NUCLEAR POWER MUST BE WELL REGULATED, NOT DITCHED – It is an essential weapon in the fight against climate change
March 6, 2021 Economist.
It has been ten years since a tsunami laid waste the Pacific coast of northern Honshu, Japan’s most populous island. The tsunami and the undersea earthquake which triggered it, the largest ever recorded in the region, killed nearly 20,000 people, destroyed over 100,000 homes and threw the lives of tens of millions into turmoil. The direct economic cost, estimated at over $200bn, was larger than that of any other natural disaster the world has seen. And yet for many around the world the event is remembered for just one thing: the ensuing crisis at the Fukushima Dai-ichi nuclear power plant.
The earthquake cut the plant off from outside sources of electricity. The tsunami easily topped the plant’s sea walls, flooding the underground bunkers containing its emergency generators—a foreseeable risk Japan’s neutered regulators had failed to foresee. Because there was no way to cool the reactor cores, the nuclear fuel within them began to melt; amid fire, explosion and alarming amounts of radiation, a puddle from hell began eating into the plant’s concrete foundations.
The world looked on aghast. In Shanghai and San Francisco iodine tablets and iodised salt jumped off the shelves as people looked for prophylaxis of which they had no need. In Germany the chancellor, Angela Merkel, who had long stood with business leaders against the country’s powerful anti-nuclear movement, ordered its reactors phased out. In China the world’s largest new nuclear-plant programme was put on hold. Talk of a “nuclear renaissance” to fight climate change fell silent.
The reaction, though understandable, was wrong. Nuclear power has a lot of drawbacks. Its large, slowly built plants are expensive both in absolute terms and in terms of the electricity they produce. Its very small but real risk of catastrophic failure requires a high level of regulation, and it has a disturbing history of regulatory capture, amply demonstrated in Japan. It produces extremely long-lived and toxic waste. And it is associated with the proliferation of nuclear weapons. Most of the countries outside Europe that use nuclear power have some history of attempting to develop a bomb. All these factors contribute to an unease with the technology felt, to greater or lesser extent, by people all around the world.
Against all that, though, two things must be remembered. One is that well-regulated nuclear power is safe. With the terrible Soviet-era exception of Chernobyl, nuclear disasters come without large death tolls. It was the tsunami, not radiation, that claimed nearly all those lives in Fukushima. The other is that the climate is in crisis, and nuclear plants can supply some of the vast amounts of emissions-free electricity the world needs if it is to cope. Solar and wind power are now much cheaper, but they are intermittent. Providing a reliable grid is a lot easier if some of its generating capacity can be assumed to be available all the time. Nuclear provides such capacity with no ongoing emissions, and it is doing so safely and at scale around the world.
Despite this, safe and productive nuclear plants are being closed across the rich world. Those closures and the retirement of older sites mean that advanced economies could lose two-thirds of their nuclear capacity by 2040, according to the International Energy Agency. If new fossil-fuel infrastructure fills the gap, it will last for decades. If renewables do so, the opportunity cost will be measured in gigatonnes of carbon. Renewables replacing nuclear capacity would almost always be better deployed to replace fossil-fuel capacity.
Sometimes the closure of nuclear plants is largely a matter of economics. In places where emitting carbon dioxide comes with no price, such as America, the benefits of being emissions-free are hidden from the market. That hurts nuclear, and it should be rectified. When closure is political, the onus is on Green politicians, in particular, to change their tune. To hasten the decline of nuclear power is wilfully to hobble the world in the greatest environmental struggle of all.
The argument for keeping existing nuclear plants open has been strengthened, in some places, by one of the responses to Fukushima: greater independence for nuclear regulators. Britain granted new freedom to its regulator after 2011. So did Japan. Though grander hopes for reform after the tsunami bore little fruit, Japan did largely take the regulators’ hand from the power companies’ glove. Its new supervisor has made reopening mothballed nuclear power plants harder than the government would like, but that is as it should be. In Japan more than anywhere, nuclear needs to earn back trust to be useful.
This points to nuclear’s greatest weakness. In democracies it is expensive, owing to regulation and public antipathy, which makes new nuclear power a hard sell. The technology is thus increasingly the preserve of autocracies—precisely the systems where good regulation is least likely. Having paused after Fukushima, China’s nuclear plans accelerated as part of an effort to reduce reliance on coal. China produced four times as much nuclear energy in 2019 as it did in 2011; it has 16 reactors under construction and another 39 planned. Countries wanting new nuclear plants now look to China and Russia as suppliers.
There is a strong case for democracies seeking to replace ageing nuclear plants with non-intermittent equivalents to join the importers. If Chinese reactors are designed in the knowledge that they will have to meet with the approval of independent regulators the world will be a safer place. At the same time, in boosting energy r&d to tackle the climate crisis, Western governments should be sure to give nuclear its fair share. There are real attractions to some new approaches, notably smaller reactors with lower unit costs: in platoons they can replace old plants; singly they can add incremental capacity where needed. They might perhaps be used to retrofit old fossil-fuel plants.
Nuclear power has drawbacks the size of a tsunami. But with Chinese plants being built today that will not be decommissioned until the 22nd century, it cannot simply be wished away. What is more, it has a vital role to play in the fight for a stable climate. The lesson of Fukushima is not to eschew nuclear power, it is to use it wisely. ■
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How safe is nuclear energy? Despite some notable disasters, nuclear power is one of the least deadly sources of energy
The shock caused in part by Russia’s war in Ukraine will transform the global energy industry. Governments in the West are looking to end their reliance on Russian oil and gas, which is giving a boost to climate-friendly alternatives. They include nuclear-power plants. Some countries, notably including Germany, remain fearful of another Chernobyl or Fukushima. But even when accounting for the high-profile disasters, nuclear power is very safe (see chart).
A terawatt-hour (TWh) of electricity from nuclear energy is associated with 0.03 deaths (including indirect deaths from disasters and workplace accidents at the plants). That makes it even safer than wind energy, which is associated with 0.04 deaths per TWh, mostly from accidents during the installation process, drownings on offshore sites and helicopter collisions with turbines. Only solar energy is less deadly than nuclear. Coal is the deadliest because of the air pollution it causes: one TWh is linked to 24.6 deaths.
As a rule, the safest energy sources are also the greenest. Nuclear energy produces just four tonnes of greenhouse gases per gigawatt-hour of electricity (GWh), the same as wind energy (this includes emissions from the mining of fuels, transportation and maintenance of a plant). Despite this, nuclear energy used for electricity production has been in decline since 2001 and now only accounts for a tenth of the global total. Fossil fuels still produce most of the world’s electricity: coal, gas and oil made up around 62% last year. The share of renewables has been growing over the last decade, yet wind energy makes up just 7% of the total and solar energy 4%.
Nuclear energy has had an image problem for some time. Major accidents have made it seem more deadly than it is and the storage of nuclear waste remains controversial. But attitudes are shifting. Germany had planned to turn off its remaining three nuclear plants by the end of the year. Now, amid concerns about the country’s dependence on Russian gas and soaring energy prices, its government appears to be re-considering. Britain is constructing its first new nuclear plant in more than two decades. And in France, the government is set to pay €9.7bn ($9.9bn) to fully nationalise Électricité de France, one of the world’s biggest energy suppliers, to help fund six new nuclear reactors. Nuclear appears to be back in vogue. ■
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The first underground warren for disposing of spent nuclear fuel Finland leads the way. Sweden and others may follow
Nearly half a kilometre underground, in the Precambrian bedrock of Olkiluoto, an island off the south-western coast of Finland, a rough-hewn gallery a few metres wide and similarly high runs dead-straight through the granite. Underfoot, the floor is a bit muddy, though mostly rocky. Overhead, steel meshing stops any fragments that might have been loosened by the drilling falling onto people’s heads. Neither hard-hat-mounted torches nor the headlights of an electric van can reach far enough into the stygian darkness to pick out the gallery’s end, some 350 metres away in the distance.
Within a few years, this gallery, part of the Onkalo spent nuclear fuel repository, should be a resting place for batches of waste from Finland’s two nuclear power stations to be sealed off permanently from the world. It was completed this month, the last of five almost identical tunnels that run parallel to each other, connected by a main access gallery (see diagram). If all goes well, a warren of roughly 100 more will be excavated as needed over the coming century. As new galleries open, old ones will be backfilled with clay and sealed with concrete, entombing their radioactive contents.
Cold storage for hot waste
Deep geological disposal of this sort is widely held to be the safest way to deal with the more than 260,000 tonnes of spent nuclear fuel which has accumulated in 33 countries since the first nuclear-power plants began churning out electricity in the mid-1950s, and the still larger tonnage that may be generated in the future. Spent fuel is a high-level nuclear waste. That means it is both physically hot (because of the energy released by radioactive decay) and metaphorically so—producing radiation of such intensity that it will kill a human being in short order. Yet unlike the most radioactive substances of all, which necessarily have short half-lives, spent fuel will remain hot for hundreds of thousands of years—as long, in fact, as Homo sapiens has walked Earth—before its radioactivity returns to roughly the same level as that of the ore it came from.
At the moment, the vast majority of spent fuel is kept underwater in cooling pools, often within or near the power plants that generated it. The rest is in dry store. Wet or dry, these facilities are all intended as temporary depots—way-stations on the path to permanent disposal while companies and governments wrestle with the headache of where to put the stuff permanently (or conveniently turn a blind eye to a problem which they hope will not become a crisis on their watch).
And so Finland stands, for now, as the only country to have built a complete deep geological storage facility. It is just down the road from Olkiluoto’s nuclear-power plant, which generates 21% of the country’s electricity. Operations are expected to begin in 2024 or 2025, according to Janne Mokka, chief executive of Posiva, the company behind Onkalo. Posiva applied for its operational licence in December 2021. A trial run is expected next year. Sweden is just a few years behind, with its own repository at Forsmark, directly across the water from Olkiluoto. Both use similar designs.
The basic principle of deep geological storage is to put a multiplicity of physical barriers and a great deal of stability between the waste and human beings. Spent fuel rods are first left to cool for a few decades before they are sealed into metallic capsules of a composition that depends on the repository’s geochemistry. The idea is to use something which will not corrode—at least not faster than the radioactive material within it decays.
In both Onkalo and Forsmark the water pervading the granite’s tiny fissures is free of dissolved oxygen. Copper, corrodible by oxygen but otherwise stable, can thus be used for containment. The cooled fuel rods are packed into cast-iron vessels sheathed in cylindrical copper capsules eight metres tall and 1.05 metres wide. Argon, an inert gas, is injected between the two metals and the copper welded shut by remotely operated machinery. The capsule is then cleaned and transported to a lift that lowers it 430 metres, to a place where the rocks are unperturbed by human activity, climate change or the kinds of fracturing that an ice age might impose.
All this happens inside a remotely operated assembly line on top of the lift shaft. Onkalo’s encapsulation building was finished at the end of May and its rooms are now being kitted out with robots that will manipulate the waste.
When the capsules are at the bottom of the shaft, a fleet of remotely operated vehicles will ferry them through a network of underground tunnels to whichever gallery is in the process of being filled. Once there, each will be lowered into a hole in the floor that has been lined with bentonite, an absorbent clay commonly used in cat litter. This will help to keep the copper dry. Gaps that remain will be filled with further bentonite and the hole sealed off. In Onkalo, the floor of each 350-metre gallery can accommodate 30 evenly spaced capsules, together holding 65 tonnes of spent fuel. Once full, galleries will be backfilled with yet more bentonite before their entrances are sealed with a reinforced-concrete cap. Et voilà. Goodnight, sleep tight.
Nor will any unwitting adventurer easily blunder across the place in future to wake the sleeping horror lying beneath. In 100 years’ time, Posiva will fill the whole site in, remove all traces of buildings from the surface and hand responsibility over to the Finnish government. The thinking is that leaving no trace or indication of what lies below is preferable to signposting the repository for the curious to investigate.
Eventually, the containers may corrode. How long that will take is debated. In 2007 Peter Szakalos, a chemist in Sweden, published a study suggesting copper canisters can do so even in oxygen-free water, and that this could cause them to crack within decades or centuries, not millennia. These findings caused some angst among regulators in Sweden and Finland. Nevertheless, in January of this year, Swedish authorities announced that their concerns had been allayed and construction at Formsark was given the go-ahead.
The current consensus is that corrosion rates, combined with the rates of processes which might bring any radioactive material towards the surface, are so slow that by the time anything does get there it will pose little risk to whatever life is around.
The technology needed to dispose of Finland’s waste is thus now in place. But, crucially for Onkalo’s success, the government has also, through decades of careful communication and negotiation, obtained popular buy-in for the project.
“It represents 50 years of building trust,” says Mr Mokka. That trust-building started with the local power plant. On June 11th, at a summer fair in a town square in Rauma, 20km down the road from the repository, children tottered about holding balloons emblazoned with the logo of the local electricity company. Jenna, a young mother, described how she visited the plant on a school trip when she was a little older than her own child is now. Most people are fine with a nuclear facility just up the road, she says. It is an important employer, and the property taxes its operators pay help local finances. Of the final five sites that had appropriate geology to host Onkalo, two had local populations that were extremely pro-nuclear. Both were next to nuclear-power plants.
Other countries face more difficulties. France’s deep-storage efforts, though well advanced, are plagued by demonstrations. America’s Yucca Mountain project, in Nevada, is stalled by state-level opposition. But feelings could change over coming decades, and technological advances may make recycling spent fuel first before disposing of it—something France does already—a more attractive option. But regardless of whether nuclear power experiences a comeback, just solving the problem of that 260,000 tonnes of existing waste will surely require lots of digging. ■
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Energy security gives climate-friendly nuclear-power plants a new appeal To make good on it they have to get easier to build
The world’s largest crane, Big Carl, trundles up and down the railway which bisects the site. To the south are cavernous temporary structures which serve as factory floors, sheltered from the elements, cranking out modules of steel and concrete. Big Carl (pictured, above) takes gentle hold of these components, lifts, turns and gently sets them down. Piece by gigantic piece, the newest nuclear power plant in the Western world is taking shape. When it is finished its two nuclear reactors will be able to supply Britain’s grid with 3.2 gigawatts (gw) of power, providing about 7% of the country’s electricity needs.
Over the four years that Hinkley Point c (hpc) has been under construction on the edge of the Bristol Channel in the west of England, it has consistently been held up as an example of the industry’s current problems. Nuclear energy’s long-standing cost and schedule issues used to mean it was hard put to compete with natural gas and coal. Now they make it hard for nuclear to compete with ever-cheapening renewable energy.
When the British government and edf Energy, the plant’s owner, signed the relevant contracts in 2013, hpc was expected to produce a megawatt-hour for £92 (then $145). The same amount of energy from a new offshore wind farm was at the time expected to cost £125. Nine years on, hpc is two years behind schedule and £10bn over budget; so its power will cost more. Offshore-wind producers, for their part, are offering energy at less than £50 (now $60) per megawatt-hour. The cost of electricity from solar panels has fallen yet further. Campaigners who have long seen nuclear as dangerous can now call on economists who say it is just too expensive.
Beyond all that, the plant faces the problem of being built by a company in increasingly dire straits. The other European plants based on the reactor design edf calls epr—the design used at Hinkley—are also behind schedule. Its existing reactors in France are causing concern, too. Corrosion problems discovered in 2021 have seen a number of them shut down for inspection and repair at a time when the cost of natural gas, and thus electricity, has soared.
High prices have meant the amount the company has had to pay to cover its lack of performance is particularly high; in March it announced its profits would be €11bn lower as a result. Another €8.4bn hit came through the French government’s order that edf supply electricity to re-sellers below the wholesale market rate to protect consumers from cost increases.
For all its woes, though, by the standards of Western-designed and -built nuclear plants, hpc is ahead of the curve. The eprs at Olkiluoto in Finland and at the Flamanville c plant in France started construction in 2005 and 2007 respectively. Neither has yet been paid for a watt fed into the grid. The same is true of Vogtle, an American plant designed around two Westinghouse ap1000 reactors which began construction in 2009; by 2017 it had driven Westinghouse into bankruptcy. All three are between two and three times over their original budget and getting on for a decade behind schedule.
To see reactors completed and connected to the grid with any degree of regularity and timeliness you must go instead to China and Russia. Between 2008 and 2021 Rosatom, a state-owned firm, started and completed ten reactors at five power plants in Russia. China has been building reactors of various designs, including ap1000s and eprs. The China General Nuclear Power Group set to work on its two eprs in Taishan, in southern China, after construction was already under way at Olkiluoto and Flamanville and finished by 2019.
This has meant that those Western countries still interested in building nuclear power plants have increasingly looked to non-Western companies to build them. At the beginning of this year Rosatom was expecting to build four reactors in the eu, 7% of the 70gw of nuclear capacity it has plans for beyond Russia’s borders. In February Britain’s nuclear regulator approved the Hualong One, a Chinese reactor design, for use at Bradwell, a nuclear site in Essex.
Then came the war in Ukraine. On February 15th, as Russian forces massed on Ukraine’s border, Bulgaria definitively nixed any Russian involvement with a nuclear plant that was to be built next to the northern town of Belene. Finland’s Minister for Economic Affairs, Mika Lintila, has repeatedly said that it would now be “absolutely impossible” to grant a permit for a planned Russian-built nuclear plant in Hanhikivi to go ahead. In March the Czech Republic excluded Russian reactors from a tender for which they had previously been the leading candidate.
Heat and light
Hungary’s opposition has been attacking plans for two new Russian reactors at the Paks plant in the centre of the country on the basis that they would expose the country to untenable Russian influence. Viktor Orban, the pro-Russia prime minister, might be immune to their arguments. But Western sanctions make it doubtful that Rosatom could complete the build. A more general worry about inimical control over such assets has seen the Chinese plans for Bradwell put in doubt.
At the same time as sending countries already interested in new nuclear plants in search of new companies to build them, the invasion of Ukraine also underscores a more general energy-security argument in favour of nuclear power plants: they can afford their owners a security of electricity supply. The eu’s reliance on Russian gas has boosted Russia’s income even as its artillery flattens Ukrainian cities; since mid-June, Russian moves to limit that supply have sent prices through the roof.
If European countries had more nuclear plants, their reliance on Russian gas would be reduced; there is a reason why Finland, where the practical alternative has long been Russian gas, is keen on the technology. When President Emmanuel Macron of France announced on February 10th that the country would be building a new set of nuclear plants, he praised renewables and nuclear as the “most sovereign” way of producing electricity. During a visit to hpc in April, British prime minister Boris Johnson was explicit that the reactor was part of an “energy-security strategy”: “We cannot allow our country to be dependent on Russian oil and gas.”
As Mr Macron noted, energy security adds to the technology’s pre-existing appeals; it is comparatively safe and it is climate friendly, both of which make it preferable to fossil fuels (see chart). According to an analysis by Our World in Data, a research organisation, burning coal to generate a terawatt-hour (twh) of electricity is associated with some 24.6 deaths, largely because of particulate air pollution. Natural gas is about ten times less deadly. Including roughly 4,000 deaths linked to the Chernobyl disaster and the 573 people who, according to Yomiuri Shimbun, a newspaper, died as a result of “fatigue or the aggravation of a chronic disease due to the [Fukushima] disaster” the number for nuclear is just 0.03 deaths per twh.
As to climate, if industrialised countries are to do their bit in keeping the rise in global average temperature, compared with that of the pre-industrial age, well below 2°C—the target set in the Paris agreement of 2015—they need quickly to purge fossil fuels from electricity grids. Plausible models show clearly that, even with big grids and a lot more energy-storage capacity than is available today, this is much cheaper when the grid includes not just wind and solar, which are both intermittent, but also “firm” generation which produces electricity at a relatively steady rate.
It has long been argued that this role might be taken by fossil-fuel-powered plants fitted with technology for carbon capture and storage (ccs) and that may yet be the case; but there has been almost no deployment of the technology at large scale yet. Hydroelectricity and nuclear power are the only methods of producing such power without emitting carbon dioxide that have ever been deployed on a large scale. And sites suitable for big new hydroelectric plants in developed countries are very few and far between.
Saving the planet
The climate case for nuclear has given rise to a lot of excitement about new types of reactor, notably smaller ones which make more use of components created in factories far from their sites. But these small modular reactors (smrs), promising as they may be, are still for the most part at early stages of development. The only proven form of nuclear power that can be expected to provide fresh gigawatts to rich-country grids in the 2030s is the form that is around today: big, slow-to-build and cumbersome reactors like the epr.
This means that hpc is not just the latest in a line of thousand-days-late, billions-of-dollars-short boondoggles. The plant is a crucial test of whether Western financing, construction and supply chains can be improved in ways that curb the industry’s chronic time and cost overruns. To the extent that it can be built more efficiently than its predecessors, and pave the way for future construction to be better still, it is a bellwether for the industry.
One of the reasons that nuclear plants have to be built better is that they need to cost less. Financing is always going to be a bit expensive, because even before you take the almost certain delays into account the time frame for building them is a lot longer than that for other sorts of large power plant. “You don’t start getting paid until you produce electricity on the grid,” says Julia Pyke of edf, who leads the financing for the next British plant the company is planning, Sizewell C. “The longer your construction period, the more you roll up interest.”
If the time required was long but predictable that would be one thing. But the risk that the project will run into trouble which sees the schedule drawn out further, or even cancellation, means the plants do not just have to borrow for a long time, they also have to borrow at high rates.
These uncertainties reflect the fact that nuclear construction often fails to meet the high standards to which it is understandably held. When regulators notice things, they have to be put right. The concrete used at Olkiluoto was initially not up to scratch, with too much water in the mix. Then there were problems with the systems used to monitor and control the plant, leading to legal battles with two contractors, France’s Areva and Germany’s Siemens. Flamanville is dogged by faulty welding. According to Reuters, a news agency, 800 of the 3,000 people working on the plant are repairing bad welds.
In one way these delays can be seen as reassuring badges of the technology’s safety; regulators came, found shortcomings and had them fixed. It is hard to be sure that the same would happen on Russian and Chinese projects, either at home or in export markets such as Egypt or Pakistan. And there is some reason to believe that a system where there was more experience with new builds would see fewer such cock-ups. Unfortunately the cock-ups, by adding to the costs, make new reactors rarer and building up that experience harder.
No Western country has a workforce with experience in making the things both well and quickly (hpc is the first to be built in Britain for 30 years). Supply chains are not only hugely complicated but also bespoke, not routine. They thus tend towards the crufty. This results in failure reinforcing failure. Building goes badly; investors, aware of the risks of delay or cancellation, charge a lot for the money they provide; demand for new plants goes down; no one learns to do the building better.
To break this cycle requires both better building and new financing models. The construction at hpc is using modern planning and prefabrication techniques which are designed to make the build more likely to come in on time. Instead of being welded piece-by-piece, in situ, reactor components are built “offline”, away from the reactor itself, then hoisted into place: hence the need for a very big crane. Similar sorts of reform have been tried before; the ap1000, in particular, was designed with this sort of approach in mind. This time they may actually be working. Simon Gould, a specialist welder with tissot Industrie who worked on both Flamanville and Olkiluoto calls the Hinkley system “a game changer”. edf says construction of the second of hpc’s reactors is going 30% faster than construction of the first did as the new approach hits its stride.
Sizewell c should benefit not just from this process improvement, but also from a financing regime called the Regulated Asset Base (rab). Already used in other British infrastructure projects, it allows interest payments to be covered by charges to consumers’ bills during the construction period. Similar arrangements have been tried before for American nuclear plants. Britain’s National Audit Office thinks the version it has designed is better.
Paying for it all
Having consumers pay off interest during construction reduces the size of the principal on which interest must be paid in future, thereby reducing overall costs. For example, for a loan of £8bn with an interest rate of 9%, which is the rate at which edf was able to borrow money for Hinkley, the accumulated interest on the loan is larger than the principal by the time construction is completed. The company reckons that some 60% of hpc’s final cost will be the cost of financing its construction.
On March 31st Parliament passed legislation allowing rab to be adopted for Sizewell c. The decision to go ahead with the plant is expected any day. Ms Pyke expects the rab deal will not just allow interest to be paid off before earnings begin but also lower the rate at which lenders charge interest in the first place, though by how much she cannot say. In return for their enforced upfront generosity, consumers should, in the long term, get cheaper electricity. At hpc, edf was able to get the government to agree to a high price for its electricity more or less in perpetuity to overcome the acknowledged hurdle of the financing costs. At Sizewell it will face a regime that allows prices to come down over time on the say-so of a yet-to-be-instituted regulator.
Other companies based in democracies make nuclear plants, but they are untried in Europe. Japan’s nuclear industry has built many power plants at home, and after restarting those closed down post-Fukushima, has plans for more. But it has never built overseas. Two Japanese plants planned for Britain have fallen through in the past decade. Westinghouse, now owned by a private equity group, makes money on refuelling and maintenance but, understandably after its losses at Vogtle, has no firm construction plans.
That said, Westinghouse is in talks with both Poland and the Czech Republic about the reactors they want to build. Poland has also been talking to Korea Electric Power Corporation, better known as kepco. The company has never yet built a plant in Europe, but it has built one overseas, in the uae, and is owned by a democratic and friendly government. In March that government’s new leader, President Yoon Suk-yeol, said he would abandon the previous government’s policy of phasing out nuclear energy, and committed to boosting the export of nuclear reactors.
New vendors could improve the outlook. So might the eventual deployment of smrs. An American company called NuScale has a deal to build a set of six small reactors in Romania which together would supply 462mw to the grid. Rolls-Royce, a British engineering company, is touting larger smrs, each of which produces more than all six of those NuScale ones; it, too, is in talks with Poland.
If such designs really do allow power plants to get up and running in just a few years, new interest could bloom in both Europe and America. But that is not a reason for abandoning attempts to make big nuclear plants cheaper and easier to build. To replace the electricity generated by burning Russian gas and substitute Western-designed nuclear plants for cancelled Russian ones, Europe would need at least 40gw of new nuclear capacity over the coming decade and a half. That is plenty for all. And if Europe could get good enough at big plants to offer them for export that would be a significant bonus. A world in which all new nuclear programmes have to rely on China and Russia is geopolitically unappealing.
Big Carl, it seems, must do more than lift the 1,000-tonne loads he faces at hpc. He has a potentially world-improving industry to set straight. ■
==============================================================Nuclear power
A firm founded by Bill Gates bets on a novel nuclear reactor The hope is that it will work well with renewable-dominated power grids
Since handing over the reins as Microsoft’s chief executive in 2000, Bill Gates has been best-known for his philanthropy. The Bill and Melinda Gates Foundation, one of the world’s largest charities, has given billions of dollars to vaccination drives, family-planning clinics, research into drug treatments for malaria and more.
But Mr Gates has not abandoned the business world entirely. On June 2nd TerraPower, a company he founded in 2008, announced that it would build a demonstration of an exotic, high-tech nuclear power station in Wyoming. The firm’s Natrium reactor is one of a gaggle of new designs that have emerged in recent years, as engineers try to come up with cheaper, simpler nuclear power plants that can provide low-carbon electricity with fewer of the cost and safety worries that have plagued the industry in the past.
The Natrium reactor makes two big changes to the standard nuclear-power-plant design. It replaces the liquid water that normally courses through the core with hot, liquid sodium (natrium, in Latin). And instead of using the heat generated by the reactor to make electricity directly, it first employs it to heat a tank of molten salt that acts as a giant battery. The upshot, the firm hopes, will be a cheaper reactor that is better suited to power grids that will increasingly be dominated by intermittent sources of energy such as wind turbines and solar panels.
Start with the reactor itself. Most nuclear power plants are light-water reactors (lwrs), a technology developed in America in the 1950s. They use ordinary water both to cool the reactor core and to increase the intensity of the chain-reaction by moderating the speed of the neutrons that are emitted when uranium atoms split. Thus slowed, these neutrons are more likely to go on to split more atoms in turn.
Natrium employs hot, liquid sodium as a coolant, and dispenses with the moderator entirely. This is another idea that dates back to the 1950s, but one which has never been widely deployed. Yet sodium offers several advantages as a coolant, says Chris Levesque, TerraPower’s boss. The liquid sodium’s high temperature—around 500°C—makes the reactor more efficient. At the same time, liquid sodium is much less corrosive to pipes than hot water. And though the water in lwrs is pumped through at high pressure, Natrium is designed to operate at close to atmospheric pressure. That means pipes, containment buildings and the like can be less beefy without affecting safety. TerraPower reckons its reactor needs only 20% of the concrete required by an lwr of equivalent power, which helps keep down costs.
The firm’s second big idea is its molten-salt energy-storage system. Inspiration for this came from the solar-power industry, says Mr Levesque. Solar-thermal systems (in contradistinction to the more familiar photovoltaic ones that generate electricity directly) have, for several years, used similar tanks to store excess solar energy harvested during the day. In Natrium’s case, the sodium coolant transfers heat from the reactor into the molten-salt tanks. A separate set of pipes then removes heat from the tanks and uses it to produce electricity.
It all looks good on paper. But then, nuclear power always does. The industry has been plagued by delays and cost overruns for decades. Existing sodium-cooled reactors, most of which are experimental, have a spotty record. A plant in Japan suffered a serious fire in 1995 and was shut down for over a decade. The Superphénix reactor in France, built in 1974, proved extremely unreliable, and was offline for years at a time. It closed for good in 1998. (Other reactors, such as the Fast Flux Test Facility in Washington state, have better records.)
The Union of Concerned Scientists, an American not-for-profit organisation, argues in a report published in March that sodium’s advantages as a coolant are counterbalanced by drawbacks. One is that a reactor which ran too hot might see its power output rise as a consequence. Unlike water, the loss of which shuts a reactor down for lack of moderation, sodium slightly damps the chain-reaction. If bubbles of sodium vapour formed in the coolant, that damping effect would diminish, risking a dangerous feedback loop of rising temperatures and growing power output.
The physics of such judgments are tricky. Few countries have as much nuclear experience as France, which generates around 70% of its electricity that way. Yet in 2015 French regulators said they could not determine whether sodium-cooled reactors are significantly safer than modern lwrs. TerraPower, moreover, insists that its Natrium plant is designed in a way that makes runaway reactions impossible.
America’s government, for its part, thinks the technology has merit. It is chipping in $80m to help TerraPower build the demonstration plant, which the firm says should be ready by 2028. In the meantime, says Mr Levesque, TerraPower has been fielding inquiries from electricity firms interested in its technology. Whether Mr Gates’s bet on a nuclear-power revival will pay off remains to be seen.