ZE PAK and Synthos Green Energy Form Joint Venture for Six Small Modular Reactors at Poland’s Pątnów Site
Polish energy group ZE PAK and nuclear developer SGE, formerly known as Synthos Green Energy, have agreed to form a joint venture to build up to six small modular reactors (SMRs) at ZE PAK’s coal plant site in Pątnów, in the Konin region of central Poland, according to World Nuclear News. The project would use GE Vernova Hitachi’s BWRX-300 design, for a combined capacity of 1,800 MWe once all six units are built.
Under the arrangement, ZE PAK contributes the land rights at Pątnów, where its lignite-fired plant currently operates, while SGE brings its position as a co-investor in the standard BWRX-300 design. ZE PAK may remain a minority shareholder in the project company in later years, or sell its stake outright to SGE; no timeline for construction or first power has been disclosed.
A Second Track for Poland’s SMR Push
The Pątnów venture is distinct from Poland’s state-led reactor programme, where the Ministry of Climate and Environment, state utility PGE and Polskie Elektrownie Jądrowe (PEJ) are developing large Westinghouse AP1000 units at Lubiatowo-Kopalino, a project recently delayed to 2036 for its first unit, with a second large plant agreed between the ministry, PEJ and PGE in October. Poland has issued decisions-in-principle covering 26 BWRX-300 units across six sites in total, with SGE as the lead industrial partner on the SMR track, separate from the AP1000 programme that is now ordering long-lead components from Westinghouse.
SGE’s involvement extends beyond Poland: the company has also proposed 14 SMRs across three UK sites, currently under review in Britain’s Advanced Nuclear Framework programme, positioning it as one of the most active private developers of the BWRX-300 design in Europe.
BWRX-300: From Design to First Deployments
The BWRX-300 is a 300 MWe boiling water reactor developed by GE Vernova Hitachi Nuclear Energy, marketed as a simplified, smaller-footprint descendant of conventional boiling water reactor technology. The first unit is under construction at Ontario Power Generation’s Darlington site in Canada, while in the United States, the Nuclear Regulatory Commission has issued a construction permit for a BWRX-300 at the Tennessee Valley Authority’s Clinch River site. No BWRX-300 has yet reached commercial operation anywhere in the world, so Poland’s Pątnów project would add to a design still working through its first wave of construction rather than one with an operating track record.
ZE PAK’s decision to repurpose a lignite plant site reflects a broader pattern among Polish coal operators, which face closures under EU carbon pricing and face pressure to replace dispatchable capacity as coal retires. Piotr Żak, president of ZE PAK, said Poland needs reliable, domestic sources of electricity, while SGE founder Michał Sołowow said the agreement lays a foundation for deploying six BWRX-300 units safely and efficiently.
Status: Agreement to Form a Venture, Not a Final Investment Decision
World Nuclear News’s report describes the step as an agreement between ZE PAK and SGE to establish the joint venture itself; it does not describe a final investment decision, financing arrangement or construction start date. Securing financing, a site-specific licence from Poland’s National Atomic Energy Agency, and a commercial structure for the project company are among the steps that would typically follow before construction begins. For six units at 300 MWe each, total project costs for comparable BWRX-300 programmes elsewhere have been estimated in the billions of dollars, though neither company has disclosed a cost figure for Pątnów.
Sources: World Nuclear News, “Joint venture formed for six-unit SMR plant in Poland,” October 15, 2026 (project structure, capacity, quotes); NEI Magazine and Polish industry press (background on the 2021 ZE PAK–Synthos cooperation agreement and site history); World Nuclear News, “Poland Delays First Nuclear Plant to 2036, Sets 2040 for Second,” October 2026 (AP1000 programme timeline); World Nuclear News, “Poland’s Ministry, PEJ and PGE Sign Agreement on Second Nuclear Plant,” October 2026 (EJ2 programme).
Illustrative image. Photo: Nuclear Regulatory Commission, Public domain, via Wikimedia Commons — source
