Hold on I’ll try and dig up that search result again.

Maybe it was nuclear power plants.

https://cerncourier.com/a/teslas-high-gradient-march/

Global view Distribution of superconducting particle accelerators using SRF structures for electrons (orange), protons (purple) and heavy ions (pink). More than 30 SRF accelerators are in operation (circles), approximately 15 are presently under construction (triangles) and more than 10 future projects are under consideration (squares). Credit: CERN

Particle accelerators using SRF technologies have been applied widely, from small facilities for medical applications up to large-scale projects for particle physics, nuclear physics, neutron sources and free-electron lasers (see “Global view” figure). Five large-scale (> 100 cavities) SRF projects are currently under construction in three regions: ESS in Europe, FRIB and LCLS-II in the US, and SHINE (China) and RAON (Korea) in Asia. Close international collaboration will continue to support progress in these and future projects, including SRF thin-film technology relevant for a possible future circular electron–positron collider. Perhaps the next wave of SRF technology will be the maturation of economical small-scale applications with high multiplicity and international standards. As an ultimate huge future SRF project, realising an ILC will indeed require sustained broad international collaboration.

Looks like they may be talking about particle accelerators rather than supercolliders. I’m not physicsy enough to know the difference, nor if an accelerator could be involved in the sorts of things that the supercolliders get accused of being in.

Me either. Feel free to confirm, I may have misread or the chart may have been inaccurate.

Prior to that chart I’d been under the impression there were only a handful worldwide.