Study of Ra-226 recycling in the Ra-226 (p,2n) Ac-225 production route

SCK•CEN Mentor

Maertens Dominic,, +32 (0)14 33 32 69

Expert group


SCK•CEN Co-mentor

Cardinaels Thomas , , +32 (0)14 33 32 00


Ra-226 (T1/2: 1600 y) has a long history in the medical field, and is once again becoming attractive for production of new radionuclides in the niche of Targeted Alpha Therapy (TAT). Cyclotron irradiation can produce the short-lived Ac-225 (T1/2: 10 d) by the nuclear reaction Ra-226 (p,2n) Ac-225. After irradiation, Ac-225 is separated from Ra-226 and its progeny, and intensely purified for clinical applications. Next, the rare and valuable Ra-226 needs to be recycled as much as possible, while minimizing radioactive waste. A number of feasible separation and purification schemes were identified, that each require different approaches to recycle the Ra-226 target material. The liquid waste containing traces of Ra-226 also require special treatment options, that often rely on a sulfate (co-)precipitation step for final decontamination.


The aim of this study is to evaluate the different separation and purification schemes, with the primary focus on the recycling of Ra-226 in the entire process. Also the possible impurities of the encapsulation material of the Ra-226 irradiation target need to be taken into account. A great part of the experimental work can be performed using Ba as a chemical analogue for Ra, and quantification of the process samples by means of ICP-MS. Ac-225, Ra-223 (T1/2: 11,43 d) and Ra-225  (T1/2: 14,9 d) radiotracers are available at SCK•CEN, and can be used in the final phase for validation experiments, and can quantified by HPGe gamma spectroscopy.

The minimum diploma level of the candidate needs to be

Academic bachelor

The candidate needs to have a background in

Chemistry , Academic bachelor in chemical engineering or chemistry

Estimated duration

1 semester