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SMALL MODULAR REACTORS, ESPECIALLY PEBBLE BED MODULAR REACTORS, ARE AFRICA’S BEST FUTURE
by Dr. Kelvin Kemm, ©2019
(Sep. 21, 2019) — Hydro power is a good way to generate electricity. In most political circles, it is considered environment-friendly because it does not produce carbon dioxide, and it is not complicated. Norway has extensive hydro and can claim to have very green energy, which Norwegians do.
Hydro is wonderful, in fact – if you have the water. Norway’s hydro dams are constructed between rather vertical rock walls, which form the famous Norwegian fjords and tower above Norwegian valleys. Many of these geological formations are permanently topped with ice and snow, which constantly melts into reservoirs behind the dams and is supplemented by regular rainfall, keeping water supplies plentiful and the water height and volume essentially constant.
Africa is different, and its electricity supply challenges are quite monumental. The continent is larger than the USA, China, India and Europe combined. The standard common flat map projection is based on Europe for historical reasons and does not adequately portray the true size of Africa.
Many African countries have very little electricity, and again a major challenge is their size. South Africa alone is the size of all Western Europe. The distance from its capital city, Pretoria, to its southernmost city, Cape Town, is equal to that from Rome to London, or New York to Milwaukee.
Many African countries are less than 20% electrified, some only 10% electrified. Some 700 million Africans still have no electricity or have it only a few hours a week, at totally unpredictable times. Many African countries also rely heavily on hydro power; in fact quite a few are 100% hydro. That is environmentally and politically great, except for those who hate damming rivers. But there is a snag.
African hydroelectric systems tend to involve very wide, flat expanses of water, and many African countries are rather dry, so evaporation off their reservoir surfaces is dramatic. The only way their reservoirs are filled is from periodic rainfall, not constant ice and snow runoff. Rainfall can be really “periodic,” and water levels can fall quickly when prolonged drought conditions set in.
In South Africa, large dams are built to accommodate droughts of up to five years. A year ago a number of South African dams were down to 15% of capacity. Cape Town started preparing for a drinking water emergency. Thankfully enough rains came just in time to stave off real trouble.
In South Africa the issue involved drinking water more than electricity, because South Africa has a relatively small percentage of hydro-power. But as the moment, Zimbabwe’s large Kariba Dam is only 25% full and it is very important for Zimbabwean electricity production. They are very worried.
Many African leaders have very wisely said they cannot possibly continue to base 21st-century economies on African hydro-power. Mother Nature cannot be cajoled into arranging for more rain.
Another problem with expanding African hydro-power is that all the cheapest sites were used first. For hydro, one has to build dams where it is possible to dam a geological feature to create the dam. Due to Africa’s size, each potential new site is very much further away from consumers. Many also provide major engineering challenges due to the lack of Norwegian-style fjord rock walls.
Coal. South Africa is blessed with huge quantities of coal and is a major coal exporter. Coal moves continuously by rail to a port where it is loaded onto ships by automatic systems that pick entire railway trucks up and tip them upside-down. Most African countries, however, have no coal, oil or natural gas. Turning them from 20% electrified to, say, 75% electrified is extremely challenging.
The energy minister of a landlocked African country recently told me that, if they imported coal from South Africa, the only way to do it would be by overland rail, across vast distances. Making matters even worse, the train would have to cross four international borders. Those distances and political risks make coal imports out of the question. The same arguments apply to oil and gas imports through incredibly long pipelines, or by road tankers. The geographical and political risks are just too great.
Solar. Some enthusiasts loudly advocate solar and wind power, noting that much of Africa has good conditions for solar power. However, one still cannot escape the glaring reality that you get solar only part of the day, and get zero at night. You also get next-to-nothing when it rains, or when daytimes are cloudy. Dust on the solar panels knocks out a substantial portion of their electrical output. An enthusiastic European vendor may advise you to just wash the panels regularly. Europeans use automatic water washers. Simple! But Africa has no water to spray daily onto solar panels.
Much of Africa is also prone to violent storms. Hail can sweep over an area, or great winds can blow for several hours. Violent African storms usually last only a very short time, but time enough to wipe out, or badly damage, a huge array of solar panels.
There are undoubtedly special applications for solar: in remote areas or to provide power to users who only need it during lunchtime. But powering a national solar grid to reach 75% of your people is another story, and producing one megawatt of solar power requires an area the size of a football field.
Wind power faces similar issues. Wind turbines have to be placed where there is sufficient wind. That can be far from the consumer. Wind is intermittent and seasonal. Handling intermittent power on a grid that needs stable power is a constant control nightmare. Wind enthusiasts say, if you put in enough turbines, thousands of them, the wind is always blowing somewhere. That’s not always true.
Meteorological data show that wind incidence patterns tend to vary greatly over very large areas thousands of kilometres across, covering multiple countries. Low wind over the whole area is not only possible, but likely. Turbines kill birds and bats by the thousands. With both wind and solar, one gets locked into foreign suppliers for raw materials, finished products and much of the maintenance.
Nuclear power is the world’s future. Nuclear has a few inherent disadvantages. It is without doubt the cleanest, greenest and safest form of power production. Contrary to what you may have heard about the Fukushima nuclear plant that was hit by the 2011 tsunami, not one single person was killed or injured by nuclear radiation. Not one. Also, no private property was harmed by radiation.
Another major advantage of nuclear power is that it uses so little fuel. The total annual fuel usage of even a large nuclear plant can be carried in a couple of trucks. It can be airlifted-in, if need be. There is no need for long supply lines, which can be prone to weather or political disruptions. Nuclear reactors are refuelled only every 18 months.
Critics say nuclear is expensive. It’s not if you look at the total life cycle. A modern reactor is designed to last for 60 years and will probably last for 80 – versus 15-20 for wind turbines and solar panels. While money must be spent upfront in construction, benefits are reaped over many decades. What is required is an innovative approach to the project-cycle funding. Right now in South Africa, nuclear-generated electricity is the cheapest by far. The current nuclear plant, Koeberg, is over 30 years old and is now running very profitably, since the construction costs have been paid off.
Another plus is that the price of uranium is almost irrelevant. Such a little amount of uranium is used in a nuclear plant that even if the international uranium price were to double, it would make extremely little difference to the annual fuel bill. It is nothing like a variation in coal or oil prices.
Large-scale nuclear needs water cooling, which means plants must be built on a coastline or on a large inland water source. But big nuclear is probably too large for many nations to start with. There is a second solution: SMR-class Small Modular Reactors that are currently being developed. South Africa’s SMR is the Pebble Bed Modular Reactor – and a small PBMR can be only 10% the size of a large traditional reactor. A PBMR does not need large water cooling, so you can place it anywhere.
In fact, close to the point of consumption is no problem. “Modular” means that you can add extra reactors to the initial system, as you wish or need, when you wish or need. It’s something like adding extra locomotives to a large train, all controlled by one driver.
PBMRs are also considerably cheaper than large reactors. So, a very viable answer for any African country is to plan for PBMR nuclear systems. One PBMR reactor will produce 100 to 200 Megawatts, depending on its design. As the country requires more power, it simply installs more PMBRs.
An important consideration with nuclear power in Africa is for countries to work together. Africa needs a nuclear network for operations, training and general nuclear development. In the spirit of Fourth Industrial Revolution thinking, now is the time to plan an African nuclear network. Thankfully a number of African countries have already launched that process.
Dr Kelvin Kemm of Pretoria, South Africa is a nuclear physicist, CEO of the project management company Nuclear Africa (Pty) Ltd, and consultant on strategic development of various industries.