The merchant shipping industry is hoping to go nuclear.
Despite the reactor disaster at the Fukushima power station in Japan last year and the fallout that blanketed the nuclear sector, the cargo ships and tankers of the future could one day be powered by atomic energy.
Last month, in the German port city of Hamburg, delegates at a conference on marine propulsion discussed the progress being made to design and build a new generation of merchant ships to be powered by onboard nuclear reactors.
The current research focus is on power plants for liquefied natural gas (LNG) carriers and oil tankers - huge ships common in the waters of the Gulf. But that is not all as the shipping industry believes there is equal scope for container ships and bulk carriers to be fuelled by atomic energy. But they will not be cheap.
"The purchase price of the nuclear propelled ship would be considerably greater than that of an equivalent conventional ship," says John Carlton, a professor of marine engineering at the City University London, one of the keynote speakers at the forthcoming Hamburg conference.
However, for the conventionally propelled ship, the through-life fuel costs are high and are likely to rise further, especially with any introduction of carbon tax.
In contrast, the price of uranium enriched to commercial levels is much cheaper than conventional fuels. Therefore, the fuel costs become very much less for the nuclear ship.
The Russians already have two nuclear powered ice breakers-cum-cruise ships and a freighter plying their Arctic waters.
The marine engine manufacturers Babcock, and the international ship classification society Lloyd's Register, are already far advanced in research and development work and despite the technical and political hurdles they face, both believe the age of the nuclear-powered merchant ship will soon be with us.
The main drivers are the rising cost of traditional fuel, and the coming tranche of emissions regulations aimed at limiting the world's merchant fleet's power to pollute. And those are big problems, says Prof Carlton.
The world merchant fleet has an installed power capacity of 410 million kW; that is 9 per cent of world electricity generating capacity. It costs a lot to power that using fossil fuels, and it generates a lot of greenhouse gases in the process. "Also, it is clear that there is a perception that CO2 and greenhouse gases present a significant threat for the future. [In that context] there is growing acceptance that the use of nuclear power for ship propulsion is beneficial," says Prof Carlton.
"Some countries are suggesting that serious consideration should be given to nuclear propulsion for merchant ships. In a recently produced UK government memorandum detailing options for decarbonising Britain by 2050, the section on international shipping suggests 'building and maintaining a new fleet of nuclear-powered container ships and passenger ships.'"
Lloyd's Register is leading a consortium made up of the Greek tanker operator Enterprises Shipping and Trading, the US engine designer Hyperion Power Generation and the British naval architect BMT Nigel Gee, to examine the marine applications for small modular reactors (SMRs) in tankers. "Changes in oil regulation are driving the shipping industry's move to nuclear power," says Vince Jenkins, a Lloyd's Register global marine risk advisor.
"By 2020, ships will have to switch from today's heavy fuel oil to distillate fuels to reduce NOx [nitrogen oxide] and SOx [sulphur Oxide] greenhouse gases, which will be expensive. Unlike other low-carbon forms of energy, only nuclear power would be powerful enough to be able to completely replace a diesel engine."
Babcock International Group Marine Division has already completed a study to investigate the commercial implications of developing a nuclear-powered LNG carrier, based on its work as the support contractor for the Royal Navy's nuclear submarine fleet.
"The study was undertaken to determine the commercial feasibility of utilising nuclear power for the main propulsion and auxiliary power generation on board an LNG carrier," says David Dobson, Babcock's integrated technology commercial projects director.
"The company believes that a number of benefits could be realised by the use of nuclear powered vessels for LNG. Low emissions is one of these, as the nuclear plant would eliminate CO2, NOx and SOx emissions.
"Additionally, the vessel's large power-generation requirements would be supplied by a relatively compact power source compared to normal power methods for this vessel type - a space saving that would maximise cargo capacity," he says.
"Further benefits would include the significant reduction in noise generation, reducing the environmental impact of the vessel."
However, all experts agree safety and public perception will play major roles in deciding the future of this technology. As for the former, the UN International Maritime Organisation (IMO) adopted a code of safety for nuclear merchant ships, Resolution A.491(XII), in 1981, which is still extant and could be updated. Also Lloyd's Register has maintained a set of provisional rules for nuclear-propelled merchant ships, which it has recently completely revised. Public opinion is a different matter. Both Mr Dobson and Mr Jenkins agree it could be partly assuaged by initially using nuclear powered ships on set routes avoiding enclosed waters, such as from Los Angeles to Shanghai.
Lloyd's Register is also looking a design concepts that could place the power plant separately from the cargo-carrying hull, enabling the ship to be split while still offshore allowing the non-nuclear cargo section to detach and go into port.
"The role of the land-based nuclear regulator and the views of the flag and port state controls will be critical for the successful implementation of marine nuclear propulsion," Prof Carlton says.
"Mutual acceptance of certification between different countries will become the key to nuclear ship operation and voyage planning."