This site seems to have a good timeline and breakdown of the problems that lead to the current situation with the nuclear reactors that are having issues. It’s an interesting read.
Some important points to consider:
- Two unprecedented natural disasters struck the plants within about a one hour timeframe.
- The cooling systems themselves were not damaged by either the quake or the tsunami.
- The sequential disasters caused the failure of two layers of power systems for the cooling system – outside power was disrupted by the quake, and the multiply redundant on-site diesel generators were wiped out by the tsunami.
- The third layer of backups – battery power for the cooling systems – worked exactly as designed.
- The fourth layer of backups – mobile diesel generators brought in from off-site – appear to have failed due to not having the proper plugs to connect to the plant’s cooling systems. This is entirely feasible, as this is a 40 year old reactor (installed in 1971), and the general state of confusion and crisis throughout the nation caused by the quake and tsunami.
So, just for the normal cooling systems to fail required the failure of four redundant systems – one of which had it’s own built-in redundant backups – before a meltdown became even a possibility. There were multiple emergency procedures already planned and ready when that happened.
There comes a point when designing anything where creating safety procedures becomes an exercise in ridiculousness. The plant survived two of the worst disasters in Japan’s recorded history in the space of one hour, without a reactor breach, and with all backup systems operating as designed for eight hours afterwards. Human error (the wrong plugs for the outside generators), exacerbated by the scale of the disasters (which likely prevented the proper plugs being brought in in time), is what led to the current situation, not poor design.
TANSTAAFL applies to all forms of power generation. There is no perfect way to power a modern society – nuclear, coal, oil, and gas all have inherent dangers and pollution. Solar and wind are unreliable and insufficient to meet our needs, and have their own environmental costs. Simply cutting our energy production to meet the abilities of “green” power generation would result in the deaths of hundreds of thousands, if not millions. Nuclear is still the best option.
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