Physical Insights

An independent scientist’s observations on society, technology, energy, science and the environment. “Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Many passengers would rather have stayed home.” – Carl Sagan

Green Heretic: environmentalist Mark Lynas investigates nuclear energy.

leave a comment »

“Card carrying” UK Green and climate change expert Mark Lynas has been scorned by eco-colleagues for that greatest of big-G Green heresies: Daring to investigate and discuss nuclear energy, in any rational fact-motivated way.

“Except, well, I don’t believe that any more. Just a month ago I had a Damascene conversion: the Green case against nuclear power is based largely on myth and dogma.”

This investigation of what Lynas has learned, how he’s thought about it, how his views have changed, and how people have responded to him for it, is very much worth reading.

I was going to back up Lynas’ positions by posting this on the discussion thread on his website – but it’s a bit long and I don’t think they will post it, so I’ll post the following here instead.

I will cite or respond to a number of previous comment posts, in chronological order as you read down through the thread:

Theo:

“The idea of burning up all the stockpiles of old waste is VERY appealing. But then you mention the new waste products being “inert in a couple of centuries” and all waste being safe in “less than a thousand years”.

Do you really know that an informed and well-resourced civil society which could manage this legacy is going to be around in even 100 years? I’d say there’s a good chance it won’t. We would still be gambling with the health and safety of future humans – my own descendants – and I have an ethical sticking point there.”

Well, the radioactive fission products in the nuclear fuel, caesium-137 and strontium-90 for example, the significantly radioactive radionuclides which can’t be further “burned” as fuel, remain significantly radioactive and potentially dangerous for about 300 years, so that’s the chronological scale you’re talking about if you want to talk about geological deposition and isolation of radioactive waste.

But future generations, their societies and their civilizations are not responsible for perpetuating the longevity of the isolation of this radioactivity from the environment in such a repository – half a kilometer of rock is responsible for that, amongst other things.
When these repositories are designed and set up properly, as with the work of SKB in Sweden, loaded up with material and sealed, they do not require any future work, monitoring, maintainence or anything, ever, and future generations need not have anything to do with it.

Peter Brown:

“But is the old processed fuel really available? Is it not encased in concrete or vitrified or otherwise taken out of the system?”

You raise a valid point. Clearly the nuclear fuel and material that contains valuable stuff – uranium, plutonium and other actinides that make for good “fuel” – along with other valuable, usable materials in the fission products – should not be sealed up in concrete or glass or synrock or so forth; it’s terribly wasteful!

Maurice Spurway:

“But the huge construction programme over that period will ADD to CO2 emissions.”

The same can be said of wind turbines, photovoltaic cells, hydroelectric dams, or, really, construction of anything and everything.

shaun burnie:

“In the run up to the 20 year anniversary of Chernobyl the IAEA and WHO released a report that stated 4,000 deaths.”

If you quote, say, 4000 deaths from Chernobyl, I’ll accept that. The figure of 56 or so deaths that you often hear is the figure of deaths that we absolutely factually know happened and absolutely, factually can be causally linked to the Chernobyl accident. I think most people accept that there were many thousands of deaths, but it’s just so hard to construct factually accurate data about who did and did not die as a result of the Chernobyl accident.

Yes, there were many thousands of deaths, in all likelihood. The trouble is, instead of considering things scientifically, discussions of Chernobyl are treated with emotion and dogma.
For example, consider the following.

Some people say that there are children in Belarus or in the Ukraine today who have thyroid cancer, or are at risk of developing thyroid cancer, because of the Chernobyl disaster. When I hear that, however, I know that it is entirely false, and no amount of purported studies or reports make it true.

No, there are no children in the Ukraine below the age of seven who are at an elevated risk of developing thyroid cancer due to the Chernobyl accident. In fact, there are no people in the Ukraine, or Belarus, below 19 or so years of age who are at any increased risk of developing thyroid cancer due to the Chernobyl accident.

Why? Because they were never exposed to any radioactive iodine-131 source term.

I-131 has a short half-life: 8 days. The Chernobyl Forum puts the release of I-131 from Chernobyl at 1.8 EBq – that’s 1.8 x 10^18 Bq; a hell of a lot of radioactivity. Because of what happened to Chernobyl Unit 4, and because Iodine is so volatile and reactive, that represents nearly the entire amount of I-131 in the nuclear fuel of the hot, operating reactor.

Just one year after the disaster, 0nly 0.88 microcuries of 131I remained in the environment, undecayed. There are no children being exposed to 131I from Chernobyl today. The only people with an increased risk of thyroid cancer are those who were there in 1986-1987, during and immediately after the accident, when the 131I was present.

I have seen anti-nuclear dogma-packing “Greens” go absolutely nuts at me when presented with the above information, and I’ve been called all kinds of names. This kind of thing is a very useful litmus test to see if a person is prepared to treat nuclear safety as a science-based issue, or if they’re confined to dogma alone.

Furthermore, and more to the point, whilst a lot of people were harmed at Chernobyl, it just has no relevance to nuclear power in the world today, outside of the Soviet Union.

To consider just how far departed from nuclear power in the Western world Chernobyl was, consider this. In the 1940s, Edward Teller realized that the primitive graphite piles reactors used for weapons production at Hanford were potentially dangerous – they were graphite-moderated, water-cooled, had significant positive void coefficients of reactivity, had no real containment structures, and could suffer dangerous, explosive power excursions if they were forcibly restarted from a condition of xenon-135 poisoning and operated at a very low power level.

Edward Teller took reactor safety very seriously, and studied it very carefully. He ruffled a lot of feathers, as he carried on about the things that were not safe. Some derisively called him “the reactor opposer”. But thanks to his lobbying, no more such graphite piles were built ever again, aside from those very first few graphite reactors at Hanford, even though if building plutonium bombs is your goal, they’re the easiest, cheapest way to do it.

In short, everything that happened in the dangerous reactor at Chernobyl in 1986 was completely understood… nearly 40 years before the disaster.

Perhaps we might have given that information to the Reds – but I don’t think Teller and his colleagues would have approved that idea.

Alex Dickson:

“We are running out of Uranium on this little planet of ours. At the present level of usage in some 440 reactors generating some 363 gigawatts 67,000 tonnes of natural uranium are required each year. Increasingly lower grade ores will have to be mined and more energy will be expended in its extraction and refining process than will result from the nuclear reactors.”

Yes, something like that quantity of uranium is mined each year – to support the ridiculous current fuel cycles where most of the uranium-238 and a good portion of the U-235 is simply put aside as “depleted uranium”, then the fuel is irradiated, and the resulting fuel, which is still made up of 96% unchanged uranium, plus some plutonium and actinides, is called “waste” – it’s an incredibly wasteful, ridiculous and indeed unsustainable process, and that’s coming from a strong advocate of nuclear energy.

If you take natural uranium or thorium out of the earth, and burn it efficiently, converting all the uranium-238 into energy via intermediate transmutation into Pu-239, as well as fissioning the U-235, and you have an efficiency of, say, 75% utilization of the energy content of the nuclear fuel in the reactor, driving a Brayton-cycle powerplant with 50% efficiency, then the generation of one gigawatt of electric power for one year requires a mere one tonne of uranium (or thorium).

Since your reading matter seems to be limited to Bernard Cohen and his ilk, (it was he who described plutonium as one of humanity’s greatest gifts I think was it not?) I’d suggest some alternatives – such as the Mancuso-Stewart-Kneale study on Hanford workers…

Cohen publishes transparent, sensible, peer-reviewed science. If you want to attack what he says, I suggest you attack Cohen’s science with your own science – in the scientific world, this is always welcome. Nothing Mancuso writes is backed up by a body of peer-reviewed science. Cohen is quite correct – Humanity will need sensible, sustainable nuclear fission fuel cycles to drive its future – and the Uranium-238 fuel cycle is part of that.

“Another problem for nuclear energy right now is the existence of supply chain bottlenecks: notably large steel forging capacity, and expertise.”

Regarding this business about the pressure vessel forgings, Russia has their own forging capacity, Japan has theirs, and AREVA is building new forging capacity to support their new builds.

More to the point, only conventional Pressurized Light Water Reactors require these pressure vessels. So, if it’s a problem, don’t use use them.

Instead of conventional PLWRs, if those forgings are not readily available, why not consider the use of CANDU PHWRs, Pebble Bed Modular Reactors, Liquid Fluoride or Molten Salt Reactors, Liquid-Metal Fast Reactors, or any of the other, better, reactor designs that don’t require these forgings?

“The jobs are sorely needed too and this was always the promise of ‘New-Technologies’! So where are the jobs? The amount of jobs per £ billion building nukes is miniscule next to a national programme of investment in jobs in renewables!”

You know, when they introduced looms into the textile industry in Britain in the early 1800s, they said exactly the same thing – it threatens jobs!

If all we wanted was lots of jobs for everybody, we could just get rid of all trucks, and people could carry stuff around on their heads. (A hat tip Rod Adams for that little gem.) Yes, if you try and scale up solar and wind to the scale of nuclear energy generation, you’d need heaps of jobs – and yet you people try and tell us that these are more economical alternatives to nuclear power? Which is it?

The fact is, nuclear power isn’t anywhere near as ‘cheap’ as they claim when one factors in the de-comissioning costs! Something that never gets done because the taxpayer is still expected to come up with that money as well… what was it? £70+ billion at a recent estimate (but of course nobody really knows because how do you know what it’ll ‘cost’ in a thousand years time)? Add de-commissioning costs to the ‘cost’ of nuclear power ‘at the plug’ and your hairdryer becomes the most expensive hairdryer in history!

It certainly doesn’t take a thousand years to decommission a nuclear power plant. The cost of decommissioning a nuclear power plant is much significant than the initial capital investment to build the plant – even if that cost is hundreds of millions of dollars, divided into every kilowatt-hour of electricity sold to the grid over the 50-year lifetime of a nuclear power plant and paid for by customers of nuclear electricity, it’s an insignificant cost.

Having said ALL of that the real danger is this civilisation of ours (that seems to be teetering on the edge of a global catastrophy of its own making), leaving a toxic technology legacy that nobody understands in the future, which poisons future generations for hundreds of thousands of years and yes it is hundreds of thousands… Plutonium has a Half-Life of 250,000 years (which means if an ounce of plutonium kills you in ten minutes now… in 250,000 years it will take twenty minutes for you to die!) The stuff is just too dangerous to leave for future generations…

Of course, plutonium-239 has a half-life of just over 24,000 years. Plutonium (which nuclide?) does not have a half-life of 250,000 years… that’s nothing more than ridiculous, mendacious nonsense.
In any case, why should the half-life matter? This material is potent fuel, valuable fuel, that is most certainly not “waste”… it’s valuable fuel that can be fissioned to generate abundant clean energy for our society.

“Slowing economic activity (aka GDP or GNP) by half would cut our energy needs by 75%!”

You know, I’m pretty sure that the economy is not actually a moving object with mass and kinetic energy. Perhaps your example is a good example of a big problem which is of relevance to our problem here – taking some hyperbolic nonsense and dressing it to sound like it’s physics?

Written by Luke Weston

October 3, 2008 at 12:55 am

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: