Tuesday, May 20, 2008

Westinghouse AP1000 Site Evaluation - 3

The American Way

The US has it easy for site evaluations. They have something called early site permits, and it all hinges on the USNRC blessing of registered designs. All the site owner has to do, is produce this diagram:

Plus a whole book on landslides, volcanoes, etc.

This diagram is a ground response spectrum. The upper line is the 30%g curve, to which the new designs have been certified. As long as you produce a line that is below this, you can plonk any old nuclear plant you want on your site. Certainly, an AP1000!

The US has always been quite different from Canada in the nuclear regulation department. In fact, I've been living with Canadian regulation all my life! In the US, everything is precisely written into a zillion regulations with yes/no answers. Line up all the ducks in a row, and you get your license. Thus, it is ingrained in law that if you get your curve below the standard design, then you get your license, no matter what!

We don't have that here. In fact, it's usually an endless talk-shop with some result at the end. In the days when we were competent, it always ended up as a contest of wills. We would just choose something, and dared the board to pull the plug on the whole thing! In other words, we just soldiered on, doing the right thing, and dragged the regulators with us.

Not so, now. They are always trying to get some pre-approval from the CNSC, which is like pulling teeth! The CNSC has not pre-approved any designs, and has not stamped a response spectrum on them. There is no methodology of taking an existing design and plonking it at Darlington. I tried to get worked out at the CSA meetings, but failed miserably.

Anyway, we look next at how this response spectrum thing is completely wrong scientifically, and how all the earthquake scientists run away from it screaming. It's only the grisly old engineers who stick to this 30-year-old methodology.

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