CALCULATION OF REACTOR ACCIDENT SAFETY GOALS

The US Nuclear Regulatory Commission is in the process of developing safety goals for the operation of nuclear power plants. At present, two safety goals (individual early fatality risk and individual latent cancer fatality risk) and three quantitative risk goals (severe accident frequency, conditional probability of containment failure, and large release frequency) are emerging from this development. Each of these goals requires that the expected value for a quantity be less than a specified value, where the expectation is calculated over imprecisely known parameters required in the analysis. This presentation provides a description of the calculations involved in the determination of these goals, including uncertainty analysis, sensitivity analysis and estimation of expected values. Results obtained in a probabilistic risk assessment performed for internally initiated accidents at the Surry Nuclear Power Station as part of the NUREG-1150 analyses are used for illustration.