The horrible case of Candu feeders - I

This is a very long story, horribly painful for me to write, but I shall go at it in stabs.

When I was going through school, my talent was in standard Newtonian physics. I would score the highest marks, when it came to dynamics, fluid flow, stress, etc. That quantum stuff did not impress me much -- spin of electrons -- quantum tunneling -- blah!

I especially liked to use fundamental physics to solve dynamics problems, using finite differences, and the physical laws at tiny time steps. I did all sorts of stuff with that!

When I first joined the big company, I could use all this talent, since we were doing big, high-energy things. I could also use logical thinking, to make things work. But as things went on, we weren't doing much anymore, except wash the floors. Logical thinking and hard-core physics had a long snooze.

When we were building, a lot of good thinking went into the seismic design of the structures and systems. Unfortunately, the scientific thought was 'frozen' at the time of construction, and never touched again. Which is too bad, since I'm told that science has changed a bit in 30 years. :)

All those earthquake assumptions from 30 years ago, have now been shown to be bad (good enough at the time!). We actually knew at the time, that we didn't know much, so a heck of a lot of extras (conservatism) went into the construction. That usually meant we doubled the thickness of the concrete, steel, pipes, etc.

Frozen, 30-year-old assumptions, and 30 year old seismic analysis techniques, now take a big toll. For the feeders, it could mean something like an extra billion dollars (minimum!) in unnecessary costs.

(to be continued)