Hungary’s 2.4-GW Paks II nuclear expansion could be delayed until 2035, potentially narrowing the margin between commissioning of the new reactors and retirement of the country’s existing nuclear fleet.
The existing Paks plant consists of four Soviet-era units with combined capacity of about 2 GW, whose shutdowns are expected to begin between 2032 and 2037.
Paks II is designed to replace and expand that capacity with two VVER-1200 reactors totalling 2.4 GW.
An internal Rosatom construction timetable cited in the report places provisional acceptance of unit 6 on Dec. 30, 2034. Because commercial operation would follow that milestone, completion could move into 2035.
That would be later than earlier Hungarian government indications that the reactors could be completed in 2031-2032.
The project has already missed earlier milestones. First concrete for unit 5, originally expected in March 2025, was poured in February 2026. First concrete for unit 6 is scheduled for September 2026.
Rosatom has said construction is proceeding according to the timetable agreed with Hungary but has not publicly given a firm commissioning date. Foundation work on unit 5 was reported to be about 80% complete and expected to finish by year-end.
Further delays would increase the risk of a period in which Hungary’s existing reactors begin retiring before Paks II is fully operational, raising longer-term questions over replacement capacity, imports and security of supply.
