Radiological Consequences and Risk Analysis for On-Site Workers During PSA Fault Sequences

Abstract

Radiological consequences and risk of death for members of the public from accidents resulting in exposure to ionizing radiation are often mentioned for pressurized water reactor (PWR) nuclear power plants. At the same time, for on-site workers, dose control is preferable. From the perspective of total radiological risk control for PWR nuclear power plants, radiological risk and frequency–dose acceptance criteria are established based on international guidance and practices in this research. The related evaluation methodology is also developed, including the fault sequences grouping principles, workers grouping principles, the calculation method for different exposure pathways, and the assessment of the risk of death, to accurately reflect the dose evaluation for on-site workers. Based on the inputs from a typical third-generation nuclear power plant, the above risk acceptance criteria and evaluation methodology are verified by analyzing radiological consequences from PSA fault sequences. The sensitivity and uncertainty analysis of L1 PSA modeling is also considered in the verification. The individual risk of death for different groups of on-site workers, the risk of death in each nuclear island building, and the risk of death from different fault sequences can be obtained from the established methodology and the verification results can guide and improve the radiological consequences analysis and radiological protection for on-site workers during accident conditions. The acceptance criteria and evaluation methodology presented can also assist in the risk control and As Low As Reasonably Practicable demonstration of nuclear facilities.