[724doorE]

Ron, there is probably not one good answer to that one. Nuc plants probably use neat stuff like inconel, monel, and nickel based alloys for a number of reasons. While chemistry in a conventional plant is important, it is doublly important in a nuc plant as are corrosion products. Not only is there the idea of corrosion, but there is stress invoved as well due to the pressure of the fluids on the tubes. Add to that thermal cycles due to operations, and it all leads to stress corrosion cracking. It also leads to crud buildup and that crud can become radioactive. The fluid can be cleaned by use of resen ion exchangers, but the crud particles can't. So the less crud all the better. That means minimize corrosion, which means use the best materials for the most likely corrosion and strength considerations, and of course the need for strict chemistry to minimize corrosive conditions. Oh and remember one thing, Civilian nuc plants are driven by the almighty dollar, TMI didn't happen because nuc power is bad, it happend becuase repetitive safety measures were over-ridden and not understood buy certain operators at the wrong time. Bad, bad luck. Navy plants simply can not afford to sustain a reactor casualty, it wouldn't be an acceptable risk politically. Systems are triple redundant, procedures are strictly adhered to, and cost is not as much an object. Never say never, but highly less likely is a safe bet.

Oh and before someone makes some comment about R-waste....what about the many strip mines that litter our world that will never be fixed due to coal excavation. Come on, it takes at least two 125 car coal trains aday to keep a conventionl plant up and each one of those cars carries 100 tons or more of coal! A reactor runs off of one fuel load for years. I'd gladly trade miles of hole in the earth from coal digging for a few cans of waste products that can be properly dealt with. The problem is people belive that they aren't true or not.. my .02