Uranyl Salt Reactors for Mo-99 Production

Chris Cooling

Molybdenum 99

• Fission product• Half life of 66 hours• Decays to Tc-99m• Tc-99m has a half life of 6 hours• Tc-99m a radioactive tracer used in diagnostic

medicine• Demand is currently exceeding supply

Current Production Methods

• Bombarding targets with neutrons– HEU targets to induce fission– Mo-98

• Current reactors– NRU, Canada– HFR, Netherlands– SAFARI-1, South Africa– BR2, Belgium– OSIRIS, France– Opal, Australia

Uranyl Salt Reactors• Uranyl Sulphate or

Uranyl Nitrate dissolved in acid (100-300gU/l)

• Water acts as the moderator

• Low temperatures• LEU or natural uranium• Many research reactors

in early days of nuclear

Uranyl Salt Reactors

• Reactivity Feedback– Void production– Thermal feedback

• Challenges– Materials challenges– Complex multi-physics– Regulatory challenges

Advantages of Uranyl Salt Reactors in the Production of Mo-99

• LEU as opposed to HEU• Lower power• Continuous processing possible

The Medical Isotope Production System (MIPS)

• AHR designed to produce Mo-99• Uranyl Nitrate• Array of 4x220kW reactors• ~80l of fuel• Cooled internally by water-filled

cooling coils

My Work

• Modelling of MIPS for regulatory and optimisation purposes– 2D and 3D multi-physics models– Point kinetics models

FETCH

• Based upon AMCG’s FLUIDITY program• Couples fluid mechanics and neutronics

calculations• Multi-phase flow• Embedded cooling coils

FETCH Example – CRAC 43

• Increase in solution height

• Void and temperature feedback

Goals

• Improve heat transfer models• Implement boiling models• Validate point kinetics model

Questions?