The controlled fission chain reaction is already underway in the reactor, although the reactor power is very close to zero.
“This is a very important milestone in the commissioning of the nuclear reactor. It is the moment when we have vivified the nuclear fuel in the reactor, and we are bringing the reactor to life. It should be at full power in early 2023.”
Branislav Strýček, Director General of Slovenské elektrárne
Slovenske elektrarne thus achieved another important milestone in the nuclear installation commissioning:
- Slovenske elektrarne started Mochovce 3 commissioning on 9 September 2022, when initial nuclear fuel loading was started
- Once the fuel loading was completed, they started reactor assembly on 12 September, which was completed on 20 September 2022.
- Unit 3 successfully passed all tightness and strength tests of the primary circuit and containment.
- The first reactor criticality was reached on 22 October 2022.
“Today we are starting the physical start-up tests and bringing the reactor to power. The first reactor start-up includes complex tests, in which all characteristics of the reactor core are verified in real conditions.”
Martin Mráz, Mochovce NPP Director
After the tests are completed in the next few days, Mochovce 3 will move from physical to power start-up. This means that heat from the reactor will be sufficient to heat up water and generate steam to spin the turbines. The reactor’s output will gradually increase and at 20 % the plant will be synchronised to the Slovak electricity grid for the first time.
First megawatthours to the grid
In the next phase of commissioning, so-called power start-up, the reactor power is increased step by step and a number of tests are carried out. Various situations will be simulated that the plant will probably never experience in normal operation.
The power level is gradually increased until the reactor finally reaches 100 % power. It is only in this second start-up phase that the first megawatt-hours from the new Mochovce 3 unit, with no carbon dioxide emissions, will get to the Slovak electricity grid.
Completion of commissioning and test operation
Commissioning is completed with 144-hour trial run of Mochovce 3 at full capacity. Slovakia will thus become energy self-contained in terms of electricity production in 2023. The new unit’s lifetime is planned to be 60 years at least.
Source: Slovenske elektrarne