The two nuclear reactions that give great amounts of energy are fission (splitting of heavy atom nucleuses) and fusion (melting light atom nucleuses together). It is only the fission process that we can control and use for energy exploiting.

The Uranium reactor.

Unfortunately there are some disadvantages with fission of the Uranium isotops ₉₂U²³⁵ and ₉₂U²³⁸ we use today:

1. The fission products have long half-lives regarding dangerous radiation.

2. The fission is difficult to control because it is a chain reaction propelling itself. Three neutrones are made in each fission of a nucleus and only one is used and thereby removed. You need to have a super absorption of neutrons to remove enough of the spares to prevent an uncontrolled situation. The control is then by definition difficult and it has happened failures. A complete meltdown of the reactor may then take place and huge amounts of radioactive material will be released. The Tsjernobyl disaster is an example of this and there have been other "almost" accidents in other reactors worldwide.

3. In the process Plutonium and Uranium²³⁸ are made that can be extracted and used as atomic bomb material.

The Thorium reactor.

The principle of a Thorium reactor is to use one neutron to make a nuclear change of Thorium to Uranium, ₉₀Th²³² to ₉₂U²³³ (to breed Uranium from Thorium). The Uranium then catch another neutron, becomes unstable and will do a fission. Two neutrones are then freed in addition to energy and waste products. What is then the benfit of this process?

1. The waste products of a fission of ₉₂U²³³ have shorter half-lives concerning dangerous radiation. Compared to the Unranium reactor waste products the Thorium have only 1/10000 of the Uranium waste radiation after 500 years. It is then more safe to store the waste products without leaking into the ground water.

2. The Thorium reactor will use the same number of neutrones as the process makes. (2 in and 2 out). If you do not have a "neutronpump" blowing neutrones into the process it will stop immedialtely. A pump is easier to controll than an absorption.

3. It is almost impossible to make bomb material from the Thorium reactor processes.

In order to make a neutronpump work continiously a lot of energy is demanded, but the reactor will deliver more than 30 times more energy than it consumes.