Background. The HBRR (HFIR Beryllium Reflector Replacement) project. ORNL is preparing to replace HFIR’s permanent beryllium reflector, along with other key reactor core components, to sustain and enhance HFIR’s operational performance. This effort requires the disassembly of the reactor and neutron instruments and will result in a period of extended downtime beginning in 2028. The HBRR effort includes a approximately 4000 sq.ft. expansion to the...