Inertial Confinement Fusion

The hope and promise for nuclear energy is in nuclear fusion, which doesn't have many of the problems attendant with fission. Fusion has yet to be used to produce electrical power, but there are major research projects underway to reach that goal.

Fusion offers certain distinct advantages over fission. It, like fission, produces no CO₂. There is an abundant fuel supply for fusion. "The major fuel, deuterium, may be readily extracted from ordinary water, which is available to all nations. The surface waters of the earth contain more than 10 million million tons of deuterium, an essentially inexhaustible supply. The tritium required would be produced from lithium, which is available from land deposits or from sea water which contains thousands of years' supply." This contrasts with the fuels for fission, which are relatively rare isotopes of uranium, ²³⁵U or plutonium, ²³⁹Pu. Also, plutonium, Pu, is a by-product of the ²³⁵U fission reaction and both ²³⁵U and plutonium can potentially be used by terrorists to make bombs, which raises the issue of security. Raw materials and by-products related to fusion are not suitable for producing nuclear weapons, so the raw materials are not apparent terrorist targets, and handling and disposal of the raw materials and by-products are very much less onerous.  "Radioactivity will be produced by neutrons interacting with the reactor structure, but careful materials selection is expected to minimize the handling and ultimate disposal of activated materials."

There is one main challenge in the development of nuclear fusion for peaceful applications, that is, containing the nuclear reaction. There are two research approaches studying the problem, one is magnetic confinement and the other inertial confinement.

 

The National Ignition Facility (NIF), which is under construction at Lawrence Livermore National Laboratory (LLNL) is investigating inertial confinement fusion. NIF has 192 laser beams that will produce 1.8 MJ of energy aimed at a small target containing a mixture of deuterium and tritium. The laser produces heat and temperatures that are comparable to the sun and stars; enough to fuse the deuterium and tritium nucleii and release more energy than was put in by the laser.