The new nuclear power: what SMRs are and why they are at the center of the energy debate

While the debate on the energy transition becomes increasingly heated, the term "new nuclear" has firmly entered the Italian political and economic agenda. But what is it, exactly? Unlike traditional large-scale reactors (the so-called third generation), which require enormous financial investments, at least a decade of construction sites and an impressive structural footprint, the new technological wave focuses everything on flexibility, passive safety and modularity. The heart of the turning point is represented by the fourth generation SMRs (Small Modular Reactors) and AMRs (Advanced Modular Reactors). If the giants of the past were built entirely in situ, the mini-reactors of the future are designed to be assembled in a factory and transported by road or rail, drastically reducing installation times and costs.

There remains a non-negligible problem: timing. Unlike renewable technologies, in fact, at the moment "new nuclear" still remains at project level: there are no commercial plants of this type in the world, except for two officially operational SMRs, one in China and the other in Russia, about which too little is known. To see mass commercial diffusion on European and Western soil, therefore, it will still take many years: the roadmaps of the main industrial consortia set the deadlines optimistically around 2035.

How does an SMR mini-reactor differ, technically, from a traditional nuclear power plant?

The key difference lies in the scale and method of construction. A traditional reactor usually has a power of more than 1,000 electrical megawatts, while an SMR, by definition, has a power of less than 300 megawatts. This small size allows for modularity: the components are not cast in concrete directly on the power plant site, but mass-produced within specialized industrial factories. This reduces the margins of construction error, optimizes the supply chain and allows you to add power "modules" according to the real needs of the network, a bit as if they were modular bricks.