(August 10, 2020)

From reactor to patients

Research reactors are reactors that, instead of generating electricity, are primarily used to produce neutrons for other applications. These neutrons can be used for various purposes, such as to produce 99Mo by irradiating uranium-235 targets.

Being a radioisotope, 99Mo is an unstable atom that undergoes decay. It takes 66 hours for half of any 99Mo produced to decay — this is known as its half-life. The decay product of 99Mo, also called its ‘daughter product’, is 99mTc.

To get 99mTc, the irradiated uranium-235 targets are moved to a processing installation, usually near a research reactor, to separate 99Mo from the other fission products and purify it. The purified 99Mo is then transported to a production facility for 99Mo/99mTc generators — devices used to safely hold, transport and chemically extract 99mTc from 99Mo directly on site at a hospital or other medical facility.