Estimates of the service lifetime of 304 stainless steel for use in the blanket region of the LANL ABC system

Abstract

The corrosion and fluence limits of stainless steel were evaluated to determine if it could be used as a blanket material in the accelerator-based conversion of plutonium (ABC) system at Los Alamos National Laboratory (LANL). Data from the Molten Salt Breeder Reactor program at Oak Ridge National Laboratory and the redox potential of the ABC system indicated that, from a corrosion perspective, 304L stainless steel might be useful for system components having lifetimes of up to 2 years. To determine the applicability of 304 stainless steel, its service lifetime was estimated from fluence-limit data used in the design of the Fast Flux Test Facility. The fluxes for components of the system were calculated with the Monte Carlo N-Particle (MCNP) code. After fluence limits of the stainless steel components were calculated for various temperatures, the expected lifetimes of the components were established for various fluxes and temperatures, based on 5 and 10% residual ductility criteria. The results showed that expected lifetimes for the components would be less than 1.6 years, and therefore, they do not meet the present goal of replacing the components every 2 years. However, it should be noted that the data obtained in this research are tentative and are likely to change as the LANL ABC system design moves forward.