Uranium Is So Last Century — Enter Thorium, the New Green Nuke

[nabraxas]

Named for the Norse god of thunder, thorium is a lustrous silvery-white metal. It’s only slightly radioactive; you could carry a lump of it in your pocket without harm. On the periodic table of elements, it’s found in the bottom row, along with other dense, radioactive substances — including uranium and plutonium — known as actinides.

Actinides are dense because their nuclei contain large numbers of neutrons and protons. But it’s the strange behavior of those nuclei that has long made actinides the stuff of wonder. At intervals that can vary from every millisecond to every hundred thousand years, actinides spin off particles and decay into more stable elements. And if you pack together enough of certain actinide atoms, their nuclei will erupt in a powerful release of energy.

To understand the magic and terror of those two processes working in concert, think of a game of pool played in 3-D. The nucleus of the atom is a group of balls, or particles, racked at the center. Shoot the cue ball — a stray neutron — and the cluster breaks apart, or fissions. Now imagine the same game played with trillions of racked nuclei. Balls propelled by the first collision crash into nearby clusters, which fly apart, their stray neutrons colliding with yet more clusters. Voilè0: a nuclear chain reaction.

Actinides are the only materials that split apart this way, and if the collisions are uncontrolled, you unleash hell: a nuclear explosion. But if you can control the conditions in which these reactions happen — by both controlling the number of stray neutrons and regulating the temperature, as is done in the core of a nuclear reactor — you get useful energy. Racks of these nuclei crash together, creating a hot glowing pile of radioactive material. If you pump water past the material, the water turns to steam, which can spin a turbine to make electricity.

Uranium is currently the actinide of choice for the industry, used (sometimes with a little plutonium) in 100 percent of the world’s commercial reactors. But it’s a problematic fuel. In most reactors, sustaining a chain reaction requires extremely rare uranium-235, which must be purified, or enriched, from far more common U-238. The reactors also leave behind plutonium-239, itself radioactive (and useful to technologically sophisticated organizations bent on making bombs). And conventional uranium-fueled reactors require lots of engineering, including neutron-absorbing control rods to damp the reaction and gargantuan pressurized vessels to move water through the reactor core. If something goes kerflooey, the surrounding countryside gets blanketed with radioactivity (think Chernobyl). Even if things go well, toxic waste is left over.

When he took over as head of Oak Ridge in 1955, Alvin Weinberg realized that thorium by itself could start to solve these problems. It’s abundant — the US has at least 175,000 tons of the stuff — and doesn’t require costly processing. It is also extraordinarily efficient as a nuclear fuel. As it decays in a reactor core, its byproducts produce more neutrons per collision than conventional fuel. The more neutrons per collision, the more energy generated, the less total fuel consumed, and the less radioactive nastiness left behind.

Even better, Weinberg realized that you could use thorium in an entirely new kind of reactor, one that would have zero risk of meltdown. The design is based on the lab’s finding that thorium dissolves in hot liquid fluoride salts. This fission soup is poured into tubes in the core of the reactor, where the nuclear chain reaction — the billiard balls colliding — happens. The system makes the reactor self-regulating: When the soup gets too hot it expands and flows out of the tubes — slowing fission and eliminating the possibility of another Chernobyl. Any actinide can work in this method, but thorium is particularly well suited because it is so efficient at the high temperatures at which fission occurs in the soup.

In 1965, Weinberg and his team built a working reactor, one that suspended the byproducts of thorium in a molten salt bath, and he spent the rest of his 18-year tenure trying to make thorium the heart of the nation’s atomic power effort. He failed. Uranium reactors had already been established, and Hyman Rickover, de facto head of the US nuclear program, wanted the plutonium from uranium-powered nuclear plants to make bombs. Increasingly shunted aside, Weinberg was finally forced out in 1973.

the rest ov the 2 page article:

http://www.wired.com/magazine/2009/12/ff_new_nukes/

[Statakak]

Wikipepia "The thorium fuel cycle mainly creates Uranium-233 which can be used for making nuclear weapons, and since there are no neutrons from spontaneous fission of U-233, U-233 can be used easily in a gun-type nuclear bomb"

I think this means that it would be perfect to make 'Depleted Uranium' tank and artillery shells like we used against the Iraqis in the 'gulf wars'

It works really well because on impact the uranium metal vaporizes causing a large explosion

Allied forces working on tanks which had been hit by friendly fire suffered radiation poisoning

The cancer rate in these regions rose substantially (to aprox 150% of pre-war rate)

Fission Is So Last Century - Enter FUSION (The real Green Nuke)

- power through union not division. The process that powers the Sun.

http://www.iter.org

[ergoamide]

Gun type does mean shot out of a gun. It's the simplest and easiest type of nuclear bomb to develop. It gets the name gun type because it the way it works is by slamming or "shooting" one peice of enriched uranium into another thereby compressing them and hey presto bang. The reactor design the guy came up with is pretty interesting to. the article has riminded me of a letter sent into the paper the other day. This guy was in absolute hysterics about the 2 aussie physicists that developed a way to enrich uranium using lasers. He seemed convinced that terrorists were gonna get hold of the technology and make a nuke which is IMO one a very silly idea, sure i'll bet they'd like one but there is no way they will ever be able to make one.

[mr me]

Thorium is still a radioactive substance and that fact will likely scare people/voters. Nuclear power plants have proved to be very safe but are still heavily resisted by green groups. Nuclear power is the primary source of electricity in France but next door in Germany a decision by the Social Democrats together with the Greens(when they were in power) was made to phase it out. Now that they are out of power and some sense has returned, there may be moves to construct more plants. A good start might be with Thorium based power generation.

[ref1ect1ons]

my vote is for sonoluminescence, the full documentry includes the research of anither great scientist who expands on somoliminsecence