3D Printing Can Help Produce Radiopharmaceuticals

The European patent was granted to scientists from the National Centre for Nuclear Research in Poland for manufacturing uranium targets using 3D printing. This will contribute to the production of molybdenum-99 radioisotope needed for current diagnostics. The patent application was financially supported by the Foundation for Polish Science, and the project itself was implemented by the NOMATEN MAB NCBJ Center of Excellence.

“Molybdenum-99 is most commonly produced by irradiating small targets containing low-enriched uranium-235 with neutrons”, says MSc. Eng. Maciej Lipka, one of the co-authors of the patent. “Reactor neutrons have a limited ability to penetrate the target material. To ensure that as many uranium-235 nuclei as possible are converted to molybdenum-99, the targets are typically prepared as thin plates from a dispersion of uranium or its oxide or silicide in aluminum. The tile production process does not leave much room for optimization. Therefore, we proposed a different way to prepare uranium targets: spatial printing by laser powder sintering.”

Molybdenum-99 is most commonly produced by irradiating small targets containing low-enriched uranium-235 with neutrons. Reactor neutrons have a limited ability to penetrate the target material. To ensure that as many uranium-235 nuclei as possible are converted to molybdenum-99, the targets are typically prepared as thin plates from a dispersion of uranium or its oxide or silicide in aluminum. The tile production process does not leave much room for optimization. Therefore, researchers proposed a different way to prepare uranium targets: spatial printing by laser powder sintering. Maciej Lipka, one of the co-authors of the patent told about this.

Laser sintering of metal powders is a type of 3D printing based on the use of a laser of appropriate power to selectively melt a thin layer of powder, previously evenly distributed in-side the container on the working platform. After the first layer is fixed, the platform is lowered slightly, the next layer of powder is applied and the whole cycle can be repeated as many times as required.

In a target exposed to neutrons, nuclear reactions take place, the byproduct of which is heat. The use of 3D printing allows you to optimize the shape of the targets so that the heat is more effectively dissipated to the environment. The targets themselves would therefore heat up less, and this would increase the uranium-235 content in them. As a result, more molybdenum-99 could be produced per exposure.

A promising aspect of the patent relates to the potential to increase the processing efficiency of the uranium-235. In each irradiated target, some of the nuclei of this isotope do not undergo nuclear transformations. The shapes of the printed targets can therefore be designed to increase the amount of uranium recovered. Once extracted, it could be used to build more targets.

According to the National Centre for Nuclear Research