GDES will work for the development of technical sealing solutions in the Tokamak complex, awarding our Thermal Protection team the SHORT-TERM OPENINGS SEALING (STOS) contract.

This new project includes the design, qualification, supply, and installation of sealing systems for electrical and mixed penetrations, meeting the stringent barrier requirements defined by ITER Organization.

The contract is divided into two main phases:

Qualification : including fire tests (+/- 5kPa), combustibility, air tightness with thermal cycles, water tightness (including post-seismic), chemical resistance, radiation aging, and smoke toxicity.

Installation : GDES will handle the installation of Lot 2 solutions (mixed penetrations).

The Thermal Protection team, composed of around twenty specialists, lead this ambitious project from our French subsidiary GDES Revanti SAS, further consolidating our position in the French nuclear market and the ITER ecosystem.

This contract represents a further step in GDES’s strategy to deliver innovative, high‑value engineering solutions for demanding nuclear environments. In addition, the qualification of the systems developed under the STOS contract may be leveraged across other areas of the ITER complex with similar barrier requirements, enabling resource optimisation and reducing future capital expenditure.

This milestone builds upon the successful delivery of the IVC BUSBAR sealing project (encapsulated busbars), undertaken by our team within the reactor building since 2024, and further reinforces ITER’s confidence in GDES’s technical capability and execution performance.