Sunday, April 20, 2014

Win win: Energy from (nuclear) waste

Molten-Salt Reactor Experiment, ORNL
Did you know about the Waste Annihilating Molten Salt (WAMS) reactor idea? I didn't, though it sounds similar in principle - passively safe - to the molten salt thorium reactor which ran for 4 years at Oak Ridge National Laboratory. Why aren't these means of both generating massive amounts of power plus ridding the world of highly active nuclear waste at the top of the energy agenda?

Sunday, February 23, 2014

Shit, euphemisms and a bear of very little brain

To me, the word 'poo', now ubiquitous, is deeply insulting to its ursine homonym Pooh, aka Winnie the Pooh, that famous and actually rather smart bear created by A A Milne. I mention this because 'poo' has crept into serious science writing and science programmes put out by the likes of the BBC.

A letter in New Scientist (15 February 2014, p.34) prompted me to write this post, firstly because the use of the word 'poo' gets up my nose (when my children were young, we as a family, used the word shit) and secondly because of Stuart Tallack's aforementioned letter. Since it is not preserved in the magazine's online archive, I reproduce part of it here. Indeed, it could have been written by me:

I am not 5 years old and so don't need the prissy and childish word "poo" to assault my eyes. Excreta, faeces or droppings are perfectly acceptable; dung is perhaps not, as it implies manure. Shit was originally used without any connotation of vulgarity and should re-enter respectable society. But please, not "poo". What next? Articles on genitalia using such euphemisms as "front bottom", "naughty bits" and "meat and two veg"?

Thank you, Stuart! It needed saying. Now I'm off for a shit... and maybe I'll read one of my favourite Pooh stories while I sit on the bog (throne, john etc.). Got that?

Tuesday, February 26, 2013

Waste not, want not: nuclear fuel recycling

Prototype for the Integral Fast Reactor
"Down in the dumps" (New Scientist, 16/2/13, p 28) rather depressingly reveals that as far as radioactive nuclear waste is concerned, nothing has changed in decades and the repository route for dealing with nuclear waste may never be acceptable. One might say the thinking on waste disposal had vitrified!

Yet there is a solution available: PRISM reactors, based on the proven passively-safe Integral Fast Reactor. These can 'burn' plutonium (the UK has 100 tonnes), actinides, and depleted uranium (UK has 35,000 tonnes). IFRs are highly efficient and versatile, burning almost all their fuel. By contrast, a Light Water Reactor (e.g. Sizewell B) uses 0.65 per cent of the energy in the original uranium ore resulting in the radioactive waste, currently such a headache. The waste produced by IFRs is about 1/20th of that from an LWR. Its radioactivity within 200 years is about the same as mined uranium ore so no long-term repository is necessary.

David MacKay, chief scientist at the Department of Energy and Climate Change, says that there is enough energy in the UK's waste stockpile to power the country for more than 500 years. So why are we still obsessed with repositories? Why not use the 'waste' to make vast amounts of carbon-free electricity, simultaneously destroying almost all the 'nasties'?

Friday, January 25, 2013

Organics versus GM: throwing the baby out with the bathwater

Organics versus GM: sounds like some sort of war, doesn't it? And unfortunately, that's the way it's been portrayed in the media, particularly in Europe. As for me, I have undergone a slow conversion in my thinking over the last 15 years from strongly anti-GM to cautiously pro. Here, I want to explain why.

I have been growing organic fruit and vegetables on and off in several different countries in the world all my life, albeit in a small way. For the last 12 years, my wife and I have been growing commercially for a small box scheme, certified by the Soil Association (one of the several UK organic licensing bodies). In the 1990s, I was heavily involved in the anti-GM movement, helping organise protests, demonstrations, writing to the press and the supermarkets. I even went on the radio once and had a rant about Monsanto and the big corporations. I also started a website for kids which began with an illustrated guide to genetic engineering. (It's still there now – joined by another seven guides to issues which will be of great importance to the kids who are going to inherit our rather damaged world).

But as the years have passed and as it has become abundantly clear that people are not dying in droves because of GM, I've changed my mind. The famous economist John Maynard Keynes is alleged to have said to a critic who accused him of a U-turn, "When the facts change, I change my mind. What do you do, sir?" I am a scientist by training and so I constantly question and revise my views according to the evidence available. Sadly, the organic movement and other mainstream 'green' organisations remain as intransigent as ever in their views on genetic engineering: they seem to be stuck in a time warp 30 years out of date. Perhaps they, like politicians, don't wish to be seen performing a U-turn despite good reasons for doing so.

Basically, I don't understand why certain types of GM crops can't be approved for use with organic systems. It's hard enough growing organically as it is without constantly shooting yourself in the foot by refusing to move with the times. Let's just take one example. Last year, potato blight struck early in the soggy, damp non-summer. The result was that my potato crop was about a quarter of what it normally is. Yet there is a blight resistant GM potato which has been developed in the public domain. If only I could have used that! But I can't because it's against the organic regulations and even if I wasn't organic, I still wouldn't be able to use it because of all the 'green' protests which have made sure that it never sees the light of day; not for organic growers nor for any conventional growers.

What's so terrible about this potato? Is it Frankenfood? No, it's just an ordinary potato with one gene inserted from a wild potato which happens to show resistance to the dreaded Phytophthera infestans, the fungal late blight which caused the Irish potato famine in the 1840s when over a million people died of starvation. Alarmingly  the fungus has begun to reproduce sexually over recent years which makes it much more virulent. It had previously reproduced itself asexually and was relatively easily controlled by spraying fungicides or growing somewhat resistant potato varieties.

So why not embrace this GM potato? The introduced gene comes from the same genus - Solanum - and so is not even transgenic. Why is this potato 'bad' whereas the blight resistant Sárpo potato, bred over many years by conventional means, is good? (I was growing a Sárpo variety and it succumbed to the blight like the others.)  Of course, blight resistant GM potatoes, like the Sárpo varieties, will sooner or later be overcome by P. infestans. It's an arms race and this is where GM potatoes can leap ahead because it only takes a year or two to splice blight resistance into the genome and grow the resulting plant. It took the Sarvari family, who developed the Sárpo potatoes, some 40 years of careful selection of resistance traits to produce truly blight resistant varieties. As Pamela Ronald, Professor of Plant Pathology and Chair of the Plant Genomics Program at the University of California, Davis says: "To meet the appetites of the world's population without drastically hurting the environment requires a visionary new approach: combining genetic engineering and organic farming". She and her husband co-authored 'Tomorrow's Table' which, argues Stewart Brand, makes  "a persuasive case that, far from contradictory, the merging of genetic engineering and organic farming offers our best shot at truly sustainable agriculture".

I agree. It seems to me that organic farming regulations are throwing the baby out with the bathwater. Of course there's  'bad' GM where the profit motive comes before anything else. That was the origin of RoundupReady soybeans, a first generation GM seed which locked farmers into buying Monsanto's brand of glyphosate herbicide. But there's plenty of publicly-funded GM research which is not-for-profit and genuinely attempting to help all farmers grow food crops which don't require multiple applications of 'chemicals' (conventionally-grown potatoes may need 15 applications of fungicide per year). It is an indication of the success of the 'green' anti-GM movement that nothing GM can be grown in Europe. 

I think organic regulations should include carefully-chosen GM varieties, each selected on its merits, properly trialled (and not trashed) and tested. That way, organic growers could lead the way forward to a more sustainable agricultural system which can dispense with many 'chemicals' and give good yields under difficult conditions such as those we experience in 'summer' 2012. 

Then there's modifying C3 plants like rice to adopt the more efficient C4 photosynthesis. Why is that not acceptable? It will produce far more rice on the same amount of land. And sooner of later, GM is going to make it possible for non-leguminous major crop plants to form nitrogen-fixing symbioses with Rhizobia  bacteria. This would make a huge impact on staple crops such as the grass family (wheat, maize, rice) which provide more than half of all calories eaten by humans. It would counteract the synthetic nitrogen overload which is seriously affecting one of the nine planetary boundaries. Would the anti-GM protesters still trash any trials? Shouldn't organic regulations embrace such development? Properly regulated and monitored, genetic engineering is an incredibly useful tool which could and should be available for all growers. Why not use it?

Tuesday, March 15, 2011

After Fukushima: a way forward for nuclear power?

The post-tsunami disaster at the Fukushima Daiichi nuclear complex in Japan raises critical questions: Can nuclear power ever be completely safe? Should the world - which had been in the process of gearing up to build many more nuclear plants - now abandon them totally? What's the alternative as we strive to reduce consumption of fossil fuels?

Double damage: This is a double disaster,  firstly to Japan and its people (the horrifying drama is still unfolding as I write), and secondly to plans to increase nuclear electricity generation worldwide. Nuclear power is essentially carbon-free and without it, there would be a huge increase in coal-powered generation. Coal is the most polluting of fossil fuels: 1 ton of coal burned produces around 2.8 tons of CO2.

Lessons learned the hard way: What lessons can we learn from Fukushima and earlier nuclear disasters like Chernobyl?
  1. never build reactors near earthquake-prone plate boundaries
  2. never build them in coastal districts known to be vulnerable to tsunamis or rising sealevels
  3. build them with robust containment which can withstand hydrogen explosions, wartime enemy action, aircraft crashes
  4. don't use nuclear fuels which create dangerous and long-lived radioactive waste 
And the solution? Nuclear power is going to be needed in a big way to help us kick some of the fossil fuel habit whilst supporting our energy needs. Which is the lesser evil? Global 'meltdown' due to even more rapid climate change, exacerbated if more coal is burned because nuclear power is abandoned? Or nuclear power?

But supposing there was a way to have our nuclear cake and to eat it. A way which is truly safe and within our grasp right now. There are two fundamental changes which the nuclear industry can adopt to make future nuclear power safe and acceptable. One is a change of fuel and the other a change of containment:
  1. stop using uranium/MOX fuels and replace with thorium: no meltdowns, no bomb-making potential, no enrichment needed, radioactive waste short lived. Thorium reactors were abandoned early on by the nuclear industry during the Cold War because they could not be used for making nuclear weapons (which need enriched U-235 and plutonium)
  2. the containment problem, illustrated horrifically by the Fukushima reactors, can be solved by building all future reactors deep underground. Each reactor should have a large water store above it for passive emergency cooling, employing gravity and not pumps (which failed at Fukushima). The undergound installation, at the end of its design life, can be decommissioned by sealing it complete with its complement of spent thorium fuel whose radioactivity declines in tens of years rather than thousands.
 We all need energy, and much of what we use is electricity. Small but populous nations like Japan and the northern European countries cannot afford to take the risk, no matter how small, of  future Fukushimas or Chernobyls. Adopting the two proposals may be more expensive but consider the enormous cost Japan will have to bear to clean up the mess and build replacement energy-generating capacity. And then there are decommissioning costs...

Suddenly, thorium-fuelled reactors underground look like a technology which, unlike fusion power, is ready and waiting in the wings. Its time has come. How can we make it happen?

................................................................................................

For more on thorium reactors, see Greener Than A Thousand Suns and  Liquid Fluoride Thorium Reactors.

    Monday, December 21, 2009

    Copenhagen: a brief requiem

    Copenhagen...
    Hopenhagen?
    Nopenhagen!
    Nohope-enhagen :-(

    Business as usual.

    (But it's still the planet, stupid).

    To cheer yourself up, listen to The Now Show's interpretation of what went wrong. Happy Solstice!

    Tuesday, October 20, 2009

    Planning for the future

    The wind turbine pictured is a 6kW machine, courtesy of Proven. The SUV is by IFCAR via WikipediaQuestion: which one of the above machines needs planning permission before you can buy and use it?
    The answer, of course, is the wind turbine. This particular turbine should generate enough electricity in an a year to save more than 7 tonnes of CO2.

    The SUV doesn't need planning permission to buy; just a lot of money. Much more than the turbine. It will generate more CO2 each year than the turbine will save. It will also cost much more to buy and to run.

    Revised question: which of the above machines should have planning permission
    before you can buy and use it?
    It's a no-brainer and a good example of the cockeyed system we have to change in order to tackle the planet's climate woes and overconsumption. As you might guess, I am in the throes of trying to get planning permission for installing a 6kW turbine on my farm.