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Rebuttal

(Response by Sevior and Flitney in blue)

Jan Willem Storm van Leeuwen

Introduction

This paper is a rebuttal of a Media Release by the University of Melbourne:

New investigation shows nuclear power will last longer, cause less emissions

Media Release, Wednesday 21 December 2005

http://uninews.unimelb.edu.au/articleid_3096.html

This Media Release (full text: see Appendix) is based on the work by Martin Sevior, who published his findings on the web site www.nuclearinfo.net.

The work described on http://nuclearinfo.net is the result of a group of Physicists who are listed as the authors of the site. All the results reported there have been subject to peer review. In the case of the full energy analysis the work was subject to close scrutiny by a number of group members. The Full Energy Analysis and critique of the Storm van Leeuwan and Smith paper was was a joint work of Associate Professor Sevior and Dr. Adrian Flitney. We have jointly prepared this response too.

In this rebuttal I will examine the two main issues - construction of nuclear power plants and uranium - on the basis of two quotes from above Media Release.

The first quote refers to the energy needed for construction of a nuclear power plant and the related emission of carbondioxide (CO2) and other greenhouse gases:

The University of Melbourne research group investigated the energy required to build and operate a nuclear power plant. To this end they employed independently audited statistics made available by the Swedish Energy Utility, Vattenfall.

The scientists find that the energy cost to build a power plant would be 'paid back' within one and a half months of its establishment, and that the disposal of nuclear waste would add just one and a half more months to that total. Van Leeuwen and Smith predicted that nuclear power plants would take 7 - 10 years to 'pay back' these energy costs.”

The second quote refers to the energy needed for extraction of uranium from ores:

They also investigated the energy cost of mining uranium from the Olympic Dam mine in South Australia and found that it is at least 10 times smaller than predicted by van Leeuwen and Smith. Consequently the world's uranium resource base is likely to be hundreds of times greater than the previous research suggested. ”

Construction of a nuclear power plant

Sevior discards without any reasoning the calculations of the construction energy of a nuclear power plant from all studies in the past and adopts the figures of Vattenfall (see below) without question.

The point was to demonstrate world best practise with an obvious, quantifiable and verifiable data point. There are plenty of examples of bad practises in Nuclear Power. We list them on the web site. We see no point in pursing bad practises in the future. The Vattenfall Environment Product Description (EPD) provides data that covers the entire Nuclear Power generation cycle including power plant construction, decommissioning and waste disposal. Other studies make assumptions that necessarily have large uncertainties and are averaged over many cases of good and bad practise. Furthermore the Vattenfall EPD data have been independently audited and required by law to not be misleading.

See the Swedish EPD requirements here:

http://www.environdec.com/whatisepd/

Quoting from this document:

The overall goals of an EPD is, "through communication of verifiable and accurate information, that is not misleading, on environmental aspects of products and services, to encourage the demand for and supply of those products and services that cause less stress on the environment, thereby stimulating the potential for market-driven continuous environmental improvement".

Vattenfall

The quoted publication [1] of Vattenfall AB, a Swedish utility, is an evironmental analysis, called an EPD (Environmental Product Declaration), not an energy analysis. This becomes clear by reading the document thoroughly and is confirmed by Birgit Bodlund (Senior Adviser Environmental Affairs, Vattenfall) in a personal communication (17 December 2001). The EPD is made to comply with certain Swedish regulations.

The Vattenfall EPD cannot be compared with the energy analyses quoted on our web site (www.stormsmith.nl) and the energy analysis we did, see Chapter 3. An energy analysis comprises all energy flows related to the investigated object: not only the direct energy consumption, but indirect and embodied energy flows as well.

The Vattenfall EPD, while not specifically designed to be an energy analysis, provides the data required for an energy analysis. We take responsibility for employing the data provided by the EPD in this manner.

The EPD explicitly includes all the inputs used in the construction of the NPP. These include the energyware used throughout the full nuclear cycle, including the energy embodied in the construction of the NPP. It would not be possible to determine the environmental impact without  these considerations.  The EPD also includes estimates of the energy inputs that may have been neglected and places limits on them.

The EPD report states that some data are missing from the processes needed to fabricate nuclear fuel from uranium, such as greenhouse gas emissions, because the suppliers did not provide those data. Vattenfall estimated the underestimation of the emissions, caused by the absence of the data, at a few percents, but failed to explain how the estimate was made.

Page  14 of the 2004 EPD (available as a pdf from http://www.environdec.com/reg/026/) explicitly lists these under-estimations. They also state that in the case of the under-estimation they use generic data. The impact of these omissions was judged to be acceptably small (less than 10%) by the crediting agency.

The energy figures in the EPD report refer to the direct electricity consumption by  the mentioned processes of the nuclear chain, as far as it is not provided by the nuclear power plant itself. The electricity consumption is converted into primary energy units, according to the fuel mix of the electricity generation at the site of each process. So the amounts of fossil fuels and CO2 emissions stated refer only to the direct electricity consumption.

The EPD explicitly lists the energy costs embodied in the form of coal, natural gas, wood, and hydro-electricity used in the construction and decommissioning of the NPP. These are the full energy costs, not just electricity used in the construction. If these were not included the EPD would be misleading as it would under-estimate the CO2 and other polluting gas emissions from the use of nuclear power provided by Vattenfall. Such an omission would not have been allowed by the crediting agency. Vattenfall have provided a spreadsheet, published on the http://nuclearinfo.net  website (http://www.nuclearinfo.net/Nuclearpower/WebHomeEnergyLifecycleOfNuclear_Power/Energy_per_lifecycle_phase_Ian_Martin_051124-1.xls ), which explicitly lists all the energy inputs used in the construction of the NPP. A private communication from Caroline Setterwall of Vattenfall confirms that the numbers in the spreadsheet and those employed by the EPD are the total energy used, not just the electrical energy.

As the electricity consumption in most processes are a minor part of the total direct energy consumption, the total amounts of fossil fuel burnt and hence the CO2 emission are much larger than stated in the Vattenfall EPD. This 'omission' is not the fault of Vattenfall: apparently these data needed not to be included in the EPD.

This is a misunderstanding of the EPD. These data are explicitly included and listed in the energy construction cost. To do otherwise would be misleading and an explicit violation of the EPD requirements.

Figures of some processes not yet in existence (e.g. deep repository) are not included in the Vattenfall EPD. However, figures of the direct electricity usage of dismantling of the nuclear power plant and of a waste facility do. Vattenfall failed to explain how these estimates were made.

Sweden has developed test facilities for deep underground storage over a period of 20 years. Presumably the energy listed in the spreadsheet (as published on the http://nuclearinfo.net website) is based on the extensive data acquired from this research. It is reasonable to assume that Vattenfall can make these estimates, given the research undertaken for the disposal of waste.

Some figures given in the EPD are not as solid as they may seem, because Vattenfall assumed a lifetime of 40 years with an average load factor of 0.85, or 34 full-power years (FPY). Through 2002 the three Forsmark nuclear power plants (connected to the grid in 1980-1985) together reached an operational lifetime of 16.1 FPY. Up until now no nuclear plant in the world reached more than 24 FPY, so an expected lifetime of 34 FPY is not based on practical experience with any nuclear power plant in the world.

The NPP shows no sign of requiring decommissioning before the end of it's lifetime. Second Generation Nuclear Power plants only became operational 30 years ago. In fact Vattenfall has applied for permission to increase the electrical generating capacity of the Forsmark Nuclear power plant.

http://www.energorisk.com.ua/english/News_arc/Archiv_2004/October/NISL151004.htm

It has already received permission to increase capacity for the Ringhals facility.

See http://www.worldnuclear.org/_news_feature/index.cfm?NN_Flash=0&site=2

It appears perfectly reasonable to assume the NPP will operate until the end of it's projected 40 year lifetime.

Certification

The EPD by Vattenfall of June 2004 is certified by the accredited certification body BVQI Svenska AB. 'Certified' means that the Certifier found the Vattenfall EPD to comply with the normative documents from the Swedish Environmental Council. The certification is valid until June 2007.

'Certified' does not mean 'peer reviewed' in the scientific sense. Which peer review has an expiration date?

It is true that "certified" does not mean "peer reviewed", however, it does mean verified as valid by an independent agency. The EPD explicitly requires that the documentation not be misleading. A factor of 20 discrepancy (as predicted by Storm-Smith) easily meets the criteria of being "misleading".

Regarding the certification date, this makes perfect sense in the context of the purpose of the EPD. The operation of the facility is on-going and in principle could change with time. The “expiration date” allows for a future assessment of the facility.

Stormsmith study

Construction energy requirements

Most calculations of the construction energy in other studies are based on nuclear power plant designs of the 1970-1971 vintage. Since 1970 the specific mass of construction materials of a 1 GW(e) LWR power plant increased from 100-200 Gg in 1970 to 800-1400 Gg in the late 1990s (1 Gg = 1 gigagram = 1000 metric tonnes).

In our study the energy required for construction is calculated in three different ways (see Chapter 3, www.stormsmith.nl). The calculations are based on reactors completed during the 1990s. We found a range of 31-174 PJ (1 PJ = 1 petajoule = 1015 joule). The main calculations are based on 81 PJ as the most plausible value. A fourth approach (not yet on the web site), based on materials needed for construction, resulted in a range of 40-120 PJ, with a mean value of 80 PJ. The range in values is due partly to uncertainties in the available data, partly to different amounts of construction materials: some nuclear power plants may contain 1400 Gg materials, other 800 Gg, depending on geographic conditions and regulations.

The Storm-Smith study makes numerous assumptions that relate dollar costs to energy content. It is not obvious that this is the best way to measure energy cost. Their predictions for the energy cost of NPP construction are vastly larger than the empirical data provided by Vattenfall.

Vattenfall are in the best position to measure their own NPPs and their data have been credited by an independent agency.

CO2 emissions

The calculated CO2 emission of the construction of a nuclear power plant lies within the range of 2500-7500 Gg.

This prediction is considerably larger than the empirical Vattenfall data which, normalized to a 1 GW power plant operating at 85% capacity over a 40 year operational lifetime is approximately 150 Gg. See page 15 of the EPD.

The order of magnitude of our results is confirmed by an ExternE study in the UK from 1998 [2]. According to [2], the construction of Sizewell B, a 1250 MW(e) PWR, produced 3740 Gg CO2.

This estimate was made by employing a theory similar to the Storm-Smith predictions. The Belgian  ExternE study estimates the total CO2 emissions to be 4.5 g/KW-Hr which is inline with the Vattenfall data of 3.5 g/KW-Hr. This 4.5 g/KW-Hr figure includes the total emissions summed over the life-cycle of the NPP including construction, operation, decommissioning, reprocessing and final waste disposal.

See:

http://externe.jrc.es/Belgium+Nuclear.htm

Assuming the CO2 is produced by burning oil (producing 75 gramCO2/MJ), the figure of 3740 Gg CO2 would mean 50 PJ is consumed in construction of the power plant.

What this ExternE study actually did was to apportion the cost of construction within the total sectorial expenditure of the sector and multiply by the greenhouse gas emission of the sector. It's not obvious that this actually measures the greenhouse gas emissions or the energy cost of construction of the NPP. This is the methodology of Storm-Smith. The direct measurement approach taken by Vattenfall is not prone to this.

Using the 150 Gg number from the Vattenfall EPD, one gets 2 PJ. The low value presumably reflects the low CO2 emission rate of energy generation in Sweden.

Assuming an operational lifetime of 34 FPY, construction alone would cause a specific CO2 emission of 10 gramCO2/kWh. In our calculations we assumed 24 FPY as average operational lifetime. As pointed out before, no nuclear plant in the world achieved 24 FPY until now, so as a world average it is a uncertain value. With 24 FPY the specific emission would be about 14 gramCO2/kWh.

As noted earlier this is considerably greater than the Vattenfall and Belgian ExternE studies.

An average lifetime for an NPP is uncertain since many reactors that have been constructed have not reached the end of their lifespans. Vattenfall is a recent design using world's best practise so there is no reason at this stage to assume that it will not operate for its full designed lifespan of 34 FPY.

Other greenhouse gases

In 2001 the US enrichment plants alone emitted 405.5 Mg of freon 114 (CFC-114) [3]. The  US fleet of nuclear reactors produced 769 billion kWh in 2001. Freon-114 has a GWP of 9300-9800, meaning that one mass unit of freon-114 has the global warming potential of 9300-9800 mass units of carbon dioxide.

Assumed that all enrichment work was done for US customers only, the freon emission means a specific GHG emission of 5 grams CO2 equivalents per kilowatt-hour, from enrichment alone.

In all processes from uranium ore to nuclear fuel very large amounts of fluorine, chlorine and compounds of these elements are used, often in combination with organic solvents. Fluoro-compounds are essential in these processes, because enrichment of uranium requires uranium hexafluoride (UF6), the only gaseous compound of uranium. For each reactor each year about 160-180 Mg (1 Mg = 1 megaghram = 1 metric tonne) have to be converted into uranium hexafluoride. After enrichment the compound has to be reconverted into a stable oxide, e.g. uranium dioxide UO2.

The Vattenfall EPD noticed the absence of data on emission of greenhouse gases by processes needed to convert uranium ore into nuclear fuel, as is pointed out above.

As with all chemical plants, significant amounts of those compounds will be lost to the environment, due to unavoidable process losses. No chemical plant is leakproof. From a chemical point of view, it is conceivable that in several processes potent GHG's arise or are used. Notably chloro- and fluorohydrocarbons (CFCs) have global warming potentials (GWP), many thousands times stronger than carbon dioxide.

Page 13 of the EPD lists all the emissions in the Nuclear Fuel cycle used by Vattenfall. The CFC emission rate is listed as 6.71x10-7 grams/KW-Hr. The EPD also estimates that the effect of under-reporting to be less than 10% of the reported emissions. The case of the American enrichment facilities are not relevant since none were used by Vattenfall.

The nuclear industry should commit itself to publish a thorough and independent analysis of the emissions of greenhouse gases in all processes of the nuclear chain, before claiming that nuclear energy produces less greenhouse gases than other energy systems or even that nuclear is carbon-free or GHG-free.

We fully endorse complete transparency.

Finally we note that Vattenfall's EPD estimates the decommissioning and waste disposal energy costs. Given that this has not yet occurred this estimate is inherently uncertain. However in both cases Vattenfall have well developed plans and can reasonably be expected to have costed them correctly.

We stand by our point that the Vattenfall EPD provides a valuable data point that demonstrates world best-practise and that this is in large disagreement with the Storm-Smith predictions.

Uranium

Sevior refers on his website to a publication concerning the Olympic Dam operations [4].

Olympic Dam produces copper as well as uranium. Only the amount of copper produced is mentioned on the website [4], so most probably all figures refer exclusively to the copper extraction.

Sevior contacted Dr. Roger Higgins head of Base-Metals operation for BHP-Billiton. He confirmed that the numbers listed in the document refer to the total energy usage of the entire operation. ie It includes all the energy used for all the mine outputs.

The figures as presented on the website of [4] are not appropiate for an energy analysis of the nuclear fuel cycle, because too many parameters are unknown.

While many parameters are unknown, and unfortunately after consulting with Dr. Higgins can not be easily obtained, the energy consumption of the entire mine is definitely an upper limit on the energy required to mine Uranium alone.

Do the cited amounts of 'energy usage' refer to electricity generation only, like the figures in the EPD of Forsmark by Vattenfall, or to usage in trucks, excavators and other fossil-fuel-burning equipment, or to both?

As noted earlier, the Vattenfall EPD includes all forms of energy not just electricity. The Olympic Dam data are that the electrical energy is 54% of the total energy consumed.

Which figures refer to the uranium extraction?

What about the indirect energy usage, embodied in maintenance, chemicals, capital goods and all other activities related tot the mining and milling operations?

The Storm-Smith apportion the energy cost of Uranium mining and milling in the ratio 1:4 respectively. The energy cost of mining comes from Rotty et al in 1975 [1]and the milling cost from two studies also published in 1975 and 1976 by Kistemaker[2].

If Kistenmaker was right the energy cost of milling the Uranium would be some 48 PetaJoules. Even if this was provided entirely by Diesel Fuel, at price of $1 per litre of fuel, it would cost BHP-Billiton about 1 billion dollars in fuel costs alone to supply this energy. The price of Uranium has recently risen to $40 per Kg.  Olympic Dam produces around 4600 tonnes of Uranium each year and so BHP-Billiton would earn around 180 million dollars from it's Uranium sales at current prices

If Storm-Smith were right, BHP-Billiton would lose hundreds of millions of dollars each year by Milling Uranium. Since the mine is profitable, this is not the case.

Diesel fuel is about the cheapest form of transportable energy.  If the 60 PJ of energy were supplied as embodied in some other form, it would cost BHP-Billiton even more.

The prices we quote are of course only guides but are almost certain to be correct to within a factor of 1.5. It is nowhere near enough to account for the discrepancy.

The figures we used in our study to assess the energy requirements of uranium extraction originate from tens of peer-reviewed publications, all from the nuclear industry itself. These publications are based on empirical facts and surveys of actual mines.

The two studies actually employed by Storm-Smith  were published in the mid-1970's. All later studies of Uranium mines have been ignored by Storm-Smith. We have taken the time to look at 2 other mines which are currently operating and which have published environmental assessments of their operations. These are the Ranger mine in the Northern Territory of Australian and the Rossing Mine in Namibia.

The Ranger mine is considered by Storm-Smith to be a "soft-rock" mine. It has an ore concentration of 0.25% by weight.

Assuming the yield at 0.25% concentration to be 1, Storm-Smith predict the energy cost of mining and milling at Ranger is 0.275/(1*0.25) = 1100.0 GJ/tonne.

As part of their ISO14001 certification, Ranger[3] report their energy cost to be 165 GJ/Tonne.

This is substantially smaller than the storm-Smith prediction.

The Rossing [4] Mine in Nambia operates at an ore concentration of 0.035% by weight. At this concentration Storm-Smith predict it to have a yield of 0.8. Storm-Smith classify Rossing to be a "hard-rock" mine. So they predict the energy cost to be:

654/(0.8*0.035) = 23000 GJ/Tonne Uranium produced

The Mine produces around 3000 tonnes of Uranium annually, so Storm-Smith predict the total energy cost of the Rossing mine to be 69 PJ. Rossing reports their on-site energy usage to be 1 PJ, a factor 69 times smaller than predicted by Storm-Smith. If the 69 PJ predicted by Storm-Smith to be necessary for operation of the mine were provided via Diesel fuel (the cheapest option)  it would cost Rossing 1.8 Billion dollars per year. At current prices, the sale of 3000 tonnes of Uranium would only bring around 120 million dollars per year. The entire country of Nambia[5] only consumes 50 PJ of energy annually.

In all three cases Storm-Smith clearly over-predict the energy of Uranium mining and milling. The over-prediction becomes absurdly large at low ore concentrations

  

On basis of only one publication Sevior dismisses, without reasoning, our results concerning uranium extraction. Are all those other authors really wrong?

Only two studies are actually used in the paper of Storm-Smith. Both were published in the mid-1970's. Our work shows that this work is not reliable and in fact leads to outrageously high predictions for the energy cost of Uranium mining for modern mines and mills.

Conclusion

Associate Professor Sevior based far-reaching conclusions on just two - misread - publications. Implicitely Sevior dismisses without reasoning the results of tens of peer reviewed studies on both discussed subjects, construction and uranium extraction.

In my view this is not good scientific practice.

We did not misread either publication. Further investigations on our part verify our investigations and give stronger weight to our conclusions that the energy costs of the Nuclear Fuel cycle, including Uranium Mining and Milling, are such that are such that there are far greater Uranium resources available than predicted by the Storm-Smith study.

Associate Professor Dr. Martin Sevior

Dr. Adrian Flitney

School of Physics

University of Melbourne

Parkville, Vic.

Australia

References.

[1] Rotty, R.M., A.M. Perry & D.B. Reister, Net energy from nuclear power, ORAU-IEA-75-3,

     Institute for Energy Analysis, Oak Ridge Associated Universities, November 1975.

[2] Kistemaker, J., Energie-analyse van de totale kernenergiecyclus gebaseerd op licht-water

    reactoren, Sthcting voor Fundamentele Onderzoek der Materie (FOM), summer 1975 (in

    Dutch).

    Kistemaker, J., Aanvulling op: Energie-analyse van de totale kernenergiecyclus gebaseerd op licht-water reactoren, LSEO 818, juli 1976 (in Dutch).

[3] Ranger http://www.energyres.com.au/corporate/era-se-03.pdf

[4] Rossing http://www.rossing.com/2004performance.htm

[5] Nambia Energy Consumption http://www.eia.doe.gov/emeu/world/country/cntry_WA.html

Jan Willem Storm van Leeuwen

Ceedata Consulting

Legstraat 1-B

4861 RK  Chaam

Netherlands

tel. +31 161 491369

fax +31 161 492879

email: storm@ceedata.nl


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