Special Report: Fukushima and the Future of Nuclear Power

Editor's Note: This is part of IEEE Spectrum's ongoing coverage of Japan's earthquake and nuclear emergency.

Yukio Edano, the Japanese government’s chief cabinet secretary, said in a nationally televised press conference in Tokyo that at 3:36 p.m. today an explosion occurred in a reactor of the Fukushima Dai-1 plant and caused the outer wall of the structure containing the reactor to collapse. He said that water in the reactor dropped when the pumping system failed, causing steam to be generated which filled the space outside the reactor and the inner walls of the outer structure. This in turn generated hydrogen which mixed with the steam and caused the explosion.

“Because there was no oxygen in the container, there was no explosion in the container, so there was no damage,” said Edano. “And there was no great amount of radiation leaked.”

Earlier, he said TEPCO had begun venting steam from the container to reduce the growing pressure inside. As a result, the density of radiation around the structure rose to the level of 1015 microsieverts produced in 1 hour. “After the explosion, the pressure inside the container fell and remains at a very low level,” says Edano. At the same time, the density of radiation also fell to 860 microsieverts, and by 6.48 p.m. it had fallen further to 70.5 microsieverts.

TEPCO has now decided to flood the container with seawater to bring down the temperature. After the government consulted with other experts and TEPCO, it gave its consent to what is “an unprecedented step,” says Edano.

 Photo: TEPCO/Reuters

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This Dutch City Is Road-Testing Vehicle-to-Grid Tech

Utrecht leads the world in using EVs for grid storage

10 min read
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.

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