Dr. Petar Kardjilov, a qualified expert at NTW
The lack of transparency in Bulgarian nuclear power industry has remained constant since the Chernobyl disaster. In Bulgaria there was no official announcement until the third day of the catastrophe of Lenin NPP reactor 4 and the state media were silent. When the government finally communicated news of the accident is was presented as limited and not particularly dangerous. Emphasis was placed on the fact that there was absolutely no danger to Bulgaria, although the radioactive cloud reached the country within a few days. The situation has not changed much since the totalitarian era.
The 2019 media freedom ranking of Reporters without Borders Bulgaria for the second consecutive year remains at a terrifying 111th place – last place in the European Union and the Balkans. Key obstacles for journalists are an inefficient justice system and corruption. One of the most prominent indications of this situation is the manner of informing the public and considering issues in the field of nuclear energy. Government and opposition politicians compete with one another each week in in the televised promotion of Bulgarian nuclear power plant construction needs (with old Russian reactors and in the seismic area of the Vrancha fault) in the Belene district on the Danube. Yet information about the problems, risks and incidents that have occurred at the existing Kozloduy NPP barely break through in the most influential media and are factually complete and correct in only a few independent Internet news media. The last incident in Unit 6 of Kozloduy NPP on Wednesday 3rd July was yet another case of concealing information in this area.
The following message appeared on the web page of Kozloduy NPP on 3rd July: “On 3rd July, 2019 at 1:50 pm the Sixth Kozloduy NPP Unit was disconnected from the country’s energy system after the electric protection was activated. All systems of the block have worked according to the design algorithms. At the moment the Nuclear Power Plant teams remove the causes of electrical protection activation. Once the equipment is operational, Unit 6 will again become part of the power system.” However, no such message was uploaded on the Energy Ministry website neither was it published on the Nuclear Regulatory Agency website. However the head of the Nuclear Regulatory Agency, Lachezar Kostov said in an interview for Routers the same afternoon: “The shutdown was triggered because of an anomaly in the second circuit – the power generation equipment and not due to a fault in the plant’s nuclear reactor. There was no danger of any radioactive contamination”.
All of evening television news networks on television channels broadcasted only a brief interview with the Energy Minister Temenujka Petkova, who assured the public that everything was fine and hat her colleagues from the Kozloduy NPP had acted quickly, correctly and professionally. Only the private national television station bTV invited the former chairman of the Nuclear Regulatory Agency and current independent expert on nuclear energy Prof. Georgi Kaschiev to comment the day after the incident.
According to Prof. Kaschiev the technical cause of the incident is the loosening of a signal cable in one of the terminals. This resulted in a short circuit that activated the mechanism for electrical protection of the generator and shut down the entire generator. He reported that there were at least five similar incidents in Unit 6 in 2005, 2011, 2012, 2015 and 2017 stating that such incidents are far from harmless and their accumulation is a serious alarm for professionals. Prof. Kaschiev explained that a huge flow of energy moves from the reactor, which is transformed into steam, the steam rotates the turbine and the mechanical energy of rotation in the generator turns into electricity. When you put a plug at the end of this stream the system may break. Therefore, the turbine is immediately shut down automatically, the reactor power is reduced as a group of drivers is thrown straight into it and others move downwards with a working speed. In this case, it is good that they have not lost the vacuum in the condensers. They can take up to 40% of the nominal steam flow, not through the turbine but through the condensers, so they have to reduce the reactor power to 40%. This process is very heavy. It happens within seconds with great changes in temperature and pressure. The reduction in reactor power is delayed by a few seconds, and there is a huge amount of energy in the primary circuit. As a general rule, the pressure in the secondary circuit is increased and protective devices are activated which release steam into the atmosphere. This creates a sound that is heard for kilometers, said Kaschiev and added:
“This is a thermal shock to the equipment and, if there are any defects, they are generally expanding, new ones may emerge. The number of such modes is limited over the lifetime of the reactor. Each such regime consumes a part of this resource. The power must be increased by 1% for one hour, and in this mode it drops from 100% to 40% within a few seconds. So from this point of view incidents like this are definitely undesirable. For example, for nuclear fuel tablets (fuel pins) at nominal power the average temperature is 1200 degrees or more. In the event of a sharp fall in the temperature, cracks in the tablets may occur. The fuel tablets are the first barrier, they retain the radioactive fission products. However, under such conditions gaseous products such as crypton, xenon, iodine are released out of them and accumulate under the shells, and if there are cracks in the shells, gas can go out of the coolant.”
In 2016, a five-member panel of the Supreme Administrative Court decided that the lifetime of the Kozloduy NPP units 5 and 6 could be extended without environmental impact assessments (EIA). The Court’s decision was taken despite the firm position of many organizations, citizens and two Romanian ministers that a full EIA should be carried out to extend the operation of the old reactors. On November 6, the National Regulator Agency issued a license to extend Unit 5 operation for 10 years, ignoring 11 problems identified by the IAEA Pre-SALTO mission in their nuclear safety assessment of both units. In their report, Pre-SALTO experts state there are 11 problems concerning “fundamental areas for improvement in the future”. This subject had a plausible representation in Bulgaria only by two news media on the Internet.
A second joint meeting between Romanian and Bulgarian experts, citizens, NGOs and representatives of the Bulgarian State Enterprise for Radioactive Waste occurred in Craiova, Romania on 17 July. The meeting was conducted as a part of the Project Complaint Mechanism (PCM) on behalf of the European Bank for Reconstruction and Development. The PCM was triggered by the civil society of Craiova and Dolj District due to the Bulgarian project to build a National Repository for low and intermediate-active short and long-lived radioactive waste on the site of Kozloduy NPP, only four kilometers away from the Danube and the border with Romania. Funding is administered by the EBRD and is within the Kozloduy NPP Units 1-4 Decommissioning Programme and the National Disposal Facility. There is also a media blackout in Bulgaria about number of violations of national and international law and the IAEA recommendations concerning the National repository. Representatives of Romanian and Bulgarian civil society have decided to send a letter of complaint to the donor countries, the European Commission and the EBRD on Monday 29 July. We will inform about the contents of the letter and the problems with the National Radioactive Waste Repository in Bulgaria in a subsequent article.
Petar Kardjilov obtained a PhD in Public Communications and Information Sciences at Sofia and specializes in risk and crisis communication. He Is also a public relations expert, member of the Union of Scientists in Bulgaria and Nuclear Transparency Watch.