by EDZANI RATSIBI
JOHANNESBURG – NUCLEAR technology is one of the growing technologies in the world used in various sectors apart from the energy one. Nuclear technology makes use of radioisotopes in sectors such as: medicine, food and agriculture, transport, consumer products, mining, industry, water resources and the environment, and scientific research. Radioisotopes are produced in nuclear reactors (both research and power reactors) and accelerators (cyclotrons).
The South African Nuclear Energy Corporation (Necsa) has a MTR 20MW tank-in-pool research reactor, SAFARI-1 that is used for radioisotope production and research purposes.
Radioisotopes produced at SAFARI-1 are processed at NTP isotope processing facilities and then transported to over 50 countries.
Applications of Radioisotopes
Over 40 million nuclear medicine procedures are performed yearly all over the world, making the demand for radioisotopes increase with each year. Nuclear medicine uses radioisotopes for diagnostic and therapeutic purposes.
Technetium-99m (Tc-99) is the most commonly used radioisotope in nuclear medicine, used in over 80% of nuclear medicine procedures. Tc-99 is produced as a daughter product of Molebdenum-99 (Mo-99). Mo-99 is produced in research reactors. SAFARI-1 produces about a third of the world’s Mo-99 supply.
SAFARI-1 irradiates Low Enriched Uranium (LEU) Molybdenum plates in its core to produce Mo-99, the plates are processed at NTP isotopes facilities and packed into Tc-99 generators (a lead pot enclosing a glass tube containing the radioisotope) then transported to various clients. Tc-99m has a short half-life of 66 hrs, thus the Tc generators contain Mo-99 radioisotope when in transit.
Other uses of radioisotopes in nuclear medicine include sterilization of medical products using gamma rays from Cobult-60 (Co-60).
Various other isotopes such as: Gadolinium-153 (bone density measurements), Lutetium-177 (targeted therapy for treatment of cancer and other diseases), Iridium-192 (brachytherapy to treat tumours), Samarium-153 (metabolic radiotherapy for the treatment of pain from bone metastases), Ytterbium-176 (optical fibres, dopant for garnet crystals in lasers), and Yttrium-90 (Y2O3) (materials coating) are irradiated in the SAFARI-1 core.
With technology advancing and use of electronic devices on the rise, high quality semiconductor power devices are on demand. The use of silicon as a semiconducting material is favoured by various industries.
Neutron Transmutation Doping (NTD) of Silicon is offered at SAFARI-1 using its poolside facility. About 1 ton of Silicon is irradiated each month and shipped to semiconductor manufacturing companies.
SAFARI-1 is being utilised to help advance human life, be it in the medical fraternity or industrial fraternity. The benefits of Nuclear Technology are in our everyday life.
NB: Edzani Ratsibi – Women in Nuclear South Africa (WiNSA) Necsa Chairperson.
– CAJ News