But What About Fusion?

It is so inviting... to think that our planet can be powered from ocean water. That, as you probably well know, is the expectation of many who would eschew other forms of energy generation. "Cold fusion" - which many of us would hope to be a viable energy source - is unproven. Which leads, naturally, to the hot variety. And I do mean hot!

You may remember from your freshman days at Hormesis U., that both deuterium and tritium are isotopes of hydrogen. (See chapter 5 if your memory is a bit rusty.) As it is generally understood, a fusion reaction in the sun occurs at temperatures in excess of 1,000,000 degrees Fahrenheit, when a deuterium and a tritium atom are crushed together to form helium and expel a neutron. It would be much cleaner if two deuterium atoms could do the trick without a neutron chaperone, but the universe just wasn't made that way. And while it's true that there is a virtually infinite supply of deuterium in ocean water, the horrible fact is: there isn't any tritium. (OK, a few quadrillion atoms or so, but not any that we can extract.) In fact, in the entire United States, there isn't much tritium at all, since your government considers this beta emitter - used on luminous watch dials - to be hazardous to your life. (Please be appreciative.)

Where would we get the tritium? I don't know, and I don't think anyone else does either. But there are other problems that I suspect are overwhelming in light of our present-day engineering and material capabilities - and may be physically impossible to solve. [For more on this subject, see the August 1999 edition of The Energy Advocate, published by Howard Hayden, professor emeritus of Physics, University of Connecticut. P.O. Box 7595, Pueblo West, CO 81007 - or www.EnergyAdvocate.com. ($35/year.)]

First, the energy required to magnetically contain the process (the only way it can be contained, since these temperatures decompose all materials into constituent atoms) invariably requires more energy than can be generated. Yet if, and when, this obstacle can be overcome, we have the problem of that pesky neutron.

While other particles can be redirected magnetically to where they have little danger to humans or equipment, the electrically neutral neutron has a mind of its own. When a plethora of neutrons are released around normal materials, those materials are transmuted into other element that are typically radioactive. Wouldn't this make the fusion reactor radioactive? Yes it would, which is probably why hot-fusion experiments reportedly must be cooled-down, dismantled, and decontaminated after every test run of only a few seconds. This might prompt us to ask, "What about the delivery of energy, twenty-four hours per day, 365 days per year?" There are, in my opinion, two choices.

Isotopes of Hydrogen

Hydrogen offers a simple example of isotopes. Figure 4 shows three forms of the element: The first is just regular hydrogen, designated at H or 1H, which has one proton and no neutrons. [It has a name, protium, but it's only used by real physics nerds or trivia freaks.]

The second form, deuterium or 2H, is known as "heavy hydrogen." It has the obligatory single hydrogen proton, but also has a neutron in its nucleus. [Deuterium is the form of hydrogen that makes "heavy water," the substance on which many World War II spy novels are based. These stories are based on a factual February 1943 raid on the heavy water concentration plant operated by the Nazis in Vemork, Norway. While an earlier attempt resulted in disaster - all thirty-four commandos were either killed in glider crashes or executed by the Germans - the second raid was a textbook example of guerrilla warfare and bravery. Disabling the Vemork plant was a major setback for the Axis A-bomb program.]

Finally, the form of hydrogen known as tritium, or 3H, is seen to have two neutrons.

All three forms are known as isotopes with 1H making up 99.98% of the total hydrogen that we know about - and presumably in the universe. Both "regular" hydrogen and deuterium are stable isotopes, meaning that they don't change over time.

But tritium is anther story: it is an unstable isotope that will eventually decay or disintegrate into stable 1H. [All tritium undergoes "beta-decay" in which the neutron changes into a proton and an electron - a feat of amazing atomic legerdemain.] It is this process - where atoms go to pieces - that we normally call radioactivity.