As a result of the gas supply crisis in Europe, Bulgaria has announced the start of activities to begin producing electricity from Kozloduy 3, a 405 MW reactor that was shut down in 2006. The reactor has been purposely maintained in a condition that would allow it to be restarted within approximately one month if the country determined that its power was required. Kozloduy 4, an identical reactor, is also available if necessary. A 405 MWe reactor is roughly equivalent to 2 million cubic meters (75 million cubic feet) of natural gas per day.
Bulgaria is one of the countries that is most affected by the shut off of natural gas from Russia into Ukraine and thus into most of the European natural gas supply system. Until Bulgaria began its quest for accession into the EU, it operated six nuclear power plants (Kozloduy 1,2,3,4,5 and 6 – all Pressurized Water Reactors – Russian VVER models) at a site that had hosted nuclear plants continuously since 1974. The six units produced more electricity than the country needed, so it was a net exporter of power to many of its neighbors.
Because the reactors were built to Soviet standards, rather than Western standards, Bulgaria invested a large amount of money and effort into upgrading all of them and installing modern safety equipment. That effort enabled the country to continue operating the reactors and supplying most of its internal electrical power needs plus some of the needs of its neighbors, but the effort was not good enough for the European Union.
As enticement to shut down the reactors, the EU paid Bulgaria 200 million euro and promised accession to the EU if it would shut down units 1 and 2 in December 2002. Upon further negotiation, shutdown dates in 2006 were agreed upon for units 3 and 4 with an additional payment of 300 million euro. The Bulgarians were quite reluctant; they believed that the upgrades installed in units 3 and 4 had made the reactors fully compliant with IAEA standards, and the IAEA agreed. From Nuclear Power in Bulgaria
Then in 2003, after a 2-week scrutiny by 18 international inspectors, the World Association of Nuclear Operators (WANO) reported that units 3 & 4 met all necessary international standards for safe operation. This confirmed the earlier IAEA report. WANO said that after more than a decade of safety upgrades on units 3 & 4 in line with IAEA recommendations: “operational, seismic and design safety at Kozloduy now corresponds to the level of improvements seen at plants of similar vintage elsewhere. Many of the safety measures adopted for these plants in the design, operation and seismic areas exceeded those that were foreseen.”
The EU refused to renegotiate the previously signed agreement and established a position that prevented Bulgarian accession without shutting down the reactors. Bulgaria really wanted to become a member of the EU so it reluctantly shut down two well operated and maintained pressurized water reactors and became far more dependent on burning natural gas to produce electricity.
My hope is that once Bulgaria begins operating Kozloduy 3, it will start up Kozloduy 4 and operate both plants through the rest of their useful lives. It would be a good outcome of the crisis.