The earthquake and tsunami in Japan have important implications for energy policy – partly, of course for nuclear, but also for oil, gas and coal too. Three initial observations:
First, the immediate nuclear issues. The media hasn’t exactly played a blinder at walking the public through a quick course in reactor design 101, so bravo to Nature for pulling together this excellent primer. Here’s the layout of the BWR design installed at Fukushima, and a succint description of what went wrong and how:
…without emergency cooling, the temperature at the core of both reactors began to rise. As it did, what water that remained began to boil off, increasing the pressure inside the pellet-shape pod.
When temperatures reached around a thousand degrees Celsius, the zirconium alloy holding the fuel pellets probably began to melt or split apart. As it did, it reacted with the steam and created hydrogen gas, which is highly volatile. Operators may or may not have known what was happening when they decided to release some of the pressure from Unit 1 on Saturday. The hydrogen apparently caused a massive explosion which blew the roof off of the fuel hall, though the reactor’s outer containment vessel appears to have remained in tact (see diagram).
If, as it appears, the zirconium came apart, then some of the uranium and plutonium pellets in the fuel rods may have also melted and sunk to the bottom of the pressure vessel. In that case, the cores of units 1 and 3 are now a volatile test tube filled with radioactive fuel, melted zirconium and water.
The real danger is the melted fuel. If enough melted fuel gathers at the bottom of the reactor, it could burn through the concrete containment vessel. In a worse case scenario, the fuel could again gather to form a critical mass outside the fuel assembly. The loose fuel would restart the power-producing reactions, but in a completely uncontrolled way. This, if it happened, would lead to a full-scale nuclear meltdown.
For detailed and technically sound updates of what’s currently happening at Fukushima, the go-to site is World Nuclear News.
Second, what it means for commodity prices – above all oil, which was, of course, spiking strongly last week amid concerns about risks to production in Libya and the wider Middle East. The immediate impact has been a sharp drop in prices, to $99 a barrel according to AP (though Brent is still up at $112): AP continues that,
Three of Japan’s five largest refineries have been shut down, which will immediately crimp demand for crude. Japan is the world’s third-largest crude consumer at 4.5 million barrel a day, the second-largest net oil importer and the biggest importer of liquefied natural gas and coal.
That’s consistent with the prediction made earlier today by the FT’s Commodities Editor Javier Blas, who reckoned that
The impact of the disaster will drive prices lower in the very short term as Japanese economic activity comes to a halt – big companies such as carmakers have said they will not open on Monday, and with the country’s power supply severely disrupted, some others – particularly big electricity consumers – may not be able to open even if they try.
But, he continues,
Over the medium term, Japan is going to need huge amounts of commodities to rebuild the areas hit by the quake and tsunami. This will boost Asia’s regional demand. Besides, global energy markets are braced for a big shake-up as Japan replaces a large chunk of its nuclear power capacity – if not all of it, if Tokyo is forced to undertake big safety checks after serious problems in two of the country’s reactors – with electricity generated by burning oil, natural gas and coal…
…The International Energy Agency, the western countries’ oil watchdog, estimates that it takes about 38.8 barrels of crude oil to replace 1MW of idled nuclear power generation capacity in Japan. If the country were to replace its missing nuclear capacity with oil alone, it would have to import a further 375,000 barrels a day, on top of expected purchases this year of about 4.25m b/d. Japan is more likely to opt for a combination of oil, LNG and thermal coal, however.
Third, to pick up from where Javier leaves off, there are the longer term questions. Is the world about to back away from nuclear power (as, for instance, David Pilling suggests) – and if so, what will pick up the slack?
My own guess is that the prospects of such a global U-turn on nuclear power will recede – if the primary containment layers hold. That would allow the nuclear industry to argue, as the media moves on to other stories, that a) this was a freak event in an unusually seismically active zone and that b) even then, the reactor design prevented disaster. Whether those arguments really stack up is, of course, another question.
But if we do see a global retreat from nuclear, then the question of what new global fuel mix we head towards – and above all, the balance between natural gas and coal – will be of absolutely crucial importance to climate change, given coal’s far higher carbon intensity. But either way, emissions would rise strongly, given that nuclear is (for all its other issues) carbon-free.
