The database includes small modular reactors (SMRs) and advanced reactors. SMRs can also be “advanced”, but some SMR designs (though not all) are scaled-down versions of existing light-water reactor technology, which is why the database distinguishes between SMR units and advanced units.
The technologies in the database encompass a range of reactor types including (but not limited to) next generation water-cooled reactors (e.g., small modular light-water reactors and supercritical water-cooled reactors), non-water-cooled reactors (e.g., lead or sodium fast reactors, molten salt reactors, and high temperature gas reactors), and fusion reactors.
Some advanced reactor concepts are relatively new, while others have been under consideration for decades and used in research, test, and prototype reactors around the world.
Reactors using any of these technologies that have electric generating capacity of 300 MW or below are classified by the International Atomic Energy Agency as SMRs.