Shipping to go nuclear on climate change

Shipowners are facing difficult choices when deciding on their future newbuild strategy. Committing to a zero-carbon fuel today comes with the very real risk that the future bunkering infrastructure might not be properly developed where the vessel will trade. But what if you could build a vessel that doesn’t need to refuel for 25 years and could still sail at a higher service speed than normal despite more stringent emission requirements?

This could become a reality – a new type of nuclear-powered vessel is on the horizon, using the Molten Salt Reactor (MSR).

Experts on the nuclear option: Q&A

For generations, nuclear power has produced reliable electric power around the world but has also attracted bad press regarding concerns on safety and nuclear waste handling. To find out more about the safety and sustainability of MSR technology, we spoke to Mikal Bøe (M), CEO of Core Power UK Ltd and Edmund Hughes PhD (E) of Green Marine Associates, previously a member of the IMO Secretariat before setting up an independent consultancy that focuses on the decarbonisation of shipping.

Describe to us the nuclear-powered vessel of the future

M: It’s very important to recognise that the choice of advanced nuclear technology for sustainable shipping must meet key suitability criteria specific to our industry:

• a fuel-for-life reactor system, locks the fuel in the reactor, avoids refuelling and hence handling spent fuels in ports.
• a reactor system that remains safe in the event of an accident at sea; essentially a system we can rely on to passively shut down in the event of a collision, grounding, explosion or even a sinking without polluting the environment.
• a system that is simple and small enough to mass manufacture so that we can get the highest quality assurance in construction and the fastest incremental innovation cycle at the lowest cost.

MSR technology meets these criteria and allows for a new way to harness nuclear power. It’s the most efficient and compact advanced reactor system conceived. It consumes less than a gram of fuel to produce 24 Megawatt-hours (MWh) of 100% clean energy. This means a Capesize bulk carrier would use less than 200 kg of fuel in 25 years, with zero emissions and making little waste.

The big question: is nuclear powered shipping safe?

M: Safety is always the priority, and the passive safety features of the MSR is exactly why it is so suited to maritime applications.

We believe the MSR is a perfect civilian-grade technology that neither threatens the tactical superiority of a nuclear navy, nor poses a threat to the peace and stability of port states. Those handling export control and licensing should be made aware and confident that civilian nuclear propulsion is proposed for all the right reasons.

We will ensure that every reactor is built to the highest standards, is carefully controlled, monitored, and managed by vetted, qualified personnel. It will only be installed on floating assets which are flagged in appropriate jurisdictions.

What are the benefits of MSR technology?

M: Ships fitted with MSR technology will be faster than conventionally powered vessels, have a superior range, and potentially carry more cargo. They will not have to stop to re-fuel, they will not be subject to carbon prices and could possibly provide electric power to the ports they call.

Consider a Capesize bulk carrier, carrying ore cargoes for 25 years on a single fuel load. That’s 2.7 million nautical miles without a fuel stop. A few knots faster, a few percent more cargo, power in port to decarbonise terminals, and no carbon tax. That’s competitive. It would be a similar story for other types of vessel; car carriers shipping EVs, tankers and cruise ships for example.

Is the infrastructure in place for nuclear powered vessels?

M: MSR technology is not yet ready to be deployed. We should have sustainable, emission-free energy to meet IMO targets and the MSR will be a part of that but takes time to industrialise the ecosystem around the technology.

The necessary processes to test, legislate and approve marine MSRs will also take time. With administrations, such as the United Kingdom, proactively including nuclear powered ships in their future for the industry, we now know that it’s possible to see advanced atomic ships sooner than we once thought.

What is the economic case for nuclear?

E: As the marine MSR provides the very real prospect of ships not needing to be re-fuelled, the cost of energy to power the vessel is fixed for its commercial life. That’s great for long term contracts of affreightment (COAs) and charters.

The vessel would not be subject to the same restrictions on power or speed as those future ships using alternative fuels that have lower energy density than current hydrocarbon fuels. As such the economic case for ships powered by small modular reactors such as the marine MSR could disrupt the shipping market and provide significant competitive advantages for their owners.

M: Diesel engines are cheap but maintenance and fuel over the lifetime of the ship is expensive. On VLSFO, the total propulsion costs, including CAPEX and OPEX, of a very large container ship can be more than $1.4 billion over a 30-year period sailing at full service-speed. The marine MSRs is fuelled for life so is more expensive up front, but OPEX over the lifetime of the ship is very low. A 20,000 TEU containership would be as much as 50% cheaper to run on full service-speed with a marine MSR.

When carbon taxes for fossil fuels are introduced, either through carbon trading systems or a global levy, the economic case for MSR technology becomes even greater.

Will states allow nuclear powered ships to call at their ports?

M: Nuclear is a political hot potato but things are changing. To date, the nuclear industry has been poor at communicating to stakeholders. This led to an anti-nuclear voice dominating media and public discussions.

Nuclear power and nuclear weapons are completely different things. Reactors cannot explode, it’s against the laws of nature for that to happen. Weapons of course, are designed for that purpose.

The stigma attached to conventional nuclear technologies designed over 70 years ago are still in place today. But the old technology is very different from the MSR. If you install a conventional naval pressurised water reactor (PWR) in a merchant vessel and use civilian reactor grade fuel, refuelling would be required every couple of years. This would inevitably mean handling spent fuel in ports, which is unacceptable, as every country with a port would have to be a nuclear nation This would be putting the cart before the horse.

What we have with the MSR is a technology that changes that narrative, allows for a more widespread and distributed use of benevolent advanced nuclear in a maritime setting, and since it is so efficient, we can avoid the need for refuelling.

That means the ship provides the benefit of 100% clean power in port and then departs leaving no environmental footprint.

How popular do you expect this option will be?

E: Advanced nuclear power is best suited to the energy demands of the largest, ocean-going ships. The Fourth IMO GHG Study (2020) identifies over 12,500 ships (container, tanker, bulk carrier, cruise, reefer) where the case could be made for using nuclear power. If 20% of these were nuclear it would be a reasonable target.

M: At CORE POWER, we are currently looking at 7,300 of the world’s largest ships as being the target market for MSR technology as these account for close to 50% of all airborne emissions from our industry. By 2040 we expect to be manufacturing between 400 and 500 MSRs a year. So, by 2050 it is very possible we will be supplying thousands of these workhorse reactors to power the largest ships in our industry. If we expand that to the 12,500 largest ships, we’re effectively cutting 70% of all airborne emissions from ocean transportation, which would be transformational to the shipping and wider industries.

What risks have been identified and how can they be addressed?

E: Most of the disadvantages associated with nuclear propulsion using conventional PWR systems are removed with a marine MSR. There is no need for high pressure design specification which is much cheaper; no refuelling which reduces the risk, and of course, miniscule waste means a sustainable solution.

As such, in future the risks could be:

• Economic risk (capital cost) if shipping experiences a downturn and struggles to pay for new ships. This can be addressed through applying different cost models including leasing from reactor owner/payment for units of energy provided by reactor.
• Political risk in countries where the fear of old-nuclear still prevails. This can be addressed through international dialogue highlighting the advantages of deploying advanced nuclear technologies, as opposed to conventional nuclear especially in the context of the climate emergency.

What about nuclear waste and radioactivity?

M: Waste disposal matters. But let’s first consider the waste produced by today’s fleet.  A 20,000 TEU container vessel will typically consume 1.5 million tons of fossil fuel bunkers, corresponding to 4.8 million tons of emitted CO₂ in 30 years of service, straight into the air. Add other pollutants such as SOx, NOx and particulate matter to that, then multiply it by the number of vessels and the scale of the problem is clear to see.

Nuclear waste is seen as something different, and it is. Nuclear waste is a combination of spent fuel and unused fuel from a reactor. The unused fuel is harmless, and the spent fuel is radioactive. However, both are metals, and the Western nuclear industry is very good at managing metals. It doesn’t dissipate in air, or leak into the ground.

In an MSR the fuel is liquid so it can’t melt down. There is no water, which can form hydrogen, which is explosive, and there is no pressure which can release toxins from the reactor core. A radioactive leak which is carried by the wind, like at Fukushima is therefore impossible.

Radioactivity is not like smoke, but a ‘force field’; the further away from it you are, or the more it is shielded, the effects are reduced. It’s like the sun, which is purely radioactive and sunshine here on Earth is a huge ocean of low-level radioactivity in which we bathe in every day. We are safe because the dose is low, and we are so far away.  It’s the same with reactors. No one has died or been harmed by radioactivity from a reactor since 1986, whilst 8 million people die every year of airborne pollution from fossil fuels. We must get real about this, and fast.

How much waste is generated and what do you do with it?

M: The MSR is so fuel efficient that it leaves very little waste. A Capesize bulker would use less than 200 kg of actual fuel in 25 years of service, and that spent fuel would be the total quantity of waste at the end. The rest of the unused fuel remains in the MSR and continues to be used in the next generation of reactors. We recycle and reuse, just like we should. This is sustainability defined.

The MSR does not need to dispose of unused fuel. The 200 kg of spent fuel is a radioactive metal which is heavy and would fit in the size of a shoebox. The shoebox is placed in a dry cask made of strong shielding material, so no radioactivity is measured outside. Most of that radioactivity is gone in just 20 years.

Because the spent nuclear fuel has quite a short half-life (the time it takes for the matter to lose 50% of its radioactivity), that small cask would have to be stored for about 300 years before final disposal. Compare that to CO2 which we release into the air, and which will be with us for up to 120,000 years before being fully absorbed by nature. Again, we must compare like for like here.

Is current international safety legislation ready for nuclear powered shipping?

E: SOLAS Chapter VIII was developed and adopted over 40 years ago and very much reflects the management of risks associated with nuclear technology of the day, i.e., PWR technology.

Whilst this technology remains valid – it continues to be deployed primarily in military or specialist applications such as icebreakers. Take-up has been limited due to economic (capital cost too high compared to conventionally powered ships), political considerations (ability of nuclear-powered ships to trade globally), and proliferation (risk of fissile materials presenting a security threat).

The regulatory framework including IMO Resolution A.491(XII) Code of Safety for Nuclear Merchant Ships needs to be revised to ensure that the risks of advanced nuclear technologies are appropriately and proportionately mitigated.

Lloyd’s Register (LR) in October 2010 drafted new Provisional Rules for the Nuclear Propulsion of Merchant Ships that identify updated design goals, design principles and design details. Reviewing and updating these draft rules is now a priority and LR are working to provide additional insight into the management of risks so that new class notations can be ready before 2024.  The biggest risk remains doing nothing, as it would create a barrier to the deployment of these advanced nuclear technologies.

What about crew training and qualifications?

M: Crew working on ships powered by advanced nuclear technology will need to be able to operate the nuclear electric systems on board in all conditions. They must be relied upon to diligently perform their duties and always keep the ship and cargo safe. This is nothing new though, we already train specialist crews for gas carriers for example, though the training here will be different.

MSR powered ships will be electric. They will not be fitted with engines with moving parts which require constant maintenance and active operation. Therefore, the engineering teams on MSR powered ships will have fewer things to do, as they will not have to operate the MSR.

We expect a small group of highly trained specialists to remain on board, mostly assigned to control room duties. But as the passive fail-safes of an MSR leaves little need for operator engagement, the rest of the onboard engineering team will focus on the turbines, electric distribution systems and the electric motors and batteries.

We are in the early stages of designing dedicated training facilities and certification programs for MSR operators and other stakeholders. This will take shape over the next 4-5 years. We are working closely with ship management companies, coastguards, and universities to help design these programs.

It may be that MSR engineers are provided by the manufacturers, like arrangements in the airline industry.

E: Training of crew will be critical and is already identified in the Nuclear Code (IMO resolution A.491(XII)) and supplements the requirements of SOLAS chapter VIII to provide a technical and regulatory reference for nuclear merchant ships. But we expect that the crew will not need to interact with the reactor itself, which might be in a compartment separate to the other onboard propulsion systems and auxiliaries. Also, the monitoring of the reactor could be undertaken remotely and/or a specialist rider crew.

Explainer: The Molten Salt Reactor

Nuclear science is of course a very specialised subject. But in simple terms, MSRs operate on the same principle as a current nuclear power reactor, using controlled fission (the splitting of a large atom into smaller atoms to release energy). The heat generated by fission produces steam which drives electricity-generating turbines.

But there is a key difference with the MSR: molten salt is used in the reactor core, which acts as both a fuel and a coolant. This is in contrast with current operating reactors which use solid fuel rods and require a highly pressurised water coolant system.

This means the MSR generates less waste, can operate at higher temperatures, which leads to increased efficiencies, and at low operating pressures, which can reduce the risk of coolant loss. Therefore, the MSR is considered safer than current reactor technology and more suited to a maritime application.

Find out more

• Visit North’s Navigating Decarbonisation website at https://www.nepia.com/topics/navigating-decarbonisation/
• Article – https://inl.gov/article/southern-company-signs-agreement-with-u-s-department-of-energy-to-demonstrate-worlds-first-fast-spectrum-salt-reactor-in-collaboration-with-terrapower-idaho-national-laboratory/  
• Core Power – https://corepower.energy/
• Green Marine Associates Ltd – Click Here