Fukushima

The situation at the Fukushima Daiichi nuclear power plant in Japan remains serious, regardless of the issue getting less press attention. There have been a number of earthquakes since the 11 March earthquake and tsunami, with other nuclear power plants in Japan losing off-site electrical power, at least temporarily. Off-site power availability is imperative in order to maintain nuclear reactors cool, even after shutdown. Onagawa nuclear power plant lost two out of the three power lines supplying off-site power following the 7 April earthquake. All of its reactors have been in cold shutdown since the 11 March earthquake.

The Fukushima Daiichi accident is now at a provisional level 7 on INES. This rating considers the accidents at reactors 1, 2 and 3 as a single event on INES and uses an estimated total release to the atmosphere as a justification. The only other known nuclear accident rated at this level is the Chernobyl disaster. NISA estimates that the release of radioactive material into the atmosphere amounts to approximately 10% of the Chernobyl accident. New evacuation areas beyond the 20 km radius from the Fukushima Daiichi power plant have been established on 11 April.

The IAEA maintains a daily log of the accident. Get your updates there.

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2 Responses to “Fukushima”

  1. Cris Says:

    What I would really like to know is if they’ll be able to put an end to it. It’s now more than 1 month since it started & there are no fixes yet. This absolutely sucks!!

  2. ggl Says:

    Yes, but it takes time. First thing they have to cool down the reactors and stop any possible leaks. You can’t pour concrete over a hot reactor. Even in cold shutdown state (95°C at atmospheric pressure) heat is still being generated by means of radioactive decay and it has to be removed by recirculating water through the reactor core ultil the reactions slow down. Even spent nuclear fuel is still active for at least another 10 years, thus spent fuel pools have to be cooled during this period. Reactors 4, 5 and 6 were defuelled (maintainance) at the time of the earthquake and all of their nuclear fuel is the spent fuel pools. This didn’t stop an alledged hydrogen explosion at reactor 4 on 15 March, during the power outage that occured right after the earthquake. The problem is, partial core meltdowns took place at reactors 1, 2 and 3 during the power outage. Colling them down is an even more complicated issue right now, as fuel rod integrity has been compromised. It will take a while.

    Update:
    The residents are likely to have to stay away for some time, after plant operator Tokyo Electric Power Company said that it did not expect a ‘cold shutdown’ of all six reactors for another six to nine months.
    (Source: RTE News)

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