[en] Examines the information on the Chernobyl accident, notes that the major cause was stated to be human error by electrical engineers who attempted to carry out a turbogenerator experiment without regard to safety, but suggests that analysis of the data disclosed leads to three fundamental causes: positive feedback between power output and multiplication coefficient, which led to events which were not capable of manual control; close interaction between operating and safety systems relating to hydraulic as well as servo systems, which caused the experimenters to immobilise emergency cooling and to block reactor safety signals; simmering combustion of graphite, which aided radioactivity release. (G.M.E.)