Beznau nuclear power plant: Block 1 begins overhaul

24.04.2024 - On 26 April 2024, Block 1 of Beznau nuclear power plant (KKB) will go offline for scheduled work. After 331 days of operation, the plant will begin an almost seven-week overhaul.

Key aspects of the overhaul include comprehensive maintenance work, periodic tests and inspections. This work will focus on the core internals and the lower bushings of the reactor pressure vessel, as well as one of the two high-pressure turbines. In addition, the emergency system’s emergency power diesel generator will be exchanged for a freshly overhauled replacement unit. 

Since 1 June 2023, Block 1 has produced more than 3 billion kilowatt hours of electricity around the clock – equivalent to the electricity consumption of some 620,000 average four-person households. 

As the plant powers down, steam will be visible above the engine room (the non-nuclear part of the power plant). There is no danger to people or the environment. The overhaul will be carried out under the supervision of the Swiss Federal Nuclear Safety Inspectorate (ENSI).

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 overhaul. They then resume their contribution to Switzerland’s security of supply for around another year – which is particularly vital in the winter months.