FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

Obviously this is not a great example, but with limited resources they will obviously need to divide them appropriately.

They can't do an in-depth forensic analysis of everything without unlimited money.

Despite the 737 Max fiasco, airplanes today are far safer than ever before. Since 1970, annual deaths have been cut by >80%, while air traffic has increased by a factor of 10.

Cars have seen similar improvements. So have food hygiene, workplace safety, and most any measurable safety record I can think of.

Boeing seems to have a safety culture issue. Which is a lot worse than one dodgy plane...

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.

Yeah, this is something that I think doesn't really resonate with people well. The reactor site is 25 meters above sea level. I'm not exactly sure how high the generators were, but they were well above the level that experts thought was safe at the time. The earthquake was a 1 in 1000 year event and so there was no data on record to help them model the resultant tsunami. In the years following the tsunami, the way people modelled waves radically changed based on the new data.

There are a couple of caveats. First, there were markers saying that an historic tsunami had come in much higher than models would have predicted. However, the are very old. It's just a rock stuck in the ground with some writing on it. Stuff like that is all over Japan (there are lots of markers around where I live -- I don't think anybody pays any attention to them at all. Probably we should, but usually they just mark boring stuff ;-) ). It's like seeing a roman road marker in Europe. Interesting, but not really note worthy. It's only after the tsunami that people saw the markers and said, "Holy cow. There's a marker here showing that a tsunami came up this far". Even then it's a far cry from seeing that to saying that we need to invalidate all our wave building models.

Secondly, I think there is some evidence that in a few years preceding the tsunami that researchers were getting worried that their wave models were not correct. I think it's even the case that nuclear plant companies were aware of this. When I first moved to Japan in 2007, there used to be a section of the Meteorological Agency of Japan that showed, among other things, a map of the farthest in a tsunami would theoretically go for all parts of Japan. It also listed maximum wave size for every single place along the coast. It noted places where sea walls were not high enough and estimated worst case damages and numbers of casualties. Around about 2009 it disappeared. I tried to find out where it went and the response I got was that it needed to be updated and that it would return at some point in the future. Of course, it never came back. At the same time, I've heard that literally a few years before the Tohoku earthquake that there was serious debate about whether or not the wave models were correct. However, I think it's pretty clear that in 1967 when they started construction at Fukushima they had absolutely no idea that they were building in a potentially unsafe area.

It really sucks and I think it's fair to say that as humans we probably have too much hubris when it comes to our science. That fact that you have no reasonable way of knowing that you are making a mistake doesn't mitigate the problems that result from that mistake.