Small modular reactors gain attention but face cost, safety and waste hurdles

Small modular nuclear reactors are being promoted as fast-to-build, low-footprint power sources, yet experts warn they remain expensive, pose cumulative radiation risks and lack a solution for spent fuel.

Political leaders and tech firms are championing small modular reactors (SMRs) as a quick, compact alternative to conventional nuclear plants, highlighting their prefabricated design and modest land use of about two hectares. While the modular approach could shorten construction to as little as 18 months, each reactor’s output of 10-200 MW is far below the 1,000-1,600 MW of typical stations, implying that tens of thousands would be required for global parity.

German radiation experts warn that the sheer number of units could amplify the overall chance of a serious incident, despite lower per-reactor radioactivity. Economic analyses from the German Institute for Economic Research estimate SMR-generated power to cost at least double, and possibly up to eight times, current solar or wind rates. Moreover, the industry still lacks a permanent solution for high-level waste, with existing storage sites like Germany’s Asse facility showing signs of leakage, and only two operational SMRs—one in China and one in Russia—today.