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View from Tokyo: Meltdown and panic

Fukushima-1.JPGThe following was posted on behalf of David Cyranoski.

Japan awoke Saturday to some horrible images of houses, cars, and people being carried away by tsunami waves with body counts rising into the many hundreds. In the wake of that drama came confusing reports of what appears as though it may be at least a partial nuclear meltdown.

News programs increasingly focused on the hard hit Fukushima nuclear facility. The morning brought reports that the cooling system of one of the facility’s reactors was down. Power went out, and the backup generator, possibly damaged by the tsunami, wasn’t working either. In the afternoon, the Nuclear and Industrial Safety Agency (NISA) reported that temperatures at the reactor shot up to 2700℃, and pressure was increasing. Cesium was detected outside, leading to fears that some of the fuel had started melting.

Then, at 3:36, a building at the facility exploded. And that’s when things started getting confusing.


One station showed a video clip of the explosion, but then it reported that this was an intentional measure to relieve pressure within the facility and stopped using the video clip. (It certainly didn’t look like something a nuclear energy company would do intentionally). Other stations were reporting that the efforts to relieve pressure within the reactor through a vent had, for some reason, failed. And then a NISA official came on to say that the vent had worked and pressure had dropped from a dangerous 0.755 megapascal to a comfortable 0.555 megapascal. An increase in radiation at an external monitoring site from 4.8 microSievert (μSv)/hour to 9.979 μSv/hour was presented as evidence that the vent worked: some of the pressurized air, mixed with some radioactive materials, had been successfully released.

As the Japanese self-defense forces rushed to bring in enough water to cool the reactor, NISA said there was no reason to extend the evacuation zone—a 10 kilometer radius zone affecting some 6000 people. Other stations started to take note of a before and after difference of the reactor landscape—the rectangular building housing the number the reactor in question was now just a skeleton. News of a “strong shaking” followed by an “explosive noise” and “some white smoke” at “around 3:30” started making the rounds sometime after 4. The reports quoted NISA officials as saying the “roof had collapsed.” Those of us that had seen the video knew it had blown off. Two workers and two contractors with Tokyo Electric Power Company were injured. NISA extended the evacuation zone to 20 kilometres at both Fukushima facilities one and two, about 20 kilometres apart. Then the second facility evacuation zone was returned to 10 kilometres. At least two stations reported that the government had given up on trying to cool the reactor, leading newscasters to ask the specialists questions that didn’t get answered: what happens then?

Various experts tried to explain the shaking, some conjecturing an aftershock others offering different versions of a reactor explosion. Bit by bit, the scientists started to reach the same conclusion: the government has to tell us what’s happening. One lamented that Japan lacked a “mission center” such as what would be expected in other countries.

The experts started giving advice to those in the evacuation zone—wear long sleeves, masks, etc to cover the body and stay inside whenever possible and close any fans or vents. Meanwhile hundreds of people were being evacuated. News that helicopter evacuations had been halted due to heavy smoke were followed by reports of self defense forces’ lifting nearly 200 elderly from an assisted living facility in helicopters.

Press conferences between 5 and 7 by the chief cabinet secretary and a NISA official meant to clarify the situation clarified nothing. The main thrust was: there has been “an explosive incident” and we are looking into it. “please stay calm,” said Yukio Edano, the cabinet secretary, though the uncertainty was only building tension.

Finally, around 9, Edano explained that hydrogen collecting in the facility exploded the walls of the facility but left the steel container holding the reactor in tact. At 8:20, they started pouring in seawater but an aftershock forced it to stop at 10:15. It doesn’t seem to be filling the tank, leading to fears that there is a leak and the reactor will never be properly cooled. Edano confirmed that the plant had been emitting 1,015 μSv per hour—about the same as one would be allowed for one year—before the explosion, but he said large amounts of radiation were not being reported now. There are, however, reports that 190 people are affected by radiation.

For full coverage of the Fukushima disaster, go to Nature’s news special.

Comments

  1. Report this comment

    Anand Keathley said:

    Nuclear power is safe when it is 93 million miles away.

  2. Report this comment

    David said:

    Stupid question: How can a power plant producing energy lack energy for cooling?

  3. Report this comment

    NadePaulKuciGravMcKi said:

    reactor 3 is the real nasty one,

    MOX fuel with plutonium,

    very carcinogenic

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