[WalterBright]

The costs of the Fukushima and Deepwater Horizon were very, very high. Both could have been averted at trivial expense with simple changes to the design.

Fukushima:

badthink - the seawall is high enough that it will stop tidal waves

goodthink - what happens when the seawall is overtopped? Answer: the backup generators drown. Solution: put the backup generators on a platform.

Deepwater Horizon:

badthink - the pipe is strong enough to never break

goodthink - what happens when there's enough force to bust the pipe off? Answer: the pipe flow cannot be shut off. Solution: put a fuse (a weak spot) above the valve, so when the pipe busts off, it breaks above the valve, and the valve can be turned to shut off the flow. (The valve was located on the sea floor.)

[dghlsakjg]

This is so easy in retrospect when you know what the failure mode will be.

badthink: the Fukushima backup generators must be placed on a platform to keep them out of the range of a once in a millenium tsunami

goodthink: what happens when a typhoon comes and damages the generator on an exposed platform; an event which happens predictably and far more often than tsunamis. Answer: put the backup generators in the basement of a reactor building behind a large seawall. What catastrophe could put the reactor building completely underwater, and still have the reactor survive?

Yeah, trivial changes to the design can prevent all sorts of disasters, but you have to know what you are trying to prevent in a world of infinite complexity

[acyou]

A large seawall to be sure, but not a particularly tall one. If I recall correctly the seawall was remarkably short relative to maximum expected wave heights on a 100 year time frame.