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Why nuclear makes sense

Opinion
A couple of weeks ago the cabinet announced that the SA Nuclear Energy Corporation (Necsa) and Eskom would be joint procurement agents for the new nuclear build.

The cabinet announced this decision as Eskom being responsible for the actual construction of the nuclear power stations and Necsa being responsible for the entire nuclear fuel cycle.

What this means is that Necsa and Eskom are joint procurement agents. Eskom and Necsa have held early discussions on the actual mechanisms of how to do this. Good progress has been made.

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Uranium has to be chemically processed, which sounds simple but is incredibly complex. There are two types of uranium called isotopes, one is U-235 and the other is U-238.

Now let me explain what the fuel cycle means. Anybody who shops in a supermarket knows that cornflake boxes have a kilojoules energy rating on the box. This is usually indicated as kilojoules per gram.

A joule is a measure of energy. A kilojoule is a thousand joules. A megajoule is a thousand thousand joules, or a million joules. Now think of a million joules per kilogram, as against a thousand joules per gram. The reason I say this is, if you are thinking about power stations it is silly to talk of grams and kilojoules.

Anyway, the total energy in sugar is about 20MJ/kg. The total energy in petrol is about 50MJ/kg, so a car gets more than twice the energy out of a petrol tank full of petrol than you would get out of eating a petrol tank full of sugar. I wonder how many people eat a petrol tank’s worth of sugar in a week. The energy in coal typically falls between that of sugar and petrol, but coal varies in quality to such a degree that you cannot peg an exact figure for coal. Now think of uranium. The energy density of uranium is 76 000 000MJ/kg. Yes 76 million, compared with 20 to 50 for coal. Get the picture? You see why uranium produces so much return on investment in a nuclear power station.

Read also: Eskom to 'test' the market for nuclear

Another thing about coal is that when you burn it, it turns into other stuff, such as ash, soot, nitrous and sulphurous gases, which smell bad and can corrode your house gutters. Eskom does a very good job of removing almost all the sooty stuff and the gases from the power station smoke stacks, but a bit still gets out. That is the case with any coal-fired power station in the world. In contrast, when a uranium fuel element goes into a nuclear reactor it looks exactly the same as when it comes out. By eye nothing changes.

There’s no equivalent of uranium soot or ash to get rid of. The change that happens is that uranium atoms split and become other atoms and release a vast amount of energy, the 76 000 000MJ/kg. But all the new atoms are still contained in the fuel element, nothing gets out.

From a nuclear radiation point of view, a new fuel element containing uranium is so mild you can sit on one and eat your lunch. If you did actually do that, you would get into terrible trouble, because Koeberg fuel elements now cost R40 million each. But a spent fuel element is a different matter. Because other atoms have been produced from the splitting of the uranium, a spent fuel element is so radioactive that if you walked past one, lunch in hand, it would fry you in moments. So don't even think of sitting on a fuel element because you cannot tell the difference between a new one and a spent one.

Unlike ash and soot from coal, nothing comes out of nuclear combustion. So you can pitch your tent right next to a nuclear power station, such as Koeberg, for the Christmas holiday, with complete safety.

Unlike coal, which you dig up, wash, crush and then throw into the power station boiler furnace, uranium has to be mined, then chemically processed, then purified, made into thumb-size pellets and then packed into metal tubes which are clustered together to form the fuel elements. This sounds simple, but it is incredibly complex. It includes a step called uranium enrichment. There are two slightly different types of uranium called isotopes, one is U-235, and the other is U-238. More than 99percent is the U-238, and less than 1percent is the U-235. But it is the U-235 we want for reactors. So by an extremely complex process we take as much of the U-238 out as we can and put it aside, leaving a mixture behind enriched in U-235.

Big money

Only a handful of countries have ever succeeded in doing this. South Africa is one. It was done by Necsa years ago, but then stopped after the fabrication of fuel for Koeberg had started. The plan now is to reactivate the process to produce fuel for the new reactors. Necsa also built a fuel plant which made fuel for the pebble bed modular reactor (PBMR) programme. This fuel looks completely different and looks like solid black tennis balls. Each ball contains grains of uranium in graphite. There is now a worldwide demand for this fuel appearing over the horizon and making itself known, so we are reactivating that plant too. Necsa produced the world’s best fuel of that type, an achievement to be very proud of. PBMR fuel, produced by Necsa, is still sitting in some reactors around the world undergoing long-term testing.

There is big money in designing, producing and selling nuclear fuel of all types. South Africa has the uranium, we need to not only export it in a semi-processed form, we need to export completed fuel. We then make much more money.

What makes nuclear power so financially attractive is that so little fuel is consumed over the lifetime of a nuclear power station. So at 76 000 000MJ/kg energy density, and so few kilograms required, you really get lots of “bang for the buck.”

A coal power station consumes coal all day every day. A nuclear reactor is only refuelled every one and a half years, and even then the power station boss can pick a date that suits him. So right now, Eskom’s cheapest electricity is the nuclear electricity from Koeberg. It is way, way cheaper than solar or wind power, and cheaper than coal. Furthermore, the nuclear electricity from Koeberg will stay inexpensive for many years, because Koeberg still has decades of life left.

Read also: SA's proposed nuclear power plant unsafe - study

Nuclear power stations cost more to build in the construction phase than a coal station, but they really produce payback over a lifetime. Like buying a house, it costs you to build it but when the bond is paid off it is easy plain sailing. That is why people get bonds on houses. We build nuclear for the same reason, because there is a really good payback over the life-cycle.

It is so surprising to me how many people cannot see this. It amazes me that so many folks are so naïve that they think that the construction costs are unknown and that these costs just pass on down the line, to become an expensive electricity price later. South African engineers are not stupid, they know this. The smart guys who do nuclear construction know that you do not work out the price of a seat on a Boeing or Airbus based on its construction cost only. You work it out on many years of flying, based on economical fuel, good maintenance, skilled pilots etc.

Life-cycle cost

If the plane flies well for many years then the airline gets its money back, plus a good profit. All professional engineers know that, so that is what they design for. Same for nuclear reactors, but sadly, so many butchers, bakers and candlestick makers sprout opinions that South African engineers are a bunch of fools who never thought of the concept of a life-cycle cost, and never thought to include it in a major design. This is like telling a professional baker he never heard of baking powder, and does not know how to use it, or what it does in a cake mixture.

Necsa is a major operation, not far from Pretoria, which exports nuclear products all over the world daily. The staff there do wonders for their country and for people all over the world, whose lives are saved by nuclear medicine made at Necsa, or whose high-pressure pipes do not burst because nuclear detectors from Necsa found a microscopic crack before it led to a catastrophic failure.

The combined leadership of Eskom and Necsa in the nuclear power development plan is perfectly capable of building the nuclear power plants, in collaboration with one or more foreign partners. Not only that, but there is a worldwide export market opening up in nuclear power which Necsa has already penetrated. South Africa is not only a buyer of nuclear technology, we are also a fabricator and a seller.

The world nuclear oyster is opening. Now is the time for national pride and confidence to shine so that South Africa claims its share of the business. We are already in on the act, but we can get closer to centre stage.

Dr Kelvin Kemm, a nuclear physicist, is the chairman of Necsa.

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