Doosan TerraPower SMR cooperation has moved into a new phase as South Korea’s Doosan Enerbility secured a contract to manufacture key reactor components for TerraPower’s first Natrium advanced nuclear power plant in Wyoming.
Doosan Enerbility announced on August 14 that it will manufacture three major components for the Natrium reactor: the reactor guard vessel, reactor support structure and reactor internal structures. The equipment will be supplied for TerraPower’s first commercial-scale project in Kemmerer, Wyoming.
The manufacturing contract represents an important step for both companies. Doosan is seeking to establish itself as a global manufacturing supplier for small modular reactors and advanced nuclear projects, while TerraPower is moving its first Natrium plant from engineering and licensing into full-scale construction.
The Wyoming project is particularly significant because TerraPower received a construction permit from the U.S. Nuclear Regulatory Commission in March 2026 and officially began construction of the nuclear plant in April. TerraPower describes Kemmerer Unit 1 as being on track to become the first utility-scale advanced nuclear power plant in the United States.
For Doosan Enerbility, the contract also demonstrates how South Korea’s heavy manufacturing capabilities could participate in the emerging global market for advanced nuclear reactors.
Doosan TerraPower SMR Partnership Expands
The latest agreement did not begin with a conventional equipment order.
Doosan Enerbility and TerraPower had already been working together on the manufacturability of the reactor’s critical components.
In December 2024, Doosan signed a manufacturability review agreement covering major equipment for TerraPower’s first Natrium reactor. Since then, the company has worked on design improvements intended to make the components suitable for manufacturing.
According to Doosan, that process helped bring the design to a level of maturity where manufacturing orders could proceed.
This is an important distinction for first-of-a-kind nuclear projects.
A reactor design can be technically sophisticated on paper while still requiring substantial engineering before components can be manufactured efficiently at industrial scale.
Manufacturers need to evaluate materials, welding procedures, tolerances, inspection requirements, production sequences and quality-control processes.
Design decisions can therefore affect not only reactor performance but also whether components can be manufactured reliably, repeatedly and at an acceptable cost.
Doosan’s involvement before the manufacturing order suggests the relationship extends beyond simply producing components from completed drawings.
The Korean company has been involved in helping prepare those designs for production.
What Doosan Will Manufacture
The contract covers three categories of reactor equipment.
The first is the reactor guard vessel.
This structure provides an additional protective boundary around the reactor vessel and forms part of the reactor’s overall safety architecture.
The second is the reactor support structure.
As its name suggests, this equipment supports the reactor and must maintain structural integrity under demanding operating and safety conditions.
The third category is reactor internal structures.
These components are located within the reactor system and help support and organize equipment associated with reactor operation.
Nuclear components operate under far stricter manufacturing requirements than ordinary industrial equipment.
Materials need to meet specified standards, fabrication processes must be carefully controlled and manufacturing records need extensive documentation.
Inspection and quality assurance are also central to the process.
This is one reason companies with existing nuclear manufacturing experience can play an important role as advanced reactor developers move from design into construction.
Natrium Uses a Different Reactor Design
TerraPower’s Natrium technology differs substantially from the conventional light-water reactors that dominate today’s commercial nuclear industry.
The system uses a sodium-cooled fast reactor.
Instead of using water as the primary reactor coolant, Natrium circulates liquid sodium to transfer heat generated by nuclear fission.
The U.S. NRC describes the proposed Natrium reactor as a 345 MWe pool-type sodium fast reactor.
Liquid sodium has physical characteristics that make it attractive for certain advanced reactor designs.
It can operate at high temperatures while remaining at relatively low pressure, unlike conventional water-cooled reactors that require high-pressure systems.
This can influence reactor design and safety engineering.
However, sodium also requires specialized engineering because it reacts chemically with water and air.
The technology therefore involves a different set of materials, operating procedures and safety considerations from conventional light-water reactors.
TerraPower’s system combines the sodium fast reactor with another unusual feature: large-scale thermal energy storage.
Molten Salt Storage Makes Natrium Different
The integrated energy storage system is one of the most distinctive features of Natrium.
The reactor itself produces 345 MW of electricity.
Heat from the nuclear system can also be stored using molten salt-based thermal energy storage.
When electricity demand increases, that stored thermal energy can be used to raise the plant’s electrical output to as much as 500 MW.
TerraPower says the storage system allows the plant to increase output rapidly when the grid needs additional electricity.
This creates a different operating model from traditional nuclear plants.
Conventional reactors are particularly effective at producing large quantities of continuous electricity, but electricity grids increasingly contain variable renewable generation from solar and wind.
Those sources can change according to weather and time of day.
A nuclear plant paired with energy storage could potentially maintain steady reactor operation while changing the amount of electricity delivered to the grid.
When demand is lower, energy can be stored.
When demand rises, the storage system can help increase output.
TerraPower says its system is designed to reach 500 MW when needed and ramp output at up to 10% per minute.
That flexibility is one of the central commercial arguments behind the Natrium design.
Kemmerer Is a Major U.S. Nuclear Project
The first Natrium plant is being constructed near Kemmerer, Wyoming.
The location is closely connected to America’s changing energy infrastructure.
The project is being developed near PacifiCorp’s retiring Naughton coal plant, allowing the region to transition from coal generation toward a new source of electricity while potentially retaining energy-sector employment and infrastructure.
TerraPower initially began non-nuclear site work in June 2024.
The regulatory milestone for the nuclear plant arrived in March 2026 when the U.S. Nuclear Regulatory Commission approved its construction permit.
The U.S. Department of Energy said the permit gave TerraPower authorization to begin construction of the Natrium reactor and noted that the project could become America’s first commercial-scale next-generation nuclear power plant.
TerraPower officially announced the start of plant construction on April 23, 2026.
The company said approximately 1,600 workers would be mobilized for construction.
Once operational, the plant is expected to support approximately 250 permanent jobs.
U.S. Government Support Is Important
The Natrium project is not being developed solely as a private commercial investment.
It is part of the U.S. Department of Energy’s Advanced Reactor Demonstration Program.
The program was created to help advanced reactor technologies move from development toward commercial deployment.
Advanced nuclear projects face a difficult economic challenge.
Building the first example of a new reactor design is considerably more expensive and technically risky than manufacturing later units after the technology and supply chain have matured.
Government cost-sharing can reduce some of that initial risk.
Reuters reported in June that the U.S. government’s Advanced Reactor Demonstration Program has helped move projects from TerraPower, X-energy and Kairos Power into construction and development, with federal support covering significant portions of demonstration costs.
The goal extends beyond completing individual plants.
The broader objective is to establish technologies, licensing experience and supply chains that can support subsequent reactor deployments.
That makes suppliers such as Doosan particularly relevant.
Doosan Brings Heavy Nuclear Manufacturing Experience
Doosan Enerbility has spent decades building equipment for the conventional nuclear industry.
Its manufacturing capabilities include large nuclear forgings and major components such as reactor vessels and steam generators.
Those capabilities require extremely large production facilities, specialized materials expertise, precision machining and nuclear-grade quality assurance.
Advanced reactors may be smaller or structurally different from conventional nuclear plants, but they still require manufacturers capable of meeting demanding nuclear standards.
The Doosan TerraPower SMR contract provides a route for the Korean manufacturer to transfer those capabilities into a new generation of reactor technology.
This is strategically important because the global advanced nuclear market is still developing.
Companies that participate in early projects may gain manufacturing experience that becomes valuable if reactor designs progress into repeat deployments.
First-of-a-kind projects are therefore important not only for reactor developers but also for their suppliers.
Advanced Nuclear Needs a New Supply Chain
One of the biggest challenges facing the advanced nuclear industry is manufacturing capacity.
Many reactor developers are creating technologies that differ substantially from existing commercial nuclear plants.
Some use sodium.
Others use molten salts, helium or different fuel designs.
That diversity means supply chains cannot simply reproduce every process used for today’s large light-water reactors.
New materials, components and manufacturing methods may be required.
At the same time, nuclear manufacturing is difficult to expand quickly.
Facilities need specialized equipment.
Workers need extensive training.
Quality assurance systems must meet demanding standards.
Suppliers may also need nuclear certifications before they can manufacture safety-related components.
This creates a potential bottleneck.
A reactor developer may successfully complete its design and receive regulatory approval but still struggle to build multiple units if qualified manufacturing capacity is unavailable.
Doosan’s participation helps address part of that challenge for TerraPower.
Manufacturing Can Determine SMR Economics
Advanced reactors and SMRs are frequently promoted as a way to reduce some of the cost problems associated with traditional nuclear construction.
The theory is that more components can be standardized and manufactured in factories rather than being custom-built entirely at individual plant sites.
Factory production could allow suppliers to repeat the same processes across multiple reactor projects.
That repetition can improve productivity and potentially reduce costs.
But those benefits only appear if enough reactors are ordered.
The first unit of a new design can still be expensive because engineering, tooling and manufacturing processes are being developed for the first time.
The commercial future of advanced nuclear therefore depends partly on moving from first-of-a-kind projects to repeatable production.
The current Doosan contract is significant in that context.
The company is manufacturing equipment for TerraPower’s first plant, but the larger opportunity would come if Natrium develops into a multi-unit deployment program.
TerraPower says it is pursuing additional projects beyond Kemmerer.
TerraPower Plans Beyond Wyoming
Kemmerer Unit 1 is intended to demonstrate that Natrium can be licensed, manufactured, constructed and operated commercially.
If successful, TerraPower’s ambitions extend considerably further.
The company has been developing additional agreements for future Natrium deployment in the United States.
Demand for reliable electricity is increasing as data centers, manufacturing and electrification place new pressure on power grids.
AI infrastructure has made this issue particularly visible.
Large data centers can require hundreds of megawatts of continuous electricity, while future campuses may require substantially more.
Nuclear energy is attracting renewed attention because it can produce large quantities of electricity around the clock without direct carbon emissions from generation.
Advanced reactors are being positioned as one possible way to meet some of that demand.
TerraPower argues that Natrium’s combination of continuous nuclear generation and energy storage makes it particularly suitable for a grid containing both large industrial loads and variable renewable energy.
Whether that model becomes economically competitive at scale will depend heavily on the performance and cost of early projects such as Kemmerer.
Energy Storage Could Improve Grid Flexibility
The storage component deserves particular attention because it changes how the plant interacts with electricity markets.
A nuclear reactor is most economically productive when it operates continuously.
Electricity demand, however, changes throughout the day.
Traditional power systems have used other generators to respond to those fluctuations.
Natrium separates nuclear heat generation from electricity generation to some extent through thermal storage.
The reactor can continue producing heat while the storage system changes how much power is delivered.
TerraPower says its storage can provide elevated output for more than five hours. Its technical material lists nuclear-island output at 345 MWe and energy-storage-assisted output ranging up to 500 MWe.
This could allow the plant to provide additional electricity during periods of high demand without requiring the nuclear reactor itself to rapidly change power.
It could also help electricity systems integrate variable renewable generation.
The commercial value of that flexibility will ultimately depend on actual plant performance and electricity-market conditions.
Korea Could Benefit From the SMR Supply Chain
For South Korea, the contract demonstrates that participation in advanced nuclear does not depend entirely on developing a domestic reactor design.
There is also a substantial industrial opportunity in supplying equipment to international reactor developers.
South Korea already has a mature nuclear manufacturing ecosystem created through decades of domestic reactor construction and overseas nuclear projects.
As advanced reactors move toward commercialization, those capabilities can potentially serve multiple reactor technologies.
Doosan Enerbility has been particularly active in pursuing this opportunity.
The company has developed relationships with several advanced reactor developers as part of its strategy to become a major global SMR equipment supplier.
Each technology has different requirements, but the underlying manufacturing expertise — large-scale fabrication, precision machining, welding, materials engineering and nuclear quality control — can provide a valuable foundation.
The TerraPower agreement gives Doosan experience with sodium-cooled reactor components in addition to its conventional nuclear manufacturing portfolio.
Sodium Reactors Return to Commercial Attention
Sodium-cooled fast reactors are not a new scientific concept.
Countries have researched and operated sodium fast reactors for decades.
What is changing is the attempt to package the technology into a commercially competitive system suited to modern electricity grids.
TerraPower’s design draws partly on earlier sodium reactor experience while combining it with modern materials, digital engineering and thermal storage.
The NRC notes that Natrium incorporates features derived from GE Hitachi’s PRISM technology and TerraPower’s earlier Traveling Wave Reactor development.
That history matters because advanced nuclear technologies are often described as entirely new.
In reality, many combine decades of reactor research with newer engineering approaches.
The commercial challenge is proving that those technologies can meet modern safety requirements while being constructed at predictable cost and schedule.
Kemmerer will provide an important real-world test.
Construction Progress Will Be Closely Watched
TerraPower expects the project to become a landmark for advanced nuclear deployment.
Its current materials have targeted completion around the end of the decade, although large nuclear projects can face schedule changes as construction progresses.
Several milestones will therefore matter.
Manufacturing major reactor components is one.
Delivery and installation are another.
Construction must then proceed through extensive inspection, testing and regulatory processes before the plant can begin commercial operation.
Doosan’s equipment sits within that wider schedule.
The Korean company said its components are expected to play an important role in supporting timely construction and operation of TerraPower’s first unit.
For Doosan, delivering the components according to the required specifications and schedule could strengthen its position when future Natrium units or other advanced reactors require manufacturing partners.
SMRs Face an Economic Test
Despite growing investment, the commercial case for advanced reactors is not yet settled.
Supporters argue that smaller and more standardized reactors can reduce construction risk, enable factory manufacturing and serve locations unsuitable for very large conventional plants.
Critics point out that smaller reactors lose some economies of scale and that early projects can still be expensive.
Reuters noted these competing views when reporting on the NRC’s approval of TerraPower’s project in March.
That means the success of Kemmerer will be measured by more than whether the reactor works technically.
Cost, construction schedule, operational reliability and the performance of the energy storage system will all influence whether utilities and industrial customers order additional units.
Manufacturing is directly connected to that economic test.
If suppliers can standardize components and reduce production time across multiple plants, the economics could improve.
If every project requires extensive redesign and custom fabrication, achieving large cost reductions will be more difficult.
Doosan Positions for Repeat Orders
This is where the longer-term significance of the Doosan TerraPower SMR relationship becomes clear.
The immediate contract covers components for one reactor.
The strategic opportunity is potentially much larger.
If TerraPower successfully completes Kemmerer and proceeds with additional Natrium projects, qualified suppliers from the first unit may be well positioned to compete for repeat orders.
Doosan President Kim Jong-doo said the company plans to complete the project successfully while continuing to strengthen its SMR manufacturing capabilities and expand its role as a global supplier.
That ambition aligns with a broader shift in the nuclear industry.
Reactor developers increasingly need manufacturing partners capable of turning advanced designs into physical equipment at commercial scale.
South Korea’s nuclear supply chain could become an important part of that process.
A Milestone for Doosan and TerraPower
The contract marks a tangible transition from collaboration and engineering review into manufacturing.
Doosan and TerraPower began working on manufacturability before the Natrium reactor received its U.S. construction permit.
Now that the project has entered construction, Doosan will produce critical reactor structures for the first unit.
The timing is significant.
The NRC approved the construction permit in March 2026, and TerraPower formally began nuclear plant construction in April.
The 345 MW sodium-cooled fast reactor will be combined with molten salt energy storage capable of raising electrical output to 500 MW when needed.
If the project performs as intended, it could provide an important demonstration of how advanced nuclear generation and large-scale thermal storage can operate together.
For Doosan Enerbility, the opportunity is different but equally strategic.
The company is demonstrating that its nuclear manufacturing capabilities can be adapted to reactor technologies being developed outside South Korea.
That could become increasingly important as countries seek new sources of reliable, low-carbon electricity and advanced reactor developers move from prototypes toward commercial deployment.
The first Natrium plant is only one project, and significant construction and operational milestones remain ahead.
But the manufacturing contract shows that the advanced nuclear supply chain is beginning to move from planning into production.
For Doosan TerraPower SMR cooperation, that transition could create opportunities extending well beyond the first reactor in Wyoming.
