For nearly the last decade, BGS personnel have supported the preparation and/or review of safety basis documents for nuclear facilities/activities at NNSS. BGS provided expertise in developing the complete rewrite of the Device Assembly Facility (DAF)/National Criticality Experiments Research Center (NCERC) Documented Safety Analysis (DSA)/Technical Safety requirements (TSR) and provided a strong regulatory compliance interpretive authority service. The new DAF DSA/TSR merged two facility DSAs into a single DSA executed in accordance with DOE-STD-3009-2014 and required a safety basis that supports high explosives, nuclear and non-nuclear components, and critical experiments.
More recently, BGS personnel supported the Enhanced Capabilities for Subcritical Experiments (ECSE) at the U1a facility. The ECSE modified a Hazard Category-2 nonreactor nuclear facility to accommodate a new zero room, associated diagnostic equipment, and a 20 MeV accelerator. BGS personnel assisted in the developing the strategy to update the U1a Complex DSA to be compliant with DOE-STD-3009-2014 and merge the ECSE preliminary DSA with the complex DSA and include a second major modification simultaneously. As the U1a involves high explosive and both nuclear and non-nuclear components and activities and ECSE will introduce the accelerator to the facility, the safety basis strategy required the development of a methodology that addressed nuclear components, non-nuclear components, high explosives, accelerator and interfaces with on-site transportation. BGS personnel drew on lessons learned from the DAF safety basis rewrite to execute the project.