With climate talks ongoing in Paris, we have another “plea” from various climate scientists for action. Most notably a claim by James Hansen, Kerry Emanuel, Ken Caldeira and Tom Wigley (the gang of four as I will henceforth call them) for more nuclear power. Unfortunately, like many nuclear energy supporters they merely succeed in showing how naive and ill-informed they are regarding the topic. It does worry me when I hear such things from eminent climatologists, as it does suggest somewhat faulty logic on their part, something which we are fortunate no deniers have thought to point out.
The gang of 4 call for 61 reactors per year for the next 35 years to replace fossil fuels for electricity generation and 115 to replace all fossil fuel consumption. They don’t define what a reactor is, but let’s assume 1 GW. By contrast, something I discussed in a prior post, the IAEA seem to be aiming for a more realistic target of 6.65 GW/yr, or perhaps 21 GW/yr if we ignore certain economic constraints. So this would imply that even the pro-nuclear IAEA believe that our gang’s numbers are off by a factor of between 9 and 6.
However there are many critics of the nuclear industry, notably the authors of the World Nuclear Industry Status Report (WNISR) who argue that if anything nuclear is now in a state of terminal decline and any form of growth is unlikely. They argue that the legacy issues, the fact that so many of the world’s nuclear plants are ageing and rapidly approaching retirement (and thus will need to be decommissioned), means that any new reactor construction will simply be eaten up replacing outdated equipment. And as I discussed in a recent post, the data seems to support the WNISR position rather than of the IAEA’s.
In the UK for example, all but 1 of the country’s reactors will hit the end of their service lives within the next decade. While they may get a life extension, this will be a tricky affair and a sudden shutdown will be a constant threat, much how the Forth road bridge in Scotland was suddenly closed this week for the rest of the year, with barely a few hours notice. This is unfortunately an all to common threat when you operate anything beyond its natural service life.
So any new reactors in the UK, or indeed most western nations for that matter, will merely be replacements for plant already retired or shortly due for retirement. These legacy issues are why in recent years the rate of new reactor construction is lagging behind the rate at which reactors are retired, hence why the WNISR talks of the nuclear industry being caught in a downward death spiral.
By contrast renewables are growing at a rate of 550-590 TWh/yr, roughly equivalent to 69 GW’s at a 100% capacity factor. Note that this 550-595 TWh/yr figure accounts for the effect of low capacity factors on certain renewables. In terms of GW’s total growth for all renewables worldwide is closer to 134 GW’s electricity and 42 GW’s of heat. So renewables are already growing at the sort of rate they call for, although this is (as I will explain in a moment) not nearly fast enough.
Indeed promotion of nuclear energy, as recent events in the UK demonstrates, threatens to torpedo this high growth rate of renewables. Hence a focus on nuclear is probably counter productive and will likely have the opposite effect intended. Consider, that the UK government has now as a result of its pro-nuclear and anti-renewables stance just committed to a whole new fleet of gas fired power stations, while the renewables industry is talking about a complete halt to all work. This is why a number of pro-nuclear greens in the UK have had something of a road to Damascus moment recently and now oppose the building of Hinkley C.
Furthermore, the figures quoted earlier for nuclear from our gang of 4 seem to assume 100% capacity factors, and that we are only talking about baseload electricity. However only about 17% of global Total Final Energy Consumption is electricity (according to the IEA), and only a portion of that is baseload. While nuclear may have some advantage over certain types of renewables when it comes to baseload, for the remaining 90-85% of energy consumption we are faced with seasonal and daily fluctuations in demand as well as cycle efficiencies due to the need for energy conversion from one form to another.
Overcoming these factors means either building large energy storage systems, which given that renewables are much cheaper to install would kind of defeat the purpose of such a reactor building program. Alternatively, if you believe large scale energy storage is impossible, then massive overcapacity would be needed (as you need enough GW’s available to meet peak demand). Many of these reactors would have relatively short capacity factors (given that the load they are feeding isn’t on all of the time). Keep in mind that the average capacity factors for a peaking load power station is between to 25-40%, for a domestic boiler 10-20% or for cars under 10% (although electric vehicle chargers are likely to be a bit higher).
Factoring in all of the above and suddenly the number of reactors for our nuclear only scenario balloons massively in size, well into the hundreds of GW’s per year. Far in excess of any fantasy nuclear energy project we could ever envisage building. This is why I’m sceptical of nuclear energy. Because once you do the maths you realise the numbers simply don’t add up. So it is very worrying that such eminent scientists seem not to have done this.
The fast reactor delusion….again!
Indeed, our gang of 4 double down by then going on to advocate fast reactors. If building this vast fleet is likely impossible with existing LWR and Gas Cooled reactors, how likely do you think a program centred on reactors with even more challenging operating conditions (higher operating temperatures, increased radiation bombardment, corrosive coolants) and less of a proven track record (e.g. capacity factors less than 10%) is likely to be?
Oh, plus you’ll be needing an attached reprocessing plant, traditionally the whitest of nuclear white elephants. This is why the bulk of the nuclear industry, save a few on the fringes, is focused on sticking with what we know for the time being.
Both the Harvard study by Bunn etal (2003) and the MIT study by Kazimi etal (2011) concluded that fast reactors would only be viable if energy costs became substantially more expensive, probably well beyond the point of economic viability. And as this article by Jim Green (2014) discusses, more recent analysis by both the UK and US governments have highlighted “significant technical risk” with Fast reactors (read, they may not work and we’ve no idea how much it would cost to try and find out).
Furthermore, there is a misconception that fast reactors are some sort of magically disintegration machine. That waste placed inside will somehow “burn up”. I’m sorry but Dr Hansen needs to go back and revise physics 101. While a tiny quantity of matter within a reactor is converted into energy, the vast bulk of the matter remains, and will still be intensely radioactive when it comes out (generally the advantage is that its half life will be much shorter).
The reality is that fast reactors would, in the best case scenario, mean swapping a modest reduction in HLW for a significant increase in the volumes of ILW and LLW. And all of this assumes that this largely unproven technology actually works….and that the public would be willing to pay the enormous costs and take all the risks associated, which I’m doubtful.
In short, such nuclear fantasy delusions are very worrying as they threaten to undermine the case for climate action, as well as forcing us to question the credibility of some climate scientists. And such talk is likely to be simply used by those in power as a ploy to curb the growth in renewables. As events in the UK prove, it gives them the excuse to build more fossil fuel plants, throw a bone the way of the nuclear industry and then when they fail to deliver (as expected), they just keep the fossil fuel plants going and global warming be damned.
While nuclear may have some role in future, its likely to be minor and there’s not a lot that we can do about that. The bulk of any future cuts in carbon emissions will have to come from a combination of more renewables and greater energy conservation.