Paks II nuclear power plant expects first concrete in February 2026

The Hungarian Atomic Energy Authority (HAEA) has issued key permits allowing work to begin on pouring the first concrete for the Paks II nuclear power plant. Specifically, it has granted construction licences for the control room building, the auxiliary operations building and the technical maintenance building for Unit 5.

One of the decisions also concerns construction of Unit 6 at Paks II. Another relates to construction of Unit 5. The first “nuclear” concrete — the point at which the project is officially considered a “nuclear power plant under construction” — is scheduled for February 2026.

Incident on 30 January 2025 and the regulator’s response

On 30 January 2025, two corners of the retaining wall gave way in the southern part of the construction pit. The HAEA regulator subsequently ordered a partial suspension of work in the affected area, an assessment of the stability of the entire pit and the implementation of stabilisation measures. Once these had been completed, it authorised the resumption of work at full scale in June 2025.

Construction progress and supplier readiness

According to Rosatom, the project’s general contractor, the new permits confirm that the project complies with international, European and national nuclear safety requirements. The VVER-1200 design for the new units uses a combination of active and passive safety systems.

Hungarian Foreign Minister Péter Szijjártó said that 2 million m³ of soil had already been excavated at the site and 43,000 cement columns installed in the subsoil. Thirty buildings have been completed and another 50 are under construction. Components for the units are being manufactured in six countries; French and German companies are also involved. Rosatom is manufacturing key reactor internals and steam generators in Russia.

Fuel diversification: Framatome from 2027, Westinghouse from 2028

At the same time, Hungary is strengthening the security of fuel supplies for the operating VVER-440 units at the Paks nuclear power plant. MVM Group has signed a contract with Westinghouse worth USD 114 million for fuel supplies from 2028. According to MVM CEO Károly Mátrai, the agreement will enhance security and operational flexibility, as well as price predictability for households and businesses.

Westinghouse Nuclear Fuel President Tarik Choho added that the contract means Westinghouse supplies all VVER reactor operators in Europe and Ukraine, strengthening the security of nuclear fuel supplies.

As part of its diversification efforts, Hungary is also to receive VVER-440 fuel from Framatome from 2027. Historically, the plant has sourced fuel from Russian manufacturer TVEL.

Political and industrial framework and EU legal context

The fuel diversification announcement came during talks between Hungarian Prime Minister Viktor Orbán and US President Donald Trump. A memorandum of understanding refers to plans to deepen cooperation in civilian nuclear energy, including small modular reactors (SMRs) and spent fuel management, with the ambition of making Budapest a regional hub for the Central European SMR market.

Hungary has announced its support for the construction of up to 10 SMRs, with a potential value of up to USD 20 billion. According to the government service About Hungary, the US also pledged to exempt Hungary from any potential energy sanctions against Russia that could affect the Paks II project.

In September, the EU Court of Justice upheld Austria’s appeal against approval of Hungarian state aid for Paks II, ruling that the European Commission should have thoroughly examined whether the direct award complied with EU public procurement rules. The Commission is therefore reviewing its 2017 decision again. Hungarian officials say the ruling will neither halt nor delay the project.

Existing Paks plant and specifications of the new units

The Paks nuclear power plant, located approximately 100 km south of Budapest, currently consists of four Soviet-designed VVER-440 pressurised water reactors commissioned between 1982 and 1987. The Paks II expansion is based on an intergovernmental agreement from early 2014, under which Russian companies and international subcontractors will supply two VVER-1200 units. Financing includes a Russian state loan of up to EUR 10 billion, which is intended to cover 80% of the project’s costs.

The construction permit application for Paks II was submitted in July 2020, the permit was issued in August 2022 and a construction schedule was agreed in 2023. The aim is to connect the new units to the electricity grid in the early 2030s.