Special Report: Fukushima and the Future of Nuclear Power

Editor's Note: John Boyd is an IEEE Spectrum contributor reporting from Kawasaki, Japan. This is part of IEEE Spectrum's ongoing coverage of Japan's earthquake and nuclear emergency. For more details on how Fukushima Dai-1's nuclear reactors work and what has gone wrong so far, see our explainer.

Another major earthquake rocked northeastern Japan again Monday evening at 5:16 local time, and was followed by a number of strong aftershocks. The 7.0-magnitude quake caused some cities to lose power, and there were reports of a mudslide and the collapse of houses that had been weakened by previous shocks. The quake was felt as far away as Tokyo. Shinkansen bullet trains in the region were halted and bullet train services between the capital and Osaka in the southwest were also suspended for a short time.

Off-site power at the crippled Fukushima Dai-1 nuclear plant was lost immediately following the quake, but was restored again at 6:05 p.m. local time. During the power outage, water injections into reactors 1, 2, and 3 were halted for about 50 minutes. Though back-up diesel generators and power trucks were on hand to provide power for pumping water, a tsunami warning issued by the Meteorological Agency caused workers to evacuate from the vicinity of reactors 1 through 4, leaving no time to manually switch over to the back-up systems, according to NHK, Japan’s national broadcaster.

Tokyo Electric Power Co. (TEPCO) said that when workers returned to the site once the tsunami warning was lifted, monitoring systems showed no signs of radiation increases, and no other significant problems were found. However, as of 9 p.m. local time there was no word on when workers would resume pumping nitrogen into the No. 1 reactor, after the operation was halted by the quake. The nitrogen injections reduce the likelihood of another explosion happening through a buildup of hydrogen and oxygen in the reactor.

The quake was almost the same magnitude as the 7.1 aftershock that struck the area last Thursday night, which caused problems for other nuclear plants in the region. But this time around, the Nuclear and Industrial Safety Agency (NISA) announced that the quake had caused no serious problems at nuclear stations.

Yukio Edano, Japan's Chief Cabinet Secretary, told reporters in an afternoon press conference that the government will extend the 20-kilometer evacuation zone around the Fukushima Dai-1 nuclear plant. Until now, people living between 20 and 30 km from the plant were told they could evacuate voluntarily; the new evacuation orders will apply to some towns in the 20-to-30-km zone and beyond. Because radiations levels are relatively high in these areas, Edano said that health officials are worried about the cumulative impact of radiation on residents living there for the next six to twelve months. The government will work with the concerned municipalities on evacuating residents over the next four weeks. Edano added that the government would also designate certain areas in the 20-to-30-km zone the "emergency preparation evacuation zone," where residents would be asked to be prepared to evacuate in case of an emergency.

Meanwhile, work continued over the weekend on emptying storage tanks, a mission that included dumping thousand of tons of slightly radioactive water into in the ocean. The tanks were cleared to make storage room for highly radioactive water that had pooled in the No. 2 reactor's turbine building and outside trench. The water needs to be removed from these locations, as well as the turbine basements and trenches of reactors 1 and 3, to give workers access to the reactors' crucial cooling systems, which have been offline since the tsunami. Restoring the reactors' cooling functions would allow TEPCO to end the current stopgap efforts of constantly injecting water into the reactors to keep the fuel rods covered with cooling water. TEPCO has estimated the total amount of pooled water at 60 000 tons, so the company has made arrangements to have additional storage tanks brought to the site.

There is little time to lose, because some water levels are rising. Experts believe the most highly radioactive water was contaminated by the No. 2 reactor core, where the fuel rods are thought to have been damaged through overheating. That water has gradually been edging up the No. 2 building's trench shaft since TEPCO managed to stem a leak of contaminated water, which was gushing into the ocean via a cracked concrete pit. Nishiyama said on Sunday that water in the trench shaft had risen 12 centimeters and was now less than a meter away from spilling over the top.

IMAGE: JAPAN METEOROLOGICAL AGENCY

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This photograph shows a car with the words “We Drive Solar” on the door, connected to a charging station. A windmill can be seen in the background.

The Dutch city of Utrecht is embracing vehicle-to-grid technology, an example of which is shown here—an EV connected to a bidirectional charger. The historic Rijn en Zon windmill provides a fitting background for this scene.

We Drive Solar

Hundreds of charging stations for electric vehicles dot Utrecht’s urban landscape in the Netherlands like little electric mushrooms. Unlike those you may have grown accustomed to seeing, many of these stations don’t just charge electric cars—they can also send power from vehicle batteries to the local utility grid for use by homes and businesses.

Debates over the feasibility and value of such vehicle-to-grid technology go back decades. Those arguments are not yet settled. But big automakers like Volkswagen, Nissan, and Hyundai have moved to produce the kinds of cars that can use such bidirectional chargers—alongside similar vehicle-to-home technology, whereby your car can power your house, say, during a blackout, as promoted by Ford with its new F-150 Lightning. Given the rapid uptake of electric vehicles, many people are thinking hard about how to make the best use of all that rolling battery power.

The number of charging stations in Utrecht has risen sharply over the past decade.

“People are buying more and more electric cars,” says Eerenberg, the alderman. City officials noticed a surge in such purchases in recent years, only to hear complaints from Utrechters that they then had to go through a long application process to have a charger installed where they could use it. Eerenberg, a computer scientist by training, is still working to unwind these knots. He realizes that the city has to go faster if it is to meet the Dutch government’s mandate for all new cars to be zero-emission in eight years.

The amount of energy being used to charge EVs in Utrecht has skyrocketed in recent years.

Although similar mandates to put more zero-emission vehicles on the road in New York and California failed in the past, the pressure for vehicle electrification is higher now. And Utrecht city officials want to get ahead of demand for greener transportation solutions. This is a city that just built a central underground parking garage for 12,500 bicycles and spent years digging up a freeway that ran through the center of town, replacing it with a canal in the name of clean air and healthy urban living.

A driving force in shaping these changes is Matthijs Kok, the city’s energy-transition manager. He took me on a tour—by bicycle, naturally—of Utrecht’s new green infrastructure, pointing to some recent additions, like a stationary battery designed to store solar energy from the many panels slated for installation at a local public housing development.

This map of Utrecht shows the city’s EV-charging infrastructure. Orange dots are the locations of existing charging stations; red dots denote charging stations under development. Green dots are possible sites for future charging stations.

“This is why we all do it,” Kok says, stepping away from his propped-up bike and pointing to a brick shed that houses a 400-kilowatt transformer. These transformers are the final link in the chain that runs from the power-generating plant to high-tension wires to medium-voltage substations to low-voltage transformers to people’s kitchens.

There are thousands of these transformers in a typical city. But if too many electric cars in one area need charging, transformers like this can easily become overloaded. Bidirectional charging promises to ease such problems.

Kok works with others in city government to compile data and create maps, dividing the city into neighborhoods. Each one is annotated with data on population, types of households, vehicles, and other data. Together with a contracted data-science group, and with input from ordinary citizens, they developed a policy-driven algorithm to help pick the best locations for new charging stations. The city also included incentives for deploying bidirectional chargers in its 10-year contracts with vehicle charge-station operators. So, in these chargers went.

Experts expect bidirectional charging to work particularly well for vehicles that are part of a fleet whose movements are predictable. In such cases, an operator can readily program when to charge and discharge a car’s battery.

We Drive Solar earns credit by sending battery power from its fleet to the local grid during times of peak demand and charges the cars’ batteries back up during off-peak hours. If it does that well, drivers don’t lose any range they might need when they pick up their cars. And these daily energy trades help to keep prices down for subscribers.

Encouraging car-sharing schemes like We Drive Solar appeals to Utrecht officials because of the struggle with parking—a chronic ailment common to most growing cities. A huge construction site near the Utrecht city center will soon add 10,000 new apartments. Additional housing is welcome, but 10,000 additional cars would not be. Planners want the ratio to be more like one car for every 10 households—and the amount of dedicated public parking in the new neighborhoods will reflect that goal.

This photograph shows four parked vehicles, each with the words \u201cWe Drive Solar\u201d prominently displayed, and each plugged into a charge point.Some of the cars available from We Drive Solar, including these Hyundai Ioniq 5s, are capable of bidirectional charging.We Drive Solar

Projections for the large-scale electrification of transportation in Europe are daunting. According to a Eurelectric/Deloitte report, there could be 50 million to 70 million electric vehicles in Europe by 2030, requiring several million new charging points, bidirectional or otherwise. Power-distribution grids will need hundreds of billions of euros in investment to support these new stations.

The morning before Eerenberg sat down with me at city hall to explain Utrecht’s charge-station planning algorithm, war broke out in Ukraine. Energy prices now strain many households to the breaking point. Gasoline has reached $6 a gallon (if not more) in some places in the United States. In Germany in mid-June, the driver of a modest VW Golf had to pay about €100 (more than $100) to fill the tank. In the U.K., utility bills shot up on average by more than 50 percent on the first of April.

The war upended energy policies across the European continent and around the world, focusing people’s attention on energy independence and security, and reinforcing policies already in motion, such as the creation of emission-free zones in city centers and the replacement of conventional cars with electric ones. How best to bring about the needed changes is often unclear, but modeling can help.

Nico Brinkel, who is working on his doctorate in Wilfried van Sark’s photovoltaics-integration lab at Utrecht University, focuses his models at the local level. In his calculations, he figures that, in and around Utrecht, low-voltage grid reinforcements cost about €17,000 per transformer and about €100,000 per kilometer of replacement cable. “If we are moving to a fully electrical system, if we’re adding a lot of wind energy, a lot of solar, a lot of heat pumps, a lot of electric vehicles…,” his voice trails off. “Our grid was not designed for this.”

But the electrical infrastructure will have to keep up. One of Brinkel’s studies suggests that if a good fraction of the EV chargers are bidirectional, such costs could be spread out in a more manageable way. “Ideally, I think it would be best if all of the new chargers were bidirectional,” he says. “The extra costs are not that high.”

Berg doesn’t need convincing. He has been thinking about what bidirectional charging offers the whole of the Netherlands. He figures that 1.5 million EVs with bidirectional capabilities—in a country of 8 million cars—would balance the national grid. “You could do anything with renewable energy then,” he says.

Seeing that his country is starting with just hundreds of cars capable of bidirectional charging, 1.5 million is a big number. But one day, the Dutch might actually get there.

This article appears in the August 2022 print issue as “A Road Test for Vehicle-to-Grid Tech.”

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