Jan Leen Kloosterman

Jan Leen Kloosterman is a Professor at the Faculty of Applied Sciences, Delft University of Technology, Netherlands. His research focuses on the analysis and development of nuclear reactors and fuel cycles with emphasis on safety and sustainability, particularly thorium-based technologies. He envisions inherently safe reactors that fully utilize uranium/thorium while eliminating long-lived nuclear waste through innovations like the Thorium Molten Salt Reactor (Th-MSR). He also explores nuclear applications in medical isotope production and neutron therapy.

• Role: Professor, Faculty of Applied Sciences
• Department: Radiation Science & Technology (Reactor Physics and Nuclear Materials group)
• Contact: j.l.kloosterman@tudelft.nl

Research Interests center on nuclear reactor design, thorium fuel cycles, and molten salt reactors. His work includes:

• Thorium Molten Salt Reactor (Th-MSR): Breeding fissile U-233 from thorium, enabling self-sustaining fuel cycles with minimal proliferation risks.
• High-Temperature Reactors (VHTR/AHTR): Enhancing helium coolant temperatures for hydrogen production via thermochemical cycles like Sulfur-Iodine and UT-3.
• Nuclear Hydrogen Production: Investigating synergies between nuclear heat and hydrogen economy to decarbonize energy systems.
• Neutron Physics: Studying neutron feedback mechanisms, prompt/criticality dynamics, and fuel processing for optimal neutron economy.

Advising and Collaborations involve PhD/MSc students across reactor physics, microfluidics, fuel cycle analysis, and medical applications. Notable projects include MSR hydrogen production systems, TRISO fuel behavior, and passive safety mechanisms like freeze plugs and helium bubbling.

Labs & Teams: Leads research within the Reactor Physics and Nuclear Materials (PNR) group, collaborating with international Generation-IV MSR program stakeholders and supervising students in computational modeling, experimental reactor designs, and radiopharmaceutical synthesis.