of ▁N uc lear ▁Energy ), ▁claimed ▁that ▁I TER ▁was ▁a ▁ha z ard ▁because ▁scient ists ▁did ▁not ▁yet ▁know ▁how ▁to ▁manipulate ▁the ▁high - energy ▁de uter ium ▁and ▁tr it ium ▁hydro gen ▁is ot op es ▁used ▁in ▁the ▁fusion ▁process . ▁ ▁Reb e cca ▁Har ms , ▁Green / E FA ▁member ▁of ▁the ▁European ▁Parliament ' s ▁Committee ▁on ▁Indust ry , ▁Research