NTP Radioisotopes (Pty) Ltd, a subsidiary of Nuclear Energy Corporation of South Africa (Necsa), is aiming to become the sole supplier of molybdenum-99 (Mo-99) to the USA. Mo-99 is used in hospitals to generate technetium-99m (Tc-99m), a short-lived radioisotope which plays a key role in nuclear medicine in crucial diagnostic and imaging applications as well as in the treatment of cardiovascular diseases and tumours. The USA previously received its entire supply of Mo-99 from Canada's MDS Nordion, but the extended shut down of the NRU reactor at Chalk River has led to a severe shortage of the isotope. Amid proliferation concerns, the US Congress has called for all Mo-99 to be supplied by reactors running on low-enriched uranium (LEU), instead of high-enriched uranium (HEU). It has called for proposals for an LEU-based supply of Mo-99 for the US market. This supply should reach 3000 six-day Curies per week by mid-2013. Tenders for this process close on 11 June 2010. NTP produces Mo-99 in its Safari-1 research reactor at its Pelindaba facility in South Africa. Since 25 June 2009, the Safari-1 reactor has been running continuously on a fully LEU fuel. The change over to LEU target plates is expected to be completed this year making NPT the world's first commercial producer of Mo-99 using a fully converted LEU production process. Rob Adam, chairman of the board of NTP and CEO of Necsa, said: "Several years ago we realized LEU was the way to go. We have been gearing up for this opportunity and we are confident that our experience in industrializing nuclear technology over several decades will decide the procurement process in our favour."