Fukushima nuclear accident, Japan

Saint-Laurent-des-Eaux nuclear accident, France

Saint-Laurent-des-Eaux nuclear accident, France

The Saint-Laurent-des-Eaux nuclear power plant is a functioning nuclear power plant in central France in the Center-Loire Valley region. The nuclear installation suffered two level 4 nuclear accidents on the INES scale in 1969 and 1980. Both nuclear accidents represented a turning point in the situation of nuclear energy in France.

The nuclear power plant is located on the banks of the Loire River, in the commune of Saint-Laurent-Noin, in the department of Loire and Cher, 30 km southwest of the city of Orleans. The Dampier nuclear power plant is 70 km east of the station.

The nuclear power plant has 2 off power units with gas-cooled UNGG reactors and 2 operating units with light water reactors with pressurized water (PWR) С2 of the Framatome design. Both nuclear reactors have a capacity of 965 megawatts each.

The nuclear accident in Saint-Laurent-des-Eaux in 1969

In 2969 the French nuclear power plant in Saint-Laurent-des-Eaux suffered a major nuclear accident.

The first UNGG-type gas-cooled uranium-graphite reactor at the Saint-Laurent nuclear power plant was put into operation on March 24, 1969. After six months of its work, one of the most serious incidents occurred at the plants Nuclear of France and the world.

On the night of October 17, 1969, during refueling as a result of equipment failure and operator error, the core of the nuclear reactor partially melted. As a result, 50 kg of uranium was melted, 47 of which were subsequently collected, even manually by employees. This case was classified by level 4 of the INES scale (international scale of nuclear events), which was the most serious nuclear incident in the history of French nuclear power plants.

On October 16, 1970, one year after the accident at the first reactor of the Saint-Laurent nuclear power plant, the power unit was restored. However, the debate on the advantages and disadvantages of nuclear energy remained open in France.

Nuclear accident in Saint-Laurent-des-Eaux in 1980

On March 13, 1980, the reactor of the second A-2 power unit of the Saint-Laurent-des-Eaux nuclear power plant sharply increased its activity of nuclear fission reactions. Consequently, the thermal energy in the reactor increased uncontrollably to the point where the core melted.

The fusion of the core involved a total of 20 kilograms of melted nuclear fuel. This accident at the Saint-Laurent nuclear power plant has also been classified at level 4 on the international scale of nuclear events (INES).

According to the operation of a nuclear power plant, there are different mechanisms to control the amount of fission reactions generated in the nucleus, for example, the control rods. Nuclear accidents are often preceded by a human error. However, on this occasion, the reason for the fusion of the combustible elements was damage to the elements themselves, which led to the fusion of two of the fuel rods. As a result of the accident, the installation staff had to discharge radioactive iodine into the atmosphere from March 22 to 26, 1980.

After the accident of 1980, work was done for 29 months to clean the second reactor of molten uranium. The work to eliminate the consequences of the incidents was carried out by more than half a thousand specialists. It was suggested that, in addition to radioactive iodine, plutonium would also seep into the atmosphere in the Loire River.

The second reactor was restarted in 1983 and operated until its closure in 1992.

Data de publicació: February 7, 2020
Última revisió: February 7, 2020