Historical relationship between performance assessment for radioactive waste disposal and other types of risk assessment

This article describes the evolution of the process for assessing the hazar ds of a geologic disposal system for radioactive waste and, similarly, nucl ear power reactors, and the relationship of this process with other assessm ents of risk, particularly assessments of hazards from manufactured carcino genic chemicals during use and disposal. This perspective reviews the commo n history of scientific concepts for risk assessment developed until the 19 50s. Computational tools and techniques developed in the late 1950s and ear ly 1960s to analyze the reliability of nuclear weapon delivery systems were adopted in the early 1970s for probabilistic risk assessment of nuclear po wer reactors, a technology for which behavior was unknown. In turn, these a nalyses became an important foundation for performance assessment of nuclea r waste disposal in the late 1970s. The evaluation of risk to human health and the environment from chemical hazards is built on methods for assessing the dose response of radionuclides in the 1950s. Despite a shared backgrou nd, however, societal events, often in the form of legislation, have affect ed the development path for risk assessment for human health, producing dis similarities between these risk assessments and those for nuclear facilitie s. An important difference is the regulator's interest in accounting for un certainty.