[mikekchar]

Fukushima survived the earthquake and even survived the tsunami. The generator got wiped out, but even that wasn't what ultimately led to the disaster. It was that the battery backup eventually ran out of power (not unexpected) and the connectors for recharging it were old and of a format that isn't used any more. There was no way of recharging the battery backup and so the pumps eventually failed.

It's one of those problems where there are literally a million things that could go wrong and since the emergency system is not used normally, it's easy to overlook a critical problem.

So I agree with you. Fukushima was not a design error -- or at least not a design error that could have been reasonably fixed at the time that the reactor was originally designed. It was an error in maintenance. Obviously better to have a design where loss of power doesn't cause a melt down, but I don't think that these were available when Fukushima was built. CANDU reactors existed at that time, but I think they were still considered experimental. Pickering came online in 1971, so basically at the same time as Fukushima. I'm not familiar with other passive designs, so possibly someone else can make an observation.

But basically, as far as I can tell, Fukushima was a reasonably normal nuclear power plant for the time it was designed. The Air Max seems to have suffered from problems because of design decisions that are not considered normal.

[firethief]

> since the emergency system is not used normally, it's easy to overlook a critical problem.

This is a such an important antipattern when robustness is a goal.

[mikekchar]

Totally agree. Done it myself more times than I care to admit. One small quibble, if I may. Originally "antipattern" used to mean something that looks like a good design pattern, but will actually bite you in the end if you used it as intended. This is not so much an anti-pattern as it is an unfortunate reality (you have to maintain compatibility with external interfaces for the length of the project). How much bit rot have I seen in my career?

[firethief]

I was thinking of set-it-and-forget-it backup systems as the antipattern, as opposed to e.g. designs that regularly force the "backup" system into active use under controlled circumstances. The battery connector represents sort of a backup of the backup though, so it may not be a good example of what I was thinking of.