vSMRs' success hangs on fuel supply, transportation issues
(https://nuclear-production-assets.s3.eu-west-2.amazonaws.com/triso_particle.jpg)
Next-generation TRISO fuel particles have several layers of carbon and carbide that serve as the primary containment for radioactive material. (Source; Idaho National Laboratory)
https://www.reutersevents.com/nuclear/vsmrs-success-hangs-fuel-supply-transportation-issues (https://www.reutersevents.com/nuclear/vsmrs-success-hangs-fuel-supply-transportation-issues)