Thursday, December 1, 2016

The Legacy of Nuclear Power


Nuclear power epitomises the problems of technology choice we face. While some see it as a valuable and reliable energy source, its critics say that it it locks us into an inflexible, unforgiving, costly and risky pattern of reliance into the far future, with uncertain payoffs.  They say these characteristics, and the troubled legacy we have already inherited, imply a need to consider long term ethical and moral issues, as well as shorter term economic, and strategic concerns, and should give us reason to pause before making any further commitments. 

There is no question that nuclear fission leads to the production of very long-lived and very dangerous nuclear wastes.  OU Emeritus Prof. Andy Blowers has produced a new Earthscan book focusing on the waste management issue, and underground geological waste disposal, which is where long-term intergenerational ethical issue come to the fore. What right do we have to bequeath future generations problems we can’t solve?  In the shorter term, on what basis can communities be asked to accept the risks and uncertainties of hosting a nuclear waste disposal facility into the far future?

By looking in detail at examples around the world, he identifies some key characteristics for sites that have been selected or proposed. They have almost all been in peripheral, often economically weak areas, where local resistance and political opposition was usually unlikely or muted. In most cases, the waste sites have followed on from earlier nuclear projects: once a beachhead had been established it was easier to expand it, with economic lock-in maintaining the momentum. So attractive is this existing-site option that it almost seems to override technical geological suitability.

The specifics of the proposed disposal approaches also seem to reflect concerns about local and wider public reactions. Ideally, to reduce public concern, long-lived wasted should be buried deep and permanently, so that they can be forgotten about: out of sight, out of mind. However, this may not be the most rational approach. It is possible that, in the centuries ahead, new technologies will emerge that can make use of some of these waste- extracting value and reducing their hazards. In which case continued accessibility would be important. That may also be important if anything goes wrong with the disposal approach, or if new better disposal approaches emerge.  So the spectrum of options runs from full final irretrievable disposal to accessible long term, but still underground, storage. 

How long it would be possible to maintain accessibility is unclear: there will be limits. Moreover, in practice it will be many decades before much of the waste currently in interim surface stores, or being produced, can be disposed of in underground repositories of whatever sort. So for good or ill, we have time to see what else can be done with it.  But the inescapable bottom line is that it will have to go somewhere. This book explores the social and local community dimensions involved in that choice, but also inevitably highlights the fact that producing yet more of it will make finding a home for waste even harder. 

The current state of play in the UK is that a site for final geological disposal of the UKs high level nuclear waste is still being sought, with communities being invited to host it, possibly in return for substantial funding for local social projects. So far the only offer has been for a site in Cumbria, near Sellafield, backed by the local Copeland and Allerdale district councils. However, that was strongly opposed by Cumbria County council.  Provocatively, the government then indicated it might give local councils the final say, but so far no decision has emerged:  www.theguardian.com/environment/2013/sep/12/county-councils-nuclear-waste-dump-sites

The aim is still to have a site chosen somewhere ready for it to be started up by around 2040, but with opposition likely to be strong, it may have to be imposed. Moreover, it would take time to build and would be earmarked preferentially for the existing/current legacy waste, possibly to be loaded up from around 2060 onwards. There would not be room for the wastes from the new plants that are currently proposed to start up in the late 2020’s until around after around 2130! That would be long after these new plants would have closed, even assuming 60 year operational lives. www.gov.uk/government/uploads/system/uploads/ attachment_data/file/168047/bis-13-630-long-term-nuclear-energy-strategy.pdf

At present it is not proposed to reprocess the highly-active spent fuel from these new plants, so as to extract plutonium. That means that, thankfully, the production of large amounts of secondary wastes would be reduced: reprocessing creates a lot of intermediate and low level wastes. However, the aim is to go for high burn up of fuel, so as to improve the fuel economics: more highly enriched fuel is used, able to stay in use longer, generating more energy before fuel changes are need.  But that also means the waste fuel, with more plutonium and other byproducts included, would be much more active than conventional reprocessed fuel would have been. That would make its ‘temporary’ storage, on site at the new plants around the UK, harder, with ‘temporary’ meaning maybe 100 years before it could be finally disposed of when and if the national geological repository became available.

Meanwhile, there is the large amount of the low and intermediate level wastes, most of which at present is stored at Sellafield, though, provocatively, some lower level material seems likely to be destined for regional distribution in selected land fill sites. In addition, the fate of the 140 tonnes plutonium that has already been extracted from earlier fuel remains unclear: http://researchbriefings.files.parliament.uk/documents/POST-PN-0531/POST-PN-0531.pdf.

Like most the rest of the high level nuclear waste, it’s in temporary storage at Sellafield. Most of it is from UK plants. The governments preference is for the plutonium to be used along with reprocessed or depleted uranium 238, in Mixed Oxide Fuel (MOX), possibly for use in some of the proposed new reactors. That would involve building a new multi billion pound MOX fabrication plant. 

However, all that awaits the construction of the new power plants and a decision on MOX seems unlikely before they are built and running, if they go ahead- in the late 2020s/early 2030s. http://corecumbria.co.uk/briefings/new-build-reactor-delays-put-sellafields-plutonium-decision-on-the-back-burner/ And of course, if built, whatever fuel they use, the new plants will create yet more plutonium and wastes, so the problem continues into the far future, unless new technology emerges. It is conceivable that new types of plants could be developed that burnt up plutonium and some of the wastes, but that seems long off with unknown risks and costs, and there would still be some wastes to deal with, even with advanced fast neutron/molten salt/thorium reactors.

 As can be seen, the waste issue is complex and very long-term, and arguably best reduced by not producing more. Though we have to deal with what already exists- including around 1,400 cu meters of high level waste awaiting disposal somewhere: https://ukinventory.nda.gov.uk/. However, it won’t be easy getting agreement on where any of it is to go, as Blowers’ book makes clear, and as this recent review also concludes: https://rwm.nda.gov.uk/publication/societal-aspects-of-geological-disposal/  

The hunt for a site is supposed to start in earnest in 2017…

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