Storm Damage At Fukushima Daiichi And Onagawa

Yesterday’s storm that rolled across Japan caused considerable damage, deaths and injuries. Fukushima Daiichi wasn’t totally immune.

The tent that covers unit 1 appears to have some minor damage (images below). There are  two existing square openings in one side of the cover. Those two holes appear to now have rips or loose fabric adjacent to the holes. The sustained winds were over the design limits for the reactor cover. This raises questions about the ability to stand up to typhoons. The nitrogen injection system was also halted during the storm for some reason. A worker found the system stopped at 11am JST. More than 12 hours went by before the back up system was running. TEPCO also mentioned an even more worrying fact, it would only take 30 hours for hydrogen to reach dangerous levels in the reactors. Since it took 12 hours to bring the back up system online it is easy to imagine in a larger tropical storm or typhoon where a scenario could take place that would reach past that 30 hour mark for an outage. Equipment at the plant is largely out in the open without any real protection from significant storms.
Mainichi is now reporting that the compressor filter on the nitrogen injection system became clogged with dirt due to the storm. The audio alarm was not heard as workers were sheltering from the storm.

Onagawa nuclear plant north of Fukushima partially lost power and had the cooling system for a spent fuel pool go out. It took 20 minutes to get the cooling system restarted. No details were given about why Onagawa lost power or what systems continued to run during the issue. Mainichi is reporting that the seawater pumps may have had issues that prevented cooling systems along with a voltage drop in the transmission lines.

before and after of unit 1’s cover

This article would not be possible without the extensive efforts of the SimplyInfo research team
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