Passive Autocatalytic Recombiner (PAR) Requirements for PWRs: Value Impact Assessment

Objective: Determine whether it is cost-effective to update the existing § 50.44 requirements on combustible gas control to require passive autocatalytic recombiners for all PWRs with large-dry containment buildings. Under this approach, a backfit would be required of licensees with plants that have large dry containments in that they would have to install PARs and maintain them for the duration of the plant license. This approach would provide control over the potential for containment failure that would otherwise result from combustion of gases produced during severe (core-damage) accidents.