This is an intriguing idea, and one that I can see becoming critical over the next few decades, or never manifesting – developing a fleet of floating nuclear power plants. One company, Core Power, is working on this technology and plans to have commercially deployable plants by 2035. Company press releases touting their own technology and innovation is hardly an objective and reliable source, but that doesn’t mean the idea does not have merit. So let’s explore the pros and cons.

The first nuclear-powered ship, the USS Nautilus, was deployed in 1955. So in that sense we have had ship-based nuclear reactors operating continuously (collectively, not individually) for the last 70 years. Right now there are about 160 nuclear powered ships in operation, mostly submarines and aircraft carriers. They generally produce several hundred megawatts of electricity, compared to around 1600 for a typical large nuclear reactor. They are, however, in the range of small modular reactors which have been proposed as the next generation of land-based nuclear power. The US has operated nuclear powered ships without incident – a remarkable safety record. There have been a couple of incidents with Soviet ships, but arguably that was a Soviet problem, not an issue with the technology. In any case, that is a very long record of safe and effective operation.

Core Power wants to take this concept and adapt is for commercial energy production. They are designing nuclear power barges – large ships that are designed only to produce nuclear power, so all of their space can be dedicated to this purpose, and they can produce as much electricity as a standard nuclear power plant. They plan on using a Gen IV salt-cooled reactor design, which is inherently safer than older designs and does not require high pressure for operation and cooling.

The potential advantages of this approach are that these nuclear barges can be produced in a centralized manufacturing location, essentially a shipyard, which allows for economies of scale and mass production. They intend to leverage the existing experience and workforce for shipyards to keep costs down and production high. The barges can then be towed to the desired location. Core Power points out that 65% of economic activity occurs in coastal regions, therefore the demand for power there is high, and offshore power could provide some of that demand. Nuclear barges could be towed into port or they could be anchored farther off shore. Maintenance and waste disposal could all be handled centrally. Since there is no site preparation, that is a huge time and cost savings. Further there is no land use, and these barged could be placed relatively close to dense urban centers.

There are potential downsides. The first that comes to mind is that there isn’t a pre-existing connection to the grid. One of the advantages of land-based nuclear is that you can decommission a coal plant and then build a nuclear power plant on the same site and use the same grid connections. This of course is not a deal killer, but it will require new infrastructure. A second issue is safety. While ship-based nuclear has a long and safe history, this would be a new design. Further, a radiation leak in a coastal environment could be disastrous and this would need to be studied. I do think this concept is only viable because of the salt-cooled design, but still it will require extensive safety regulation.

And this relates to another potential problem – the mid-2030s is likely ambitious. While I think we should “warp speed” new nuclear to fight climate change, this unfortunately is not likely to happen. New projects like this can get bogged down in regulation. Safety regulation is, in itself, reasonable, and it will likely be a tough sell to speed up or streamline safety. There is a reasonable compromise between speed and safety, and I can only hope we will get close to this optimal compromise, but history tells a different story.

What about the usual complaint of nuclear waste? This is often the reason given for those who are anti-nuclear. I have discussed this before – waste is actually not that big a problem. The highly radioactive waste is short-lived, and the long half-life nuclear waste is very low level (by definition). We just need to put it somewhere. Right now this is purely a political (mostly NIMBY) problem, not a technology problem.

On balance it seems like this is an idea worth exploring. Given the looming reality of climate change, exploring all options is the best way forward. Also, Core Power plans, as a phase 2, to adapt their technology for a commercial fleet of nuclear powered ships. Ocean shipping produces about 3% of global CO2 emissions, which is not insignificant. If our cargo carriers were mostly nuclear powered that could avoid a lot of CO2 release. They are also not the only company working on this technology. A nuclear cargo ship would have more space for cargo, since it doesn’t need to carry a lot of fuel for itself. It would also be able to operate for years without refueling. This means it can be commercially viable for shipping companies.

Maritime nuclear power may turn out to be an important part of the solution to our greenhouse gas problem. The technology seems viable. The determining factor may simply be how much of a priority do we make it. Given the realities of climate change, I don’t see why we shouldn’t make it a high priority.