confusion about Thermonuclear Fusion

Thermonuclear fusion would create LOTS of nuclear waste.

Thermonuclear fusion has been "20 years in the future" for decades.

The money wasted on thermonuclear fusion could have been spent to install solar electric and solar thermal panels on a significant percentage of the buildings in the US.

Thermonuclear fusion would generate large amounts of radioactive waste and has secret military purposes.

The primary reason it is still a pipe dream is it's not very easy to capture 100 million degree celsius plasma and keep it from destroying your laboratory.

The deuterium / tritium fusion reaction (the type of fusion easiest to achieve, requires the lowest temperatures) releases a very high energy neutron that can "induce" radioactivity in nearby materials.

Deuterium + Tritium --> Helium + free neutron

Helium: two protons, two neutrons
Deuterium: one proton, one neutron (heavy hydrogen, also called "heavy water")
Tritium: one proton, two neutrons (the radioactive isotope of hydrogen)

There have been proposals for building "fusion reactors" that could make nuclear weapons materials by surrounding the core with uranium-238, otherwise known as "depleted uranium" - which the free neutrons would convert to plutonium-239 (the most important ingredient for nuclear weapons).

The steel supports of this hypothetical fusion reactor would periodically have to be replaced because the free neutrons would induce radioactivity in the metal. Claims that fusion would be free of radioactive waste are a cruel deception.

The real way to capture thermonuclear energy is with photovoltaic panels.

Thermonuclear reactor research is part of weapons research. Some forms of it are used to simulate nuclear explosions in a laboratory. It has virtually nothing to do with electricity generation.

Some fusion advocates note that fusion reactors would not release any carbon dioxide, and therefore would not have any impact on climate change. However, they ignore the fact that an enormous amount of heat would be liberated that would have massive impact on local and global climate.

A fusion reactor, if one could ever be built that would last for more than microseconds, would generate 100 million degree temperatures (Celsius). Just imagine what replicating stars in our power stations would do to local climate patterns. This makes the impact of our combustion of fossil fuels seem minor in comparison. Thermonuclear reactors would use the 100 million degree heat to boil water to spin a turbine to make electricity. If fission reactors (which only get about 500 degrees) are the equivalent of using a chainsaw to cut butter, thermonuclear reactors would be the equivalent of bringing a part of the Sun to the Earth to melt the snow off your sidewalk.

"Hot fusion" should be prohibited on planets and confined (so to speak) only to stars.


The claims for "cold fusion" may or may not have validity -- links to the more sober claims are at (a permaculture view of claims for "free energy"). If this is real, that would be worth pursuing (there does seem to be some corporate interest in these claims, which suggests at least some level of reality to the technology).

Renowned Physicist Promotes Fusion as the Solution, But Doesn't Consider Climate Impacts of 100 Million Degree Plasma Or How to Cope With Peak Oil Now


Kip S. Thorne Lecture
Thu, Mar 24 2005
University of Oregon

"Einstein's Legacy in the Modern World: From Black Holes to Quantum Cryptography" In this free lecture, renowned theoretical physicist Kip S. Thorne will trace back to Einstein such technologies as thermonuclear power, the global positioning system, lasers, bose condensates, and quantum cryptography; and such major cosmological concepts as black holes, wormholes, singularities, gravitational waves, and the shape of our universe. Kip Thorne is a professor at the California Institute of Technology and author of "Black Holes & Time Warps, Einstein's Outrageous Legacy." The lecture is held in association with the 21st Pacific Gravity Meeting at the UO March 25 and 26 and is part of the 2005 World Year of Physics celebration.

Professor Thorne praised the possibilities of thermonuclear fusion as a replacement energy source for the technologies currently used by industrial civilization. However, he admitted that its implementation, if all went well, would still be several decades in the future. When asked after the lecture what solutions he would propose for the interim between Peak Oil and the year 2050, he did not have an answer, although he conceded that photovoltaics could play a role (when asked about this low-tech means of harnessing thermonuclear fusion from the sun). He also claimed that the free neutrons emitted by a thermonuclear fusion reaction would quickly decay and would not induce radioactivity in nearby structures (given that he makes bets on theoretical physics with Steven Hawking, it's probable that he's right on this point). But, he did not apparently think through the impact of massive creation of localized heat sources with the thermonuclear plasma (100 million degrees) and the impact this heat would have on the Earth's biosphere and climatic stability.