A Beginner’s Guide to Nuclear Power

Counterpoint, ABC Radio National | 3 July 2006



A transcript of a program broadcast on 3 July 2006 on Counterpoint, ABC Radio National.


Michael Duffy, presenter of Counterpoint, ABC Radio National: Recently Prime Minister John Howard announced an inquiry into the potential role of nuclear power in Australia’s future. Julian Cribb says that a cool-headed look at all of Australia’s energy options, including nuclear, is long overdue. Wilson da Silva’s COSMOS magazine has recently featured a piece on the latest nuclear power technologies.

Michael Duffy

A few weeks ago on the program I said I thought it was a good idea the Prime Minister has launched this inquiry into nuclear power. It’s an opportunity to educate ourselves a bit more about the energy options available to Australia. Even if the inquiry itself turns out to have its limitations, the surrounding discussion can only be good. To do our bit towards that, I’ve invited some guests along today to give us a beginner’s guide to nuclear power. I apologise to those of you who have no need of such a guide but I do suspect you’re in a pretty small minority. Julian Cribb is adjunct professor in science communication at the University of Technology, Sydney, and a fellow of the Australian Academy of Technological Sciences and Engineering. You may have seen a very good article by him in The Australian’s higher education section a couple of weeks ago on some of the complexities of this subject. Our other guest is Wilson de Silva, editor of COSMOS Magazine which has just published a very interesting story on the new technology of thorium reactors.


Welcome, both of you, to the program. Julian, in broad terms, what type of things do you think most Australians ought to know about nuclear power that we don’t yet know?


Julian Cribb: Well, they should know what the pros and cons are of the different kinds of nuclear power. There is no one sort of nuclear power, there are many, many options.


Michael Duffy: So the first thing is we need to know what those options are, I suppose.


Julian Cribb: We need to know what those options are and of course we need to know what the costs are, and really how it fits in to all the other powers that we’ve got because we’ve got a lot of energy.


Michael Duffy: Yes, and we’ll talk about some of those things in a moment. Do you think this enquiry that the government is holding will help fill in some of those gaps?


Julian Cribb: I hope so. I fear that, like so much in this area for the last 25 or 30 years, it’s already picked a winner without actually looking at some of the other possibilities which may be even more attractive or sensible.


Michael Duffy: I know in your recent article you said you hoped the inquiry would replace the ‘squalid babble of self-interest and ideological prejudice that’s passed for energy debate in the past quarter of a century’. What are some of the examples of this self-interest that’s been holding us back?

Julian Cribb

Julian Cribb: Every single power-producing sector argues on behalf of its own form of energy. So you hear the coal people pushing coal, you hear the hot rock geothermal people pushing that one, you hear the solar people pushing that, and it’s very hard for policy makers or just the Australian public to make up their mind between these options. It’s like all the different brands of motor cars that are on the road; how do you choose? At the end of the day, the answer is getting the mix right. It’s not a case of which one of these energies is going to be the source of energy. Many of them are going to be sources of energy but how do we get the mix right? We need a comprehensive national approach, a policy, and that should inform the research that we do in order to fill the gaps in our knowledge.


Michael Duffy: And what about ideological prejudice? What are some of the problems that has caused?


Julian Cribb: I think, again, that’s led to advocacy of various types of energy which are ideologically perhaps preferred by some people but economically they’re not very sound. And so that’s the dilemma that we’re up against. You’ve just got a whole lot of people lobbying for their favourite energy and that is not going to get Australia to the decision it needs to take.


Michael Duffy: Do you think we’ve suffered from an absence of a better quality of debate?


Julian Cribb: Yes, I really do. I’m tired...as I say, I wrote the article because I’m tired of people banging on about their favourite form of energy. Really we need to look at the complexity of all the energy sources and make some sound decisions. We really are probably the best endowed country on Earth when it comes to energy. We’ve got fabulous choices, and we shouldn’t be confused in the way that we are confused, and we should be stalled in the way that we’re stalled. I mean, we’ve got 400 years of coal, 700 years of brown coal, we’ve probably got centuries worth of natural gas (if we don’t sell it all to the Chinese), we’ve got centuries worth of hot rock power, we’ve got endless supplies of sun and wind and tide and things like that. So really we’ve got a fantastic opportunity here to actually get it right, but we’re not.


Michael Duffy: Let’s go into some of the options here, starting with nuclear. Wilson da Silva, can you tell us the major technologies that are currently being used with nuclear power?


Wilson da Silva: Most of the nuclear power stations around the world use either water reactors, whether pressured boiling water or basically driven by water, and that is you run water through a heat exchanger, through the core, the core heats it up and, like the old fashioned coal fired power plants, it drives a turbine which generates power. Or you have these more advanced styles like breeder reactors which, aside from cooking more of the uranium and being more efficient, they’re also very good at producing plutonium which is great for weapons. So those are the two classic types, and there’s a third type that is moving in that is still experimental, nobody’s actually built a proper prototype, it’s called subcritical nuclear reactors and they’re driven by thorium instead of uranium. One of the fabulous advantages, if they ever built one of these things, is that it actually can cook old nuclear waste as part of the process.


Wilson da Silva

Michael Duffy: Does it cook it all? At the end of a number of cookings is there anything left or does it all go?


Wilson da Silva: Yes, there is, there’s an estimated (depending on who you talk to) between 3% and 15% of the waste that’s produced by a normal conventional nuclear reactor left. That waste, instead of it being some of it 90,000 years radioactive and some of it 100,000 and some of it 10,000, it is uniformly radioactive for 500 years. So it produces a small amount of waste and that waste is uniformly radioactive for 500 years, and we can imagine putting something away and sequestering it, if you like, for 500 years.


Michael Duffy: And what’s that one called?


Wilson da Silva: They are thorium reactors, basically. One is an accelerator driven nuclear reactor which I think is the best design, and there’s another one which is a thorium mix oxide fuel reactor.


Michael Duffy: And these haven’t been built yet?


Wilson da Silva: None of them. Some of the experimental ones...the second one, the mix oxide fuel, some of the experimental ones, smaller ones, have been built in Russia, and there’s a fabulous program being studied over there to burn old plutonium, basically get rid of old nuclear weapons. The accelerator driven one is still on the drawing board with some very small experiments in labs.


Michael Duffy: They’re safe presumably, are they?


Wilson da Silva: They are as safe as...


Michael Duffy: I mean compared to current ones.


Wilson da Silva: When we get to nuclear power, the issue of safety comes up, and this is where Julian and I agree, that the paucity of logical debate about this is what’s frightening because we talk about nuclear comparing it with other nuclear instead of comparing all forms of energy with each other. And yes, I think that in the 55 years that we’ve run nuclear power it’s extraordinarily safe. Less people have died than are killed every day by coal fired power plants if you count the cost of the waste that it puts into the air and the number of heart attacks it causes, et cetera, and if you factor in just the mining of it. But we’re not comparing...we keep thinking ‘oh my God, Chernobyl, Three Mile Island’ instead of thinking ‘what about all those accidents with coal?’ et cetera.


Michael Duffy: Julian, these thorium reactors sound, if they fulfil their promises, that they’re a big step forward on what we have now and they could just completely change people’s feelings about nuclear power. Is that possible?


Julian Cribb: I think so. They certainly look very promising but there’s a fair bit of R and D to do yet. There isn’t one of these things working so you’re looking at 20 to 30 years before you’ve got a decent one up and running commercially. In that time span you could have quite a lot of other energy things. Like you could have IGCC, Integrated Gasification Combined Cycle, power generation for black coal which is very clean and you can bury the CO2. It might not get around the mining problems, the mining deaths maybe that Wilson was referring to, but it would certainly get around most of the industrial fallout and greenhouse problems that people are concerned about with coal. We can certainly start looking a lot more, as I say, at hot rocks. I mean, Australia is full of hot rocks. All we have to do is inject water into them to produce steam to drive turbines. It’s a very clean form of energy. We may need to relocate our industry close to where the hot rocks are but these are things you can plan for over a 25 or 30-year planning horizon. So there’s a lot of options like that that need to be looked at in parallel, and if we’re talking nuclear, then really the ultimate nuclear is fusion, and there is work going on in the United States and Europe and elsewhere into fusion, and Australia has had a small program for quite a number of years. But at the moment it seems like we’re doing almost nothing in this area and fusion really is the ultimate clean nuclear energy.


Michael Duffy: Can you just give us the beginner’s guide to fusion as it compares with fission?


Julian Cribb: It’s what happens in the sun, basically. You’re not splitting the atoms, you’re fusing atoms together and producing energy that way. It doesn’t produce radioactive waste, so it’s a pretty safe...and it’s a controlled reaction like the sun. The art lies in actually controlling it inside a vessel or a chamber so that you can keep it running all the time. Probably we’re looking at, again, 25 to 30 years before we’ve got one of these things working properly and reliably.


Michael Duffy: But it’s conceivable that humanity will be able to do this one day, is it?


Julian Cribb: Yes. It was an Australian, Sir Mark Oliphant, who originally was the first person to realise the possibility of this, and I think it’s something that Australia, as a result, ought to be looking at very closely and we’re not.


Michael Duffy: Wilson, are there any other forms of nuclear technology that we haven’t talked about that would be helpful to know? I hear, for example, about something called a Canadian CANDU reactor, or...I think you said ‘pebble bed’ before?


Wilson da Silva: Yes, pebble beds look really interesting because they look inherently safer. It’s kind of difficult to describe the design, but instead of having one central core that’s a bomb trying to go off (which is what ultimately all nuclear reactors are) this thing is, instead of having a core, each of these little pebbles, whether carrying thorium or carrying uranium or a mix of them, are the reaction, and then you try and strip the heat out of it when the reaction is happening. The design is very attractive because it has a much more attractive failsafe option. It’s really originally designed in Germany. It’s now been taken up...because the Germans decided not to go down the nuclear path, it’s now been taken up by the US and South Africa who’s announced it’s going to build one of these things. They look very attractive. I know that one of the parliamentarians in Australia who actually has some background in physics is interested in this as a design.


Michael Duffy: Have you heard of this CANDU reactor?


Wilson da Silva: Yes, CANDU is...I think there’s two types, from what I know, of CANDU reactors, like water reactors and boiling water reactors, and they are basically a different design. It’s like saying a petrol driven car and they are 16 different models; slightly different changes.


Michael Duffy: Julian, do you think we’ve pretty much covered the major forms of nuclear technology that either exist or look possible in the next 20 years?


Julian Cribb: Unless someone finds out how to make cold fusion work, I guess...but there are so many other sorts of opportunities. As I say, we are absolutely blessed in this country with more choices than we know what to do with. Let me give you a couple of other examples. Oxy fuels for example; you take a conventional coal fired power station, you burn the pulverised coal and you take it off and you mix it with oxygen and you pump that gas straight back in again. This enables you to capture the CO2 and produce power very, very efficiently. So all you’re doing is adding some oxygen. That’s a new technology that’s being trialled in this country, it hasn’t been trialled anywhere else in the world, but it looks very promising for a country that is rich in coal. Another one is what I call 'coalathermal' which is where you just bolt a solar thermal unit onto the side of your coal fired power station and reduce its greenhouse emissions and increase its efficiency by adding a bit of sunlight. So there are a lot of mixed options, which I think is probably the logical way for Australia to go, having so many choices. It’s not like we’re like Denmark; down to one or two things that we can do. We really have a wealth of opportunities and we ought to be the people who are making the smart decisions instead of leaving it all to the Americans.


Michael Duffy: Wilson, would you like to comment on that?


Wilson da Silva: Yes. What has changed in the debate are two things. We need to get base load power which is the kind of power that you have when you get up in the morning and turn on the lights and everything has to work. You can’t rely on things like solar and wind for that...to a lesser extent, you can’t rely on hot rocks necessarily unless you move industry towards where the hot rocks are. So you kind of need to have base load power, and if you need base load power and you don’t want to produce greenhouse gases...which is what’s changing the debate. Suddenly we’re forced to...we’re thinking can we actually afford to build another 400 coal fired power stations like the Chinese are planning to do. If you believe that perhaps greenhouse gases are having a detrimental effect and will have a detrimental effect on society and on the planet, then you start looking at other options, and there’s only two that produce no greenhouse gases; that’s nuclear and hydro. And since hydro...we seem to have a shortage of water in Australia, hydro is probably less of an option for us.


Control panel of the Experimental Breeder Reactor No. 1 at the Atomic Museum

Michael Duffy: Julian, if one sits down with a spreadsheet to compare the different forms of energy, and as you’ve explained there are many, one thing that would affect an economic comparison is the existence of a carbon tax. Can you tell us what a carbon tax is, and do any countries run them successfully at the moment?


Julian Cribb: I’m not sure who’s running them successfully at the moment, but a carbon tax basically is just a penalty paid by anyone who liberates carbon to the atmosphere, and very often you can trade the amount of carbon...in theory you should be able to trade the amount of carbon with other people...if you produce less carbon then obviously you can sell your carbon entitlements to someone else and make a profit or something. That’s the idea that’s being touted around. If we don’t have a carbon tax in Australia or something that reflects the real cost of disposing of the waste, the CO2, then the problem is that a lot of these other very promising technologies, and particularly the solar technologies and so on, won’t really get market equality. We won’t be able to see them for what they’re worth within our economy, and that really is one of the difficulties. The problem with not having a carbon tax at the moment is that people are unwilling to build new power stations because if a carbon tax comes in and they’ve built an old-style power station they will go bankrupt, and if a carbon tax doesn’t come in and they’ve built a new-style power station that swallows the CO2, then they’ll go equally bankrupt because it’s a more expensive energy producer than the conventional one. So this is a political decision that needs to be taken in Australia, and it needs to be taken quickly because of our 39 coal fired power stations...an awful lot of them have reached their use-by date or are very close to it.


Michael Duffy: Can I just ask one quick question and I know you could give a very long answer to it but we don’t have all that much time. Getting back to this government enquiry for a moment, and assuming it’s going to look at some of the things we’ve been talking about, how much of the knowledge it will need is in Australia? Do we have many experts in this area? Have we done much research? I’m talking about energy in general.


Julian Cribb: Look, we’ve got tremendous experts in energy. There’s no doubt about it, we’ve got the scientists who could answer those questions adequately. The question is; will the various industry lobbies and energy lobbies let them do so objectively? This is my concern, that the whole thing is going to be driven by lobby groups rather than by what is good for the country.


Michael Duffy: But you’re reasonably happy, are you, with the amount of research that has been done on different forms of energy in Australia?


Julian Cribb: We’ve definitely got the expertise in Australia to answer questions about all the different forms of energy that we’ve got.

Michael Duffy: Wilson, very quickly, any comment on that?


Wilson da Silva: I think right down to something as theoretical as thorium or accelerated driven thorium power reactors, we even have a researcher (who, by the way, has been funded by Germany) working in Sydney. So there is the expertise, and we have the talent...if not the talent here in Australia, working with these organisations overseas. So there’s no shortage of talent, it’s the translation between our experts and the political interface. I agree with Julian that a lot of this is driven differently, not by the logic of the debate or by expert technical advice, it’s driven by industry lobby groups, unfortunately.


Michael Duffy: Thanks very much to both of you for coming in. We could talk for another couple of hours, which we don’t have, but you’ve made things a lot clearer for us, thank you. Julian Cribb is adjunct professor in science communication at the University of Technology, Sydney, and Wilson da Silva is editor of COSMOS Magazine which has just had a great feature story on thorium reactors.

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