A system for distributed non-fission production of Radionuclide Mo.99

Background

The field of medical imaging relies heavily on the use of radiopharmaceuticals, with Technetium-99m (Tc-99m) being the most widely utilized isotope for diagnostic procedures. Tc-99m is derived from the decay of Molybdenum-99 (Mo-99), which is essential for producing the short-lived tracer on-site at hospitals and clinics. Given Tc-99m’s short half-life, a steady and reliable supply of Mo-99 is critical to ensure timely and effective patient care. However, the current global infrastructure for Mo-99 production is limited, with only a handful of aging nuclear reactors responsible for the majority of supply. This centralized and fragile supply chain has led to periodic shortages, threatening the availability of vital diagnostic imaging services and highlighting the urgent need for more robust, distributed, and sustainable production methods.

Existing approaches to Mo-99 production predominantly rely on the fission of highly enriched uranium (HEU) targets within nuclear reactors. This method is fraught with significant challenges: it generates large quantities of hazardous radioactive waste, involves complex and costly waste management, and raises proliferation concerns due to the use of weapons-grade uranium. Additionally, the reactors themselves are expensive to build and maintain, and are subject to regulatory, political, and operational risks that can disrupt production. Alternative non-fission methods, such as neutron activation of molybdenum targets, have not achieved sufficient efficiency or scalability to replace reactor-based production. As a result, the field faces a pressing need for cleaner, safer, and more flexible technologies that can decentralize Mo-99 production and ensure a stable supply for medical diagnostics worldwide.

Technology

This technology enables the production of the medically vital radionuclide Molybdenum-99 (Mo-99) through a non-fission process that avoids the use of uranium and the generation of hazardous radioactive waste. The system operates by first generating neutrons, typically with a compact deuterium-tritium (D-T) neutron generator. These high-energy neutrons are moderated to an optimal energy range (6–14 MeV) and then directed onto a metal target, such as copper, which emits high-energy gamma rays (>8 MeV) as a result. These gamma rays are subsequently used to irradiate a molybdenum target enriched in Mo-100, inducing a nuclear reaction that transmutes Mo-100 into Mo-99. The apparatus is modular and can be configured for various target and moderator materials, allowing for flexible, on-demand, and distributed production of Mo-99, which is then used to generate Technetium-99m (Tc-99m) for medical imaging.

This approach is differentiated by its elimination of uranium fission, which is the predominant method for Mo-99 production but is fraught with challenges such as radioactive waste, regulatory hurdles, and reliance on centralized nuclear reactors. By leveraging neutron-induced gamma ray generation and subsequent gamma-induced transmutation, the technology allows for safer, scalable, and decentralized Mo-99 production. Its design supports continuous operation and can be tailored to local demand, reducing supply chain vulnerabilities and enabling hospitals or regional centers to produce Mo-99 as needed. Additionally, the system’s flexibility in target and moderator configuration, as well as its compatibility with various forms of molybdenum (solid, powder, or fluid suspension), further enhances its practicality and adaptability in diverse clinical and logistical settings.

Benefits

• Eliminates the need for uranium fission, reducing radioactive waste and proliferation risks.
• Enables distributed, on-demand production of Mo-99, improving supply chain resilience and accessibility.
• Uses compact, scalable neutron generators allowing flexible deployment in various locations.
• Produces medically critical Mo-99 for Tc-99m generators used in diagnostic imaging with reduced regulatory and political barriers.
• Supports continuous operation through fluid suspension embodiments, enhancing production efficiency.
• Improves safety by avoiding handling of highly enriched uranium and large nuclear reactors.
• Offers modular design adaptable to local demand and facility constraints.

Applications

• On-site hospital Mo-99 production
• Regional radiopharmacy isotope supply
• Mobile medical imaging isotope generators
• Decentralized nuclear medicine facilities

Additional info

This system generates Molybdenum-99 (Mo-99) via a non-fission process. A D-T source produces moderated neutrons (6-14 MeV) that bombard a metal target, emitting high-energy gamma rays (>8 MeV). These gamma rays then irradiate a Molybdenum-100 target, inducing its transmutation into Mo-99. This method enables distributed, on-demand radionuclide production without relying on uranium fission.