Together with its global partners, NTP Radioisotopes supplies up to a third of the world’s supply of lifesaving medical radioisotope Molybdenum-99.

Molybdenum-99 (Mo-99) is the world’s most important medical diagnostic radioisotope precursor, and is the parent isotope of technetium-99m (Tc-99m). Tc-99m is used in more than 40-million diagnostic procedures each year.

NTP Group is one of a handful of companies that is able to offer integrated Mo-99 production, processing and distribution services.

Our high-flux reactor SAFARI-1 operates about 300 days each year and our on-site processing facilities run 24-hour shifts, 365 days a year. With a dedicated transport and logistics service delivering our products around the world, safely and on time, NTP provides one of the most reliable and trusted sources of commercial Mo-99.

NTP Radioisotopes supplies the world’s largest nuclear medicine, medical imaging and radiopharmaceutical companies including Lantheus Medical Imaging, Nihon Medi-Physics, GE Healthcare, IBA Molecular and Mallinckrodt.

Fission Mo-99
Molybdenum-99 (Mo-99) is a man-made radioactive isotope that is produced through the neutron bombardment of enriched uranium-235 (U-235) targets. When a low-enriched uranium (LEU) or a highly enriched uranium (HEU) target is inserted into the core of the high-flux SAFARI-1 nuclear reactor, the target is bombarded with neutrons emitted from the reactor core. This neutron bombardment splits some of the heavy/big U-235 atoms – a process known as fission – into several smaller atoms call fission fragments/products. Around 400 different isotopes are formed in this process, including the radioactive isotopes Mo-99 and I-131.

After being irradiated for between 100 and 200 hours in SAFARI-1, the targets are removed from the reactor core and safely transported to NTP’s adjacent hot cell complex, also located at the Pelindaba site. Here, the targets are dissolved and commercially valuable isotopes like Mo-99 and iodine-131 are separated and extracted from the solution and purified to medical grade.

As soon as the Mo-99 has been purified and processed, it is tested for quality, and measured for radioactivity (this is expressed in units called Curies, which show ionising radiation). The Mo-99 is then dispensed by volume, in the form of a sodium molybdate solution. This solution is the feedstock used in technetium-99m generators.

Mo-99 has a half-life of just 66 hours. This means the number of radioactive atoms in Mo-99 decrease by half every 66 hours, or by 20% each day. Because of this, Mo-99 cannot be stockpiled, and reliable production and on-time delivery is critical to meet clinical demands.

Did you know?
SAFARI-1 in South Africa was the first commercial Mo-99 production facility to convert to low-enriched uranium (LEU) fuel, in 2009. Today over 75% of all Mo-99 produced at NTP is made using low-enriched uranium (LEU) targets.


Atomic information: Molybdenum-99

Isotope name: Molybdenum-99
Appearance: In the form of sodium molybdate in a clear solution.
Half-life: 66 hours
Emits: Beta and Gamma radiation
Used in: Technetium-99m generators
Decays to: Technetium-99m

About: Molybdenum-99 (Mo-99) is a man-made radioactive isotope. Mo-99 does not occur in nature and has to be created through neutron bombardment of other radioactive materials (usually enriched uranium-235). Mo-99 is used as an easily transportable form of its natural decay product, technetium-99m, which is the most widely used medical imaging radioisotope.