OCTAVIA: A computer code to calculate the probability of pressure vessel failure from pressure-transient occurrences

The OCTAVIA computer code has been developed to calculate the probability of pressure vessel failure from operationally caused pressure-transients which can occur in pressurized water reactors. The analysis approach is straightforward and involves calculation of vessel failure pressures using fracture mechanics methods and estimation of pressure-transient characteristics using historical, nuclear data. The Surry 1 pressure vessel is analysed to demonstrate the code's capabilities. For the exampled application, at an operating temperature of 1100F (430C), the vessel failure probability increases from 5x10-7 per reactor year at a vessel age of 2.5 years to 3x10-5 per reactor year at a vessel age of approximately 40 years. (author)