ical ) ▁non - aque ous ▁methods . ▁The ▁l anth an ide ▁flu or ides ▁are ▁difficult ▁to ▁dissol ve ▁in ▁the ▁nit ric ▁acid ▁used ▁for ▁a que ous ▁re processing ▁methods , ▁such ▁as ▁P URE X , ▁D IA ME X ▁and ▁S AN EX , ▁which ▁use ▁sol vent ▁extra ction . ▁Fl u or ide ▁vol at ility ▁is ▁only ▁one ▁of ▁several ▁py ro chem ical ▁processes ▁designed ▁to ▁re process ▁used ▁nuclear ▁fuel . ▁ ▁The ▁ Ř e ž ▁nuclear ▁research ▁inst itute ▁at ▁ Ř e ž ▁in ▁the ▁Czech ▁Republic ▁tested ▁sc rew ▁dos ers ▁that ▁fed ▁ground ▁u ran ium ▁ox ide ▁( sim ulating ▁used ▁fuel ▁pel lets ) ▁into ▁a ▁flu or in ator ▁where ▁the ▁particles ▁were ▁burn ed ▁in ▁flu or ine ▁gas ▁to ▁form ▁u ran ium ▁hex a flu or ide . ▁ ▁Table ▁of ▁relevant ▁properties ▁ ▁See ▁also ▁ ▁F Li Na K ▁Mol ten ▁salt ▁re actor ▁ ▁Notes ▁ ▁Miss ing ▁top ▁flu or ides : ▁Pr F 4 ▁( because ▁it ▁decom poses ▁at ▁ 9 0   ° C ) ▁T b F 4 ▁( because ▁it ▁decom poses ▁at ▁ 3 0 0   ° C ) ▁Ce F 4 ▁( because ▁it ▁decom poses ▁at ▁ 6 0 0   ° C ) ▁Without ▁stable ▁flu or ides : ▁Kr , ▁X e , ▁P d ▁ ▁References ▁ ▁External ▁links ▁ ▁Study ▁of ▁Elect ro chem