Loss of information from the information management computer system

Nuclear Facility: Unit 5, Kozloduy NPP

Event Title: Loss of information from the information management computer system

Event description:

On 06.06.2010, according to the programme for start-up and energy assimilation after annual outage, preparation activities for inclusion of Unit 5 main circulation pump are going on. According to the Technical Specifications of the Unit, all safety systems are in stand-by mode. At 04:51 on the monitors of the workstations of the information management computer system appear error massages. Loss of information from the system and significant delays in the implementation of the management functions of part of the controllers for management of the equipment from the operation systems are discovered. The control on the performance of the reactor is continued to be exercised by the critical parameters control system, by the programme - technical complex of the management safety systems and by the internal reactor control system. By 07:00 a system administrator has analysed the cause leaded to the failure of the information system. At 12:05 the information is restored, as well as the state and the management of the equipment by the information management computer system.