THOR: shipping’s new superhero?

Shipbuilder and designer Ulstein believes it has a concept capable of facilitating a truly sustainable, zero-emission maritime future. Is this the ‘silver bullet’ solution that the industry, and the world, has been waiting for?

ULSTEIN THOR – a key enabler for a green maritime future?
ULSTEIN THOR – a key enabler for a green maritime future?

“Everybody has the desire to make the maritime industry sustainable – to switch to zero emissions operations and meet our most ambitious climate goals. But, until now, no one’s been able to present a technological concept for the most challenging industry applications. Well, we believe this is it. THOR is the future.”

Øyvind G. Kamsvåg is used to thinking big. But, even for him, this is massive.

THOR is the future.

The Chief Designer at Norway’s Ulstein is the father of the revolutionary X-BOW®, an eye-catching vessel bow design launched in 2005 for greater operability, comfort, operational functionality and fuel efficiency. Since then the firm has followed up with the X-STERN®, while pushing innovative fuel and hybrid power solutions on their “step change” path to a zero-emission future.

In April 2022 Ulstein took a leap forward – for themselves, but also for the industry – with the debut of ULSTEIN THOR, a 149m 3R (Replenishment, Research and Rescue) vessel concept featuring a thorium Molten Salt Reactor (MSR). The sleek craft, which wouldn’t look out of place in a James Bond film, also boasts helicopter pads, firefighting equipment, rescue booms, workboats, autonomous surface vehicles and airborne drones, cranes, laboratories, and a lecture lounge.

Launched at the Seatrade Cruise Global in Miami, it instantly gained coverage far beyond traditional trade channels, appearing on BBC, CNN and international news platforms: a show of strength in keeping with its bold name.

Today, Kamsvåg is ready to explain how THOR’s “superpower” is set to make further waves worldwide.

Generating excitement

“The inclusion of the MSR is a world first,” Kamsvåg says. “This is a specially scaled reactor that uses thorium, an abundant, naturally occurring metal with low radioactivity, to generate vast amounts of clean, safe power. Basically the thorium is dissolved into liquid salt, causing a chain reaction that heats the salt, which in turn produces steam and drives a turbine creating electricity.

“It’s a tried and tested solution on land, but has never been incorporated into a vessel design… until now.”

The genius in Ulstein’s approach is that the team recognized that installing stand-alone reactors in all future vessels might seem like a step too far, and therefore created THOR as a ‘floating, multi-purpose power station’.

Kamsvåg’s colleague, Torill Muren, Lead Naval Architect at Ulstein Design & Solutions, explains:

“THOR never needs refueling. As such it can operate worldwide, roaming the oceans as a ‘super-charging’ station, helping take maritime’s short-sea battery revolution to the deep sea.

However, in the same way that it’s ‘more than just a ship’ it’s also much, much more than a floating plug socket.

Endless ambition

To help create a commercial case for THOR, Ulstein launched the concept in tandem with ULSTEIN SIF: a 100-meter long, 160 Person On Board (POB) capacity, battery-driven, Ice Class 1C expedition cruise ship. THOR, which has been specified to charge four SIF units simultaneously, thus demonstrated how cruise vessels with next-generation batteries could conduct zero-emission operations in remote, environmentally sensitive areas. In addition to charging, replenishing supplies and conducting research operations, it can also carry out rescues in remote areas, such as polar regions.

As such, it not only makes shipping greener, but safer too. And there’s more.

“We see a multitude of applications and operational capabilities where THOR’s clean power generation capacity can be utilized,” Kamsvåg notes. “Beyond the three ‘R’ functionality, the vessel’s reactor could be used as an emergency power supply for regions hit by natural disasters, epidemics, or other upheavals.

“Similarly, it could be utilized as part of society’s renewable energy mix to compensate for fluctuating power supplies – e.g., from offshore wind parks – by supporting grid networks. And THOR’s power capacity could also be tapped for producing alternative fuels, or synthetic fuels through a CO2 refinery, or for delivering shore power at ports. The possibilities are almost endless.”

Charging ahead

And, if there’s anyone out there with ‘endless’ finances, there’s a super-powered business case on the charging front, too.

Kamsvåg and Muren discuss that someone with deep pockets who “wanted to transfer the electric travel revolution from land” could even buy a fleet of THORs and suddenly create a worldwide network of floating charging stations to power green shipping.

“This is not as ‘out there’ as it sounds,” Muren states, pointing to the uptake of electric vehicles on the road in her native Norway, where, according to the Norwegian Road Traffic Information Council (OFV), as of July 2022 over 70 percent of new car sales in Norway are all-electric.

“As soon as you have the charging infrastructure, uptake accelerates exponentially. Enable the green revolution, and it will come. THOR is maritime’s enabler.”

In this regard, it’s not just a ship, it’s an essential piece of ocean infrastructure and a key piece of maritime’s zero-emission puzzle.

Crucial conversation

As striking as THOR is, and as infectiously inspiring the scale of the design team’s ambition proves to be, some major questions remain.

Firstly, is society ready for vessels with reactors and, secondly, is this even feasible? On the subject of question number one, the Ulstein team points to the fact that nuclear vessels have been roaming the seas since 1955 – calling at ports in heavily populated locations – largely under the radar of public attention or scrutiny. They are of course referring to naval ships and submarines, showing that in the spectrum of proposed “alternative future fuels” maritime reactors are “a very tried and tested solution”.

“However,” adds Muren, “there’s obviously a class and regulatory road to travel here in terms of commercial applications, and society, and industry, need to be educated. In a way, that’s why we were so keen to come out with THOR at this point – to start a serious conversation that, we believe, needs to be conducted.”

Ulstein’s Chief Designer Øyvind G. Kamsvåg and Torill Muren, Lead Naval Architect, Ulstein Design & Solutions
Ulstein’s Chief Designer Øyvind G. Kamsvåg and Torill Muren, Lead Naval Architect, Ulstein Design & Solutions

When there’s a will there’s a way

Relating to the second question, Kamsvåg makes two points, both with ‘timing’ front of mind.

“Firstly, I think there’s recognition that a viable alternative to today’s solutions needs to be made feasible. There is an ever-growing need for energy security, or even self-sufficiency, while the very pressing demand for transitioning to more sustainable ways of doing business is top of everyone’s agendas. THOR ticks all the boxes.”

As far as the technology is concerned, Kamsvåg seems convinced that MSRs offer a simpler, safer option to existing, already proven maritime reactors. He notes that technology developers are already well underway with analogous projects such as power barges and desalination plants, and the interest, as demonstrated by the media avalanche following THOR’s unveiling, is clearly there.

“But predicting exactly when all the pieces will fall into place is difficult,” he admits. “Conservatively, I’d estimate 10 to 15 years before a concept like THOR can launch. But, and it’s a very big BUT, when there’s a universal will there’s usually a way. Just look at how quickly a COVID vaccine was developed, tested and approved. A ten-year approval process was accelerated into just a year. The human race can supercharge innovation when we have to. And a green maritime industry is something we simply have to achieve.”

The vessel’s reactor could be used as an emergency power supply.

Growing momentum

Since launching the concept, the Ulstein team says they have received ‘almost exclusively positive’ feedback from stakeholders, including shipowners and leading class societies. Furthermore, the momentum for reactors as an alternative power source for the industry appears to be growing. As an example of this, the Research Council of Norway (Norges Forskningsråd, NFR) has recently allocated new funding for a maritime nuclear power project at the Norwegian University of Science and Technology (NTNU).

“We realize this concept may seem ambitious,” Kamsvåg concludes, hammering home THOR’s potential, “but we’ve been considering the possibilities of thorium since 2008. However, back then we just didn’t think the world was ready. It is now.

“Concepts like this can bring thorium’s superpower to life. That, I believe, is a mouth-watering prospect for an industry searching for its very own silver bullet.”

ULSTEIN concept designs THOR and SIF joint operations
ULSTEIN concept designs THOR and SIF joint operations

Thorium: a viable alternative fuel for maritime?

Robert McDonald, Principal Engineer, Institute for Energy Technology (IFE), says it’s time to talk thorium.

Norway-based IFE is a is a frontrunner in international energy research, with over 650 experts from 38 countries around the world. As an independent, non-profit, private research organization, it supports industry and society in the investigation and development of energy efficient processes, renewable energy solutions, future-orientated energy systems, and much more. US-born Robert McDonald is a specialist in the field of nuclear power and Small Modular Reactors – units with a power output of 10-300 Mwe – and believes society deserves to know more about the ‘enormous clean energy potential’ of thorium.

Are Small Modular Reactors (SMRs) suitable for maritime applications?

SMRs are a proven, highly efficient technology with a very small footprint compared to other renewable energy sources, such as solar and wind farms. They are usually built in factories, with final assembly on site, making them easy to install and, as they’re modular, very scalable. Their development is typically associated with land-based applications, but they also have a lot of potential for maritime. It’s my personal belief that they’re very well suited.”

What makes thorium so special?

First and foremost, it’s energy density. One ton of thorium, which is highly abundant within the Earth’s crust, especially here in Norway, produces the amount of energy equivalent to 3.5 million tons of coal. Furthermore, in the proven context of SMRs it is completely zero emissions.

Is thorium safe?

Although Thorium has been used as far back as the 1950s and 60s in reactors, it’s important to note that there are no reactors currently utilizing it. However, the testing that has been done demonstrates a great deal of promise.

Crucially, its byproducts are significantly safer than uranium (plutonium is not produced under fission) and, with shorter half-lives, degrade far faster. Weaponization is therefore not a risk, meaning greater security for commercial use. It also has less waste than uranium when used in Molten Salt Reactors, as the salt is reprocessed once used and then recycled into new fuel batches. There’s also several years between each refueling cycle! In terms of the reactors themselves, they would be housed within sealed, self-contained, lead-lined compartments, and automatically shut down if power was lost. There would be no reason to anticipate leaks if a vessel was lost either. As we have seen with previous losses of nuclear-powered vessels – namely the USS Thresher (1963) and Kursk (2000) – the integrity of the reactor compartments was not compromised.

We can never say any fuel is 100 percent safe, but we can say we know the risk picture here – unlike some other new, alternative fuels – and thorium looks very promising indeed.

What unique advantages does it offer to the maritime industry?

Aside from what we’ve already mentioned – chiefly its ‘clean’ nature and energy potential – the impact it would have on maritime operations could be transformational. At the moment every voyage, every task, is fuel-dependent; you have a finite window you must adhere to. However, if you almost never have to refuel, or to carry out maintenance (and reactor plants have significantly fewer moving parts and demand very little maintenance) then you can basically forget about energy restrictions altogether and just ‘go for it’. That is a very exciting idea.

Do you think thorium and SMRs will be onboard vessels in the near future?

I’m not going to give you a ‘definitely’, but I will say we’re speaking to a lot of stakeholders that are very interested in finding out more. Interest in thorium as a fuel, and SMR’s as a technology, is really snowballing this year, so I do think we’re going to see a lot of developments ahead. IFE, as an organization, is here to help society – and maritime – on its clean energy path to the future.


Contact us


Share this article

Facebook LinkedIn Twitter WhatsApp