By Dave Elliott
Nuclear plants do not generate carbon dioxide, so why can’t we have nuclear AND renewables, supporting each other, as a response to climate change? In evidence to the Energy and Climate Change Select Committee in July Amber Rudd MP, DECC Secretary of State, suggested that despite its high cost nuclear baseload ‘enables us to support more renewables’ and was needed since, ‘as we all know, until we get storage right, renewables are unreliable’. Can nuclear really support renewables, and is it really low carbon?
By Dave Elliott
Although there are exceptions, as I noted in my last post, the UK being one, nuclear power seems to be in decline globally and this has led to what some might see as last ditch attempts to revive its fortunes. One such is the recent Open Letter to environmentalists, originating in Australia and backed by over 70 academics globally, though nearly half from Australia: http://bravenewclimate.com/2014/12/15/an-open-letter-to-environmentalists-on-nuclear-energy/ (more…)
Reprocessing nuclear waste provides little short-term benefit because the process costs too much and uranium supplies remain plentiful, according to a new study of US nuclear waste management options by MIT, the Massachusetts Institute of Technology. The US doesn’t reprocess nuclear waste, but interest in that option has increased, not least since President Obama has blocked the development of a high level nuclear waste repository at Yucca mountain. A special Commission has been set up to explore options- which the MIT study aims to feed in to. http://web.mit.edu/newsoffice/2010/nuclear-report-0916
Reprocessing (MIT call it ‘recycling’) primarily aims to extract reusable plutonium and uranium from spent fuel, and assuming there is some use for the extracted materials, that reduces the amount of high level waste that has to be deal with- although it also generates a lot more low and intermediate waste. The extracted Plutonium and Uranium can be used as fuel for breeder reactors. Bush was keen on that idea as part of the Global Nuclear Energy Partnership arrangement- which would have seen spent fuel from reactors overseas brought to the US for reprocessing to extract its Plutonium. Obama was evidently not keen on GNEP and, with the US effectively out of it, the GNEP has now been downgraded/renamed.
The other option is to convert the Pu and Uranium into MOX- Mixed Oxide Fuel- for use in (some) conventional reactors, which is what the UK does with some of its extracted Pu, selling MOX chiefly to Japan, in return for reprocessing some of their spent fuel. But MOX is pricey and there is evidently not seen to be much incentive to go that way yet in the USA. The MIT says ‘There is no shortage of uranium resources that might constrain future commitments to build new nuclear plants for at least much of this century, and scientifically sound methods exist to manage spent nuclear fuel.’
Not everyone will agree with MIT’s assessment of the front end of the fuel cycle – i.e. on fuel availability. If a global nuclear renaissance occurs, demand for uranium will grow and there are already said to be shortages, though so far due to the lack of investment in mining and processing rather than in actual reserves. But some say ‘peak uranium’ is not far off- for example the German Energy Watch Group suggest that this may be by 2035. MIT evidently is not amongst the pessimist, though it does say that options should be kept open, since technological advances may make recycling (e.g. to stretch fuel reserves) a better choice in the future, and it also says -keep open the option of an underground, but accessible, interim, up to 100 year, storage facility, from which spent fuel could be removed later, if needed, for reprocessing and use.
MIT’s second point, on the back end of the fuel cycle, is fair enough, as far as it goes. Interim dry storage of un-reprocessed spent fuel is seen as a viable route: it’s what the US does and what UK now plans to do, since, to save money, it will not reprocess spent fuel from the proposed new reactors. The US Nuclear Regulatory Commission says that spent fuel can safely be stored on site for 60 years. The UK government has now agreed with this assessment. That of course is no long-term solution and it does have its own problem/risks, especially with the much more radioactive spent fuel that will result from high fuel burn-up approach that is to be used with the proposed new UK reactors, to improve their economics. But if you’ve produced it, it has to go somewhere!
The UK’s plan, such as it is, assumes that the spent fuel will stay at reactor sites for perhaps 60 years, while waiting for a high level waste repository to be built- at a site as yet to be determined. It’s said that this will be available by 2040. However it has been earmarked for the existing legacy waste, and wont be available for spent fuel from the proposed new plants until 2130- long after the new plants have been closed down, with ‘interim storage’ continuing somewhere for 100 years or so. But it could be more, for example if a community willing to accept a long-term waste site can’t be found.
It does sound a little open ended. Or you might say, being positive, flexible! The MIT certainly suggests adopting a flexible approach. It says the US should wait to see what happens elsewhere (e.g. in the EU) in terms of ultimate long term disposal, before committing to anything finally, but perhaps inevitably calls for a $1bn nuclear R&D programme exploring the full range of technological/fuel-cycle options. The US is already looking at new nuclear technology, including fast neutron reactors running on plutonium and uranium extracted from spent fuel. That would imply spent fuel reprocessing. However, it’s claimed that the new plants might be able to burn up some of the resultant wastes- and might also be able to use thorium as a new fuel, so avoiding uranium scarcity.
In terms of new reactor technology, the UK, Finland and France are just staying with upgraded version the standard US/French Pressurised Water Reactors, while in terms of waste, the European Commission recently produced a Nuclear Waste Directive and adopted IAEA safety standards, with geological disposal being seen as the way ahead. Two or more Member States can agree to share a final repository in one of them, but the EU is not allowed to export nuclear waste to countries outside the EU for final disposal (It seems that there had been offers from Russia to take it). So we’re stuck with it- and for some time.
And it’s not just us. China is expanding it’s nuclear programme (aiming to move from 2% of electricity now to about 4% by 2020), and although it has recently indicated that it might have to slow down a little and reduce it targets, since it was having problems replicating imported US technology (the Westinghouse AP1000), it is also looking for somewhere to put the wastes and is considering reprocessing some of its spent fuel.
There is a tremendous amount of talk these days about the costs of health care in the United States, and if the government should provide a public insurance option for citizens who either do not have health insurance or who do not like their employer-provided insurance. For those in the much of the EU, Canada, and other countries with some form of socialized health care, this may seem a tad ridiculous.
However, a recent article about resources and health care caught my attention. The article is about the supply, or declining lack thereof, of the preferred material technetium-99m as a radio-isotope for medical imaging for scanning for conditions indicating heart disease and cancer. The energy part of this equation is that it takes a nuclear reactor to create the isotope, usually starting from using highly enriched uranium. The article notes that the US is the sole supplier of this uranium except for that going into a single reactor in Australia.
This sounds like a normal story of running out of a natural resource and having to adapt technology to find a better substitute, or deal with using a lesser quality substitute. Except this material is a mine natural resource – it is created from another mined substance (uranium ore) which has yet to deplete. This is more of a production issue, but someone has to build a nuclear reactor as part of the supply chain. I’d say using UPS to ship some Chinese-made hair clips is an easier supply chain to manage.
I can only imagine the embodied energy in using these radio-isotope procedures. Given the cost and complexity of many modern medical instruments and procedures from magnetic resonance imaging (MRI) to computerized axial tomography (CAT) scans, together with the tremendous amount of research and design of the instruments, the embodied energy is large. Siemens is one company making MRI machines, and the Siemens website discusses results from a life cycle analysis indicating approximately 460 MWh/year consumed for a certain MRI model. An average household in the US might consume 10-15 MWh/yr. So we could operate all of the modern amenities to 30-45 homes for the energy operational cost of an MRI machine.
So how much will health care suffer if we don’t have technetium-99m or electricity to power MRI machines? Well, if you look at measures of life quality such as the Human Development Index of the United Nations, the marginal gain in ‘development’ (of which lifespan is 1/3 of the index) for increased energy usage is very small for the US and most industrialized countries. A recent study Julia Steinberger of the Institute of Social Ecology in Vienna, Austria shows how over the last few decades we might be eeking out increases in HDI with less energy consumption. Steinberg’s study deserves more description than one sentence, so perhaps I’ll save that for a later post! Until then, eat healthy and increase your chances of preventing the need for energy-intensive medical procedures, although I have to admit, I had an MRI once for tearing a ligament in my knee, and I don’t think it had anything to do with what I ate that day!