shiv wrote:I wonder if, in ships, the entire ship moves with the wave and shear forces acting on individual reactor components are minimized. Would that be an additional reason for earth based reactors to be more vulnerable?
Yes, the ship behaves as one structure and hence individual components are not vibrating out of sync. The analogy is like this. Assuming that you put scatter different stuff on a bed sheet and stick it to the sheet (some papers, rocks, a stone ) and two people hold each end and give it a flutter, each piece will do a crazy jig by itself and do funny things. That is the ground based reactor in an earth quake.
Now put that in a stiff steel sheet and pitch it up and down and roll it sideways, yaw it and do all sorts of stuff, the individual pieces are largely in sync with each other and dont do random things relative to each other. That is the stuff on a ship.
Notice however, that no structure is infinitely stiff and a ship too bends and flexes under it's own weight and the action of the waves, but the stuff like piping electrical connections etc are designed for that kind of motion, which anyways are rather small.
Even planes. For eg, the Concorde underwent so much aero thermic heating that it expanded by nearly a couple of dozen inches in flight and the first set of carpets on the floor were ripped apart because it was one single piece thing!
In fact the idea sounds good. Why not place all nuclear reactors on ships and float them in an artificial lake inland?
The key single point of failure is the active cooling systems and the need for a large heat sink. The way I think is to have a fully hermetically sealed reactor of the ruggedized navy type that is installed a bit off the coast in underwater some 20 to 30 meter deep water in a floating/semi submersible offshore platform or better still tethered to the bottom. Those kind of things can take any kind of pounding under any weather, esp the fully underwater ones will be totally unaffected. Now you are in direct contact with the ultimate heat sink, the ocean, no need for any Paki like pumps for cooling , you can do cooling of the core convection of primary coolant , which in turn can transfer heat to the sea water directly . You eliminate mutiple points of failure that way in a fail safe mode and in the unlikely event of something going really wrong, your Musharraf is well covered because the infinite cooling available will prevent any meltdown. Not sure if such a thing is workable on land.. Maybe in the Great Lakes in Unkil land, but definitely wouldn't pull that stunt in Ulsoor lake in Bangalore Kerala.
So even in a worst case scenario, the thing sinks to the ocean bottom, it will be perfectly fine and stable until kingdom come.No chance of any explosion due to meltdown or anything.
Atleast land acquisition wont be a problem. Out of sight, out of mind. Somehow I dont see the Mr & Mrs Karat and Mr Yechury getting on to a catamaran and picketing something some 1km out into the sea. It will draw a huge collective yawn.
I do think engineering wise, the Nuke establishment need to rethink their strategies on the entire thing. Too much dependence on all the ducks lining up all the time has been the problem. And if one duck doesn't line up and acts Paki, there is serious trouble. They need to miniaturize (easily doable as the ship board plants show), increase ruggedness, have fail safe methods in engineering based on passive designs with no or very few points of failure which are very well addressed in the design.
Sure, you could ask, but then you cant have a nuke plant away from the coast! Maybe you shouldn't! In fact, think of it. The Russian method of disposing off their Naval Nuke reactors is to encase it in lead and concrete and dunk it into the deepest ocean close by! There you are ,it gets cooled perpetually, no need for any more Pakiness, concrete hardens with cooling as time goes by, everything safely, nothing corrodes over time , no radioactivity escapes, all Piss and Plogress onree.
Think of this. If this Fukushima plant had been a barge mounted one, anchored some 500m off the shore, there would have been absolutely NO effect of either the earthquake or the Tsunami!The long wavelengh Tsunami waves rise and crest only when they encounter a shoreline. In open water, you will simply not even notice it! As for earthquakes, you have an earthquake only every 5 mins in Japan. In sea, you have an "earthquake" by wave motion every second!