Beznau nuclear power plant: Unit 1 back on grid after revision

19.5.2026 – Beznau Nuclear Power Plant (KKB) has completed the revision of Block 1 on schedule. The Swiss Federal Nuclear Safety Inspectorate (ENSI) has issued approval for the resumption of operations. KKB 1 thus enters a new operating cycle and makes an important contribution to ensuring Switzerland's safe supply of electrical energy.

Beznau Nuclear Power Plant (KKB) has completed the revision of Block 1 on schedule. The Swiss Federal Nuclear Safety Inspectorate (ENSI) has issued approval for the resumption of operations. KKB 1 thus enters a new operating cycle and makes an important contribution to ensuring Switzerland's safe supply of electrical energy.

The main focus of the revision included maintenance work, recurring inspections, and tests. Of a total of 121 fuel elements, 20 were replaced. The revision work was supervised by the nuclear regulatory authority ENSI as well as the Swiss Association for Technical Inspections SVTI. The core loading was verified by the International Atomic Energy Agency (IAEA) and the Federal Office of Energy (BFE).

Following ENSI's approval, KKB 1 gradually resumes electricity production. During the restart process, water vapor will temporarily be visible above the non-nuclear part of the plant. There is no risk to human health or the environment.

KKB reliably and safely generates around 6 terawatt-hours of electricity per year, covering approximately one-tenth of Switzerland's electricity demand. Both reactor units are taken offline in the spring/summer for fuel element replacement or revision. Afterward, they again provide their important contribution to Switzerland's energy security for around one year – particularly during the winter months.