Insights into prospective fusion reactor cooling systems from fission reactor cooling circuits

The next generations of nuclear fusion reactors, including ITER and DEMO, will consider several different cooling systems for heat dissipation, power generation and tritium breeding. This includes the water-cooled lithium-lead blanket (WCLL) design, which bears significant similarities to the water-cooled circuit in a pressurised water fission reactor. Preparatory work has begun to analyse how the water chemistry regimes used in light water reactors (LWRs) might be adapted to a fusion cooling system. Mitigation procedures from LWRs such as hydrogen water chemistry, zinc and noble metal addition may prove useful in controlling the rate of corrosion in a WCLL circuit, a system which is also subject to aggressive radiolysis products of water and high flow velocities. In addition, a fusion cooling system must cope with several unique challenges, including higher neutron energies and fluxes, thermal excursions from plasma instability and strong magnetic fields up to 10T.