On September 4, 1974, the first reactor of the "Kozloduy" NPP was put into operation.
The nuclear power plant “Kozloduy” is the first nuclear power plant in Bulgaria and in Southeast Europe.
The beginning of the Bulgarian nuclear energy was established on July 15, 1966 with the signing of an agreement on cooperation between Bulgaria and the then Soviet Union for the construction of a nuclear power plant. After a detailed technical and economic analysis, the construction site was chosen on the Danube River, near the town of Kozloduy.
NPP "Kozloduy" EAD is located 200 km north of the Bulgarian capital Sofia and 5 km east of the city of Kozloduy, on the banks of the Danube River.
The plant's production facilities and auxiliary facilities are located on an area of about 1,000 acres. To the infrastructure of the NPP "Kozloduy" it also includes its own coastal pumping station and channels for technical water supply, with which the total territory of the nuclear power plant amounts to 4,471 acres.
The projects for the plant were prepared jointly by “Toploelektroproekt” – Moscow, and “Energoproject” – Sofia. The main equipment was supplied by the Soviet Union, and individual equipment – from the then German Democratic Republic, Czechoslovakia and Hungary. The first sod for the construction of the NPP “Kozloduy” was made on October 14, 1969. In April 1970, large-scale construction activities began for the construction of the facility, which is still unique in our country to this day, in which over a hundred thousand builders and installers participated.
Several entirely Bulgarian projects have been carried out on the site of the plant, which are being implemented for the first time in world practice in the construction of nuclear power plants. Some of these technical solutions are significant engineering achievements in which specialists from other countries show great interest.
On April 6, 1970, the construction of the main building of the “Kozloduy” NPP began. with a length of 240 m, a width of 105 m and a height of 40 m. It houses the reactor hall, the engine room, the ventilation center and the electrical devices of the 440 megawatt units. In June 1972, the first reactor arrived from the Soviet Union, and on November 20 of the same year it was lowered into its shaft.
The commissioning of the first nuclear power unit of the “Kozloduy” in 1974 recorded an important national achievement in the modern history of the country – the beginning of nuclear energy not only in Bulgaria, but also in Southeast Europe.
The construction and commissioning of the nuclear power of the Bulgarian nuclear power plant takes place in three stages:
I stage: 1970 – 1975 Construction and start-up of units 1 and 2 with water-water reactors VVER-440, model B-230, with two independent channels of safety systems.
Commissioning of 1 unit: 1974
Commissioning of Unit 2: 1975
II stage: 1973 – 1982 Construction and start-up of units 3 and 4 with water-water reactors VVER-440, advanced B-230 model with triple redundancy of safety systems.
Commissioning of Unit 3: 1980
Unit 4 launch: 1982
III stage: 1980 – 1991 Construction and start-up of units 5 and 6 with VVER-1000 reactors, model B-320 with hermetic protective shell, triple redundancy of safety systems.
Commissioning of Unit 5: 1987
Unit 6 launch: 1991
In fulfillment of the commitments undertaken by Bulgaria in connection with the country's accession to the European Union, at the end of 2002, the operation of units 1 and 2 was terminated, and at the end of 2006 – at 3 and 4 block.
By Decision of the Council of Ministers dated 20.12.2008, blocks 1 and 2 were declared as facilities for radioactive waste management (RAW), and together with the necessary movable property were granted to the State Enterprise “RAO” (DP RAO). The decision determined “NPP Kozloduy” EAD to continue to operate these blocks in accordance with the received licenses for operation in the condition "E". (without production of electricity and/or thermal energy with storage of spent nuclear fuel in the near-reactor pool) until the receipt of the relevant licenses from DP RAO.
On 18.10. In 2010, the NRA issued licenses to DP RAO for the operation of units 1 and 2 as radioactive waste management facilities that are subject to decommissioning, and terminated the licenses of the “Kozloduy” for operating the first two units in operational mode – state “E”.
Block 3 and 4 were declared facilities for the management of radioactive waste, which are subject to decommissioning, by the Decision of the Council of Ministers dated 19.12.2012. By the same decision, the two blocks with the necessary movable and immovable property were made available for management of State Enterprise “RAO”. Until the necessary licenses are obtained from DP RAO, “NPP Kozloduy” EAD continues to operate units 3 and 4 in fulfillment of the operating licenses for operation in the “E” mode.
On 25.02.2013, the NRA issued licenses to DP RAW for the operation of units 3 and 4 as radioactive waste management facilities that are subject to decommissioning. In connection with the issuance of the new licenses of DP RAO, the licenses of “NPP Kozloduy” EAD for operating units 3 and 4 in operating mode – state “E”.
A new stage in the development of the nuclear power plant begins with the successful implementation of the strategic for the national energy Project for the extension of the operation period of the fifth and sixth units. With the implementation of the project, the possibility of long-term operation of the nuclear facilities is substantiated – for the fifth block until 2047, and for the sixth – until 2051. In 2017, the Nuclear Regulatory Agency (NRA) renewed the license to operate the fifth unit for 10 years. The sixth unit's license for the next 10-year period was renewed in 2019. This is the maximum term under national legislation. After its expiration, the nuclear power plant will have to apply for the extension of the licenses of the units.