Within 8 days, work gangs from Specialized Division Decommissioning of Units 1 to 4, successfully carried out an operation related to the dismantling activities in the Controlled Area (CA) – Reactor Building of Kozloduy NPP’s Unit I.
On 13th May 2020, four electric motors were removed from the Unit‘s boron unit. Two of them are part of the “Emergency feedwater pumps” system, two – part of the “Spray system” pumps. The dismantled equipment was moved by means of a specialized transport vehicle to the Size Reduction and Decontamination Workshop (SRDW). The operation was carried out under strict radiation monitoring during the whole process – both in the CA and during transportation and receipt at the workshop. The monitoring was performed by SERAW and KNPP’s specialists.
In the SRDW, the equipment was disassembled and subjected to mechanical decontamination by a shot blasting machine. Subsequent measurements in the accredited Measurement and Free Release System showed that the motors that had been operated in the Controlled Area of Unit I, have been successfully decontaminated and the values are below the levels for unconditional release from regulatory control. The equipment was transported to a site for temporary storage of free release candidates pending an order by the Chairman of the Nuclear Regulatory Agency for removal from the nuclear power plant site.
The total weight of the dismantled and decontaminated equipment is about 5.5 tonnes.
In a similar way, operations are underway for processing of more electrical equipment from the CA, which has already been dismantled and prepared for removal from the Unit. On 22nd May, five electric motors of this type of pumping systems were removed.