NUCLEAR power seems to have surged to the forefront of consciousness these days. The subject soared to the top of the mind after the monster earthquake and tsunami which ravaged parts of north-central Japan a few weeks ago. Workers are still struggling to contain the damage to a nuclear power station which was inundated by the vast mass of water surging inland a half-hour or so after the magnitude 9.0 tremor. After they have contained the extremely hot and radioactive residues from the burnt-out reactor and spent fuel rods, they will have to encase the whole thing in a gigantic monolith of concrete and leave it there to sit like the pyramids at Giza.

It is only human nature, of course, but Japan’s troubles gave pause not only to the cowering, frightened masses for whom nuclear is a terrifying prospect, but also to scientists, engineers, power executives and investors on all continents. Operators of nuclear plants as well as those either planning or actually building new ones halted or suspended operations while they took another look to figure out whether the projects they were envisioning or actually building would stand up to whatever nature could throw at it. And after looking, they went right back to work on their concepts, technical drawings, fabrication, steel forming or concrete pouring.

Let’s face it, nuclear energy is not going away – certainly not after having generated the electricity that brewed trillions of cups of morning coffee and tea, powered trains, streetcars and elevators, propelled uncountable electrons inside a zillion computer chips and captured the songs of Bob Marley, Bob Dylan and Aretha Franklin on strips of tape or polycarbonate discs or MP3 silicon chips.

Ah, yes, you say… but what about Chornobyl, Three Mile Island and Fukushima Dai-ichi? Thirty-one people died in the explosion, fire and blast of radiation from the huge power station at Chornobyl, in Ukraine, 25 years ago. The actual number of deaths from cancers and other effects of radiation range as high as several hundred thousand since the disaster. No one died at Three Mile Island, and even though the Japanese have graded their disaster at the same level as the one at Chornobyl, so far as we can tell no one has died here.

Last week fellow columnist Franklin Johnston argued forcefully for Jamaica to consider the possibility of nuclear power. It’s an idea that first occurred to me 40-odd years ago, when the Americans were all gung-ho for nuclear power. The concept has many attractions, but going nuclear is a very expensive business, which immediately puts many planners off. But that’s because of conventional thinking. The nuclear power we have been accustomed to uses uranium, one of only two naturally occurring radioactive elements.

The other is thorium, a heavy, silvery-white metal which was first isolated early in the 19th century by a Swedish chemist, Jöns Jakob Berzelius. He named it after Thor, the Norse god of thunder. Like many other elements discovered and isolated in those heady years, it sat unused until 1885, when a German scientist, Carl Auer von Welsbach, invented the gas mantle. The mantle is a fine mesh of cotton soaked in a chemical soup containing thorium and cerium, which glows with a very white light when exposed to heat. Lamps fed by gas provided the primary source of light in cities until the development of electrical generation and distribution. Mantles are still in use today in camping lanterns very similar to those some of us grew up with in the country.

Thorium is only slightly radioactive and belongs to the family of elements known as actinides. Those are the very dense, radioactive and generally highly unstable elements like uranium, plutonium and americium. Because the nuclei of these elements are tightly packed with neutrons and protons, they are extremely dense, but are inherently unstable because particles spin off causing them to decay into more stable elements.

It’s these errant particles that cause reactions. When a particle bounces into a bunch of other particles in a nucleus, it sends them flying off in all directions to bounce into other nuclei, splitting off even more particles and setting off a chain reaction. If left unchecked, you have a nuclear explosion, but if you can figure out some kind of bridle and bit for these particles, you can harness the reaction and use the heat to boil water and turn an electric turbine.

Uranium became the fuel of choice for the nuclear power industry because the US military wanted to use plutonium – the chief by-product of the reaction – to make weapons. Plutonium was identified by two American scientists, Edwin McMillan and Glenn Seaborg, in the early 1940s and they named it (very aptly, as it turned out) after Pluto, the god in Greek mythology who controlled Hades. It was used in the bomb dropped on the Japanese city of Nagasaki two days after the uranium device was unleashed on Hiroshima in 1945.

Another US scientist, Alvin Weinberg, who became head of the atomic energy facility at Oak Ridge, Tennessee, in 1955, was a proponent of thorium. The metal is much more widespread in the earth’s crust than uranium, requires less processing and is extremely efficient as a fuel. When it decays inside the reactor, its by-products produce more neutrons per collision, thus generating more energy. The reactions therefore consume far less fuel and produce considerably less radioactive rubbish. Thorium reactors can be made much smaller than today’s monsters – small enough, in fact, to be carried on a tractor-trailer and to produce just enough power for a small city.

In his 18 years of experimentation and advocacy, Weinberg discovered that the engineering for thorium reactors was far less sophisticated and finicky than for the uranium models and their very design made the reaction self-regulated. Thorium can be dissolved in hot liquid fluoride salts which circulate through tubes in the reactor core. If the liquid gets too hot, it expands and flows out of the tubes, slowing fission, cooling down and re-cycled. As a bonus, you can’t convert the by-products into bombs. But these arguments were lost on the Cold War hawks.

Nowadays though, the ball game has changed, and engineers, planners, investors and policy-makers are realising that with the mounting price of oil and gas, global warming, the deleterious effects of mining and burning coal coupled with technological advances, nuclear can be an important source of clean power.

Several countries – notably India, China and Russia – are now taking a serious look at thorium. Its ores are much more common than uranium, with India, Australia, the United States and Canada having large proven resources. It can be used not only in molten salt reactors, but with just a little tweaking works in conventional reactors as well, and since it needs reinforcement from more radioactive fuel, those reactors can eat up the large stockpiles of plutonium left over from de-commissioned nuclear weapons.

Taking all these factors into consideration, thorium power could well be in the cards for Jamaica.

keeble.mack@sympatico.ca