▁as ▁well ▁as ▁re actor ▁cool ant ▁p ump ▁and ▁polar ▁c rane ▁installation ▁in ▁unit ▁ 3 ▁during ▁ 2 0 1 8 ▁and ▁ 2 0 1 9 . ▁The ▁contain ment ▁vessel ▁top ▁head ▁was ▁set ▁during ▁a ▁site ▁visit ▁by ▁Secretary ▁of ▁Energy ▁Rick ▁Perry ▁and ▁execut ives ▁of ▁the ▁plant ' s ▁own ers . ▁Rec ent ▁progress ▁on ▁unit ▁ 4 ▁includes ▁the ▁installation ▁of ▁the ▁final ▁steam ▁generator ▁and ▁press ur izer . ▁Unit ▁ 4 ▁is ▁being ▁constructed ▁util izing ▁less ons ▁learned ▁from ▁Unit ▁ 3 ▁and ▁from ▁the ▁failed ▁Vir g il ▁C . ▁Summer ▁N uc lear ▁Gener ating ▁Station ▁( V . C . ▁Summer ) ▁project ▁and ▁as ▁a ▁result ▁the ▁order ▁in ▁which ▁some ▁components ▁are ▁being ▁installed ▁has ▁been ▁modified . ▁On ▁November ▁ 2 2 , ▁ 2 0 1 9 ▁the ▁third ▁ring ▁of ▁the ▁contain ment ▁vessel ▁was ▁set ▁for ▁unit ▁ 4 , ▁and ▁on ▁December ▁ 8 , ▁ 2 0 1 9 ▁the ▁unit ▁ 3 ▁shield ▁building ▁roof ▁was ▁set ▁above ▁the ▁unit ▁ 3 ▁contain ment ▁vessel . ▁On ▁December ▁ 1 6 , ▁ 2 0 1 9 ▁the ▁control ▁room ▁of ▁unit ▁ 3 ▁became ▁oper ational ▁and ▁is ▁now ▁available ▁for ▁testing ▁systems . ▁On ▁February ▁ 1 1 , ▁ 2 0 2 0 , ▁Southern ▁N uc lear ▁announced ▁that ▁the ▁final ▁concrete ▁pla cement ▁inside ▁the ▁Unit ▁ 3 ▁contain ment ▁vessel ▁was ▁completed