Earlier this week, a Japanese government official said that there were no plans to restart any of the reactors at the Fukushima Daini nuclear power plant.
Fukushima Daini was a textbook example of how things can go right at a nuclear power plant in the face of an extreme event, something we noted at our SafetyFirst microsite in December:
When the earthquake struck, the Fukushima Daini facility automatically shut down safely as designed. However, it went into a state of emergency following the tsunami when water damage disrupted heat removal systems in three of the four reactors.
TEPCO reactor operators were able to quickly bring reactor 3, which had retained its heat removal function, into stable condition in a matter of hours. Meanwhile, other employees worked feverishly around-the-clock to reestablish heat removal capability in the other three reactors and finished stabilizing them by March 15.
A key distinction between the post-disaster conditions at Fukushima Daini and Fukushima Daiichi was that off-site power was available at the Daini facility, whereas the Daiichi plant suffered a complete loss of electricity, including backup generators and, eventually, emergency batteries needed to power reactor cooling systems. Fukushima Daini workers were able to tap into electricity from a 500-kilovolt-transmission line – a key lifeline – to power a water injection system that helped cool the reactors as they shut down.