Unlike conventional ships that rely on fossil fuels, nuclear powered merchant ships, which can operate for long periods without refueling, have the potential to reduce operating costs and increase efficiency. Given today’s climate change and global warming, and considering that these ships will play an important role in decarbonisation, these ships could save our world.
As a matter of fact, this is not something that was not thought of or done. The USA, Japan, Germany and Russia have tried this in the past. However, this technology, which also faces many technical, economic and regulatory challenges, has unfortunately been interrupted. Despite this, promising studies are currently being carried out in this regard. Let’s first dive into the history of the use of nuclear power in cargo ships, then let’s take a look at what kind of work is being done right now.
Nuclear powered commercial ships date back to the 1950s.
The first nuclear-powered commercial ship was the “NS Savannah”, built in the late 1950s at a cost of $46.9 million and launched in 1959. It was a demonstration project funded by US government agencies that aimed to showcase the potential use of nuclear propulsion in transporting cargo and passengers. The ship’s name derives from the SS Savannah, the first steamship to cross the Atlantic Ocean.
NS Savannah had a single 74 MW Babcock & Wilcox nuclear reactor powering two steam turbines and a single propeller, had a maximum speed of 21 knots and had a range of 300,000 nautical miles on a single fuel load. With a capacity of 60 passengers and 14,040 tons of cargo, the ship served between 1962 and 1972, visited 45 ports in 20 countries and covered more than 450,000 nautical miles.
NS Savannah was decommissioned in 1971 due to the nuclear waste it dumped into the sea, the inability to control the radioactivity and the high maintenance costs. It is currently on display as a museum in Baltimore, Maryland, USA.
NS Savannah was not the only example, after which three different countries ventured into the nuclear-powered cargo ship business.
Nuclear powered commercial vessels outside of Savannah; They were “Otto Hahn” (Germany), “Mutsu” (Japan) and “Sevmorput” (Russia). Otto Hahn was launched in 1968 and carried ore and oil between Europe, South America and Africa until 1979. It was converted to a fossil fuel system in 1980 and was scrapped in 2009.
Mutsu was launched in 1974 and operated mostly for research purposes until 1992. Decommissioned in 1995, the ship was converted to a conventional powered research vessel in 1997. Launched in 1988, Sevmorput is the only nuclear powered cargo ship still active. The ship operates as an icebreaker cargo ship for the Russian Arctic region.
development of nuclear merchant ships; To date, it has faced many challenges, including high construction and operating costs, safety and security concerns, public opposition, environmental issues and regulatory hurdles. It could be used much more successfully for warships, especially submarines and aircraft carriers, where the advantages of nuclear propulsion, long endurance and high speed outweigh the costs and risks.
But the use of nuclear power on commercial ships is making a comeback.
Some shipping companies and researchers are trying to reinvigorate the idea of nuclear-powered merchant ships, especially in light of increasing pressures to decarbonize the shipping industry.
For example, a consortium of European companies called SMR-Sea is developing a concept for a modular small nuclear reactor that can be installed on existing ships or newly built ships. Another project, led by a Finnish company called Fennovoima, is investigating the feasibility of using small modular reactors to power icebreakers and other Arctic ships.
These projects aim to overcome the difficulties experienced by previous nuclear powered merchant ships by using smaller, safer and more cost-effective reactors.
Various South Korean maritime businesses and other organizations, including HMM, signed a cooperation agreement in February. As part of the cooperation, they want to create a merchant ship that works with small modular nuclear reactors, but they have not commented as they are still very early in the work.
Another initiative called NuProShip (Nuclear Propulsion of Merchant Ships) started in Norway. According to project manager Jan Emblemsvg of the Norwegian University of Science and Technology, the group behind the initiative has shortlisted six potential reactor designs that could function on a group of merchant ships, and their progress has been pretty good. In fact, Norway has a goal of running the natural gas tanker Cadiz Knutsen on nuclear power.
These last two groups we mentioned are planning to use molten salt reactors for nuclear power.
In fact, this type of fuel use since the 1960s effectively eliminates reactor meltdowns because the fuel is already molten and ready to discharge to stop a potential leak.
The problem with solid nuclear fuel is that when reactions get out of control, meltdowns can occur, causing the fuel to overheat and melt and risk breaching the reactor enclosure. Although it has been used since the 1960s, the reason why it is still not widespread and not used very actively is due to technical difficulties such as corrosion inside the reactors.
Even if these problems of the reactors are solved, adapting them to commercial cargo ships is also a problem.
A few nuclear power experts argue that large container ships can only be in active operation for 20 years. This means that the nuclear reactors placed inside the ships at such a cost are dismantled again, spending as much resources.
But that’s not insurmountable, Ondir Freire and Delvonei Alves de Andale, researchers at the Brazilian Nuclear and Energy Research Institute, believe that even though developing new reactors for large cargo ships has a high initial cost, switching from fossil fuels to nuclear power will be cost-effective in the long run. For this, they think, small reactors can be developed that can be removed from one ship and installed on another ship or some other type of facility.
There is also a legal dimension to this business, of course, it is a very important issue who will be held responsible for any accident on a nuclear powered ship. A separate regulation should be prepared and legal rules should be determined just for this area: Will the owner, operator, nuclear reactor manufacturer or the flag state, which is the country of registration of the ship, be responsible?
We have been explaining that nuclear reactors will be the energy source in general use in the world in the future and that companies are doing research in this direction. But that won’t happen anytime soon. For example, the earliest screening date set for the first nuclear reactor ship of the NuProShip project, which is one of the examples we gave, is 2035.
See the butterfly effect that SS Savannah initiated?
The Savannah, which was built in the USA in 1818 and was the first steamship to cross the Atlantic, became the ancestor of steamships, although it was scrapped due to its limited cargo capacity. For the next few decades, steamships dominated the seas.
We said that NS Savannah was also named after this ship. So, although it suffered a setback in the 1950s, this ship is seen as a pioneer for building nuclear-powered ships today and in the near future…
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