Until now, generating nuclear power has required massive facilities surrounded by acres of buildings and infrastructure. The nuclear industry is trying to change that picture—by going small. Efforts to build the nation’s first "advanced small modular reactor" (SMR) in Idaho, U.S.A., are on track for it to become operational by the mid-2020s.
Proponents of these advanced SMR say they will be easier to build and more flexible in terms of where they can be located than the larger kind. The word "modular" refers to how they will be built in factory-like settings, ready for hauling either fully assembled or in easily connected parts by truck, rail or sea.
SMR will differ from the smaller reactors already deployed because of their new technologies. These advances are intended to make it less likely or even impossible for them to melt down or explode, as happened during Japan’s Fukushima disaster. For example, they may be equipped with cooling systems that continue working even if no operators are present and all electric power is lost. In many cases, the entire SMR will be below ground to safeguard these facilities during natural disasters such as the earthquake and tsunamis that led the three Fukushima Daiichi reactors to melt down.