KKB 1 back on grid after refuelling

24.04.25 – After successfully replacing fuel elements, Axpo reconnected unit 1 of the Beznau Nuclear Power Plant (KKB) to the grid yesterday. With the reactor core reloaded, KKB 1 will start its next operation cycle. KKB produces low-carbon electricity safely and reliably, covering one tenth of Switzerland's electricity needs.

Unit 1 was disconnected from the grid April 8, 2024, for a scheduled fuel element replacement. Over the past two weeks, KKB specialists replaced 16 of the total 121 fuel elements in the reactor core. Checks, system tests and scheduled maintenance work were performed on individual components too. Around 150 external experts assisted the staff at KKB. The refuelling was verified by the International Atomic Energy Agency (IAEA) and the Swiss Federal Office of Energy (SFOE).

Following approval by the Swiss Federal Nuclear Safety Inspectorate (ENSI), unit 1 has gradually returned to power operation. The plant will reach full capacity (365 megawatt net capacity) in roughly two days.

As the plant powers up again, steam will be visible above the non-nuclear part of the plant (engine room) at times. There is no danger to people or the environment. 

The Beznau Nuclear Power Plant produces around 6 terawatt hours of electricity, safely and reliably, every year – which meets about one tenth of Switzerland’s power requirements. The two power plant blocks are taken off grid separately in spring/summer for fuel element replacement or revision. They then resume their contribution to Switzerland’s security of supply for around another year, something which is particularly vital in the winter months.