Existing reactors cannot use more than a small portion of the available nuclear fuel. The resulting energy surplus can only be captured if spent fuel is reprocessed and recycled into the fuel cycle. Improving reactor design or providing better options for reprocessing and reusing nuclear fuel would reduce hazardous waste levels and result in better use of available uranium resources.
Nuclear reactor development is divided into generations. Modern reactors in operation today belong to Generation lll. Generation III + reactors, connecting modern technology with the technology of tomorrow, are already under construction.
Future technological developments include Generation IV, which will not be put into operation until several decades from now.
Fusion energy is based on combining two light nuclei to form a new, heavier nucleus. The fusion creates large amounts of energy in the form of heat that can be used to produce electricity.
The advantages of fusion power are its potential to generate exceptionally large amounts of energy, powered by inexpensive, ordinary materials, and the fact that it leaves no hazardous waste behind. The disadvantage is that it requires extremely high temperatures, which are difficult to control. Fusion power research has been conducted since the 1950s, but when and if fusion power will become commercially viable remains unclear.