A proactive approach to reactor vessel aging management

Unit 2 at the Prairie Island nuclear power plant near Red Wing, Minn., underwent an outage in fall 2023, which included extensive work on the reactor vessel using a novel approach to replace baffle-former bolts and lower radial clevis insert bolts. The work relied on extensive analysis beforehand to determine which bolts to replace such that only the new bolts were structurally credited for performance of their safety function. This proactive approach eliminated the need for costly contingencies associated with inspections.