1999 Blayais Nuclear Power Plant flood
Encyclopedia
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. The event resulted in the loss of the plant's off-site power supply and knocked out several safety-related systems, resulting in a Level 2 event on the International Nuclear Event Scale
. The incident illustrated the potential for flooding to damage multiple items of equipment throughout a plant, weaknesses in safety measures, systems and procedures, and resulted in fundamental changes to the evaluation of flood risk at nuclear power plants and in the precautions taken.
s, is located on the Gironde estuary
near Blaye
, South Western France, operated by Électricité de France
. Due to records of over 200 floods along the estuary dating back to 585 AD, some 40 of which had been particularly extensive, the location of the plant was known to be susceptible to flooding, and reports of the 1875 floods mentioned that they were caused by a combination of a high tides and violent winds blowing along the axis of the estuary. The area had also experienced flooding during storms in the recent past, on December 13, 1981
and March 18, 1988. An official report on the 1981 floods
, published in 1982, noted that it 'would be dangerous to underestimate' the combined effects of tide and storm, and also noted that the wind had led to 'the formation of real waves on the lower flooded floodplain
'.
When the Blayais plant was designed in 1970s, it was on the basis that a height of 4 m (13.1 ft) above NGF level
would provide an 'enhanced safety level', and the base on which the plant was built was set at 4.5 m (14.8 ft) above NGF, although some components were located in basements at lower levels. The protective sea walls
around the Blayais plant were originally built to be 5.2 m (17.1 ft) above NGF level at the front of the site, and 4.75 m (15.6 ft) along the sides. The 1998 annual review of plant safety for the plant identified the need for the sea walls to be raised to 5.7 m (18.7 ft) above NGF, and envisaged that this would be carried out in 2000, although EDF later postponed the work until 2002. On 29 November 1999, the Regional Directorate for Industry, Research and the Environment sent a letter to EDF asking them to explain this delay.
caused a sudden rise of water in the estuary, flooding parts of the plant. The flooding began at around 7:30 pm, two hours before high tide, and it was later found that at its height the water had reached between 5 m (16.4 ft) and 5.3 m (17.4 ft) above NGF. The flooding also damaged the sea wall facing the Gironde, with the upper portion of the rock armour
being washed away.
Prior to the flooding, units 1, 2 and 4 were at full power, while unit 3 was shut down for refuelling. Starting from 7:30 pm all four units lost their 225 kV power supplies, while units 2 and 4 also lost their 400 kV power supplies. The isolator circuits that should have allowed units 2 and 4 to supply themselves with electricity also failed, causing these two reactors to automatically shut down, and diesel backup generators started up, maintaining power to plants 2 and 4 until the 400 kV supply was restored at around 10:20 pm. In the pumping room for unit 1, one set of the two pairs of pumps in the Essential Service Water System failed due to flooding; had both sets failed then the safety of plant would have been endangered. In both units 1 and 2, flooding in the fuel rooms put the low-head safety injection pumps and the containment spray pumps, part of the Emergency Core Cooling System (a back-up system in case of coolant loss) out of use. Over the following days, an estimated 90000 cubic metre of water would be pumped out of the flooded buildings.
) were informed, and a meeting of experts was convened at the IPSN at 7:45 am. At 9:00 am the Level 2 Internal Emergency Plan was finally activated by the Directorate of Nuclear Installation Safety (now the Nuclear Safety Authority
) and a full emergency management team of 25 people was formed, working in shifts around the clock. At noon on December 28, the incident was provisionally rated at 'level 1' on the International Nuclear Event Scale before being reclassified at 'level 2' the following day. The team was scaled back during December 30, and stood down around 6 pm the same day.
During the morning of December 28, the Institute for Nuclear Protection and Safety estimated that, if the emergency cooling water supply failed, there would have been over 10 hours in which to act before core meltdown
started.
On 5 January, the regional newspaper Sud-Ouest
ran the following headline without being contradicted: "Very close to a major accident", explaining that a catastrophe had been narrowly avoided.
A report on a number of samples taken after the flooding on January 8 and 9 found that the event had had no quantifiable effect on radiation levels.
, Chinon
, Dampierre
, Gravelines and Saint-Laurent
were all below the 'enhanced safety height' and that their safety measures should be re-examined. It also found that although the plants at Bugey
, Cruas
, Flamanville
, Golfech
, Nogent
, Paluel
, Penly
and Saint-Alban
met the first criterion, the second should be verified; and called for the plants at Fessenheim
and Tricastin to be re-examined since they were below the level of major adjacent canal
s. The consequent upgrading work, implemented over the following years, is estimated to have cost approximately 110,000,000 euro
.
In Germany, the flooding prompted the Federal Ministry for Environment, Nature Conservation and Nuclear Safety to order an evaluation of the German nuclear power plants
.
Following the events at Blayais, a new method of evaluating flood risk was developed. Instead of evaluating only the five factors required by Rule RFS I.2.e (river flood, dam failure, tide
, storm surge
and tsunami
), a further eight factors are now also evaluated: waves caused by wind on the sea; waves caused by wind on river or channel; swelling due to the operation of valves or pumps; deterioration of water retaining structures (other than dams); circuit or equipment failure; brief and intense rainfall on site; regular and continuous rainfall on site; and rises in groundwater. In addition, realistic combinations of such factors are taken into account.
Among the remedial actions taken at Blayais itself, the sea walls were raised to 8 m (26.2 ft) above NFG, – up to 3.25 m (10.7 ft) higher than before – and openings have been sealed to prevent water ingress.
under the TchernoBlaye banner (a portmanteau of the French spelling of Chernobyl
and Blaye
, the nearest town). The group gained support following the flood and their first protest march of between 1,000 and 1,500 people took place on April 23, but was blocked from reaching the plant by police using tear gas. The group continue their opposition to the plant, still under the presidency of Stéphane Lhomme.
The adequacy of the sea walls has, however, been disputed by Professor Jean-Noël Salomon, head of the Laboratory of Applied Physical Geography at Michel de Montaigne University Bordeaux 3
, who believes that, due to the potential harm and economic cost that would result from a future flood-related disaster, the sea walls should be designed to withstand simultaneous extreme events, rather than simultaneous major events.
Flood
A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...
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
Blayais Nuclear Power Plant
The Blayais Nuclear Power Plant is a nuclear plant on the banks of the Gironde estuary near Blaye, South Western France operated by Électricité de France.-Description:...
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...
being overwhelmed. The event resulted in the loss of the plant's off-site power supply and knocked out several safety-related systems, resulting in a Level 2 event 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....
. The incident illustrated the potential for flooding to damage multiple items of equipment throughout a plant, weaknesses in safety measures, systems and procedures, and resulted in fundamental changes to the evaluation of flood risk at nuclear power plants and in the precautions taken.
Background
The Blayais plant, equipped with four pressurized water reactorPressurized 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, is located on the Gironde estuary
Gironde estuary
The Gironde is a navigable estuary , in southwest France and is formed from the meeting of the rivers Dordogne and Garonne just below the centre of Bordeaux...
near Blaye
Blaye
Blaye is a commune and subprefecture in the Gironde department in Aquitaine in southwestern France.-Population:Its inhabitants are called Blayais or the Blayaises.-Geography:...
, South Western France, operated by Électricité de France
Électricité de France
Électricité de France S.A. is the second largest French utility company. Headquartered in Paris, France, with €65.2 billion in revenues in 2010, EDF operates a diverse portfolio of 120,000+ megawatts of generation capacity in Europe, Latin America, Asia, the Middle East and Africa.EDF is one of...
. Due to records of over 200 floods along the estuary dating back to 585 AD, some 40 of which had been particularly extensive, the location of the plant was known to be susceptible to flooding, and reports of the 1875 floods mentioned that they were caused by a combination of a high tides and violent winds blowing along the axis of the estuary. The area had also experienced flooding during storms in the recent past, on December 13, 1981
European storm, December 13, 1981
The European storm, December 13, 1981 was a severe storm that particularly affected southern England, Wales and south west France during December 13, 1981.In England, the storm started with violent winds and snow, which reached Cornwall during the morning...
and March 18, 1988. An official report on the 1981 floods
European storm, December 13, 1981
The European storm, December 13, 1981 was a severe storm that particularly affected southern England, Wales and south west France during December 13, 1981.In England, the storm started with violent winds and snow, which reached Cornwall during the morning...
, published in 1982, noted that it 'would be dangerous to underestimate' the combined effects of tide and storm, and also noted that the wind had led to 'the formation of real waves on the lower flooded floodplain
Floodplain
A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...
'.
When the Blayais plant was designed in 1970s, it was on the basis that a height of 4 m (13.1 ft) above NGF level
General levelling of France
The General Levelling of France forms a network of benchmarks in mainland France and Corsica, now overseen by the Institut Géographique National. It is now the official levelling network in mainland France...
would provide an 'enhanced safety level', and the base on which the plant was built was set at 4.5 m (14.8 ft) above NGF, although some components were located in basements at lower levels. The protective sea walls
Seawall
A seawall is a form of coastal defence constructed where the sea, and associated coastal processes, impact directly upon the landforms of the coast. The purpose of a seawall is to protect areas of human habitation, conservation and leisure activities from the action of tides and waves...
around the Blayais plant were originally built to be 5.2 m (17.1 ft) above NGF level at the front of the site, and 4.75 m (15.6 ft) along the sides. The 1998 annual review of plant safety for the plant identified the need for the sea walls to be raised to 5.7 m (18.7 ft) above NGF, and envisaged that this would be carried out in 2000, although EDF later postponed the work until 2002. On 29 November 1999, the Regional Directorate for Industry, Research and the Environment sent a letter to EDF asking them to explain this delay.
Flooding
On December 27, 1999, a combination of the incoming tide and exceptionally high winds produced by Storm MartinMartin (storm)
Martin was a violent European windstorm which crossed southern Europe on 27–28 December 1999, one day after another powerful storm, Lothar....
caused a sudden rise of water in the estuary, flooding parts of the plant. The flooding began at around 7:30 pm, two hours before high tide, and it was later found that at its height the water had reached between 5 m (16.4 ft) and 5.3 m (17.4 ft) above NGF. The flooding also damaged the sea wall facing the Gironde, with the upper portion of the rock armour
Riprap
Riprap — also known as rip rap, rubble, shot rock or rock armour or "Rip-rap" — is rock or other material used to armor shorelines, streambeds, bridge abutments, pilings and other shoreline structures against scour, water or ice erosion.It is made from a variety of rock types, commonly granite or...
being washed away.
Prior to the flooding, units 1, 2 and 4 were at full power, while unit 3 was shut down for refuelling. Starting from 7:30 pm all four units lost their 225 kV power supplies, while units 2 and 4 also lost their 400 kV power supplies. The isolator circuits that should have allowed units 2 and 4 to supply themselves with electricity also failed, causing these two reactors to automatically shut down, and diesel backup generators started up, maintaining power to plants 2 and 4 until the 400 kV supply was restored at around 10:20 pm. In the pumping room for unit 1, one set of the two pairs of pumps in the Essential Service Water System failed due to flooding; had both sets failed then the safety of plant would have been endangered. In both units 1 and 2, flooding in the fuel rooms put the low-head safety injection pumps and the containment spray pumps, part of the Emergency Core Cooling System (a back-up system in case of coolant loss) out of use. Over the following days, an estimated 90000 cubic metre of water would be pumped out of the flooded buildings.
Response
Around two and a half hours after the flooding began, a high-tide alarm for the estuary was triggered in the observation room of plant 4, although those in the other plants failed to activate. This should have caused the control room operators to launch a 'Level 2 Internal Emergency Plan', however this was not done as the requirement had been omitted from the operation room manual; instead they continued to follow the procedure for the loss of the off-site power supply, so failing to shut down the operating reactors at the earliest opportunity to allow the residual heat to start to dissipate. At 3:00 am on December 28, the power plant's emergency teams were called to reinforce the staff already on site; at 6:30 the management of the Institute for Nuclear Protection and Safety (now part of the Radioprotection and Nuclear Safety InstituteInstitut de radioprotection et de sûreté nucléaire
The French Institut de radioprotection et de sûreté nucléaire is a public official establishment with an industrial and commercial aspect created by the AFSSE Act and by the February 22, 2002 decreed n°2002-254...
) were informed, and a meeting of experts was convened at the IPSN at 7:45 am. At 9:00 am the Level 2 Internal Emergency Plan was finally activated by the Directorate of Nuclear Installation Safety (now the Nuclear Safety Authority
Autorité de sûreté nucléaire
The Autorité de sûreté nucléaire is an independent French administrative authority set up by law 2006-686 of 13 June 2006 concerning nuclear transparency and safety. Its task, on behalf of the State, is to regulate nuclear safety and radiation protection in order to protect workers, patients, the...
) and a full emergency management team of 25 people was formed, working in shifts around the clock. At noon on December 28, the incident was provisionally rated at 'level 1' on the International Nuclear Event Scale before being reclassified at 'level 2' the following day. The team was scaled back during December 30, and stood down around 6 pm the same day.
During the morning of December 28, the Institute for Nuclear Protection and Safety estimated that, if the emergency cooling water supply failed, there would have been over 10 hours in which to act before core meltdown
Nuclear meltdown
Nuclear meltdown is an informal term for a severe nuclear reactor accident that results in core damage from overheating. The term is not officially defined by the International Atomic Energy Agency or by the U.S. Nuclear Regulatory Commission...
started.
On 5 January, the regional newspaper Sud-Ouest
Sud-Ouest (newspaper)
Sud-Ouest is the third regional daily in France in terms of circulation. It was created in Bordeaux, on August 29, 1944 by Jacques Lemoine, as a successor to La Petite Gironde. In 1949, the Sunday edition, Sud-Ouest Dimanche was launched. Sud-Ouest covers the Gironde, the Charente, the...
ran the following headline without being contradicted: "Very close to a major accident", explaining that a catastrophe had been narrowly avoided.
A report on a number of samples taken after the flooding on January 8 and 9 found that the event had had no quantifiable effect on radiation levels.
Aftermath
The Institute for Nuclear Protection and Safety issued a report on January 17, 2000, calling for a review of the data used to calculate the height of the surface on which nuclear power stations are built. It suggested that two criteria should be met: that buildings containing equipment important for safety should be built on a surface at least as high as the highest water level plus a safety margin (the cote majorée de sécurité or 'enhanced safety height'), and that any such buildings below this level should be sealed to prevent water ingress. It also contained an initial analysis which found that, in addition to Blayais, the plants as BellevilleBelleville Nuclear Power Plant
The Belleville Nuclear Power Plant is located in Belleville-sur-Loire near Léré, Cher, along the Loire River between Nevers and Orléans . It employs approximately 620 people and consists of two large 1,300 MW P4 nuclear reactors...
, Chinon
Chinon Nuclear Power Plant
The Chinon Nuclear Power Plant is near the town of Avoine in the French Indre et Loire département, on the Loire river . The power station has seven reactors, of which three are now closed....
, Dampierre
Dampierre Nuclear Power Plant
The Dampierre nuclear power plant is located in the town of Dampierre-en-Burly , 55 km upstream of Orleans and 110 km downstream of Nevers, it uses water from the Loire for cooling.Approximately 1,100 people work at the site.-Seismic risk:...
, Gravelines and Saint-Laurent
Saint-Laurent Nuclear Power Plant
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....
were all below the 'enhanced safety height' and that their safety measures should be re-examined. It also found that although the plants at Bugey
Bugey Nuclear Power Plant
The Bugey Nuclear Power Station is located in Bugey in the Saint-Vulbas commune , about 30 km from the Swiss border. The site occupies 100 hectares. It is on the edge of the Rhône River, from where it gets its cooling water, and is about 30 km upstream from Lyon...
, Cruas
Cruas Nuclear Power Plant
The Cruas Nuclear Power Station is a Nuclear power plant located in Cruas and Meysse communes, Ardèche next to the Rhône River in France. The site is 35km north of Tricastin Nuclear Power Center and near the town of Montélimar....
, Flamanville
Flamanville Nuclear Power Plant
The Flamanville Nuclear Power Plant is located at Flamanville, Manche, France on the Cotentin Peninsula.It houses two pressurized water reactors that produce 1300 MWe each and came into service in 1986 and 1987, respectively. It produced 18.9 TWh in 2005, which amounted to 4% of the electricity...
, Golfech
Golfech Nuclear Power Plant
The Golfech Nuclear Power Plant is located in the commune of Golfech , on the border of Garonne between Agen and Toulouse on the Garonne River, from where it gets cooling water, and approximately 40 km west of Montauban.The station has two operating nuclear reactors that are both pressurized...
, Nogent
Nogent Nuclear Power Plant
The Nogent Nuclear Power Plant is located in the French commune of Nogent-sur-Seine, on the right bank of the Seine, in the west of the Aube department. It is located to the west of Troyes and south-east of Paris....
, Paluel
Paluel Nuclear Power Plant
The Nuclear power station Paluel lies within the French town Paluel in Normandy in the Département Seine-Maritime. The nuclear power station, which consists of four 1330 MWe class pressurized water reactors, is about 40 kilometers far away from the city of Dieppe and employs approx. 1,250 full...
, Penly
Penly Nuclear Power Plant
The Penly Nuclear power station is found some northeast of Dieppe. It lies on the border of two French municipalities: Penly and Saint-Martin-en-Campagne in the département of Seine-Maritime, Normandy, on the English Channel coast.-Data:...
and Saint-Alban
Saint-Alban Nuclear Power Plant
The Saint-Alban nuclear power plant is located on the Rhone river, in the Isere department 50 km upstream from Lyon in the communes of Saint-Alban-du-Rhône and Saint-Maurice-l'Exil.-Description:...
met the first criterion, the second should be verified; and called for the plants at Fessenheim
Fessenheim Nuclear Power Plant
The Fessenheim Nuclear Power Plant is located in the Fessenheim commune in the Haut-Rhin department in Alsace in north-eastern France, north east of the Mulhouse urban area, within of the border with Germany, and approximately from Switzerland...
and Tricastin to be re-examined since they were below the level of major adjacent canal
Canal
Canals are man-made channels for water. There are two types of canal:#Waterways: navigable transportation canals used for carrying ships and boats shipping goods and conveying people, further subdivided into two kinds:...
s. The consequent upgrading work, implemented over the following years, is estimated to have cost approximately 110,000,000 euro
Euro
The euro is the official currency of the eurozone: 17 of the 27 member states of the European Union. It is also the currency used by the Institutions of the European Union. The eurozone consists of Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg,...
.
In Germany, the flooding prompted the Federal Ministry for Environment, Nature Conservation and Nuclear Safety to order an evaluation of the German nuclear power plants
Nuclear power in Germany
Nuclear power in Germany accounted for 23% of national electricity consumption, before the permanent shutdown of 8 plants in March 2011. German nuclear power began with research reactors in the 1950s and 1960s with the first commercial plant coming online in 1969...
.
Following the events at Blayais, a new method of evaluating flood risk was developed. Instead of evaluating only the five factors required by Rule RFS I.2.e (river flood, dam failure, tide
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the moon and the sun and the rotation of the Earth....
, storm surge
Storm surge
A storm surge is an offshore rise of water associated with a low pressure weather system, typically tropical cyclones and strong extratropical cyclones. Storm surges are caused primarily by high winds pushing on the ocean's surface. The wind causes the water to pile up higher than the ordinary sea...
and tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
), a further eight factors are now also evaluated: waves caused by wind on the sea; waves caused by wind on river or channel; swelling due to the operation of valves or pumps; deterioration of water retaining structures (other than dams); circuit or equipment failure; brief and intense rainfall on site; regular and continuous rainfall on site; and rises in groundwater. In addition, realistic combinations of such factors are taken into account.
Among the remedial actions taken at Blayais itself, the sea walls were raised to 8 m (26.2 ft) above NFG, – up to 3.25 m (10.7 ft) higher than before – and openings have been sealed to prevent water ingress.
Protests
Twelve days prior to the floods, a local anti-nuclear group was formed by Stéphane LhommeStéphane Lhomme
Stéphane Lhomme is president of Tchernoblaye association, and was speaker of "Sortir du nucléaire" Network during 2002-2010....
under the TchernoBlaye banner (a portmanteau of the French spelling of Chernobyl
Chernobyl disaster
The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine , which was under the direct jurisdiction of the central authorities in Moscow...
and Blaye
Blaye
Blaye is a commune and subprefecture in the Gironde department in Aquitaine in southwestern France.-Population:Its inhabitants are called Blayais or the Blayaises.-Geography:...
, the nearest town). The group gained support following the flood and their first protest march of between 1,000 and 1,500 people took place on April 23, but was blocked from reaching the plant by police using tear gas. The group continue their opposition to the plant, still under the presidency of Stéphane Lhomme.
Ongoing concerns
Due to the remedial works the plant is now believed to be adequately protected from flooding, however the access roadway remains low-lying and vulnerable. Due to this, particularly since the 2011 Fukushima I nuclear accidents in Japan, concerns have been raised over the potential difficulty of getting help to the plant in an emergency.The adequacy of the sea walls has, however, been disputed by Professor Jean-Noël Salomon, head of the Laboratory of Applied Physical Geography at Michel de Montaigne University Bordeaux 3
Michel de Montaigne University Bordeaux 3
Michel de Montaigne Bordeaux 3 University is a French university, based in Bordeaux . It is under the Academy of Bordeaux.-See also:* University of Bordeaux* List of public universities in France by academy* Michel de Montaigne...
, who believes that, due to the potential harm and economic cost that would result from a future flood-related disaster, the sea walls should be designed to withstand simultaneous extreme events, rather than simultaneous major events.
See also
- Fukushima I nuclear accidents
- Nuclear power in FranceNuclear power in FranceNuclear power is the primary source of electric power in France. In 2004, 425.8 TWh out of the country's total production of 540.6 TWh of electricity was from nuclear power , the highest percentage in the world....
- Nuclear safetyNuclear safetyNuclear safety covers the actions taken to prevent nuclear and radiation accidents or to limit their consequences. This covers nuclear power plants as well as all other nuclear facilities, the transportation of nuclear materials, and the use and storage of nuclear materials for medical, power,...
- List of civilian nuclear accidents
- List of civilian nuclear incidents
- Risk assessmentRisk assessmentRisk assessment is a step in a risk management procedure. Risk assessment is the determination of quantitative or qualitative value of risk related to a concrete situation and a recognized threat...