Once upon a time I used to be a fan of nuclear energy. As far as I saw it, nuclear energy was the silver bullet solution to all of our energy problems and more. However, the more I’ve learned about the industry the more critical I’ve become.
Notably the fact that most of the economic figures in support of nuclear power (a couple of typical delusions you’ll find here and here) come straight out the Hogwarts school of magic, wizardry…. and economics (more realistic appraisals of nuclear economics can be found here and here). There is the question about the world’s limited stockpiles of fissile material, not helped by the fact that the Light water Reactors (LWR’s) that make up the bulk of our present capacity are ridiculously fuel inefficient – only about 2-3% of the fissile material is actually consumed by them! Imagine going into the GM board room and proposing a car that would throw away 98-97% of its fuel as dangerous toxic waste! you’d likely be fired on the spot! Reprocessing isn’t economic and involves turning a small pile of High level waste (HLW) into a much bigger pile of Intermediate level waste (ILW). And what are we planning to do with this waste? Various proposals have been made, but no nation on earth has yet to comprehensively solve this problem. Then there’s the glacially slow build rate of reactors, and of course, the nagging issue of nuclear safety.
But is there a better way?
Of course some supporters of nuclear energy would say that all of the problems I’ve just listed off boil down to one fateful decision taken back in the 1950’s – to build large LWR’s in preference to the many other reactor designs proposed at the time. There are a multitude of reasons why this decision was taken, I will review these factors in part 4 of this posting when we review the light water design. But regardless of the “why’s?” the fact is that the nuclear industry did embarked on this plan and is now stuck down a blind alley because of it. But one of the key reasons the LWR was chosen was cost – it was simply a lot cheaper and easier to get a program of LWR’s off the ground than anything else. Unfortunately in the process of doing this the nuclear industry laid a trap for themselves.
The LWR was originally designed by the US navy to run submarines, specifically they were small in scale with outputs of between 15-50 MWe versus the 500-1,600 MWe behemoths the civil nuclear industry use. These large “megatron” LWR’s were scaled up to the point where they became inherently unsafe – if the cooling system for any reason failed, the reactor would go into meltdown. This meant the cooling systems and all backups related to it (including its backup power generators) HAD to work perfectly i.e. critical system components. Unfortunately several accidents since then, notably TMI and Chernobyl, revealed flaws in the original design. The only way to correct these flaws was to include further safety systems, as well as by building a large concrete containment dome over the reactors to contain any radiation releases. The end result has been the size and scale of nuclear projects has ballooned in size, as has the costs of new nuclear build. All these safety critical components also need careful testing prior to commercial operation, meaning the pace of new nuclear construction has slowed to a crawl. Fukushima will now inevitably likely lead to another round of recriminations, further expensive upgrades, redesigns and a further round of reactor shutdowns.
If there’s one fact that both supporters of nuclear power and opponents have to agree on is that if the nuclear industry is to have any future, then we need to ditch these mega-LWR’s for something else. Various alternatives to the LWR have been proposed, these include:
But could these reactors actually supply us with something better? In the following series of article we will explore this question by subjecting these designs to a critical review.