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Radiochemical Separation & Processing


Illustration of REDC Building 7920 layout.

Built in the mid-1960’s in conjunction with the High Flux Isotope Reactor, ORNL operates unique, heavily shielded and remotely operated radiochemical processing facilities in two adjacent buildings that, together, are called the Radiochemical Engineering Development Center, or “REDC”. The facilities contain laboratory, glove box, and engineering-scale hot cells that are designed to process alpha, beta-gamma, and neutron-emitting radioisotopes. Process equipment is in place to dissolve, separate, recover, and purify highly radioactive products and dispose of fission product wastes.

Since the mid-1960s, the REDC has been the production, storage, and distribution center for the heavy element research and distribution program of DOE, producing significant quantities of 249Bk 252Cf, 253Es, and 257Fm. Target rods containing americium and curium are remotely fabricated in Building 7920, irradiated in the adjacent High Flux Isotope Reactor (HFIR), and then processed in the Building 7920 hot cells for separation and purification of the heavy actinide elements. The HFIR/REDC complex produces 70% of the world’s supply of 252Cf (by far the largest heavy element production effort at ORNL). Product finishing and shipment of 252Cf occurs in Building 7930.

Building 7920 is a two-level structure with a high bay area. The building houses nine connected hot cells, laboratories, and the support services and equipment for these facilities. There is also an attached office wing, shop, and storage area.  From the late-1970s until the mid-1980's, a uranium fuel cycle development effort was maintained in specially-designed equipment in one of the hot cells in Building 7920.  Solvent extraction flowsheets for processing irradiated fuels from commercial light water reactors and fast breeder reactors were developed and tested, and plutonium recovery schemes were demonstrated.  The Coupled End-To-End (CETE) Program demonstrated ORNL’s capability to study reprocessing of used nuclear fuel from  cradle to grave in hot cell and glove box environments, encompassing head-end processing, dissolution, solvent extraction, and denitration for oxide production.  Current fuel research and development is focusing on advanced dry head-end processing and is expected to provide simplification of subsequent separations or to be employed as pretreatment prior to used nuclear fuel storage.

Since 1991, Building 7920 has been used to process Mark 42 target assemblies that were irradiated at the Savannah River Site. High-purity 243Am (plus 242Pu and 244Cm) are separated and recovered in the Building 7920 hot cells for shipment to Los Alamos National Laboratory. Most recently (beginning in 2012), Building 7920 has been used for the development and demonstration of 238Pu production from 237Np targets in support of future NASA deep space missions.

Building 7930 was originally constructed for thorium fuel cycle research but it was never used for this purpose.  It is a three-level, 33,000 ft2 steel-framed, concrete structure that is divided into: Seven cells - six shielded and one unshielded; maintenance and service areas surrounding the cell complex; a cell operating area; and an office area adjacent to, but isolated from, the operating areas.  Its primary purpose today is Cf-252 production in four of the six hot cells, including: Chemical purification; fabrication, packaging, and shipping of neutron sources; recovery of Cm target material; and pool storage of Cf. Building 7930 also provides for neutron interrogation services to researchers, and storage of packaged solid Th, U, Np, Pu, and Am.

For more information, contact:
Nuclear Security and Isotope Technology Division
865.574.6136

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