KKB: annual overhaul in block 1 completed

Beznau nuclear power plant (KKB) has completed work on the overhaul of block 1 and reconnected it to the grid following approval by the Swiss Federal Nuclear Safety Inspectorate (ENSI).

The overhaul focused on comprehensive maintenance work, inspections and commissioning of new systems. Integral system tests were also carried out, as usual. Out of 121 fuel elements, 16 were replaced.

The examination of the reactor pressure vessel ordered by ENSI in 2018 was also successfully carried out. This examination revealed no changes since the production-related aluminium oxide inclusions were noted in 2015. This once again confirmed the analysis and findings of the safety case in 2018.

The employees of the KKB, around 500 in total, received support from several hundred external experts from the region, Switzerland and abroad.

Block 1 will now gradually return to normal operations and will be at full capacity in two or three days. As the plant powers up, steam will be visible above the machine hall (non-nuclear part of the plant). There is no danger to people or the environment.

The overhaul was carried out under the supervision of ENSI.