X-energy, Alleima and Doosan Enerbility announced on November 4 the first order for steam generator tubes for the Xe-100, the American company’s advanced modular reactor. Alleima received the contract from Doosan and will supply the tubes for the first Xe-100 plant in the United States.
The work is split into two stages. Alleima manufactures stainless steel tubes made from high-temperature alloys at its plant in Sandviken, Sweden. Doosan then bends them into helical coils, the heart of the steam generator. The component is classified as safety-related and has long lead times, which is why the order comes well in advance.
The destination is the first commercial Xe-100 plant: four units proposed at an industrial site in Texas, in collaboration with Dow. The project is part of the US Department of Energy’s Advanced Reactor Demonstration Program. The steam generator is designed to produce steam at up to 565 °C, a temperature that allows it to supply both electricity and process heat to industry. The Xe-100 is a helium-cooled reactor designed for 80 MWe or 200 MWt per unit.
The order builds on a December 2025 agreement between X-energy and Doosan, which reserved manufacturing capacity for 16 sets of components: pressure vessels, steam generators and nuclear-grade steel internals. Doosan has already supplied 34 reactor vessels and 124 steam generators to nuclear plants worldwide. Alleima is among the largest suppliers of steam generator tubes and also operates in the oil and gas and aerospace sectors. For the Swedish company, this is its first order of this kind for a helium-cooled SMR, and it adds to the investments it has already announced in nuclear manufacturing capacity.
Carl von Schantz, president of Alleima’s tube division, said the company is proud to support Doosan with advanced solutions for the Xe-100 program. Jesse Walker, X-energy’s head of supply chain, spoke of a growing supplier base.
The context is favorable for the company. On October 30, the Nuclear Regulatory Commission completed its safety review of the Xe-100. X-energy says it is advancing more than 11 GW of nuclear capacity across projects in the United States with Amazon, Energy Northwest and AEP, and in the United Kingdom with Centrica. The tube order shows the supply chain is moving from design to real materials.
The next step is machining the tubes and bending them into coils. If the schedule holds, the first heavy components for the Texas site could arrive well before construction begins, and the capacity reserved at Doosan for 16 sets suggests more orders will follow.
