Bohunice NPP Unit 4 goes off line for more than 3 weeks

Bohunice NPP Unit 4 goes off line for more than 3 weeks
In accordance with the 2020 plan for general overhauls, the outage will take place from Saturday 16 May.

During the shutdown of the fourth unit of the Bohunice V2 nuclear power plant, Slovenské elektrárne will replace approximately one-fifth of the fuel in the reactor and carry out planned repairs and investment projects to further increase safety of the nuclear facility.

The shutdown is scheduled for more than three weeks and, as part of measures preventing the spread of the new coronavirus, will take place without foreign suppliers.

In connection with the COVID-19 pandemic, the overhaul schedule was adjusted, similarly to the overhaul in Mochovce, and communicated with the Nuclear Regulatory Authority of the Slovak Republic. The revised general overhaul schedule will not affect the following operation of the nuclear unit.

Main activities

  • Regular non-destructive inspections of Bohunice NPP Unit 4 reactor pressure vessel.
  • Preventive maintenance on the equipment of one of the three redundant systems.
  • Overhaul of one of six steam generators.
  • Repair of one reactor coolant pump and its electric motor.
  • Tightness checks of two steam generators' tubes.

Unit 3 will also decrease its output for six days

During the overhaul of the fourth unit, Slovenské elektrárne will halve the output of the third Bohunice unit for six days. This is required due to the works on a circulating cooling water system, which is common for both Bohunice V2 units 3 and 4.

Fourteen investment projects are planned, including the innovation of the internal distribution of technical water to the secondary circuit or modifications to electrical equipment.

The director of the Bohunice nuclear power plants, Patrik Kašo, reminded all employees to follow the instructions against the spread of the new coronavirus, which have been introduced in Slovenské elektrárne. In Bohunice, as in all operations of Slovenské elektrární, safety anti-epidemical measures have been in place for the third month in a row. These include mandatory contactless body temperature measurement at the plant entrance, installation of disinfection stations or germicidal UV emitters.

Germicidal UV emitter in the control room of the Bohunice V2 nuclear power plant.

Germicidal UV emitter in the control room of the Bohunice V2 nuclear power plant.

„We are also prepared for a possible unexpected twist of the pandemic development. If that happens, we are confident that we can handle this situation together without affecting the health and safety of our employees and suppliers.“

Miroslav Tokár
Director of the Nuclear Power Plant Division
Slovenské elektrárne, a.s.

After this overhaul, in the second half of June, the works will be shifted to Bohunice NPP Unit 3, and Slovenské elektrárne will end the series of this year's planned nuclear overhaults in September at Mochovce NPP Unit 2.