Review of ISA's nuclear energy balance report

by Dave Kimble at www.peakoil.org.au
7th December 2006

Australia's review of the nuclear industry has been published in draft form for feedback. The report takes its energy balance and GHG emissions data from a report it commissioned from ISA at University of Sydney. This article looks at the ISA report.

Background
In June 2006 the Australian Federal Government commissioned a report "Uranium Mining, Processing and Nuclear Energy - Opportunities for Australia ?". Dr Ziggy Switkowski was chosen to head the Prime Ministerial Taskforce conducting the review. He has a doctorate in nuclear physics, but is better known as the former chairman of Telstra, Australia's former-monopoly telephone company.

Switkowski was appointed to the board of ANSTO (Australian Nuclear Science and Technology Organisation) in January 2006, so his appointment to this taskforce was seen by some as compromising the report's independence. In response, Switkowski then resigned from his ANSTO board position. Obviously this strategy can have had no bearing on his pro-nuclear bias. This is a report written by the nuclear industry trying to justify its very existence. If they fail to make a solid case for nuclear energy now, they will soon be out of a job.

The Taskforce in turn commissioned a report from the Integrated Sustainability Analysis team (ISA) of University of Sydney, entitled "Life-Cycle Energy Balance and Greenhouse Gas Emissions of Nuclear Energy in Australia". [ download PDF 2.75 MB ] This article looks at some of the information that appears in the ISA report.

The crude numbers for various energy sources
The report concentrates mainly on nuclear energy, but also reviews alternative sources for comparison. In their jargon, "Energy Intensity" corresponds to the reciprocal of the more familiar "ERoEI". Note also that greenhouse gas (GHG) emissions are sometimes quoted in other reports using Carbon as the measure, as opposed to "Carbon dioxide equivalent" :



The range of 10 - 130 g(CO2-e)/KW.h for light water reactors compares with a range of 7 - 22 g(CO2-e)/KW.h published by IAEA in "Nuclear Power and Sustainable Development" - a report the Australian Government was using to back its arguments only weeks ago.

The ISA report has some favourable assumptions built into its modelling of nuclear power (see below), but even so, wind turbines produce electricity with about a third of the GHG emissions.

The photovoltaic solar panels studied were flat panel multi-crystalline silicon panels, with an assumed efficiency of 13% KW.h(el)/KW.h(sun), and have ~75% greater GHG emissions than nuclear.

Uranium ore concentrations
One of the aims of the taskforce is to identify 'opportunities for Australia', so it is an important consideration as to whether Australia has enough economically viable Uranium to supply its nuclear power industry. (No consideration is given as to whether this Uranium may already be committed to export contracts.)

The ore grade is the most sensitive parameter in the nuclear equation :



Australia currently operates three Uranium mines - Ranger, Olympic Dam and Beverley. Ranger is a conventional open pit mine which the report says has 14,700 te(U) at 0.15% grade, and 29,700 te(U) at 0.23%, and a likely lifetime of 9-10 years. Unfortunately while the report was being written, the mine owners, Energy Resources of Australia Ltd (ERA) announced a revision of these numbers : 25,927 te(U) at 0.10% and 26,500 te(U) at 0.24%, and a lifetime for the mine of 2 years.

The main reason for the revision was that the stockpile of uneconomic grades (under 0.08%) held at the mill will be screened and the richer fraction (average grade 0.074%) will now be milled at some stage in the future after the mine has closed. This has the effect of increasing the total tonnage of Uranium eventually produced, but also increasing the energy needed to process it.

The ISA calculations are performed in conventional spreadsheets. Unfortunately these crucial files were not released with the report, but I have now obtained copies. [ download nuclear and other ] All the results in the report are based on an ore grade of 0.15%. This is hopelessly optimistic as it is approximately the grade currently being mined, and there is no way these grades will last for the next 35 years, and no way Australia could guarantee to keep it all for itself in an energy-hungry world.

On page 64 there is a calculation based on the very low grade of 0.01% :



This admission by ISA that Storm and Smith are correct in asserting that
0.01% ores produce GHG emissions comparable to a gas-fired power plant
must be counted as something of a breakthrough. Unfortunately the qualification "assuming Storm van Leeuwen and Smith's parameters" cannot be readily tested in the spreadsheet as many of these parameters are not adjustable. Simply changing the ore grade to 0.01% raises the GHG Intensity from the base case 57.8 to 130.2 g(CO2-e)/KW.h

The errors in the numbers for Ranger mine, and the assumption that there will be enough 0.15% ore for the lifetime of the reactors (35 years), is therefore very worrying. ISA says :

"Other potential deposits for mining in the 2020-2050 period are in SA, WA, Qld and the NT, and it is expected that exploration programs will discover substantial new resources. Therefore it is likely that the amount of uranium required to support a nuclear power program in Australia will be available from Australian resources."

The above statement is totally unscientific and pure wishful thinking, echoing the statements of the oil industry when trying to deny Peak Oil. It is obvious that the miners will develop the richest ores first and put them on the world market as soon as possible. By the time Australian reactors come on stream (2020), ore grades will have fallen considerably, and by the time the reactors are getting old (2055), the grades may be little better than net energy neutral.

The report states that the average of Australia's remaining ore grades is 0.045%, and using that value changes GHG Intensity from 57.8 to 67.8 g(CO2-e)/KW.h

Load Factor
Load Factor for a time period is the percentage of up-time multiplied by the percentage of full power. The energy and GHG intensities are very sensitive to this load factor :



ISA have chosen a load factor of 85% for their base case scenario, although they admit this will only be achieved after the first year. The reasoning behind this is weak, and relies on values achieved by the USA and Japan, who have decades of experience in nuclear power operation. US load factors were in the 60s in the 1970s.

Nuclear Engineering International magazine's article "Load factors to end June 2004" says :

"Of the 410 units for which data was obtainable, the world average annual load factor was 78.1%, and the lifetime average load factor 71.4% ."

Using the 71.4% figure in the spreadsheet instead of 85% raises the GHG emissions from 57.8 to 61.4 g(CO2-e)/KW.h

Using the 71.4% figure above and an ore grade of 0.045%, the GHG Intensity becomes 71.5 g(CO2-e)/KW.h, which is a 24% increase over the base scenario. This shows how important the assumptions for various values can be, and how misleading it can be to quote a single number representing such a complex scenario.

When these figures are used with an ore grade of 0.01%, the GHG Intensity rises to 527 g(CO2-e)/KW.h , which is 4 times larger than the 'worst case' scenario ISA is able to imagine. This level of GHG Intensity is close to the 577 g(CO2-e)/KW.h calculated for a Natural Gas (combined cycle) power plant.

The work of Storm and Smith
A number of public submissions on the Terms of Reference for the nuclear review asked that the work of Jan Willem Storm van Leeuwen and Philip Smith be specifically addressed, as they have produced results that are very unflattering to nuclear energy.

The ISA report includes a five-page analysis of the Storm and Smith methods and data, as well as numerous references to their work in the main text. Their main criticism is of the methodology used by Storm and Smith to overcome the lack of detailed process numbers. This is called 'the Average Energy Intensity' (AEI) method. Put very crudely, if you know the value of a project, and the energy intensity of the national economy (total energy consumption / $GDP), you can calculate how much energy the project uses on a pro rata basis.

The ISA criticism is that the AEI method double-counts some upstream energy costs, giving higher than normal energy intensity for nuclear power. They also point to higher than normal financial costs for planning and regulatory administration compared to 'average' construction projects, which do not imply higher energy costs are involved. Storm and Smith have refuted (to their satisfaction, at least) these criticisms in the past, and I have drawn this report to Storm's attention and he has indicated he will make a submission on it. The arguments are complex and if you want to follow them, you should read the first three chapters of the ISA report very carefully.

Although Storm and Smith's accounting methodology is different, ISA have extracted values from their model, and plugged them into the ISA model. Compared to 'typical values from the literature' the Storm-Smith figures are 645% bigger for reactor construction and decommissioning, 583% bigger for intermediate and low-level waste disposal, 320% bigger for storage (prior to disposal), and 201% bigger for high-level waste disposal. This is partly explained by Storm and Smith choosing a higher standard for the clean-up than current industry standards - ISA felt that analysing such scenarios was beyond the scope of their report.

I think this is a serious deficiency in scope that needs to be addressed. We need to have a much clearer idea of how much energy it will take to properly decommission a nuclear power plant after 35 years of operation and perhaps 40 years of cooling off. There is every reason to believe that standards for nuclear waste in the environment will be getting higher, more costly, and more energy-absorbing.

Don't forget, if it turns out that the clean-up costs so much that the power plant company goes broke, then it will be your grandchildren who suddenly find themselves, as tax-payers, stuck with a huge bill for something that happened a lifetime ago.

Conclusion
I am sure there is still a lot of argument to be had on this subject. The ISA report seems to be an attempt to make a complex subject transparent to those able to follow the maths. It is a pity that such an important issue will probably be decided politically, without the politicians having any idea what they are letting society in for.

Feedback on the draft closes on 12th December 2006, see the government web-site :
http://www.pmc.gov.au/umpner/reports.cfm

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Related articles by DK :
"Is there enough Uranium to run a nuclear industry big enough to take over from fossil fuels ?"

"Does nuclear energy produce no CO2 ?" - photo essay

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