Various new forms of nuclear energy are in development, hoping to address the drawbacks of conventional nuclear. Nuclear power based on thorium, rather than uranium, may be able to provide higher energy security for countries that do not have a large supply of uranium. Small modular reactors may also have several advantages over current large reactors: it should be possible to build them faster, and their modularization would allow for cost reductions via learning-by-doing. Several countries are attempting to develop nuclear fusion reactors, which would generate very small amounts of waste and no risk of explosions.