▁ ▁In ▁ 1 9 8 5 , ▁H B - Line ▁began ▁producing ▁plut on ium - 2 3 8 ▁for ▁NASA ' s ▁deep - space ▁expl oration ▁program . ▁The ▁L - Re actor ▁was ▁restart ed ▁and ▁C - Re actor ▁shut ▁down . ▁A ▁full - scale ▁ground water ▁rem ed iation ▁system ▁constructed ▁in ▁M - Area . ▁ ▁Const ruction ▁of ▁Salt stone ▁and ▁of ▁the ▁Rep lacement ▁T rit ium ▁Fac ility ▁began ▁in ▁ 1 9 8 6 . ▁In ▁ 1 9 8 7 , ▁Du P ont ▁not ified ▁DO E ▁that ▁it ▁would ▁not ▁continue ▁to ▁operate ▁and ▁manage ▁the ▁site . ▁The ▁E ff lu ent ▁Tre at ment ▁Project ▁( ET P ) ▁construction ▁began . ▁ ▁In ▁ 1 9 8 8 , ▁K , ▁L ▁and ▁P ▁React ors ▁were ▁shut ▁down . ▁An ▁E ff lu ent ▁Tre at ment ▁Fac ility ▁began ▁operations ▁to ▁treat ▁low - level ▁radio active ▁waste water ▁from ▁the ▁F ▁and ▁H ▁Area ▁Se par ations ▁facilities . ▁In ▁ 1 9 8 9 , ▁the ▁site ▁was ▁included ▁on ▁the ▁National ▁Prior ity ▁List ▁and ▁became ▁reg ulated ▁by ▁the ▁E PA . ▁West ing house ▁Sav ann ah ▁River ▁Company ▁( WS RC ) ▁assumed ▁management ▁and ▁operation ▁of ▁site ▁facilities . ▁The ▁name ▁of ▁the ▁facility ▁changed ▁from ▁Sav ann ah ▁River ▁Plant ▁( SR P ) ▁to ▁Sav ann ah ▁River ▁Site ▁( S RS ).