Project for long-term storage of radioactive waste in Eastern Sweden | Multiphase, multidisciplinary energy infrastructure project at a depth of 500 m | Planned contract volume of several hundred million Swiss francs

Glattpark (Opfikon), 18 June 2025 – Implenia has signed an “Early Contractor Involvement” contract with Swedish company SKB (Svensk Kärnbränslehantering AB) to build the first underground section of a deep repository for radioactive waste near the Forsmark nuclear power plant in Eastern Sweden. The project includes the phases planning, design and construction of an access tunnel to the first storage level, three vertical shafts for ventilation and an elevator, a central area as well as main and transport tunnels – all at depths of up to 500 m. The planning phase will begin in autumn 2025 and will be followed by the design and construction phases. The project will be finished by 2033. Across all project phases, the contract volume amounts to several hundred million Swiss francs.

"We are very proud to have been awarded this important contract and would like to thank SKB for the trust they have placed in us. The project requires a great deal of geological and technical tunnelling expertise and precision,” says Erwin Scherer, Head Division Civil Engineering at Implenia: “Winning this contract is testimony to our many years of expertise in the planning and execution of large, multidisciplinary infrastructure projects, including our specialisation in tunnel and energy infrastructure. We look forward to working together as partners!"

"Building the deep repository is an important step in our mission to safely dispose of radioactive waste. We are pleased to have signed a collaboration agreement with Implenia as Implenia possesses solid expertise and experience in rock excavation and infrastructure projects," says Stefan Engdahl, CEO of SKB.

The client SKB plans to expand the deep repository into an underground system covering up to 4 km² and around 66 km of tunnels by the 2080s. It will then offer space for storing up to 12,000 t of radioactive material in rock that is 1.9 billion years old.

The scope of the contract with Implenia includes the planning, design and construction of an access tunnel to the first storage level, three vertical shafts for ventilation and an elevator, a central area as well as main and transport tunnels (image: ©SKB).

Visualisation of the entire future deep geological repository near the Forsmark nuclear power plant in Eastern Sweden (image: ©SKB).

Contact for media:
Corporate Communications, T +41 58 474 74 77, communication@implenia.com 

Contact for Investors and Analysts:
Investor Relations, T +41 58 474 35 04, ir@implenia.com 

Dates for investors:
20 August 2025: Interim results 2025, Analysts and Media Conference
4 March 2026: Annual results 2025, Analysts and Media Conference

As Switzerland’s leading construction and real estate service provider, Implenia develops, builds and manages homes, workplaces and infrastructure for future generations in Switzerland and Germany. It also offers tunnelling and related infrastructure services in other markets. Formed in 2006, the company can look back on around 150 years of construction tradition. Implenia brings together the know-how of its highly skilled development, planning and execution units under the umbrella of an integrated multinational construction and real estate service provider. With its broad offering and the expertise of its specialists, the Group realises large, complex projects and provides client-centric support across the entire life cycle of a building or structure. It focuses on client needs and on striking a sustainable balance between commercial success and social and environmental responsibility. Implenia, with its headquarters in Opfikon near Zurich, employs more than 9,000 (FTE) people across Europe and posted revenue of CHF 3.6 billion in 2024. The company is listed on the SIX Swiss Exchange (IMPN, CH0023868554). More information can be found at implenia.com.