A comparison of safety culture associated with three engineered systems inJapan and the United States

The internationally reported nuclear criticality accident at JCO in Tokaimu ra, Japan has further eroded public confidence in nuclear energy, its relat ed facilities and the (Japanese) government's ability to handle such a cris is. The JCO accident marked the sixth nuclear-related incident since 1995. The existing state of "safety culture" is being questioned and re-evaluated at a national level. In this work the safety culture associated with engin eered systems(ES) such as the automobile, commercial airplane and nuclear p ower plants(NPP) are evaluated based cm a scale-analysis(SA), via propositi on of two fundamental parameters called eigenmetrics. The identified eigen- metrics are time- (tau) and number-scales (N) describing both ES and human factors, at the individual and/or societal levels. The SA approach is appro priate because human perception of risk (POR), perception of benefit (POB) and level of (technology) acceptance ( LOA) are inherently subjective, ther efore "fuzzy" and rarely quantifiable in exact magnitude. POR expressed in terms of the psychometric factors "dread risk" and "unknown risk", contain both time- and number-scale elements. The JCO accident, as well as auto-fat alities, commercial airline accidents and hypothetical NPP accidents are ch aracterized in terms of tau, N and two additional derived parameters of rel evance, Nr and N/tau. We contend that LOA infers a POB at least two orders of magnitude larger than POR. The "amplification" influence elf mass media is also deduced as being 100 to 1 000 fold the actual number of fatalities/ serious injuries in a nuclear-related accident.