Although new nuclear power plants are now being proposed, their design are advanced versions of the existing light water reactors in the United States.
However, liquid metal cooled fast breeder reactors may be a much better choice.
Check out these web sites
Wikipedia-Integral Fast Reactor
Argonne National Labs-History
I actually took a tour of a fast breeder, liquid metal cooled nuclear reactor run by Argonne National Labs back in the late 80's and early 90's. It was incredible technology.
+ Can be built in relatively small sizes
+ Needs fuel brought into the site about once every 70 years (rather than every 18 months)
+ Fuel rods can be replaced without shutting reactor down
+ Fuel rods can be reprocess on site
+ If all cooling is lost at the same time, the reactor just shuts itself down.
Reason? Primary and secondary cooling is from liquid sodium which has a much higher
heat capacity and boiling point than water. Also, the fuel rods are made from a metallic
form of Plutonium rather than an oxide form of uranium. So, when cooling is removed and
the reaction heats up, the metal fuel rods expand until the nuclei get to far apart to sustain
the chain reaction and the reaction shuts down. This shutdown occurs at a temperature
well below the boiling point of the liquid sodium.
+ Since the fuel rods can be reprocessed on site, the long half life waste can simply be put
back into the reactor and bombarded until they are destroyed.
+ Although waste is generated, it is a much lower volume, less radioactive and takes far less
time to decay to safe levels than the waste from current reactors.
The fear, mainly from the press, concerning breeder reactors is that they produce more fuel than they consume. These days, that sounds like a great feature. However, it is not true. The fuel is Plutonium (yes security has to be higher since this is the fuel of atomic bombs, but if anyone comes in contact with it directly, they will die in minutes). The Plutonium is surrounded by a jacket of uranium. As the Plutonium decays creating heat to drive the reactor, it also bombards the uranium converting some of it to Plutonium. This process is where the term "breeder" reactor comes from. Obviously, with the right amount of uranium, more fuel can be produced than that reactor needs and this fuel can be used for other reactors. If additional fuel is not needed, than the jacket just contains less uranium.
When I asked why we were not building these smaller, safer reactors, I was told that they were researchers, not marketers. Also, off the record I was told that General Electric was a partner and preferred to push their advanced light water reactor technology than deal with the media, the politicians and environmentalists citing the need to fear breeder reactors.
Thanks to President Carter, reprocessing of fuel rods is not allowed in the U.S. Neither is shipping them. So, believe it or not, all the spent rods are still being stored at each reactor site (no waste dump is available in the U.S. since Yucca Mountain is still not approved and built).
Thanks to President Clinton, the Argonne National Labs program on the liquid metal cooled breeder reactor was terminated.