The Deep, Dark Gold.


Pouring, winding from the wound, riven
deep in the Earth’s good side; the black
blood pulses that twists the mainspring,
driving the human surface mechanics.
Oil is transformed into money – black gold
fabricates paper-transactions and promises.
The price of a barrel, sprung on a delicate
fulcrum, pitching joy into stultification and despair.
Riven side in the corpus of the new god,
and we expect many human sacrifices, 5 billion
or so when all the oil is gone.
Meanwhile eyes flinch in horror at intoxicated
beaches, wetlands, birds, livelihoods and dreams,
that do not yet see the half of what is to come.”

Christopher James Rhodes.

“Reading Means Business on Climate Change.”


I did put some thoughts together prompted in part by a chat I had with Tony Pettit, who is a consultant for Reading Council, and whom I met at the above entitled event on January 12th (2012) at Reading University, “Transition Town Reading and London Commuting”,, in reference to the daily commute. In part the article is a simplification of the truth but it does stress the point that similar numbers of workers commute both from the town of Reading to jobs in other locations (mostly London) and into Reading from its environs (again that is mostly London).

As a follow-up, I have been asked to write something about the meeting per se, and as the title might suggest, its intention was to aim toward Reading becoming a low-carbon town (if not zero) by actions involving local businesses, the local authority, and other major local employers, not least its university. Indeed, the University of Reading has, as its new Vice Chancellor, Sir David Bell stressed, signed-up to cut its carbon emissions to the tune of 35% by 2015/2015. This reinforces a statement made by the previous VC, Professor Gordon Marshall: “As leaders in climate science research and mitigation and with responsibilities to show educational leadership, we want to be seen to be acting responsibly to mitigate our own environmental impact. The benefits of this programme will be felt not just in terms of global CO2 emissions impact but on reduced energy costs – a direct and significant benefit to the University.”

Peter Harper, from the Centre for Alternative Technology: spoke next under the title ‘Taking Decarbonisation Seriously: What Would it be Like?’ (summarised below); followed by Dennis Moynihan of the Institute for Sustainability: ‘Towards Low-Carbon Communities: Making the Magic Happen’. Sally Coble from the Environment Agency and Ben Burfoot from RBC both reported on the Reading Climate Change Partnership and the progress made by the Council to date, with the aim to reduce the Town’s carbon emissions by 50% by 2020. Quite a tall order, to be sure!

That said, significant progress has been made, e.g.almost 2000 homes have been insulated through the Heatseekers initiative, 24 businesses have committed to 10:10 (a carbon emission reduction scheme, and there are 24% fewer car trips to the centre of town compared with 2006 (possibly rising fuel prices may have contributed to this). The Council’s current energy generation is over target, mainly from landfill gas, supplies of which will soon be exhausted. There is also a photovoltaic (PV) initiative to be implemented, with a budget of £5 million. The Town’s total carbon emissions were given at almost 1 million tonnes in 2005, but by 2009, this had fallen to just over 800,000 tonnes. This accords to a reduction by 22% which is the best for any unitary borough in the south east. It is often unclear whether such figures refer to elemental carbon or carbon dioxide, and if the latter, should be multiplied by a factor of almost 4.

For me, the set of workshops were the most useful. That said, I am amazed by the lack of awareness of peak oil and its implications. One man said that he couldn’t understand why there was such emphasis on installing trams. As he put it: “A tram is just a bus that only goes one way!” I disabused this line of thinking, informing him that the reason for favouring trams is that they are powered by electricity which can be generated from various different sources (e.g. coal, gas, nuclear, renewables) whereas a conventional bus needs liquid fuels derived from crude oil. There was some fiasco a while back over the claim that some of the Reading bus-fleet ran on ethanol fermented from sugar grown in the UK, whereas in fact it was derived from wood-pulp shipped over from Sweden, rather defeating the object!

The following is a fine distillation of Peter Harper’s talk, “Taking Decarbonisation Seriously”, sent to me from GREN news:
By international standards the UK is doing well and it is important to recognise that small entities, be that the UK or Reading, are significant as exemplars. However, it is deeply worrying that it is thought possible that with concerted international action we could keep warming below 2C which is estimated to give a 75% chance of avoiding the risk of ‘dangerous climate change’ – not very good odds. The UK is currently spending above its fair share of the affordable world carbon budget, especially when emissions elsewhere on our behalf are considered. The CAT emphasise that ‘physics trumps politics’ (‘the Cnut principle’). We must start with physics and adjust the politics and economics to fit. Given the UK’s history of emissions they need to be not just zero carbon but negative carbon to clear a fair space in the budget for developing countries. CAT have drawn up a scheme to achieve this involving alternative technologies but the necessary negative carbon cannot be achieved without lifestyle changes too eg although most people would still travel in cars there would be lower individual ownership. More drastically air miles would need to be cut by 60% – to the level of the 1970s. The large amount of biomass required would change the appearance of the countryside and require a reduction in grazing livestock with knock on effects for diet. The net result would be a shift in the livestock/crop protein ratio from 55:45 to 33:67. It would also mean a better and more secure diet (with fewer imports) and more people in land-based jobs.

Insisting on maintaing the status quo will eventually destroy it. Applying the necessary adjustments will keep as much as possible of the status quo.
The consequences of their scheme are:
Greater energy security as more is produced in the UK
Deal with Peak Oil/Gas
Decarbonising the economy sorts out most other environmental problems as well
High employment
A positive balance of payments
Greater food security (but fewer cows)
Improved diet
Better prospects for our children
This is our chance to make the inevitable transition from seeking ‘more’ to seeking ‘better’. Like our children, there comes a time when the economy has to stop growing bigger and get nicer!

In the conversation with Tony Pettit, it became clear that Reading depends both on its workforce travelling out of the town (principally to London) to their jobs and workers mainly from London travelling into Reading to do jobs here. The vast majority of these daily journeys are made by car, and so in the face of Peak Oil it does seem like a kind of madness to waste fuel both ways round, rather than reskilling the citizens of Reading to do the jobs here, and the same for London. This may be the principal change that will be made in the future, driven most likely by rising fuel prices, and the major means of reducing carbon emissions in Reading. I do wonder, however, once the provision of oil becomes compromised, whether these jobs – particularly of the high-tech variety, in Reading – will exist in ten or twenty years time, and the necessary reskilling should more effectively be made in terms of sustainable employment, such as empowers the building of a strong local economy for Reading.

Can Solar Fuels Prevent an Imminent Petroluem Fuels Crisis?


In a nutshell, the answer to the question posed in the title of this article is, “No”. The full article can be found at It will also be published in the next issue of the journal Science Progress. I am merely putting the concluding section here, which refers to localisation and Transition Towns.

Overall summary and outlook.

In conclusion, we are faced with an overall serious energy problem, and most pressingly the challenge of how to fill the enlarging hole created by a declining production of conventional crude oil. It appears almost certain that there will be profound efforts made in obtaining “unconventional oil” from shale and in liberating gas from various geological formations by “fracking”; the production of “synthetic crude” from tar-sands will doubtless increase too. Noting that world light crude oil production peaked in 2005, it is increasingly the heavy oils, e.g. from the Orinoco Belt in Venezuela, that will need to be recovered and processed, requiring the building of a new swathe of oil refineries that can handle this kind of material. Thus, not only are supplies of conventional crude oil going to fall, but what is recovered will be increasingly difficult to process. How difficult it is to produce an energy resource is usually expressed by the Energy Returned on Energy Invested (EROEI). Thus in the halcyon days of the Texan “giant gushers”, 100 barrels of crude oil could be recovered using the energy equivalent to that contained in one barrel of crude oil, which gives an EROEI = 100. The figure has fallen since then, and presently EROEIs in the range 11 -18 are obtained for North Sea (Brent Crude) oil, and as low as 3 – 5 for heavy oil and tar sands “oil”.

Although shale-oil production and use is hardly environmentally “clean”, taking account of its carbon emissions (both in the retorting of shale and in burning the final fuel) and large water demand (3 – 10 barrels of water to produce each barrel of oil), it is trumpeted in some quarters that the US will become self-sufficient in “oil” by 2020. Current US production of shale-oil is around 0.5 mbd, and is predicted to rise to 3 mbd by 2020, but this must be gauged against a loss of conventional oil by 29 mbd across the world. Can solar fuels fill the gap? As we have seen, much of the solar fuel technology is very much at the research stage. Most of what is ongoing aims to produce H2, but even if half the “new” platinum recovered annually were used to fabricate fuel cells, only something like 1% of the billion road vehicles currently in existence could be so substituted by “hydrogen cars” over the next 10 years. Hence, a global transportation network based on hydrogen/fuel cells, let alone a full-scale solar hydrogen economy, is a pipe-dream. If hydrogen can be made renewably on the grand scale, as an energy carrier (it is not really a fuel, since it must be created from primary energy sources), it will probably need to be used by combustion.

The fabrication of electric cars runs into similar resource difficulties, especially in terms of rare earth metals, and so a strategy based on liquid fuels would seem most sensible. Liquid fuels are furthermore entirely compatible with the prevailing transportation infrastructure, in regard to the distribution of fuels and their deployment in internal combustion engines. The Fischer-Tropsch (FT) process is a well-established technology for converting syngas to liquid hydrocarbons, but the means to obtain H2 + CO on a large scale without using fossil fuels is not. Even when (or if) those clean technologies based on artificial photosynthesis are developed, a whole new generation and scale of FT plants will need to be installed, which at the level envisaged would take decades. Any such timescale must be judged against that for the depletion of conventional crude oil. Of those approaches considered here for the production of liquid fuels, the use of genetically engineered cyanobacteria looks the most promising, but even so, meeting the global demand for them seems to be a bridge too far. Producing millions of electric cars is just not a practical proposition, and the only realistic means to move people around in number using electrical power is with light railway and tram systems. The notion of personalised transport will be relegated to history by massive fuel prices, and an absence of any cheaper “car ownership” option. Our global civilization is underpinned almost entirely by crude oil – as refined into liquid fuels for transporting people and consumer goods around nations; for growing and distributing food; for mining coal, shale and all kinds of minerals, including metallic ores and rock phosphate for agriculture; and as a raw feedstock for the chemical industry, to make pharmaceuticals and to support healthcare. If our stalwart “black gold” is set to abandon us over the next few decades, and it is not possible on that same timescale to produce alternative liquid fuels – “the supply side” – we can only address the problem from the demand side.

This means a substantial curbing of transportation and a relocalisation of society, to become more locally sufficient, e.g. in food production, at the community level.
Such are the aims of the “Transition Town” movement. It is likely that energy production will become increasingly decentralized, and done at the smaller scale, to power such communities. Fuel too, e.g. for local agriculture, might be produced from algae at least on a regional scale, as integrated with water treatment schemes to conserve the resource of phosphate, and to avert algal blooms. Methods of regenerative agriculture, including permaculture, provide means to food production that demand far less in their input of fuels, fertilizers and pesticides, and actually rebuild the carbon content of soil. It is thought that 40% of anthropogenic CO2 emissions might be sequestered in soil using no-till practices. Solar energy may also be harvested usefully and directly in the form of heat (rather than converting it to a fuel), at greater efficiency than through PV, using concentrating solar thermal power plants, roof-based water heating systems, solar cookers, solar stills and water sterilization units, and homes especially designed to absorb and retain thermal energy. Though the foreseeable transition to a lower energy and more localised way of life is unequivocally daunting, there is hope.

Transition Play to be Performed at Reading Water Fest (2012).


Members of the fanSHEN theatre company ( are making a play entitled “Green and Pleasant Land”. As they describe it: “this is the story of a search for a happier, more environmentally sustainable future. Audience members will pedal bicycle-powered generators to play pre-recorded sound, all set and props will be recycled and it will tour entirely by bike and train. Subject to confirmation, it will be on as part of Water Fest in Reading this June. This is interactive, physical theatre, aimed toward audiences aged 11 and upwards.”

When they approached me to ask for a meeting they said: “We’re making the piece in a series of residencies in different parts of England and we really want to meet local people and find out about your vision of a more sustainable future. How do you perceive the present situation, how do you see things changing and how does living in Reading affect your relationship with sustainability?”

It is very difficult to provide a snappy response to “what is sustainability?” because it is not a single question and to try and answer it exposes different layers of cloth. One of the key points that I suppose I had known, but not previously found myself espousing explicitly, is that devising an energy descent plan, which is the vital and underpinning action in the transition to a post peak-oil world, necessarily means “ruining the economy” in the global sense that growth, far from being subsumed in our thoughts and plans as limitless, must run in reverse and recession is inevitable.

Now, having said this, my own instinct is panic! However, if we can’t access plentiful cheap oil, the effect will be to put a huge and relentless brake on transport at all local, regional, national and global scales. Put simply, if the price of fuel becomes £5/litre, the majority will no longer be able to put petrol in their car, and will necessarily look for work closer to home. The moment of economic necessity will be the critical fulcrum point when people change their behaviour. Moreover, jobs that people currently commute to may suddenly cease to exist.There will be a massive draw-down on the kind of industrialised farming that uses diesel fuels to run tractors, combine harvesters etc. and synthetic nitrogen fertilisers derived from natural gas, pesticides that are made from crude oil, and mined rock phosphate. There is the broader issue of commodities, all of which depend on oil either as a manufacturing raw carbon source or to provide energy at some stage in one of their processes of fabrication.

Having admitted and identified the source of my fear, I have to confess that, rather like the way the different spices come through one after the other in a good curry, I also feel a definite sense of excitement. I suppose the unknown is always rather like this, a mixture of fear and an underlying tingle in the senses that one is also being presented with a blank sheet, and that there are new prospects to be had. So, rather than an inexorable decline into doom, as the resources for global growth fall insufficient to maintain it, I begin to glimpse the prospects of a new growth at the local and community level. Clearly we cannot switch overnight to an energy-free world, but a realistic energy descent that uses less oil by say 5%/year is an identifiable and direct first step to address the most pressing issue that confronts us. If choice is not persuadable then economics will be the driver of change in this direction, in the fist of rising fuel prices as noted earlier.

The skills of the “old” should be recorded while they can still teach them to us. There will be plenty to do in the future, much of it manual and local, and these new occupations will come to replace the employment that currently is provided by global growth and actions, but which are not sustainable. In this transition there will almost certainly be tremendous hardship and the world population of humans will very likely decline. Whether the brave new world that is indicated will be better than the one we have now, filled with more fulfilled and happier people, is debatable since the nature of humans will likely remain what it has ever been. That said, it is the only world there will be. We should not fear our current economic plight nor be fooled that things will spring back up again to where they were in the good times. They won’t, and our only salvation is to grow at the local level.

Approach from Dr Richard Nunes at Reading University


This is my response to an email from Dr Nunes asking if we might be interested in his research on Transition in society at Reading University. The links are below his message if anyone is interested, along with his contact details.. I don’t see any direct connection between what they are doing and TT Reading just yet, but as things progress, perhaps. It’s good to know that Transition is being taken seriously, even in academia now!

Dear Richard,

a very interesting piece – especially as I am a Springsteen fan! The comments to your blog posting are entirely salient, and it is good to be reminded that Transition is not new, in the sense of the establishment of “ecclesia” in response to the Pax Romana. If there has been an effective Pax Universalis since the end of WWII, of a global world economy, which is failing due to failing resources, especially crude oil, or will do so shortly, then Transition might be seen as a community-led response.

Seriously, I think that transitioning Reading will be no mean undertaking. The “successful” T-towns – that is to say, with an Energy Descent Plan, which is core to the philosophy and business of Transition – are those with populations of < 10,000, out in the sticks somewhere.

In Reading, we have a population of around 250,000, and are highly dependent on London to bring money into the town. An almost equal number of workers commute out of Reading daily (mostly to London) and from the surrounds, many from London, to do jobs in Reading for which there is an insufficient local skills-base.

Reading remains a town – as in the name of the football club – but is the size of many cities. Therefore, our problems/challenges are quite different from say, Totnes, Lewes, Dunbar, Lampeter, Kinsale etc. where at least a plan has been devised. Even there, however, putting the plan into practice to become effectively “oil-free” over a period of 20 years, is another matter.

Meanwhile, we are working on devising an EDAP for Reading, which is very much a “work in progress”.

I am forwarding the link to other members of the TT Reading group.(I thought posting it on the blog here would be the best way)



On 06/03/2012 11:14, Richard J. Nunes wrote:
Dear Prof. Rhodes,

We met briefly at the RCCP ‘Reading means business on climate change’ in
January. It was a pleasure meeting you, Justin(?) and Ornella. I just want to share with you a blog post that was uploaded last week; there is a link to our research on Transition in that post as well. Also, there are a couple of comments already and I would welcome your thoughts. I will set aside some time later this week to reply to comments.

If there is anyone in the TT Reading network who might be interested in our research, please forward the link to them.


Dr. Richard J. Nunes
Lecturer in Real Estate and Planning
Henley Business School
University of Reading
Whiteknights Campus
Tel: +44(0) 118 378 6229
Mbl:+44(0) 790 656 8558
Skype: r.j.nunes229

New MSc/PG
Dip/PG Cert International Planning and Sustainable Urban Management

New Territorial Development, Cohesion and Spatial Planning (2011)

The Thorium Age Waits in the Wings.


There is much written to the effect that thorium might prove a more viable nuclear fuel, and an energy industry based upon it, than the current uranium-based process which serves to provide both energy and weapons – including “depleted uranium” for armaments and missiles. There are different ways in which energy might be extracted from thorium, one of which is the accelerator-driven system (ADS). Such accelerators need massive amounts of electricity to run them, as all particle accelerators do, but these are required to produce a beam of protons of such intensity that until 10 years ago the prevailing technology meant that it could not have been done. As noted below, an alternative means to use thorium as a fuel is in a liquid fluoride reactor (LFR), also termed a molten salt reactor, which avoids the use of solid oxide nuclear fuels. Indeed, China has made the decision to develop an LFR-based thorium-power programme, to be active by 2020.

Rather like nuclear fusion, the working ADS technology is some way off, and may never happen, although Professor Egil Lillestol of Bergen University in Norway is pushing that the world should use thorium in such ADS reactors. Using thorium as a nuclear fuel is a laudable idea, as is amply demonstrated in the blog “Energy from Thorium” ( to which there is a link on this blog (above left). However, the European Union has pulled the plug on funding for the thorium ADS programme, which was directed by Professor Carlo Rubbia, the Nobel Prizewinner, who has now abandoned his efforts to press forward the programme, and instead concentrated on solar energy, which was another of his activities. Rubbia had appointed Lillestol as leader of the CERN physics division over two decades ago, in 1989, who believes that the cause is not lost.

Thorium has many advantages, not the least being its greater abundance than uranium. It is often quoted that there is three times as much thorium as there is uranium. Uranium is around 2 – 3 parts per million in abundance in most soils, and this proportion rises especially where phosphate rocks are present, to anywhere between 50 and 1000 ppm. This is still only in the range 0.005% – 0.1% and so even the best soils are not obvious places to look for uranium. However, somewhere around 6 ppm as an average for thorium in the Earth’s crust is a reasonable estimate. There are thorium mineral deposits that contain up to 12% of the element, located at the following tonnages in Turkey (380,000), Australia (300,000), India (290,000), Canada and the US combined (260,000)… and Norway (170,000), perhaps explaining part of Lillestol’s enthusiasm for thorium based nuclear power. Indeed, Norway is very well endowed with natural fuel resources, including gas, oil, coal, and it would appear, thorium.

An alternative technology to the ADS is the “Liquid Fluoride Reactor” (LFR), which is described and discussed in considerable detail on the blog, and reading this has convinced me that the LFR may provide the best means to achieve our future nuclear energy programme. Thorium exists naturally as thorium-232, which is not of itself a viable nuclear fuel. However, by absorption of relatively low energy “slow” neutrons, it is converted to protactinium 233, which must be removed from the reactor (otherwise it absorbs another neutron and becomes protactinium 234) and allowed to decay over about 28 days to uranium 233, which is fissile, and can be returned to the reactor as a fuel, and to breed more uranium 233 from thorium. The “breeding” cycle can be kicked-off using plutonium say, to provide the initial supply of neutrons, and indeed the LFR would be a useful way of disposing of weapons grade plutonium and uranium from the world’s stockpiles while converting it into useful energy.

The LFR makes in-situ reprocessing possible, much more easily than is the case for solid-fuel based reactors. I believe there have been two working LFR’s to date, and if implemented, the technology would avoid using uranium-plutonium fast breeder reactors, which need high energy “fast” neutrons to convert uranium 238 which is not fissile to plutonium 239 which is. The LFR is inherently safer and does not require liquid sodium as a coolant, while it also avoids the risk of plutonium getting into the hands of terrorists. It is worth noting that while uranium 235 and plutonium 239 could be shielded to avoid detection as a “bomb in a suitcase”, uranium 233 could not, because it is always contaminated with uranium 232, which is a strong gamma-ray emitter, and is far less easily concealed.

It has been claimed that thorium produces “250 times more energy per unit of weight” than uranium. Now this isn’t simply a “logs versus coal on the fire” kind of argument, but presumably refers to the fact that while essentially all the thorium can be used as a fuel, the uranium must be enriched in uranium 235, the rest being “thrown away” and hence wasted as “depleted” uranium 238 (unless it is bred into plutonium). If both the thorium and uranium were used to breed uranium 233 or plutonium 239, then presumably their relative “heat output” weight for weight should be about the same as final fission fuels? If this is wrong, will someone please explain this to me as I should be interested to know?

However, allowing that the LFR in-situ reprocessing is a far easier and less dangerous procedure, the simple sums are that contained in 248 million tonnes of natural uranium, available as a reserve, are 1.79 million tonnes of uranium 235 + 246.2 million tonnes of uranium 238. Hence by enrichment 35 million tonnes (Mt) of uranium containing 3.2% uranium 235 (from the original 0.71%) are obtained. This “enriched fraction” would contain 1.12 Mt of (235) + 33.88 Mt of (238), leaving in the other “depleted” fraction 248 – 35 Mt = 213 Mt of the original 248 Mt, and containing 0.67 Mt (235) + 212.3 Mt (238). Thus we have accessed 1.79 – 0.67 = 1.12 Mt of (235) = 1.12/224 = 4.52 x 10*-3 or 0.452% of the original total uranium. Thus on a relative basis thorium (assuming 100% of it can be used) is 100/0.452 = 221 times as good weight for weight, which is close to the figure claimed, and a small variation in enrichment to a slightly higher level as is sometimes done probably would get us to an advantage factor of 250!

Plutonium is a by-product of normal operation of a uranium-fuelled fission reactor. 95 to 97% of the fuel in the reactor is uranium 238. Some of this uranium is converted to plutonium 239 and plutonium 241 – usually about 1000 kg forms after a year of operation. At the end of the cycle (a year to 2 years, typically), very little uranium 235 is left and about 30% of the power produced by the reactor actually comes from plutonium. Hence a degree of “breeding” happens intrinsically and so the practical advantage of uranium raises its head from 1/250 (accepting that figure) to 1/192, which still weighs enormously in favour of thorium!

As a rough estimate, 1.4 million tonnes of thorium (about one third the world uranium claimed, which is enough to last another 50 years as a fission fuel) would keep us going for about 200/3 x 50 = 3,333 years. Even if we were to produce all the world’s electricity from nuclear that is currently produced using fossil fuels (which would certainly cut our CO2 emissions), we would be O.K. for 3,333/4 = 833 years. More thorium would doubtless be found if it were looked for, and so the basic raw material is not at issue. Being more abundant in most deposits than uranium, its extraction would place less pressure on other fossil fuel resources used for mining and extracting it. Indeed, thorium-electricity could be piped in for that purpose.

It all sounds great: however, the infrastructure would be huge to switch over entirely to thorium, as it would to switch to anything else including hydrogen and biofuels. It is this that is the huge mountain of resistance there will be to all kinds of new technology. My belief is that through cuts in energy use following post peak oil (and peak gas), we may be able to produce liquid fuels from coal, possibly using electricity produced from thorium, Thorium produces less of a nuclear waste problem finally, since fewer actinides result from the thorium fuel cycle than that from uranium. Renewables should be implemented wherever possible too, in the final energy mix that will be the fulcrum on which the survival of human civilization is poised.

Thorium Nuclear Power – A Lesson From Norway.


Norway holds a resource of 170,000 tonnes of thorium, which amounts to 15% of the world’s total of 1.2 million tonnes. There is far more thorium than that within the earth’s crust all told, averaging 8 ppm compared with around 2.8 ppm for uranium, but the above figures refer to richer ores, most commonly monazite sand which contains up to 12% of thorium. There is some opinion that thorium nuclear power might be a better environmental/energy-strategy for Norway than relying on carbon-capture which many consider to be uneconomic. However, the matter of thorium reactors is not straightforward. Professor Egil Lillestol of Bergen University has been pushing thorium for some years now, and thinks that Norway should set the trend in building a prototype accelerator-driven reactor in which a massive particle accelerator converts thorium-232 to uranium-233 by irradiating it with slow (spallation) neutrons generated by the impact of a 1.6 GeV proton beam on a lead target. The conversion is not direct, and involves the initial formation of thorium-233, which decays rapidly to protactinium-233, and then to uranium-233 over a period of about a month. Hence presumably reprocessing is involved in the final stage, since if the protactinium-233 is left in the reactor it will be at least partly converted to protactinium-234, which is not a useful fissile material.

It may well turn out that thorium is the better nuclear fuel as compared with uranium, since it offers the advantages that: (1) it is present in around 3 times the abundance of uranium on Earth, overall, (2) it can be bred into the fissile nuclear fuel uranium-233, (3) far less plutonium and other transuranic elements are produced than is the case from uranium fuel, (4) the thorium fuel cycle might be used to consume plutonium, thus reducing the nuclear stockpile while converting it into useful electrical energy.

However, it is a very big accelerator that will be needed to do the job, and the estimated costs for the project are about 500 million Euros. There are various advantages cited for this type of reactor, including the claim that it can be stopped easily if things get out of hand, and that it produces less long-lived nuclear waste than the uranium-fuelled fission reactors that are currently in common use. However, there are a whole host of scientific and engineering challenges that need to be overcome, and even identified in the first place because nobody has ever built one of these reactors, and hence the plans are still only on the drawing board.

As I have already stressed, it is a very big accelerator that will be needed if the project has any chance of success, so big in fact that there are none with sufficient power anywhere in the world. Some of the suggestions include using molten lead as the coolant for the system, but the reactor would run at a temperature above 700 degrees C. when the material becomes corrosive. A number of countries (including the US, Russia, the UK, France and Japan) have entrenched firm investments in uranium based reactors, and will use them for as long as they can. There are sizeable quantities of uranium on the world market, although the price has recently soared. Nonetheless, there is likely to be resistance to the research and development of a brand-new technology based on thorium, in view of huge costs that will effectively be borne by the Norwegian taxpayer if they go it alone down this unlit path.

The immediate future doesn’t look optimistic for thorium, certainly with the untested accelerator-driven reactors, and yet two thorium reactors have been operated, which were of the far simpler molten-salt reactor kind. Thus it might prove more expedient to invest in this at least tried technology, which could extend the useful lifetime of nuclear power by hundreds of years. The reason is that converting thorium-232 to uranium-233 is a form of “breeder” technology meaning that practically 100% of the thorium can be processed ultimately into nuclear fuel, rather than just the 0.7% uranium-235 isotope that exists in naturally occurring uranium, and which requires enrichment before it can be used. Indeed, the 99+% of uranium-238 can be converted into plutonium-239 and this used in fuel-rods, but there are many negative connotations attached to plutonium, which is almost the “p-word” for the nuclear industry: i.e. unmentionable, certainly in the tabloid press. There are serious issues of terrorism – dirty bombs at the very least, if not an out and out A-bomb detonation involving plutonium. The word alone would swathe a city and the world with fear. Uranium-233 made from thorium is harder to conceal than plutonium, since it is always contaminated with uranium-232, a strong gamma-ray emitter, and accordingly quite easily detected “in a suitcase” than plutonium which is principally an alpha-particle emitter and far more readily hidden.

There is no doubt that we will see a rise in nuclear power and for a number of reasons – cutting CO2 emissions, and securing energy supplies. Most of current thinking is based around using uranium as the fuel to drive it, but thorium could prove a very useful supplement and might power a new generation of reactors when we are short of uranium and do need to “breed” fuel if it proves uneconomic to mine poor quality uranium ores. I maintain my reservations about how long other resources, e.g. oil and gas will last, with which to mine and process either uranium or thorium, but if the latter appears viable in the longer run, I suggest that molten salt (liquid fluoride) reactors would be a better approach than the far more complex (and as yet untested) accelerator-driven systems.

The latter are reminiscent in scale to the putative nuclear-fusion reactors, said to mimic processes in stars, e.g. the sun, of which a working model is not expected for at least another 60 years. No one should forget that we need to make our energy provisions against a backdrop of 10 – 20 years at best, as oil and then gas begin to run short (the “Oil Dearth Era”). We do not want to back a loser now, as it is a one-off bet with the future of civilization resting on the outcome of this particular race.

Related Reading. There is also a link at the top left hand corner of this blog.

The Achilles Heel of Algal Biofuels – Peak Phosphate.


The depletion of world rock phosphate reserves will restrict the amount of food that can be grown across the world, a situation that can only be compounded by the production of biofuels, including the potential large-scale generation of biodiesel from algae. The world population has risen to its present number of 7 billion in consequence of cheap fertilizers, pesticides and energy sources, particularly oil. Almost all modern farming has been engineered to depend on phosphate fertilizers, and those made from natural gas, e.g. ammonium nitrate, and on oil to run farm machinery and to distribute the final produce. A peak in worldwide production of rock phosphate is expected by 2030, which lends fears over how much food the world will be able to grow in the future, against a rising number of mouths to feed. Consensus of opinion is that we are close to the peak in world oil production too.

World rock phosphate production amounts to around 140 million tonnes, and food production is already being thought compromised by rock phosphate resource depletion. In comparison, we would need 472 million tonnes of the mineral to grow sufficient algae to replace all the oil-derived fuels used in the world. The US produces less than 40 million tonnes of rock phosphate annually, but would require enough to produce around 25% of the world’s total algal diesel, in accord with its current “share” of world petroleum-based fuel, or 88 million tonnes of rock phosphate. Hence, for the US, security of fuel supply could not be met by algae-to-diesel production using even all its indigenous rock phosphate output, and significant further imports would be needed. This is in addition to the amount of the mineral necessary to maintain agriculture.

It is salutary that there remains a competition between growing crops (algae) for fuel and those for food, even if not directly in terms of land, for the fertilizers that both depend upon. This illustrates for me the complex and interconnected nature of, indeed Nature, and which like any stressed chain, will ultimately converge its forces onto the weakest link in the “it takes energy to extract energy” sequence. It seems quite clear that with food production already stressed, the production of (algal) biofuels will never be accomplished on a scale anywhere close to matching current world petroleum fuel use (>20 billion barrels/annum). Thus, the days of a society based around personalized transport run on liquid fuels are numbered. We must reconsider too our methods of farming, to reduce inputs of fertilisers, pesticides and fuel. Freshwater supplies are also at issue, in the complex transition to a more localised age that uses its resources much more efficiently.

There is a Hubbert-type analysis of human population growth which indicates that rather than rising to the putative “9 billion by 2050” scenario, it will instead peak around the year 2025 at 7.3 billion, and then fall. It is probably significant too that that population growth curve fits very closely both with that for world phosphate production and another for world oil production. It seems to me highly indicative that it is the decline in resources that will underpin our demise in numbers as is true of any species: from a colony of human beings growing on the Earth, to a colony of bacteria growing on agar nutrient in a Petri-dish.

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