Български
| Nuclear Facility: | Unit 5, Kozloduy NPP | ||||
| Date: | 22.01.2021 | Time: | 01:16 | ||
| Event title: Reactor scram of Unit 5 | |||||
| Event description: | |||||
| On 22.01.2021 Unit 5 operated at rated power. During the implementation of activities to secure equipment for planned maintenance (maintenance of power supply switchgear of the train one of a safety system) loss of power supply to the sensors from that train has occurred. The loss of power supply to the sensors has led to activation of technological protections and as a result four main circulation pumps have switched off and automatic reactor scram has occurred. At 01:16 Unit 5 has been disconnected from the electrical grid. The technological protection algorithms have operated without any deviations. Activities to restore the power supply of the sensors have been performed. The unit equipment condition has been inspected. In the period from 03:32 to 03:38 the four main circulation pumps consecutively have been switched on and a process for reaching minimum controlled power level of the reactor has been initiated. There has been no violation of the operational limits and conditions and respectively there have not been any changes in the radiological conditions. | |||||
| INES rating of the event: | Below Scale/Level 0 No safety significance | ||||
