Civilian Nuclear Power

Remarks by James Lovelock,
a genuine and well-informed environmentalist,

Inaugural Ceremony of the World Nuclear University
4 September 2003

A Large, Sustainably Renewable Energy Resource

A Source of Hydrogen

In the USA, just under 20% of the electrical energy consumed is produced by nuclear power plants, which emit no carbon dioxide during operation. Just about 50% of the electrical energy is supplied by burning coal. The total weight of poisons (Oxides of sulphur and nitrogen, carcinogenic particulates, mercury vapor, heavy metals, arsenic, even radioactivity) emitted annually by coal burning is hundreds or even thousands of times by weight the output of "nuclear wastes" from nuclear plants. The big difference is that the coal burners emit many of their poisons in gaseous form straight into the atmosphere.
The total weight of carbon dioxide is many thousands of times as much as the nuclear waste.

These facts apply to nuclear technology currently in commercial use, which wastes over 99% of the uranium mined, although an efficient safe replacement technology was proven in April 1986. Its expected yearly production of nuclear waste, for a one-Gigawatt (one thousand Megawatt) generator, was 1700 pounds, i.e. less than a ton. An equivalent coal powered plant produces about 1,275,000 tons — of carbon dioxide, poisonous and acidic gases, carcinogenic fly ash, and poisonous solid ash.
This efficient nuclear technology would reduce nuclear wastes by a factor of twenty to a hundred, in mass, and by a thousand or more in duration. Carbon dioxide, of course, lasts for ever.

The Case for National Nuclear Energy

I shall expand this section, but the gist of it is, that:

There is another option Hydrogen fusion reactors but I doubt that anything less than a national government can afford the research. Progress in this field has been dismally slow since the 1950's.

Some Physics

The uranium isotope 235U is fissile. That is, when hit by a neutron, it is liable to break into two large pieces called fission products and two or more neutrons. These fission products, and the neutrons, add up to a very slightly smaller mass than the original nucleus. The difference is converted to a prodigious amount of energy, because in Einstein's mass-> energy equation, the mass is multiplied by the square of the speed of light, which is so large that light seems instantaneous to us.

The energy being released was originally created, in the natural synthesis of the heavy elements, by the prodigious cataclysm of energy that attends the gravitational collapse of a blue giant star, nova, or supernova. It's not the usual kind of fossil energy. Radioactive isotopes also power the tectonic forces and geothermal plumes.

When uranium ore is extracted and turned into yellowcake, uranium oxide, it can be reduced in the usual way with carbon to get chemically pure uranium. I call this natural uranium. Of this, about 0.7% is 235U, which is directly usable in a reactor that moderates its neutron flux to thermal speeds. The rest of it is 238U, which isn't fissile. In the United States, a mere 50 million pounds or so of uranium oxide, per year, supplies our civilian nuclear reactors. That's about 25 thousand tons, including the oxygen.

More than 80% of the uranium is thrown away as 'depleted uranium' from the 'enrichment' process. About 96% of the 'enriched' uranium that goes into the reactors becomes "nuclear waste" because it isn't fissile. Even so, the energy available from the rare fissile isotope supplies about 20% of our electric energy. Some of the neutrons are captured by the non-fissile isotope that constitutes the rest of the fuel rod, and about 30% of the energy comes from the fact that the isotope produced (239Pu ) is also fissile.

However, a 'fast' reactor is designed so that more of the non-fissile isotope 238U that constitutes the rest of fuel rods, will capture neutrons and become fissile. The ideal fast reactor design will reprocess the spent rods into new fuel rods and fission product waste.

Fissile isotopes are an energy resource. The interesting thing about neutron capture by uranium is that it creates a new fissile isotope. 238U becomes 239U, almost immediately 239Np (neptunium) and then 239Pu, the undeservedly notorious plutonium.
Pure 239Pu is a material from which a devastating bomb can be made, as was proved at the 'Trinity' experiment, and later upon Nagasaki.
But it is also every bit as good a nuclear fuel as the laboriously produced 235U, which forms up to 5% of the 'enriched' uranium for reactor fuel rods. Moreover, if the neutron bombardment is allowed to continue for a profitable power cycle, the plutonium becomes contaminated with the next higher isotope, 240Pu, making it useless for a bomb.

It still performs well in a civilian fast reactor, because the requirements for an explosion are very different from a controlled steady chain reaction.
To put it another way, fissile isotopes are a sustainably renewable energy resource.

In fact, considering that if less than a hundredth part of a few thousands of tons of natural uranium is enough fissile uranium for 20% of the USA's electric energy comsumption, whereas it takes thousands of millions of tons of coal to supply 50%, it should be obvious that if fast reactor technology were used, those few thousand tons of uranium could be producing a hundred times 20% of our present annual demand in electrical energy — and with a far smaller output of waste! It would not, of course, all be available in one year. But it means that one year's uranium supply could provide fuel for a hundred years. Or better, could supply all of our electricity for twenty years. Or five times our electric demand for four years. That's close to our total energy consumption. The total nameplate capacity of USA's nuclear reactors is close to 100 GW.

There are several designs for fast reactors to renew fissile isotopes in this way. The best is the Integral Fast Reactor, the IFR, developed in Idaho by Argonne National Labs.

Consider the backlog of 'spent uranium' and 'depleted uranium' from the last 20 years. Suppose one percent of the uranium mined is now used up. We have enough uranium, if it be recycled, for 99x20x20% of a year's electrical demand. If it were enriched with just enough plutonium from our nuclear weapons stockpiles, or even from reprocessing the "nuclear waste problem", and fed into another 400 GW worth of fast reactors of the IFR design, there would be enough fuel to displace all of the coal burning and gas burning plants, and to last for 200 years!

A Source of Hydrogen

You can make hydrogen from methane, but it's pointless except for fertilizers.
You can pass hot steam over glowing coal (or charcoal) and remove the oxygen as carbon dioxide. This is called 'water gas'.
You can electrolyse an aqueous solution of any electolyte, e.g. salt water.
The last of these is the only one that doesn't depend upon sending carbon dioxide into the atmosphere. So hydrogen is essentially bottled electricity. How do you get the electricity?

Obviously, if you had abundant nuclear power, you switch the power plants to feed the hydrogen-production factories, at off-peak. The hydroelectric dams in the Columbia River basin used to do the same thing for aluminum production.

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