The plan emphasizes ensuring a stable supply of major medical isotopes. It aims to address supply gaps by researching and constructing internationally advanced research reactors and supporting experimental production facilities. This will enable differentiated production and stable supply of key medical isotopes such as molybdenum-99, carbon-14, strontium-89, yttrium-90, iodine-125, iodine-131, and lutetium-177, while breaking through technologies for developing and producing new medical isotopes.
Molybdenum-99 (??Mo) is a radioactive isotope of molybdenum, with 42 protons, 57 neutrons, and a half-life of approximately 65.94 hours. It decays via beta emission, producing technetium-99m (???Tc), a widely used medical radioisotope. Its physical properties include the release of beta particles and gamma rays during decay, with moderate energy levels, and its short half-life necessitates continuous reactor production to ensure supply.
Globally, most molybdenum-99 is produced in nuclear reactors using high-enriched or low-enriched uranium targets, which are irradiated and chemically separated. Currently, China’s medical molybdenum-99 supply heavily relies on imports. To reduce this dependency and enhance production safety, Chinese researchers successfully produced a medical-grade molybdenum-99 sample with 99% nuclear purity in June 2024 using domestically developed low-enriched uranium targets, passing on-site acceptance after a meticulously designed reactor irradiation process.
In applications, molybdenum-99 is a cornerstone of nuclear medicine diagnostics. Its decay product, technetium-99m, with a 6-hour half-life, is ideal for detection by SPECT equipment due to its chemically active nature, allowing it to bind with various compounds for organ imaging. Clinically, it is used for cardiac imaging to assess myocardial ischemia via perfusion agents, bone scans to detect tumors or fractures, and functional checks of the thyroid, kidneys, and liver.
Beyond medicine, molybdenum-99 finds use in industrial and research fields. It serves as a radioactive tracer in material and environmental sciences to study substance migration and transformation, and in nuclear physics research to understand atomic nuclear structures and decay patterns.
