Beyond design basis
The acceptance of a GDA (generic design assessment) for the UK EPR (European pressurise water reactor) in December was reported by the press but nobody got particularly enthusiastic about it. We will have to make up for this because it is a very significant event. We will go through the safety features of this design which have been accepted by the regulators.
Like all good journalists we will start at the wrong end with consideration of beyond design basis accidents. These are big events which have not been incorporated in the reactor design but have none the less to be considered – like major natural disasters such as the vast tsunami in Japan. We do not, thank goodness, have such events in this country but there may be other flooding events or other extreme natural disasters of equal significance.
The EPR design was originally undertaken by French and German organisations in collaboration. At the time Germany was under pressure to produce reactor designs which were so safe there was no need to include any evacuation of the public in any emergency plan. This was still done in Japan where they decided to adopt levels of radiation release that were ten times lower than considered necessary in other countries for evacuation of local people. Evacuation of people is considered by the media and public as being the mark of a really serious accident.
To reduce the possibility of this with the EPR a core catcher was included in the design. This assumes the reactor core has melted its way through the bottom of the reactor vessel and reached the floor of the containment building. Partly as a joke this was originally named a China syndrome in which it would carry on down to China. Never mind the molten core of the Earth. It was of course taken up by the makers of fictitious films and is now virtually a real situation that needs to be considered.
The core catcher is a fairly simple passive feature which will channel the molten core material (referred to as corium) out across a large area sector of the containment building floor so that the heat can be dissipated to cooling water embedded in the concrete floor and walls. Some wastage of concrete is also allowed for. The rest of the floor is occupied by a huge pool of water to supply coolant circuits.
The Japanese have regrettably demonstrated that a partial melt down of a reactor core and penetration of the lower part of the pressure vessel is possible. We believe other countries have taken note of the case and will prevent such accidents in the future. If they have not then let them see how much it is going to cost the Japanese.
The fracking process has been described by American critics as a ponzi energy scheme. It is said that whereas the production from a conventional well declines at about 5-8% per year, it can remain productive for decades. In contrast the first- year decline in shale wells is over 60%, and about 90% of a well’s production occurs in the first five years. Shale gas is a ‘ponzi’ scheme in which new wells are needed simply to replace production from wells drilled a few years before – a “drilling treadmill”.
The shale production process then requires large numbers of wells to be drilled, and the steel piping put down may have to be abandoned or removed after some five years. Shale oil and gas production could be expensive, with a low return on energy produced over energy invested.
It is also argued that methane leakage may be a problem. The global warming potential of methane is 20-25 times more than carbon dioxide although it only remains in the atmosphere for about 12 years compared with up to 90 years for carbon dioxide. It is claimed that 3.6% to 7.9% of the methane from shale-gas production escapes to the atmosphere, from venting and leaks, over the life- time of a well. These methane emissions are at least 30% more than, and perhaps more than twice as damaging, as those from conventional gas plants, and comparable to coal.
A critical report by the consultants Wood Mackenzie estimates that the UK’s dependency on gas imports in the 2020 to 2025 timeframe will grow by 60-85%, to 50 to 75 billion cubic metres per annum. If this were to be delivered from indigenous shale gas resource in this timeframe it would require a world class resource and a few thousand wells, something that is both improbable and unpractical. “Consequently, we think it is unlikely that shale gas production from the UK alone will have a material impact on the UK’s gas price dynamics to 2025,” This is of course disputed by the shale enthusiasts.
Whatever the outcome the UK energy policy is heading for disaster. The planned growth in wind power will require an increase in gas-fired electricity to back up the intermittency, with a consequent increase in carbon emissions from combustion and/or methane leakage. More gas plants will be needed, whether the gas from indigenous shale or imports, to replace old coal plants which now have to be shut down. With the delays and apparent indecision over building new nuclear capacity we will be dependent on ponzi and/or imported gas until the first nuclear stations come into operation in the early 2020s as the start of a major expansion.
Sense and non-sense
It may seem presumptuous to criticise the Oxford professor of Energy Policy, Dieter Helm’s, pronouncements on energy when much of what he says is obviously sensible.
Writing in the Spectator (20.11.2012) on the need to develop new sources of electricity he rightly deplores burning coal, “the dominant fuel in China and the growing fuel of choice in Europe” as disastrous. (The main increase of carbon emissions in Germany is a consequence of the nuclear shutdown). But his main target is the emphasis now being placed on renewable energy.
“What is not well understood is that current renewables like wind turbines, rooftop solar and biomass stand no serious chance of making much difference to decarbonisation. It’s very simply a matter of scale. Wind turbines are each very small. Even the biggest — say 5 MWe — are trivial compared with a 500 – 1,000
MWe conventional power station. Even this comparison fails to do justice to the scale of the problem. Wind works about 20 to 30 per cent of the time. So the 5 MWe is more like 2 MWe for the comparison. To generate enough power to make a difference, vast areas of the planet’s surface and its shallow waters would need to be covered in wind farms.
Current solar panels are very energy-inefficient, and like wind they would be needed on a vast scale in northern latitudes to make much difference. Biomass is worse still: corn ethanol in the US is not even carbon-neutral, requires vast land areas and drives up food prices for the world’s poor. Timber-based products for burning in power stations require a lot of energy to turn into fuels delivered to a power station, and release stored carbon. Think of biomass as the reverse of CCS — instead of storing the carbon through photosynthesis, this is fast-track release, like opening up a CCS storage facility.
Faced with the practical impossibility of current renewables bridging the gap, and the sheer scale of coal’s pollution, what are Britain and Europe’s politicians doing? They are presiding over a dash for coal and channeling scarce customers’ monies towards wind farms, solar panels and biofuels. It’s not only blinkered, but also incredibly expensive.”
Yet when it comes to making recommendations for the future it seems that a degree of personal prejudice against nuclear power creeps in. Apart from the recommendation of a stable long-term carbon price to reduce carbon emissions Helm, despite his previous criticisms, believes in some as yet unknown “future renewables” to be based on the “three fundamental energy sources – geothermal, gravity solar and nuclear.” But he had previously, in the same article, already dismissed nuclear- “Nuclear will decline by about a quarter at the global level in the next couple of decades, as old plant is retired (or forcibly closed, as in Germany), whether or not there is major new build.”
But of his three fundamental energy sources nuclear is the only one for which a clear expansion can be foreseen. Geothermal has been explored, and abandoned through the ‘hot rocks’ programme. Gravity is presumably hydro power, where most large scale sites have already been developed. Far from declining nuclear seems set for a major expansion.
Helm may have been too-much influenced by the events in ‘Old Europe’ where Germany, Italy, Switzerland and Belgium have, in an over-reaction to Fukushima, proposed to close down, or refrain from building new nuclear stations. In contrast many of the countries of ‘New Europe’ – Bulgaria, Czechoslovakia, Finland, Hungary, Poland, Romania – are now expanding their existing nuclear capacity or planning to build new stations. But the main expansion is coming from the countries of Asia and the Middle East which are now experiencing high economic growth and will need an increase in energy to support it. It is not only the giants of China and India, where large expansions of nuclear capacity are being proposed, but eight of the ten ASEAN countries now have plans to build nuclear stations, possibly through a coordinated programme. In the Middle East, the first nuclear station in the United Arab Emirates, Barakah, now being built by South Korea is expected to come into operation in 2017 (an enviable construction time of only five years) with one additional reactor becoming operational each year up to 2020. The UAE is also proposing to finance a South Korean bid to build nuclear stations in Turkey. A further twelve countries in the Middle East, including oil-rich Saudi Arabia and Kuwait Saudi Arabia, are also considering the construction of nuclear stations. Even Japan, under its new government, is considering reopening its nuclear stations, closed after Fukushima.
The latest projections of nuclear power growth from the IAEA also show that Helm’s pessimistic view of nuclear power is based on a parochial view of possible developments in Western Europe. He is seemingly unaware of what is happening in the rest of the world. The latest projections of the IAEA (Sept 2012) predict world nuclear power capacity growing in 2030, by 25 per cent in the low projection and by 100 per cent, in the high projection – from 370GWe today to 456GWe (low) or 740GWe (high). Most of the growth will be in the Far East, which includes China and the Republic of Korea with capacity growing from 80 GWe at the end of 2011, to 153 GWe in 2030 in the low projection, and to 274 GWe in the high. It is only in Western Europe that a fall could be anticipated from 115 GWe at the end of 2011 to 70 GWe in 2030, with possibly a small increase to 126 GWe. In contrast growth in Eastern Europe is expected to rise to between 82GWe to 108GWe by 2030. Total world capacity is forecast as growing from 370 GWe to 501-746 in 2030 and 560-1228 by 2050. Figures from the IEA and WNA are slightly higher.
Sadly, the nuclear pessimism which Helm reflects seems likely to lead to the economic – and social? – decline of Western Europe. There are warnings that with a continued lack of growth and widespread unemployment, particularly among the young, social unrest and riots are likely in a number of European countries.
Without energy there can be no growth.