The Navy is pushing ahead with a five-year, $163 million dollar plan make megawatt free electron lasers. So by the end of 2012 or the beginning of 2013, the goal is to have a new megawatt laser prototype.
Previous megawatt lasers like the Tactical High Energy Laser (THEL)required hundreds of gallons of toxic chemicals for each shot. So a “mobile system” was eight cargo containers in size.
Superconducting engines are 1/3 of the weight (69 tons instead of 200 tons) and half the size of conventional engines and are up to 10% more fuel efficient at low speed A typical destroyer has 200,000 gallons of fuel (300 gallons per ton is 6700 tons of fuel).
Existing nuclear powered submarines tend to have one or two reactors in the 190MW range. The nuclear reactors for naval ships range in size up to 550MW. A nuclear aircraft carrier can have eight of the 190MW reactors.
Naval reactors are pressurized water, liquid-metal-cooled, or boiling water types, which differ from commercial reactors producing electricity in that:
Naval reactors have a high power density in a small volume; some run on low-enriched uranium (requiring frequent refuelings), others run on highly enriched uranium (>20% U-235, varying from over 96% in U.S. submarines (They do not need to be refueled as often and are quieter in operation from smaller core) to between 30–40% in Russian submarines to lower levels in some others), the fuel is not UO2 (Uranium Oxide) but a metal-zirconium alloy (circa 15% U with 93% enrichment, or more U with lower enrichment), the design enables a compact pressure vessel while maintaining safety.
If this is to scale then the reactor and engine take up half the nuclear submarines volume. With the reactor within a 33 foot hull diameter and about 25 feet long for about 25,000 cubic feet of volume.
Here is a site with a lot of details on naval nuclear reactors.
The navy nuclear reactors are about 1100 to 2250 tons.
Nuclear batteries (Uraniam hydride reactors) could also be developed by 2012 and could offer smaller power sources for powering Megawatt lasers or new railguns. A nuclear power source would lighter be than an fossil fuel engine and fuel. The uranium hydride or other liquid core reactors would be smaller than current reactors.
Hellbores are measured in megatons/second.
1 megaton is equal to 4.183 X 10**15 joules One watt is one joule/second.