1999 Blayais Nuclear Power Plant flood
45°15′21″N 0°41′35″W / 45.255833°N 0.693056°W
The 1999 Blayais Nuclear Power Plant flood was a
Background
The Blayais plant, equipped with four
When the Blayais plant was designed in the 1970s, it was on the basis that a height of 4.0 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 (15 ft) above NGF,[4] 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 ft) above NGF level at the front of the site, and 4.75 m (15.6 ft) along the sides.[6] The 1998 annual review of plant safety for the plant identified the need for the sea walls to be raised to 5.7 m (19 ft) above NGF, and envisaged that this would be carried out in 2000, although EDF later postponed the work until 2002.[6] On 29 November 1999, the Regional Directorate for Industry, Research and the Environment sent a letter to EDF asking them to explain this delay.[6]
Flooding
On December 27, 1999, a combination of the incoming tide and exceptionally high winds produced by
Prior to the flooding, units 1, 2 and 4 were at full power, while unit 3 was shut down for refuelling.
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;[1] 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 decay heat to start to dissipate.[6] 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 Institute) were informed, and a meeting of experts was convened at the IPSN at 7:45 am.[6] 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.[6] At noon on December 28, the incident was provisionally rated at 'level 1' on the International Nuclear Event Scale[7] before being reclassified at 'level 2' the following day.[8] The team was scaled back during December 30, and stood down around 6 pm the same day.[6]
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.[6]
On 5 January, the regional newspaper
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.[10]
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.[6] It also contained an initial analysis which found that, in addition to Blayais, the plants as Belleville, Chinon, Dampierre, Gravelines and Saint-Laurent were all below the 'enhanced safety height' and that their safety measures should be re-examined.[6] 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 canals.[6] The consequent upgrading work, implemented over the following years, is estimated to have cost approximately 110,000,000 euro.[3]
In Germany, the flooding prompted the
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.[3]
Among the remedial actions taken at Blayais itself, the sea walls were raised to 8.0 m (26.2 ft) above NFG,[4] – up to 3.25 m (10.7 ft) higher than before – and openings have been sealed to prevent water ingress.[3]
Protests
Twelve days prior to the floods, a local
Ongoing concerns
The remedial works are believed to now adequately protect the plant from flooding, but the access roadway remains low-lying and vulnerable. Due to this, particularly since the 2011
The seawalls at Blayais are now higher than the tsunami that hit Japan, knocking out the cooling systems at Fukushima Dai-ichi. The adequacy of the sea walls has, however, been disputed by Professor Jean-Noël Salomon, head of the Laboratory of Applied Physical Geography at
See also
- Fukushima I nuclear accidents
- Nuclear power in France
- Nuclear safety
- List of civilian nuclear accidents
- List of civilian nuclear incidents
- Risk assessment
References
- ^ a b c d e f g h i j k l Generic Results and Conclusions of Re-evaluating the Flooding in French and German Nuclear Power Plants Archived 2011-10-06 at the Wayback Machine J. M. Mattéi, E. Vial, V. Rebour, H. Liemersdorf, M. Türschmann, Eurosafe Forum 2001, published 2001, accessed 2011-03-21
- ^ COMMUNIQUE N°7 - INCIDENT SUR LE SITE DU BLAYAIS Archived 2013-05-27 at the Wayback Machine ASN, published 1999-12-30, accessed 2011-03-22
- ^ a b c d Lessons Learned from 1999 Blayais Flood: Overview of the EDF Flood Risk Management Plan, Eric de Fraguier, EDF, published 2010-03-11, accessed 2011-03-22
- ^ a b c d e f L'inondation dans la basse vallée de la Garonne et l'estuaire de la Gironde lors de la "tempête du siècle" (27-28 décembre 1999) / Flooding in the Garonne valley and the Gironde estuary caused by the "storm of the century" (27-28 December 1999) Salomon Jean-Noël, Géomorphologie: Relief, Processus, Environnement, Avril-juin, vol. 8, n°2. pp. 127-134, doi: 10.3406/morfo.2002.1134, accessed 2011-03-25
- ^ Crue de la Garonne, décembre 1981: éléments pour une analyse, A Dalmolin, Délégation régionale à l'architecture et à l'environnement d'Aquitaine, published 1982
- ^ a b c d e f g h i j k l m n o p Rapport sur l'inondation du site du Blayais survenue le 27 décembre 1999 Institute for Nuclear Protection and Safety, published 2000-01-17, accessed 2011-03-21
- ^ COMMUNIQUE N° 2 - INCIDENT SUR LE SITE DU BLAYAIS Archived 2011-07-22 at the Wayback Machine ASN, published 1999-12-28, accessed 2011-03-22
- ^ COMMUNIQUE N° 4 - INCIDENT SUR LE SITE DU BLAYAIS Archived 2011-07-22 at the Wayback Machine ASN, published 1999-12-29, accessed 2011-03-22
- ^ Sud-Ouest, 5 janvier 2000 - Centrale de Blaye: Très près de l'accident majeur
- ^ Point radioécologique de l'estuaire de la Gironde immédiatement après l'inondation du 27 décembre 1999 (Prélèvements des 8 et 9 janvier 2000) Institute for Nuclear Protection and Safety, published 2000-01-17, accessed 2011-03-21
- ^ a b L'histoire de TchernoBlaye TchernoBlaye, accessed 2011-03-29
- ^ In brief Archived 2012-03-26 at the Wayback Machine WISE, accessed 2011-03-29
- Sud-Ouest, published 2011-03-14, accessed 2011-03-22
- ^ La centrale nucléaire du Blayais suscite l'inquiétude, actualité Reuters Archived 2011-03-26 at the Wayback Machine Le Point, published 2011-03-21, accessed 2011-03-22