Offshore construction specialist Allseas has unveiled a 5-year plan to begin using nuclear power via integration of small modular reactors (SMR) both on land and aboard its vessel fleet. SMRs are advanced nuclear reactors that have a power capacity of up to 300 MW(e) per unit—about one-third of the generating capacity of traditional nuclear reactors—and can produce a significant amount of low-carbon electricity. Allseas called the decision “the next bold step” in delivering clean energy both onshore and offshore.
Allseas said it chose the nuclear route due in part to its energy density and scalability. Other alternative fuels, such as hydrogen and ammonia, face both cost and availability issues, according to the company.
The contractor will utilize high-temperature gas-cooled reactors (HTGRs) in the 25-MWe range for their deployment plans, touting the fourth-generation reactor technology’s ability to generate energy without combustion or emissions. The first HTGR design dates to the late 1940s. The first HTGR to produce electricity was in the US and operated from 1966 to 1974.
HTGRs are powered by TRISO fuel particles made up of a uranium, carbon, and oxygen fuel kernel. TRISO stands for TRi-structural ISOtropic particle fuel. According to the US Department of Energy, the kernel is encapsulated by three layers of carbon- and ceramic-based materials that prevent the release of radioactive fission products. The particles themselves are no bigger than a poppyseed but are very robust.
Delft University of Technology will contribute to Allseas its learnings from more than a decade of work on an “inherently safe” microreactor based on HTR technology.
Allseas is exploring different approaches to managing waste from the reactors, including the potential recycling and reuse of graphite and used TRISO fuel.
In the first year of Allseas’ 5-year plan, design studies for offshore and onshore use will be completed, followed by development of a prototype reactor. Discussions with stakeholders like the Dutch Authority for Nuclear Safety and Radiation Protection, International Maritime Organization, and International Atomic Energy Agency will begin.
“Our goal is to start production at a dedicated facility by 2030,” said Stephanie Heerema, project manager nuclear developments at Allseas. “Initial deployment will likely begin on land while offshore regulations are finalized, followed by application on our own vessels and broader industry adoption. This aligns with our own sustainability targets—30% emissions reduction by 2030 and net-zero operations by 2050.”
Allseas operates a diverse fleet of construction vessels including its flagship heavy-lift vessel Pioneering Spirit. That vessel, along with its deepsea mining vessel Hidden Gem and pipelay vessels Solitaire and Audacia, are all likely candidates for the SMR retrofit.
