▁the ▁plant ' s ▁design ▁can ▁handle ▁the ▁increased ▁power ▁level . ▁Unit   1 ▁was ▁u pr ated ▁during ▁its ▁Spring ▁ 2 0 0 8 ▁ref uel ing ▁out age , ▁and ▁Unit   2 ▁was ▁u pr ated ▁in ▁the ▁Fall ▁out age ▁of ▁the ▁same ▁year . ▁ ▁Inc idents ▁and ▁acc idents ▁ ▁L oss ▁of ▁power ▁A ▁loss ▁of ▁elect rical ▁power ▁in ▁the ▁plant ▁occurred ▁on ▁March ▁ 2 0 , ▁ 1 9 9 0 . ▁ ▁At ▁ 9 : 2 0   a . m ., ▁a ▁tr uck ▁carrying ▁fuel ▁and ▁lub ric ants ▁in ▁the ▁plant ' s ▁ 2 3 0 k V ▁switch yard ▁back ed ▁into ▁a ▁support ▁column ▁for ▁the ▁fe eder ▁line ▁supp lying ▁power ▁to ▁the ▁Unit   1 - A ▁reserve ▁auxili ary ▁transform er ▁( R AT ). ▁At ▁the ▁time , ▁the ▁ 1 - B ▁R AT ▁was ▁de - ener g ized ▁for ▁maintenance ▁and ▁R AT ▁ 1 - A ▁was ▁power ing ▁both ▁trains ▁of ▁emer gency ▁elect rical ▁power . ▁ ▁The ▁non - emer gency ▁elect rical ▁trains ▁were ▁being ▁power ed ▁by ▁back - feed ing ▁from ▁the ▁switch yard ▁through ▁the ▁main ▁step - up ▁transform er ▁to ▁the ▁ 1 - A ▁and ▁ 1 - B ▁unit ▁auxili ary ▁transform ers ▁( U AT ). ▁Additionally , ▁emer gency ▁dies el ▁generator ▁( ED G ) ▁ 1 - B ▁was ▁out