As a shipbuilder and designer with more than a century of history, Ulstein has a proven resilience when it comes to adapting to maritime’s ever-changing political and economic landscape. Although the group is centred around its Ulsteinvik yard in Western Norway, which today specialises in offshore and expedition cruise ships, it’s nowadays perhaps most closely associated with its trailblazing X-BOW® inverted bow concept which today can be found on more than 100 vessels around the world. With European yards fighting what may well be a losing battle with their Asian rivals, there’s also a realisation that the company’s continued success may well lie in developing innovative intellectual properties that can be licensed to other builders.
Earlier this year, the company made fresh ripples with the announcement of the Ulstein Thor, a concept design for a 149m 3R (Replenishment, Research and Rescue) vessel that would be powered by a thorium molten salt reactor (MSR). The Ulstein Thor would essentially serve as a mobile nuclear power station with which other battery-powered vessels could rendezvous to recharge. While mooted as a potential solution to allow zero-emission expedition ships to operate in the Norwegian fjords and other remote or environmentally sensitive areas, Ulstein is keen to emphasise that really this is just the tip of the iceberg when it comes to Thor’s potential applications.
Thorium is an element found in relative abundance in Norway and Ulstein began considering the possibilities for such vessels as long ago as 2008, before concluding the political environment might be unsympathetic to such historically controversial technologies. However, the growing urgency to develop low- and zero-carbon energy solutions, combined with the renewed interest in MSRs as an inherently more stable alternative to traditional (pressurised water reactor) technology as a viable option for shipping, spearheaded by the likes of UK-based Core Power prompted a rethink.
Torill Muren, lead naval architect, Ulstein Design & Solutions, explains: “One of the reasons we took it up again is our work with expedition ships going to remote areas and the particular lack of infrastructure when it comes to power. Of course, the world energy crisis is one of the reasons why this makes sense as well as the war in Ukraine.”
Ulstein’s chief designer, Øyvind Gjerde Kamsvåg, adds: “The project started in January when we were challenged to develop a new way to attract new clients. We were supposed to go to the Seatrade trade show in April and it was a natural development of looking into how to establish zero-emission exploration cruising.”
Simultaneously with Thor, Ulstein also revealed a concept design named after the mythological Norse hero’s partner, Sif, in this instance a battery-driven cruise ship capable of accommodating 80 passengers and 80 crew. Both the designs include Ulstein’s trademark X-BOW®. The company reckons that a single Thor vessel could be responsible for the recharging of as many as four ships cruising within a particular area. Dynamic positioning or anchors would be used during these charging operations, with a drone vehicle used to transfer the charging plug between the ships. With the rapid advances being made in battery technology it’s estimated that the passenger vessel could be fully charged in as little as six hours.
“It might not be built that way in the future but it’s a starting point to enable discussions,” says Kamsvåg. “That’s an important point of these concepts: how to move forward with zero emissions. It’s not just about making a ship with an MSR, because anybody could do that, but also developing an infrastructure around the logistics. The enabling part of the project is as important as the MSR itself.”
Naturally, the question arises of why not install the MSR directly on the vessel itself. Notwithstanding that passengers might be reluctant to travel for extended periods onboard a nuclear vessel (despite the inherent stability of MSR technology) the energy generated is well in excess of that required for vessels of this size and would lead to significant wastage. Another factor is likely to be the expertise required to operate the reactor core.
Although the unveiling of Thor and Sif were fully intended to be headline-grabbers, Ulstein is looking well beyond the expedition ship sector for potential applications of MSR technology as a viable option, particularly for vessels where other alternatives such as hydrogen and ammonia would present infrastructure problems. Container vessels, tankers and naval ships have all been discussed as possible options, particularly those engaged in deep-sea transportation. It might also be considered as a means of supplementing offshore wind power, which by nature can be prone to outages.
“The main reason we did this was we wanted to start this discussion and try to influence both class societies, politicians and the general public. That’s the most important to us,” says Muren.
Ulstein envisages its role as integrating MSRs into ship designs, leaving the nuclear technology to some of the merging experts in this field. Discussions have already taken place with Core Power and Copenhagen-based Seaborg Technologies, as well as the Institute for Energy Technology (IFE), which operates Norway’s two nuclear reactors.
Meanwhile, Kamsvåg says there’s been positive feedback from two major classification societies who are keen to lend their expertise to any future projects, not to mention some speculative interest from flag states. Clearly it’s still early days but with momentum growing behind MSR, perhaps it won’t be too long before Ulstein-designed nuclear vessels take to the seas.
