What happened at TMI was wildly exaggerated by anti-nuke activists. Obviously they took full advantage of the public's ignorance to instill fear into the public such that Nuclear was DOA in the years and decades after their agitative activism. And, so here we are.
TMI has been consistently lowballed by nuke advocates.
In particular, its very large "venting" of radioactive krypton gas that ran down to the river and spread out in neighborhoods on the riverbanks is never counted among its impacts.