Gen IV nukes: Another piece of the puzzle

In an effort to give us all a break from the "much wailing and gnashing of teeth" associated with pending Federal health care legislation, I decided to work through a subject that has been on my mind recently: That being the much needed, and hopefully soon mandated, drastic reduction of carbon emissions worldwide. As we all know, weaning ourselves from the combustion of coal is not going to be easy or cheap, but the puzzle is coming together, piece by piece.

Before I get into the subject of this diary, I want to talk a little about human behavior, and our tendency toward opposition. We love to choose a side, and then bravely defend that side against all who would (dare) to attack it. While engaged in this conflict, the primary function of education is to probe for the enemy's weaknesses, so we can stand at the summit waving our glorious flag. Unfortunately, by leading our research by the hand instead of the other way around, nobody wins. It may be human nature, but it is a flaw, nonetheless, and one we should take pains to avoid.

Within the nuclear energy debate, this polarization has existed for decades. Instead of examining the subject and discussing it rationally, one side argues that it's perfectly safe, pooh-poohing any concerns that are brought up, while the other side stacks building-blocks of worst-case scenarios until it becomes a teetering structure that can't help but fall. I will readily admit that I have belonged to the latter camp for about as long as I can remember, but I do believe we are on the cusp of a new type of nuke that may bring both sides back together.

At least some of the science behind Generation IV nuclear reactor technology is not new:

During the 1960s, the USA developed the molten salt fast reactor as the primary back-up option for the conventional fast breeder reactor, and a small prototype was operated. Recent work has focused on lithium and beryllium fluoride coolant with dissolved thorium and 233U fuel.

The Molten Salt Reactor (MSR) (as pictured above) is one of six different designs that are under consideration by the Generation IV International Forum (GIF), but most of them share similar characteristics that, for the most part, have solved issues that kept me (and many others) from supporting nuclear energy in the past:

Most of the six systems employ a closed nuclear fuel cycle to maximize the resource base and minimize the amount of high-level wastes needed to be sent to a repository. Three of the six are fast reactors, one can be built as a fast reactor, one is described as epithermal, and only two operate with slow neutrons like today's plants.

Only one is cooled by light water, two are helium-cooled and the others have a lead-bismuth, sodium or fluoride salt coolant. The latter three operate at low pressure, with significant safety advantages. The last has the uranium fuel dissolved in the circulating coolant. Temperatures range from 510°C to 1000°C, compared with less than 330°C for today's light water reactors—this means that four of the reactors can be used for thermochemical hydrogen production.

it is significant that to address non-proliferation concerns, the fast neutron reactors are not conventional fast breeders, ie they do not have a blanket assembly where plutonium-239 is produced. Instead, plutonium production takes place in the core, where burn-up is high and the proportion of plutonium isotopes other than Pu-239 remains high. In addition, new reprocessing technologies will enable the fuel to be recycled without separating the plutonium.

Nuclear energy, needing considerably less fuel at the beginning of the cycle, with a fraction of the radioactive wastes at the end of the cycle our current reactors leave, producing little or no weapons-grade plutonium, and not dependent upon millions of gallons of cool stream/river/lake water to operate safely. I'm sitting here, trying to cook up an argument for my life-long anti-nuke position, and I'm drawing a blank. And I'm happy about that, which is weird. ;)