Independent Assessment of Safety System Management at Los Alamos National Laboratory Plutonium Facility Building 4 at Technical Area 55
Office of Enterprise Assessments
May 22, 2026
Estimated Read Time min
May 2026,
Independent Assessment of Safety System Management at Los Alamos National Laboratory Plutonium Facility Building 4 at Technical Area 55
The U.S. Department of Energy (DOE) Office of Enterprise Assessments (EA) conducted an independent assessment of the effectiveness of safety system management (SSM) at the Los Alamos National Laboratory (LANL) Plutonium Facility, Building 4, at Technical Area 55, from May to July 2025. LANL is managed and operated by Triad National Security, LLC (Triad) for the National Nuclear Security Administration (NNSA) and is overseen by the NNSA Los Alamos Field Office (NA-LA). This assessment was performed within the broader context of targeted SSM assessments at selected high hazard (i.e., hazard category 1 and 2) nuclear facilities across the DOE complex. The purpose of this assessment was to evaluate whether the selected safety systems (i.e., the safety significant [SS] ventilation system, which operates in conjunction with the safety class [SC] confinement system, and the SS full-scale test facility [FSTF]) were appropriately functionally classified and are operated and maintained in a manner that ensures they can reliably perform their intended safety function of protecting workers and the public from analyzed hazards. This assessment also evaluated the effectiveness of NA-LA oversight of LANL’s SSM processes.