Exploring Novel Production Pathways for the Medical Isotope 99 Mo
99 Mo is one of the most extensively utilized diagnostic radionuclides in nuclear medicine. Conventional 99 Mo production relies predominantly on research reactors, which face challenges such as the vulnerabilities of a concentrated supply chain, aging infrastructure, nuclear proliferation risks, and substantial generation of radioactive waste. To explore more sustainable and safer production technologies, the research team has proposed a novel technical approach. This method employs high-energy electrons generated by an electron accelerator to directly irradiate a flowing molten salt target containing natural uranium for 99 Mo production.
Photofission-Dominated Production Mechanism
In this approach, 99 Mo is primarily generated through the photofission reaction of 238 U. This process eliminates the reliance on 235 U, allowing for the direct use of natural or even depleted uranium. This significantly mitigates nuclear proliferation risks and offers substantial advantages in terms of material security. As noted by Thomas Ruth in Nature: "The production rate of 99 Mo is several orders of magnitude lower, but this is outweighed by the advantage of using safer materials".
Systematic Optimization Analysis of Key Parameters
The research team identified fluoride-based molten salt systems as the optimal target material due to their higher bremsstrahlung energy loss rate and superior photon yield, which contribute to a higher 99 Mo production rate. An electron beam energy range of 40–80 MeV is recommended. Furthermore, temperature field analysis of the flowing molten salt confirmed that the system can effectively prevent localized overheating and salt boiling, validating its engineering feasibility.
Capacity Assessment Demonstrating Potential for Scalable Application
The maximum annual production capacity of 99 Mo via this technical route is estimated to reach approximately 4486.49 Ci, sufficient for several hundred thousand to a million medical diagnostic procedures. This output corresponds to approximately 16.37% of China's projected demand for 2030, demonstrating the potential for economically viable, large-scale production capability of this approach.
Advancing the Security of Nuclear Medicine Isotope Supply
This research integrates advanced accelerator technology with molten salt chemistry, proposing a non-reactor-based, low-risk, and high-capacity production route for 99 Mo. It provides a new technical pathway for establishing distributed, modular 99 Mo production bases within China, contributing to reduced external dependency and safeguarding public health.
The complete study is via by DOI: https://doi.org/10.1007/s41365-026-01908-3
Nuclear Science and Techniques
Computational simulation/modeling
Not applicable
Production of 99Mo via photofission reaction in natural-uranium-bearing molten salt targets
9-Feb-2026