Thursday, 15 December 2016

Nuclear takes lion's share of energy subsidies with little climate benefit

Letter sent to The Times:
Matt Ridley fails to mention the huge amount of taxpayer-funded and electricity bill payer-funded subsidies that have been allocated to the nuclear sector (“Climate Change Act has cost us the earth,” Comment, Dec 12; http://www.thetimes.co.uk/article/climate-change-act-has-cost-us-the-earth-qqhxr7k2p), in the mistaken belief by ministers responsible for energy policy over the past decade ie Ed Miliband (Labour); Chris Huhne and Sir Ed Davey (Lib Dem) and now Greg Clark (Conservative), that nuclear energy is a meaningful way to reduce carbon emissions.

Production of nuclear electricity is not carbon free, because the production of nuclear fuel for these reactors is significantly energy intensive. While it is true that most nuclear reactors do not emit CO2 at the point of generation, reactors are a small part of the nuclear fuel cycle, which emits large amounts of CO2. These arise from the so-called front end of the fuel cycle - uranium mining, ore milling, uranium hexafluoride conversion, fuel enrichment and, finally, fabrication of the fuel rods. Moreover, nuclear waste management at the "back end" is already energy-hungry in the  treatment, conditioning, transportation and final disposal in some future repository (if ministers ever give the green light).

Thus full  life-cycle analyses are essential to assess the true impact of the entire processes. A number of such studies have examined CO2 emissions - commonly expressed as CO2 equivalents per kWh - for different methods of producing electricity. The most comprehensive model has been created by the ├ľko Institut (https://www.oeko.de/en/), which advises the German environment ministry, and by Professors Jan Willem Storm Van Leeuwen and the late Philip Smith at the University of Groningen, in the Netherlands (eg .’Nuclear Power: the Energy Balance’ http://jayhanson.us/_Energy/NuclearPower.pdf)

Both studies conclude that the nuclear fuel cycle can emit relatively large amounts of CO2 .The lower the uranium concentration in ore, the more CO2 generated; and as a means of enrichment, gas diffusion was much more energy intensive - and thus CO2 emitting - than centrifuge separation.

Using sensible assumptions, Professors Smith and Van Leeuwen determined that nuclear generation produced about a third as much CO2 per kWh as conventional mid-sized gas-fired electricity generation.

The global research on this matter has been excellently synthesized in a paper “Valuing the greenhouse gas emissions from nuclear power: A critical survey,” published in the journal Energy Policy in 2008 by Professor Benjamin Sovacool, now director of the Centre on Innovation and Energy Demand and leader of the Sussex Energy Group at the University of Sussex.( (http://pbadupws.nrc.gov/docs/ML1006/ML100601133.pdf)

The current secretary of state for Business, Energy and Industrial Strategy, Dr Clark, and his officials should take note

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