Saint-Laurent Nuclear Power Plant
Encyclopedia
The Saint-Laurent Nuclear Power
Station is located in the commune of Saint-Laurent-Nouan
in Loir-et-Cher
on the Loire River – 28 km downstream from Blois
and 30 km upstream from Orléans
.
The site includes two operating pressurized water reactor
s (each 900MWe), which began operation in 1983. They are cooled by the water of the Loire River.
Two other UNGG reactor
s used to exist at the site, which were brought into service in 1969 and 1971 and were retired in April 1990 and June 1992.
The site employs approximately 670 regular workers.
in one of the gas cooled reactors began to melt. This event was classified at 4 on the International Nuclear Event Scale
(INES), and is, as of March 2011, the most serious civil nuclear power accident in France.
On March 13, 1980 there was some annealing
that occurred in the graphite
of one of the reactors, causing a brief heat excursion. This was also classified as 4 on the INES and has been called the worst nuclear accident in France
. Much later, the Institute of Marine Biochemistry at the École normale supérieure de Montrouge
claimed that they found traces of plutonium
in the river which they believed was released in the 1980 or 1969 accident many years ago.
, identified the Saint-Laurent plant as being at risk of flooding, and called for its safety measures to be re-examined. Plans to build a flood wall
around the site were made but abandoned, it is thought, due the cost.
Nuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...
Station is located in the commune of Saint-Laurent-Nouan
Saint-Laurent-Nouan
Saint-Laurent-Nouan is a commune in the Loir-et-Cher department of central France.-History:Saint-Laurent-Nouan was formed in 1972 from the merger of the two former communes, Saint-Laurent-des-Eaux and Nouan-sur-Loire.-References:*...
in Loir-et-Cher
Loir-et-Cher
Loir-et-Cher is a département in north-central France named after the rivers Loir and Cher.-History:Loir-et-Cher is one of the original 83 departments created during the French Revolution on 4 March 1790. It was created from parts of the former provinces of Orléanais and...
on the Loire River – 28 km downstream from Blois
Blois
Blois is the capital of Loir-et-Cher department in central France, situated on the banks of the lower river Loire between Orléans and Tours.-History:...
and 30 km upstream from Orléans
Orléans
-Prehistory and Roman:Cenabum was a Gallic stronghold, one of the principal towns of the Carnutes tribe where the Druids held their annual assembly. It was conquered and destroyed by Julius Caesar in 52 BC, then rebuilt under the Roman Empire...
.
The site includes two operating pressurized water reactor
Pressurized water reactor
Pressurized water reactors constitute a large majority of all western nuclear power plants and are one of three types of light water reactor , the other types being boiling water reactors and supercritical water reactors...
s (each 900MWe), which began operation in 1983. They are cooled by the water of the Loire River.
Two other UNGG reactor
UNGG reactor
The UNGG is an obsolete design of nuclear power reactor developed by France. It was graphite moderated, cooled by carbon dioxide, and fueled with natural uranium metal....
s used to exist at the site, which were brought into service in 1969 and 1971 and were retired in April 1990 and June 1992.
The site employs approximately 670 regular workers.
Incidents
On October 17, 1969 50 kg of uraniumUranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
in one of the gas cooled reactors began to melt. This event was classified at 4 on the International Nuclear Event Scale
International Nuclear Event Scale
The International Nuclear and Radiological Event Scale was introduced in 1990 by the International Atomic Energy Agency in order to enable prompt communication of safety significance information in case of nuclear accidents....
(INES), and is, as of March 2011, the most serious civil nuclear power accident in France.
On March 13, 1980 there was some annealing
Annealing (metallurgy)
Annealing, in metallurgy and materials science, is a heat treatment wherein a material is altered, causing changes in its properties such as strength and hardness. It is a process that produces conditions by heating to above the recrystallization temperature, maintaining a suitable temperature, and...
that occurred in the graphite
Graphite
The mineral graphite is one of the allotropes of carbon. It was named by Abraham Gottlob Werner in 1789 from the Ancient Greek γράφω , "to draw/write", for its use in pencils, where it is commonly called lead . Unlike diamond , graphite is an electrical conductor, a semimetal...
of one of the reactors, causing a brief heat excursion. This was also classified as 4 on the INES and has been called the worst nuclear accident in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
. Much later, the Institute of Marine Biochemistry at the École normale supérieure de Montrouge
Montrouge
Montrouge is a commune in the southern Parisian suburbs, located from the center of Paris, France. It is one of the most densely populated municipalities in Europe...
claimed that they found traces of plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
in the river which they believed was released in the 1980 or 1969 accident many years ago.
Flood risk
The initial report following the 1999 Blayais Nuclear Power Plant flood1999 Blayais Nuclear Power Plant flood
The 1999 Blayais Nuclear Power Plant flood was a flood that took place on the evening of December 27, 1999. It was caused when a combination of the tide and high winds led to the sea walls of the Blayais Nuclear Power Plant in France being overwhelmed...
, identified the Saint-Laurent plant as being at risk of flooding, and called for its safety measures to be re-examined. Plans to build a flood wall
Flood wall
A flood wall is a primarily vertical artificial barrier designed to temporarily contain the waters of a river or other waterway which may rise to unusual levels during seasonal or extreme weather events...
around the site were made but abandoned, it is thought, due the cost.