Design Studies for the Optimization of ²³⁸Pu Production in NpO₂ Targets Irradiated at the High Flux Isotope Reactor

Journal Article · 21 November 2019 · Nuclear Technology

DOI: https://doi.org/10.1080/00295450.2019.1674594 · OSTI ID:1649564

Daily, Charles  ^[1]; McDuffee, Joel  ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Efforts to reestablish a domestic ²³⁸Pu production capability in support of National Aeronautics and Space Administration mission objectives are ongoing throughout the U.S. Department of Energy complex. The Plutonium-238 Supply Project (PSP) was initiated in response to a report published by the National Research Council in 2011 stating that “without a restart of ²³⁸Pu production, it will be impossible for the United States, or any other country, to conduct certain important types of planetary missions after this decade.” The PSP is targeting a sustained, constant production rate of 1.5 kg/year of heat source PuO₂ for several years. Design and optimization studies of ²³⁷Np-bearing targets are underway at Oak Ridge National Laboratory (ORNL). It is anticipated that targets will be irradiated in ORNL’s High Flux Isotope Reactor (HFIR) and in the Advanced Test Reactor (ATR) at Idaho National Laboratory. A variety of target materials, containments, arrangements, and irradiation histories have been analyzed, and the results indicate that a sufficient quantity of ²³⁸Pu can be produced in HFIR and ATR to fulfill the PSP’s constant production rate target. This paper focuses on the design and optimization of new target configurations containing pellets that are (1) ~93% of the theoretical density of NpO₂, (2) loaded into pins of cladding materials that can be handled as solid waste following postirradiation ²³⁸Pu recovery operations, (3) irradiated in various vertical experiment facility (VXF) locations in the HFIR permanent beryllium reflector, and (4) rotated within and/or moved to another VXF location following each HFIR operational cycle to maximize 238Pu production and minimize peak heat generation rates.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1649564
• Journal Information: Nuclear Technology, Journal Name: Nuclear Technology Journal Issue: 8 Vol. 206; ISSN 0029-5450
• Publisher: Taylor & Francis - formerly American Nuclear Society (ANS)Copyright Statement
• Country of Publication: United States
• Language: English