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Results for “Ac-225 production”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Examination of Ac-225 production from Ra-226 using fast reactor JOYO

In this study, the authors investigated the method of producing the radionuclide Ac{sup 225} used for targeted alpha therapy (TAT). Currently, Ac{sup 225} is mainly generated from ORNL's Th{sup 229} generator, and the annual production amount is limited to about 63 GBq, and methods for generating it using accelerators are under development in each country. The method using an accelerator has the advantage of being able to generate Ac{sup 225} from a small amount of target nuclides with high efficiency but has the disadvantage of not being able to irradiate a large amount of target nuclides at once due to the small irradiation area. Therefore, the authors investigated a method to generate Ac{sup 225} by neutron irradiation of Ra{sup 226} as a target nuclide using the experimental fast reactor JOYO, which has abundant neutrons and a large loading region. Irradiation of Ra{sup 226} with fast neutrons causes a (n, 2n) reaction to generate Ra{sup 225}, and then decay to produce Ac{sup 225}. In addition, although harmful Ac{sup 227} is also produced at the same time by the (n,γ) reaction, first of all the actinium isotope is chemically separated and eliminated. Since the remaining Ra{sup 225} collapses and Ac{sup 225} is produced, pure Ac{sup 225} can be extracted by performing chemical separation again. As a result of the analysis, 1 g of Ra{sup 226} is irradiated with JOYO for 60 days, and milking is performed 4 times every 17.5 days. By doing these three times a year, it was found that about 50 GBq of Ac{sup 225} was generated. (authors)

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2020

SRF Resonators for a bi-directional Energy Ramping Upgrade of the Isotope Production Facility Beamline at LANL

The LANL Isotope Production Facility (IPF) is one of the two high-current proton linear accelerators operated under the auspices of the DOE Office of Nuclear Physics Isotope Development and Production for Research Applications Program. The IPF beamline operates with a fixed 100-MeV energy proton beam, diverted from the LANSCE accelerator and guided towards the isotope production target station. The fixed beam energy limits the number of isotopes that can be produced at IPF, and adversely affects the purity of isotopes produced at non-optimal energies. In particular, the IPF program is receiving increasing numbers of requests for high purity isotopes such as Np-236 (national security applications) and Re-186 (medical therapy). These are typically produced via (p,n) and (p,2n) nuclear reactions, requiring very tight control of the incident energies on the production targets to ensure an end product with a high radionuclidic purity. It is well known that this level of energy control cannot be achieved when a 100 MeV beam of mono-energetic protons is degraded to the required energies, typically below 30 MeV, as too much energy spread is acquired. Operating the IPF beamline at lower, mono-energetic beam energies such as at 40 MeV will allow the required tight energy control in target assemblies to ensure a high purity product. In addition, NP has requested a LANL/BNL/ORNL collaboration focus on establishing a national large-scale production capability for the therapy isotope Ac-225. Recent nuclear cross section measurements done at LANL show that due to a steep rise in production cross section towards higher proton energies (See Figure 2), proton beams at energies substantially greater than 100 MeV will be highly beneficial for Ac-225 production [AC255]. Such higher-energy beams cannot be delivered to IPF at present. Lower-energy beams (70 MeV and 40 MeV) can be delivered but only in sole-use mode; all other LANSCE users must be offline during 70 MeV or 40 MeV operation.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2026

Ra-226 extraction and purification from simulated uranium tailings

Growing demand for Ac-225 has outstripped current production, increasing interest in alternative production routes. Furthermore, these often rely on irradiations of Ra-226, yet Ra-226 supplies are also limited. Uranium tailings provide an abundant source of Ra-226, though separation from these complex matrices remains challenging. A laboratory-scale process was developed to recover Ra-226 from simulated U-tailings. After acid leaching, Ra remained adsorbed on refractory oxides and silicates. An additional CaCl₂ leach of the residue raised recovery to ~ 64%. Subsequent purifications, including precipitation, ion-exchange, and extraction chromatography (TK101), achieved chemical yields up to 73 ± 7%, producing 7.68 ± 0.1 µCi of high-purity Ra-226.

and nuclear chemistry↗
DOE OSTI2025

Radioisotope production at the Spallation Neutron Source: Design concept of isotope production target

Upon completion of the Second Target Station (STS) Project in the mid 2030s, the Spallation Neutron Source accelerator at Oak Ridge National Laboratory will deliver a 2.7 MW proton beam to the neutron production targets. In the post-STS phase, the accelerator will have a reserve beam power capacity of at least 100 kW beyond what the two neutron production targets will receive, which could potentially be ramped up to 300 kW. In this paper, a design concept for a radioisotope production target that could utilize 250 kW of the reserve beam power capacity is presented. The target consists of thorium discs encapsulated in 316L austenitic steel shells that are cooled by water. The estimated post-irradiation activity of Ac-225 and Ra-225, critical medical radioisotopes used in targeted alpha therapy cancer treatment, is calculated at the end of bombardment after a 14 day long irradiation time. Thermal and structural analyses are performed on the basis of calculated nuclear heating data. The technical feasibility of a high-power target under a 250-kW beam load with an extremely low duty factor of $3.5\cdot 10^{-6}$ is presented from thermal, structural and fatigue lifetime perspectives.

Lee, Yong Joong [ORNL] (ORCID:0000000298381723)↗