Less than 70 nuclear power plants satisfy most of all the electrical energy need in the USA. They produce about 1,000 GW of electricity a year in total. The complete electricity-generating ability in the world is around 3,500 GW a year. Nuclear contamination is very dangerous but also extremely rare in occurrence, and when it happens, these accidents are always extremely well publicized. The main danger from a nuclear reactor is a meltdown of the core and the dispersion of radioactivity, exactly what happend in the Fukushima plant in Japan in March 2011.
19.9% of net generation is nuclear. The two types of reactor processes in use are:
- PWR (pressurized water reactor). Heat is removed from the reactor by water flowing in a closed pressurized loop, and then transferred to a second water loop at lower pressure. This loop will boil and produce steam. No radioactivity ever leaves the reactor.
- BWR (boiling water reactor). Water boils in the reactor itself, and the steam goes directly to the turbine generator. Tiny amounts of radioactivity are introduced into the pipes and turbine.
When nuclear fuel in a reactor has been depleted, it can be stored or recycled, which often reduces the need to buy new fuel. The fuel that is stored is sealed in glass containers that are later treated and stored in these two ways:
- Storage of sealed containers in very deep volcanic seashore ditches where they slowly assimilate again with the core of the earth. Eventually, the containers will melt back into the magma that exists in the center of the earth, which is naturally readioactive.
- Land storage (granite, volcanic tuff, salt, shale). Suitable storage sites are still being researched. This form of sturage actually has less of a perspective because of the NIMBY mentality ("Not In My Back Yard").
Storage of spent fuel poses the following two threats:
- Abuse of the material for nuclear weapons production by terrorists.
Despite its bad name, nuclear power is a extremely handy and economic form of energy production. It is much cleaner than burning fossil fuel which emits carbon dioxide, along with SOx as well as NOx. In addition to green (totally free) energy, nuclear power plants provide the least expensive source of energy in operation.