Director​/Head of Radiochemistry & Isotope Production

Subcritical Systems, Inc. is a venture-backed startup in Austin, Texas, developing accelerator-driven systems. We are the only U.S. commercial manufacturer of accelerator cavities. We aim to do for accelerator cavities what SpaceX did for rockets and commercialize them for power production, medical isotopes, semiconductor manufacturing, and waste transmutation.

We are developing the Energy Amplifier, a novel nuclear fission system in which a particle accelerator drives a subcritical core. The design makes
* meltdown* physically impossible and supports clean power production. Its inherent safety provides a more streamlined licensing path. Our founding team includes deep-tech entrepreneurs who have built several multibillion-dollar companies and former U.S. national laboratory leaders with extensive accelerator and nuclear expertise.

We are expanding our team as we advance licensing, regulatory submissions, and construction of our first Energy Amplifier. Learn more at

The position will lead the development, commissioning, and operation of Subcritical Systems’ accelerator-based radioisotope production capability. The role is responsible for establishing an integrated isotope production program spanning target development, irradiation, radio chemical processing, purification, quality control, and delivery of medical and industrial radioisotopes. This individual will build the radiochemistry and isotope production strategy, develop cGMP-quality processing capabilities, and ensure the program is aligned with emerging radiopharmaceutical demand and clinical development pipelines in North America, Europe, and Asia.

• Lead the development and operation of a proton accelerator-based radioisotope production program.
• Define the isotope production roadmap based on technical feasibility, market demand, radiopharmaceutical development pipelines, and clinical requirements.
• Develop irradiation, target handling, radio chemical processing, purification, and recovery workflows for medical and industrial isotopes.
• Lead the design, specification, installation, commissioning, and qualification of hot cells, radiochemistry laboratories, and associated isotope-processing infrastructure.
• Design and implement cGMP-quality chemical separation and purification processes for radioactive materials.
• Establish robust, reproducible production workflows covering target receipt, irradiation, transfer, dissolution, separation, purification, formulation, QC, and waste handling.
• Partner with accelerator physics and engineering teams to optimize beam energy, current, irradiation conditions, target design, cooling, and isotope yield.
• Develop and maintain isotope production models incorporating nuclear reaction cross-sections, radionuclidic purity, decay, production yield, and processing timelines.
• Establish quality systems, batch documentation, analytical methods, specifications, and release criteria appropriate for radiopharmaceutical precursor and isotope production.
• Ensure radiochemistry operations comply with applicable radiation safety, environmental, GMP, transportation, and regulatory requirements.
• Build and lead a multidisciplinary team spanning radiochemistry, isotope production, analytical chemistry, targetry, quality, and operations.
• Maintain a detailed understanding of emerging radiopharmaceutical clinical programs and translate future isotope demand into production strategy and capacity planning.

• PhD or advanced degree in Radiochemistry, Nuclear Chemistry, Chemistry, Chemical Engineering, Nuclear Engineering, or a closely related discipline.
• 8+ years of experience in radioisotope production, radiochemistry, radiopharmaceutical manufacturing, or accelerator-based nuclear…