They’ve been successfully employed for much longer than most people realize
This year is an historic one for nuclear power, with the first reactors winning U.S. government approval for construction since 1978. Some have seen the green lighting of two Westinghouse AP1000 reactors to be built in Georgia as the start of a revival of nuclear power in the West, but this may be a false dawn because of the problems besetting conventional reactors. It may be that when a new boom in nuclear power comes, it won’t be led by giant gigawatt installations, but by batteries of small modular reactors (SMRs) with very different principles from those of previous generations. But though a technology of great diversity and potential, many obstacles stand in its path. Gizmag takes an in-depth look at the many forms of SMRs, their advantages, and the challenges they must overcome.
Globally, there is a growing demand for electricity that is cheap, reliable and abundant. There’s also an increasing need to find sources of energy that do not rely on doing business with hostile or unstable nations. At the same time, recent concerns over global warming have resulted in many governments pledging their nations to reduce the amount of carbon dioxide they generate and new, stricter environmental regulations threaten to close coal-powered plants across Europe and the United States. The hope was that massive investments in alternative technologies such as solar and wind power would make up for this cut in generating capacity, but the inefficiencies and intermittent nature of these technologies made it clear that something with the capacity and reliability of coal and natural gas plants was needed. Nuclear, in other words.
The problem is that nuclear energy is the proverbial political hot potato – even in early days when the new energy source exploded onto the world scene. The tremendous amount of energy locked in the atom held the promise of a future like something out of a technological Arabian Nights. It would be a world where electricity was too cheap to meter, deserts would bloom, ships would circle the Earth on a lump of fuel the size of a baseball, planes would fly for months without landing, the sick would be healed and even cars would be atom powered. But though nuclear power did bring about incredible changes in our world, in its primary role, generating electricity for homes and industry, it ended up as less of a miracle and more of a very complicated way of boiling water.
Not only complicated, but expensive and potentially dangerous. Though hundreds of reactors were built all over the world and some countries, such as France, generate most of their electricity from it, nuclear power has faced continuing questions over cost, safety, waste disposal and proliferation. One hundred and four nuclear plants provide the United States with 20 percent of the nation’s power, but a building permit hadn’t been issued since 1978 with no new reactors coming on line since 1996 and after the uproar from the environmental movement after nuclear accidents at Three Mile Island, Chernobyl and Fukushima, it seemed unlikely that any more would ever be approved – until now. This fierce domestic opposition to nuclear power has caused many governments to take an almost schizophrenic stance regarding the atom.
Germany, for example, decided to abandon nuclear power completely in favor of alternative energy, but then the severe winter of 2011-12 got so cold that the Danube was freezing and Berlin had to put some of the mothballed reactors back into service. This opposition also means that many Western countries have a shortage of nuclear engineers because many see it as a dying industry not worth getting into. This is particularly acute in the United States and Britain, neither of which have retained the capacity for building the huge reactor vessels and must farm this out to overseas manufacturers.
Worse, nuclear power suffers from the natural gas boom brought on by new drilling techniques and fracking that opened up vast new gas fields in the West and dropped the price of gas to the point where coal and nuclear have a hard time matching it.
And money is one of the key problems facing a revival of nuclear power. Up until now, the sort of reactors used for generating electricity have tended toward the gigantic with reactors reaching gigawatt levels of output. With plants that large, small wonder that the cost of construction combined with obtaining permits, securing insurance and meeting legal challenges from environmentalist groups can push the cost of a conventional nuclear plant toward as much as US$9 billion. It also means very long build times of ten or fifteen years. This isn’t helped by the fact that nuclear plants are custom designed from scratch in multi-billion dollar exercises in re-inventing the wheel. With so much time and money involved, an unforeseen change in regulations or discovery of something like a geological fault under the reactor site can make this a case of putting a lot of very expensive eggs in a very insecure basket.
Then there are safety issues. Reactor design is safer today than ever before. The Fukushima accident happened because Fukushima’s reactors are a very old design – as old as the oldest active American reactors. If the earthquake and tsunami that hit Fukushima had hit a modern reactor, the disaster probably would never have happened. However, large conventional reactors still have safety issues because they require very fast reaction times to prevent damage in the event of an accident. Accidents can progress so fast in a reactor that the operators must take action within hours, perhaps even minutes. If a meltdown accident does occur, the large amount of fuel in the reactor means that a great deal of radioactive material may be released into the atmosphere. That makes time an essential element.
The enriched uranium fuel used in conventional reactions also poses a problem for nuclear weapons proliferation. Contrary to popular belief, the uranium used in reactors and even the plutonium that some reactors produce are useless for building nuclear bombs (the isotope ratios are all wrong), but the processes needed to produce nuclear fuel and bomb materials are almost exactly the same. So, though conventional reactors may not be a proliferation threat, the enrichment plants that service them are.
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