for american experts , perhaps the most reassuring aspect of the project is that the design is far more comparable to the american nuclear facility at three mile island , where damage after a 1979 accident was limited , than to the soviet installation at chernobyl. ; most experts agreed that the safety devices at juragua , including five -foot-thick concrete and steel domes encasing the reactors , preclude off-site contamination of the kind that occurred at chernobyl in april 1986 . ;