Tuesday, March 11, 2008

Ontario's Nuclear Choice - AP1000 Geology and Seismic

The 7000 pages of the NRC submission make for an interesting read. Of interest here are the geology and seismic requirements, which closely follow the IAEA guidelines. I don't think the Bruce Caves could pass these specifications.

All of these new plants are designed for a generic 30% g, standard US spectrum. When I was with the CSA nuclear seismic standards, I foresaw these 7000 pages, and wanted the new CSA code dedicated to handling this stuff. Alas, no such luck!

Our problem in Canada is that we never believed in the US standard spectrum, and have no way of formally certifying that a given site is adequate for the design. In the old days, we would determine the seismic parameters, and make a new custom design for those numbers.

The US NRC has declared that 30% g is adequate for most sites in the East, whatever that means. The documentation outlines their method of seismic analysis. They start with the site plan for the nuclear island, since nobody cars about the turbines!
From this, they make a finite element model, which is really just a Lego model of bricks.

Now, this looks very fancy, but then they reduce the whole thing into a single lumpy stick for the actual seismic analysis.

Our seismic site evaluations are different from the US, so now we have to go into this, and compare. As well, they specify a whole suite of geology, and geophysics that we have to do, and we haven't started on that!

Next up will be the Chinese multi-plant layout and how that would fit on the Darlington postage stamp. I just read how the Minister has dismissed Wesleyville, which is one of those decisions with a billion dollar price tag.

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