Italy’s Ansaldo Nucleare has completed two modernisation projects at the Krško NPP in Slovenia for nuclear utility Nuklearna Elektrarna Krško (NEK). These were the upgrade of the water treatment system and the replacement of the waste gas compressor package. In both initiatives, the company acted as main contractor, managing engineering, procurement, construction, installation, and commissioning activities. In February 2026, NEK also awarded Ansaldo Nucleare a new contract for the revamping of the plant’s Fire Protection System, scheduled for completion in 2027.
The water treatment system upgrade enhances operational flexibility and automates the production of demineralised water for reactor feed. The new configuration includes multiple treatment lines and a modern Distributed Control System (DCS), enabling improved supervision and largely automated operation. The project was completed in October 2025 and became fully operational in April 2026.
The waste gas compressor package replacement project involved replacing two waste gas compressors with new units. Ansaldo Nucleare’s expertise in ASME certification and US–EU nuclear standards supported the design and supply of related heat exchangers. Due to limited space in the plant, the compressors were transported disassembled and reassembled on site. Acceptance Tests were completed on schedule, and hand‑over signed in November 2025.
“All these activities reinforce our long‑standing collaboration with NEK,” said Daniela Gentile, CEO of Ansaldo Nucleare. “By managing complex upgrade projects under demanding conditions, we support NEK in maintaining the highest standards of safety, efficiency, and operational reliability. Slovenia is a strategic energy partner: in 2025, Italy imported around 5 TWh of electricity Slovenia about 10% of its total electricity imports.
“We would like to express our appreciation for the successful completion of the project,” said NEK in a statement. “NEK is putting strong efforts to secure its supply chain to achieve the highest industry standards. Having reliable partners is one of the key success factors. Based on good results and lessons learned from past projects completed together with Ansaldo Nucleare, we remain open to future opportunities for cooperation.”
