Wednesday, 29 October 2014

Comparing carbon emissions of wind and nuclear power

The wikipedia page is sourced from the IPCC [page 982].

Aggregated results of literature review of LCAs of GHG emissions from electricity generation technologies (g CO2 eq/kWh).

IPCC figures for Nuclear, Wind, Gas:
NuclearWindGasAv W+GAv W+2G
25th percentile88422215284
50th percentile1612469241317
75th percentile4520548284372

PS: The last 2 columns are mine. They are averages of wind and gas. Av W+G = Wind:Gas @ 50:50; Av W+2G = Wind:Gas @ 33:67

The wikipedia link only shows the 50th percentile. Estimates vary over ranges of 81 to 2 for wind, and 220 to 1 for nuclear. There's clearly vast disagreement among scientists, engineers, and economists over what the true values are. I think the IPCC should've done their own studies. At the very least, the IPCC should have excluded some of the outlier estimates. Afterall: this is one of the most important 'findings' of their report.

The carbon emission intensity figures one sees for wind always pretend it to be an independent source. It's never. Wind is totally dependent on fossil fuels. From time to time, UK wind drops to low levels throughout.

At times like that fossil fuels generate electricity or the lights go out. When calculating carbon emissions from wind I factored in the necessary fossil fuel (Av W+G, Av W+2G columns) The last 2 columns are carbon emission values for Wind and Gas combined. Carbon emissions (g CO2 eq/kWh) of 241 or 317 for wind and gas combined tell the real story.

Roll on the day when we get nuclear power using Gen IV reactors fueled on reprocessed spent nuclear fuel. This will considerably cut the nuclear power carbon footprint.

The large variation in emissions estimated from the collection of studies arises from the different methodologies used - those on the low end, says Sovacool, tended to leave parts of the lifecycle out of their analyses, while those on the high end often made unrealistic assumptions about the amount of energy used in some parts of the lifecycle. The largest source of carbon emissions, accounting for 38 per cent of the average total, is the "frontend" of the fuel cycle, which includes mining and milling uranium ore, and the relatively energy-intensive conversion and enrichment process, which boosts the level of uranium-235 in the fuel to useable levels. Construction (12 per cent), operation (17 per cent largely because of backup generators using fossil fuels during downtime), fuel processing and waste disposal (14 per cent) and decommissioning (18 per cent) make up the total mean emissions.

An alternative to the IPCC figures, considered superior by many, are those from NREL.

The economics of wind power

How much steel and concrete for the fabrication of windmills and nuclear reactors?

EPR nuclear reactorTypical modern windmill
Power1,600 MW2 MW
Coeff production (h/an)7000 h (80% of 8760 h)1750 h (20% of 8760 h)
Life time60 years15 years
Total production in TWh (over entire lifetime)670 TWh0.053 TWh
Tons of steel40,000150
Tons of concrete200,0001000
Tons of steel per TWh602830
Tons of concrete per TWh30018900

For the same amount of electricity produced, windmills require 50 times more steel and 60 times more concrete than nuclear reactors.

This is with the EPR reactor which is a rather "heavy" reactor (more steel and concrete than its’ competitors, such as the AP-1000).

EFN / Bruno Comby / 7 02 2007

Per Peterson provides a different comparison kinder to wind but using old wind technology. He compares energy cost of building plants: Nuclear, Wind, Coal, Natural Gas.

Monday, 27 October 2014

Simple Molten Salt Reactor, by Moltex LLP

Moltex LLP is a small UK engineering design company based in London. On 20 Oct Ian Scott of Moltex presented his SMSR, lasting 15 minutes, at a House of Lords meeting.

Ian was influenced by the very first Molten salt design from 1950, which placed molten fuel inside narrow cylinders. Ian's design has several such cylinders full of fuel inside a tank of coolant. Both coolant and fuel are molten salts. The fuel circulates in these cylinders by convection, as does the coolant in the tank. A 1 GWe reactor will have a tank about 8 metres in diameter. There are no pumps moving molten salts - circulation is all done by convection. The tank will be a nickel alloy, probably Hastelloy. No moderator either, so it's a fast reactor. Ian reckons the reactor will last many decades.

Stated advantages of the SMSR

  • unpressurized
  • the reaction is barely critical
  • no volatile fissile materials will be left in the reactor (gases will bubble out)
  • safe coolant
  • no pumps
  • materials are all standard industrial parts
  • cheap
  • fuel will be made from spent nuclear fuel, SNF, extracted by a "simple single-stage process".

Potential Issues:

  • The primary coolant is sodium chloride. Natural chlorine is a mixture of isotopes: mainly Cl-35, Cl-37. Cl-36 is present as a trace, and is radioactive, half-life = 300k years, undergoing mainly beta decay to Ar-36, S-36. The thermal neutron cross-section of chlorine-35 = 35.5 σa/barns [can't find the fast version, but the thermal spectrum is worryingly high]. It looks like quite a lot of neutrons may be lost to chlorine-35 absorption, producing chlorine-36 which is radioactive. Ian does not believe enough neutrons will be lost to make the reactor too inefficient, but the coolant will become radioactive. A way around this is to use isotopically separated chlorine-37 in the coolant salt. Using chlorine-37 alone, will prevent chlorine-36 forming and Cl-37 is stable against neutron bombardment. Several quite inexpensive routes are available for the separation of Cl-35 / Cl-37. The cost estimate has been done, still giving a very viable project.
  • The fuel tubes are a consumable item with an anticipated 5 year life, functioning in a similar manner to fuel rods and needing periodic replacement.

A thorium breeder?

Ian believes that a converter makes economic sense now. A breeder will have to wait till the future:

There would then be an economic case for developing a nuclear breeder version of the reactor (this exists now in outline), which would operate on the thorium fuel cycle. That outline design is far simpler, safer and cheaper than current designs for sodium cooled fast breeder reactors.
- [Moltex Energy LLP – Written evidence, section 29]

The best introduction to the SMSR may be references: 6, 4 [translated via Google], 2, 1, in that order. Refs. 2, 1, 3 contain all the detail.

  1. Slides
  2. Evidence to House of Lords, pages: "Moltex Energy LLP – Written evidence"
  3. Patent Application WO-2014128457-A1
  4. Blog on Moltex (in French)
  5. Moltex LLP
  6. Next Big Future - UK MSRs

Earth used to be much more radioactive in the past

In the regions of the former Soviet Union that were highly contaminated by the fallout from the Chernobyl accident, the increased radiation dose rate for local inhabitants is far less than the dose rate in areas of high natural radiation (see figure 2). In those places, the entire man-made contribution to radiation dose amounts to a mere 0.2% of the natural component.
Three and a half billion years ago, when life on Earth began, the natural level of ionizing radiation at the planet’s surface was about three to five times higher than it is now.2 Quite possibly, that radiation was needed to initiate life on Earth. And it may be essential to sustain extant life-forms, as suggested by experiments with protozoa and bacteria.3
At the early stages of evolution, increasingly complex organisms developed powerful defense mechanisms against such adverse radiation effects as mutation and malignant change. Those effects originate in the cell nucleus, where the DNA is their primary target. That evolution has apparently proceeded for so long is proof, in part, of the effectiveness of living things’ defenses against radiation.
Other adverse effects—which lead to acute radiation sickness and premature death in humans—also originate in the cell, but outside its nucleus. For them to take place requires radiation doses thousands of times higher than those from natural sources. A nuclear explosion or cyclotron beam could deliver such a dose; so could a defective medical or industrial radiation source. (The malfunctioning Chernobyl reactor, whose radiation claimed 28 lives, is one example.)
Figure 2. Average individual global radiation dose in the 1990s from nuclear explosions, the Chernobyl accident, and commercial nuclear power plants combined was about 0.4% of the average natural dose of 2.2 mSv per year. In areas of Belarus, Ukraine, and Russia that were highly contaminated by Chernobyl fallout, the average individual dose was actually much lower than that in the regions with high natural radiation. The greatest man-made contribution to radiation dose has been irradiation from x-ray diagnostics in medicine, which accounts for about 20% of the average natural radiation dose. Natural exposure is assumed to be stable. The temporal trends in medical and local Chernobyl exposures are not presented. (Based on data from UNSCEAR.)
  1. Radiation risk and ethics, by Zbigniew Jaworowski, Physics Today, 52(9), Sep 1999, pp. 24-29
  2. P. A. Karam, S. A. Leslie, in Proc. 9th Congress of the International Radiation Protection Association, International Atomic Energy Authority, Vienna, Austria (1996), p. 12.
  3. H. Planel et al., Health Physics 52(5), 571 (1987).

Monday, 6 October 2014

Best UK Electricity Policy - wait for molten salt reactors

No need to waste more money on wind, nor Hinkley C. Molten salt reactors will arrive soon. We can burn cheap fracked gas for electricity till then. The IMSR is

8 years to demonstration reactor
- David LeBlanc, 2013.

Q: What is the IMSR
A: The Integral Molten Salt Reactor is designed by David LeBlanc for Canadian nuclear startup Terrestrial Energy. It will be a Gen IV small modular reactor (SMR). A variation of the Denatured Molten Salt Reactor (DMSR), dating from 1980. By applying the KISS principle (Keep It Simple Stupid), the IMSR seeks to quickly pass regulatory approval. It uses:

  • LEU fuel (5% to 10% U-235 enrichment)
  • thermal neutrons, but with "substantial U-238 fast fission bonus"
  • Conversion ratio = 0.9
  • Has a much smaller waste footprint (even with no reprocessing)
  • Is orders of magnitude safer due to intrinsic, passive safety systems, that prevent any major accident
  • Operates at normal pressure, so preventing any possible air-borne contamination (as happened at Chernobyl and Fukushima). A total disaster scenario would only see local contamination.
  • Uses denatured fuel, so avoiding all proliferation risks
  • Uses only ⅙ the fuel of a LWR for same power output.
  • Will be able to generate electricity costing less than 1¢ / kWh (unit)
  • It is much cheaper to build than current reactors. The reactor vessel is much smaller and thinner. It does not need a huge, 8 foot thick, concrete dome around it. It will not need a spent fuel pool. Reactor operation is simpler and safer. Overnight costs should be < 13% of Hinkley C, with a construction time of less than 3 years per module.

Q: Is it real?
A: Yes. Terrestrial Energy have industrial partners and a business plan to guarantee finance from Canadian industrialists for industrial heat applications.

Q: How does the IMSR perform so well?
A: The key is minimal parasitic loss of neutrons

  • No internal reactor structure
  • No burnable poisons
  • Less neutron leakage
  • ½ of all fission products and all important Xe-135 leave due to Off Gas system
  • Comparing parasitic losses:
    3% - 5%

Q: Do we have enough uranium to fuel it?
A: Yes. There's thousands of years worth of easily accessible uranium available to fuel enough IMSRs to make all the planet's electricity. Although current 'known uranium reserves' are limited, we can find huge reserves of less concentrated ore. Even at a cost of $300/kg (many times the current world price), IMSR electricity will still be cheap

At the simplest, it can run without reprocessing for 30 years.

A better run mode will reprocess fuel after 10 years to remove fission products [using cheap pyro- / electro- / vacuum distillation processes which are ~ 1/7; the cost of PUREX]. Whether or not reprocessing will be cost effective is a separate issue. PUREX ~ $2000/kg of fuel produced. If simple reprocessing was 10% of that: $200/kg, it would need to compete with Uranium currently costing $78/kg. Reprocessing has other advantages - lowering the amount of waste, removing TRU from waste and putting it back into the reactor.

IMSR Cost estimates ($ / MWh):
------ IMSR ------
Old NuclearCoalNew LWRfirstmodule
Operating, Maintenance, Labor/Materials6.
Pensions, Insurance, Taxes1.
Regulatory Fees1.
Property Taxes2.
Decommissioning and DOE waste costs5.
Administrative / overheads1.

Table copied from Nextbigfuture, who think the IMSR can get down to 0.86 cents per Kwh.


The myth of subsidised carbon fuels

The myth that fossil fuels are subsidised by government has become common sense in recent years. It's based upon a deliberate confusion between subsidy and tax. A tax is money taken from person A and given to person B. It's most commonly understood in terms of taxes we pay the government: VAT, NI, Income tax, fuel duty, ... Another way to understand tax is in terms of the rentier concept. A rentier is a person collecting tax. In this 2nd definition, a landlord can be seen as taxing his tenants. A subsidy is more complex than tax. Subsidies may be a direct payment made from government to industry. An example of such may be loan guarantees, to the extent that the guarantee lowers the rate at which capital is borrowed, or reduces insurance that may have to be taken out. A subsidy can also result when government regulations mandate that one industry makes payments to another. Such examples happen in electricity generation. Wind and solar electricity having preferential access to the grid at guaranteed prices. This forces higher costs other generators. For example CCGT (gas) plants must be frequently turned on and off as wind generation rises and falls. It takes 50 minutes or so for such a gas plant to warm up before it is generating electricity. CCGT owners pay additional costs in reduced efficiency of fuel, labour and capital.

Let's compare actual taxes on fossil fuel with supposed subsidies

With rough calculations I calculate the UK taxing carbon fuels, at least, 3 times more than it subsidises them.

These are UK estimates.

Various UK taxes on fossil fuel

£ bn
Fuel duty (2009):25.89
VAT on duty (2009):3.88
Carbon tax (2013):2.28
VAT on electricity (2012):0.75
Total tax32.81
Subsidies (2013):11.25
Tax - subsidy21.56

Some assumptions:

  • 27.30% = percentage of carbon in CO2
  • UK carbon tax = £18/tonne of carbon.
  • Fossil fuel subsidies represent 0.45% of GDP (BBC)
  • UK GDP ~ £2500 bn.
  • 75% of UK electricity is generated from fossil fuels
  • VAT on electricity is 5%, payable only by domestic users.

2013 UK Greenhouse Gas Emissions & estimated carbon taxes

(MtCO2)C tax (bn)
Other solid fuel10.20.050
PS: I have little idea how the BBC work out that fossil fuels are subsidised to the tune of 0.45% of GDP. A big part of the subsidy seems to be for taxes which we don't pay! What will the bureaucratic newspeak machine tell us next: that the UK subsidise the labour market by X% because British workers don't pay 100% income tax?
In the UK, for example, value added tax (VAT) on gas and electricity is 5% rather than the 20% charged on most other goods
Let's remember that energy is both the master commodity, and a major factor in determining labour productivity. Energy taxes are a direct tax on the whole economy and upon future productivity increases. [see: How did we British get our empire?]


Sunday, 5 October 2014

Ian Fairlie Fukushima Speech

I'm posting this here because Dr. Ian Fairlie represents himself as a serious scientist. There are numerous wrong statements below.

  • What kind of scientist calls the rest of the scientific community: IAEA, WHO and UNSCEAR - denialists?
  • After reactor shutdown, there were no criticalities
  • A criticality is not the same as a explosion
  • Zirconium alloy cladding in fuel ponds did not catch fire

Chernobyl Congress (IPPNW conference) Berlin. 9 April 2011, Ian Fairlie speech

Good morning,

I'm going to deviate a little bit from my talk this morning, partly because I've just been told I've got 10 minutes and partly because I don't want to over-egg the cake. I think most of you have got the message that Chernobyl was far more serious and ... ... ...

I come from Britain. I would like to pay tribute to Germany. I feel glad to be back in a same country, in many ways. I noticed, in the last few weeks, that you have had some lander elections in Rheinland-Pfalz and Baden-Württemberg, where the reigning pro-nuclear party were kicked out and the greens and SDP were put in. Congratulations [makes clenched-fist salute, followed by audience cheers]

What's actually happening is that we have a nuclear government in Britain, who are nuclear diehards, who are denying what's going on at Fukushima. Interestingly, they put up a chief scientist who has said: "nuclear melt downs - don't worry, don't worry", he said. At the same time, the British government were sending 20 charter jets to Tokyo to take out all British nationals. Well, I have a phrase about that and it's this: "don't believe a word what the government says, believe what it does", always, always. What's happening right now in Britain is that the government is planning full steam ahead to build nuclear power stations, to be built by your wonderful German companies RWE and EON. And I say to the government, no no, no no, don't send us your nuclear power companies send us you green politicians instead. Because we could do with them in Britain, we really could. Anyway that's the politics of it over with, a wee bit.

I know I'm moving away from this, what I'm supposed to talk about. But, to me, Fukushima is more important. Basically we've been overtaken by events. And when this [conference] was organized, Fukushima hadn't happened. So I'm going to spend my remaining 5 minutes talking about a little bit about what I know about Fukushima. I've cleared this with the chair, she said fine. I get about 100 emails a day concerning Fukushima. It's almost information overload. But I'm going to give you the basic bits of information that I see gleaning, coming from this.

I think that Fukushima is already more serious than Chernobyl, already. And it's going to last for a long time. Already IAEA and Japanese Tepco officials are saying that we have to look to the long term on this they said. 3 to 4 years that the accident is going to continue. Their words not mine. 3 to 4 years. [feigned laughter] That's crazy. Chernobyl was over and done with in 10 days in terms of emissions from the reactor. 10 days. Well here we are and we're all of 35 days in and counting.

What I see in there, in 4 of the reactors and their fuels ponds. That's reactors 1, 2, 3, and 4. Fukushima Daiichi. There are meltdowns in at least 2 of the reactors. And by meltdowns that means that the fuel has already gone through the reactor vessel, and has probably gone through the containment vessel too, and into the building floor and it's only a matter of time before it goes into the soil. We have already seen fuel cladding fires in the fuel ponds. In other words, each of the 4 stricken reactors. I'm not talking about reactors 5 and 6. We'll leave them to one side. They are clad in zirconium and what's happening is that the fuel ponds have, in at least, 2 cases 3 and 4, the fuel ponds, the water has drained out, exposing the fuel and the cladding has caught on fire. The cladding is made of zirconium and it reacts with air spontaneously. And you have fires. When the fuel starts burning you have direct ejection of fission products and activation products straight into the atmosphere, and that's what has been happening there. That's why the radioactivity contaminates the surrounding area.

In addition to that it's even worse. There have been a number of scientists looking at the official data reckon that there have been criticality ...

Criticality means that when the configuration of the fissile material comes together enough for a sudden flash or explosion and release of vast numbers of neutrons which is the reason why there have been sudden huge increases in radiation exposing nuclear workers. The poor nuclear workers there. Criticality, we don't think that happened at Chernobyl. We're not sure but we don't think it did whereas it seems to be happening at Fukushima. In addition that there's been thousands of gallons (liters) of radioactive water discharged into the sea. There's been huge amounts of air emissions to the point whereby, in children's playgrounds and schools about 60 to 70 kilometres away we seeing annual doses - hourly doses (which if you worked it up to an annual dose) would be 250 mSv per year. That's ghastly. This is in children's playgrounds. The situation in Japan is, I think, is probably as worse if not worse than Chernobyl right now, but it's going to get worse, I think. Many people have said that it's going to get worse than better.

Already in Tokyo, the population of 30 million, in the greater population area, the situation is very dire. Most young women of child-bearing age have gone. Have fled to the south, and south-west of the country. The car manufacturing companies cannot continue to work because their workers, who are following their wives, have moved to the south west of the country. It's not admitted, apparently, but according to anecdotal ... the big car companies have all closed down. This is serious. We're coming to a situation of societal breakdown, in many ways. I feel very, very vexed and sorry for the Japanese society. They deserve better than this.

Yet what do we see in our countries around the world. Our British government is venal. It refuses to learn about what's going on here. It has announced an enquiry into the matter but it still says that does not matter. Not matter what the enquiry says we are still going to go ahead with the nuclear power program in Britain. Well, as the previous speaker said, do these people think that we are crazy. Who are stupid here. Is it the politicians who are stupid rather than our electorates? I'm very angry about this. And all I can say to you is that I hope that in Britain, we have some local elections coming up and national elections in Wales and Scotland coming up. I hope the government get their comeuppance as they are sadly due it. I'll just finish off by saying that I have hope for the future. I hope that we will learn from the sad, sad, events at Chernobyl, and now that they have been reinforced by the even worse events in Fukushima, politicians will actually wake up and realize that the nuclear technology is a failed technology and that we should abandon it. Not just in Germany but throughout the world. There is one green-lining, or shall I say silver-lining to this and that is that despite what the IAEA and the WHO and UNSCEAR have said in their denials of the effects of Chernobyl and Fukushima there is a silver-lining and it's this that tens of thousands, seventy or eighty thousand people throughout the world in about 1000 organizations have organized themselves into Chernobyl children's projects. CCPs. And what they do is, they organize holidays and healthcare for the children in the affected areas. My heart goes out to them. I help them free of charge. I think that what they are doing is wonderful. I think their actions are a silent rebuke to the official pro-nuclear organizations in this world.