View source for Engineering:Saint-Laurent Nuclear Power Plant

{{Short description|Nuclear power plant located in France}}
{{Infobox power station
| name                    = Saint-Laurent Nuclear Power Plant
| name_official           = Centrale Nucléaire de Saint-Laurent
| image                   = Saint-laurent-nouan.JPG
| image_caption           = Saint-Laurent Nuclear Power Plant
| location_map_size       = 
| location_map_caption    = 
| coordinates             = {{coord|47|43|12|N|01|34|39|E|region:FR_type:landmark|display=inline,title}}
| country                 = France
| location                = Saint-Laurent-Nouan
| status                  = Operational
| construction_began      = 1963
| commissioned            = {{start date and age|24 March 1969}}<br/>(Saint-Laurent A)<br/>{{start date and age|1983}}<br/>(Saint-Laurent B)
| decommissioned          = {{end date and age|1990}}<br/>(Saint-Laurent A-1)<br/>{{end date and age|1991}}<br/>(Saint-Laurent A-2)
| cost                    = 
| operator                = EDF 
| ps_units_operational    = 2 x 956&nbsp;MW
| ps_units_decommissioned = 1 x 390&nbsp;MW<br>1 x 450&nbsp;MW
| np_reactor_type         = GCR (retired)<br>[[Engineering:Pressurized water reactor|PWR]]
| np_reactor_supplier     = Framatome
| ps_units_manu_model     = [[Company:Alstom|Alstom]]
| ps_electrical_capacity  = 1,912
| ps_annual_generation    = 12,918
|ps_electrical_cap_fac = 77.1%<!-- 12,918,000 MWh/year / ( 1,912 MW * 365 days/year * 24h/day) = 0.771 -->
| website                 = {{URL|http://www.edf.fr/35075i/Accueilfr/InfosNucleaire/Planrapproche/Lessitesfrancais/Saint_Laurent.html}}
}}
The '''Saint-Laurent Nuclear Power Station''' is located in the commune of Saint-Laurent-Nouan in Loir-et-Cher on the Loire — {{convert|28|km|abbr=on}} upstream from Blois and {{convert|30|km|abbr=on}} downstream from Orléans.

The site includes two operating [[Engineering:Pressurized water reactor|pressurized water reactor]]s (each 900MWe), which began operation in 1983.  They are cooled by the water of the Loire River.

Two [[Engineering:UNGG reactor|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.<ref>[http://nucleaire.cea.fr/fr/publications/pdf/Elecnuc2006.pdf Elecnuc: Nuclear Power Plants in the World, CEA, 2006 ]</ref>

The site employs approximately 670 regular workers.

==Incidents==
On 17 October 1969, 50&nbsp;kg of [[Chemistry:Uranium|uranium]] in one of the gas-cooled reactors began to melt{{Citation needed|date=October 2019}}.  This event was classified at 4 on the [[Physics:International Nuclear Event Scale|International Nuclear Event Scale]] (INES),<ref name="IAEA-INES-Examples">{{cite web|url=http://www.iaea.org/Publications/Factsheets/English/ines.pdf|title=INES - The International Nuclear and Radiological Event Scale|date=1 August 2008|publisher=[[Organization:International Atomic Energy Agency|International Atomic Energy Agency]]|pages=2|accessdate=13 March 2011}}</ref> and is, as of December 2011, the most severe civil nuclear power accident in France.<ref name=echos-11-03-18>[https://archive.today/20120907010452/http://www.lesechos.fr/entreprises-secteurs/energie-environnement/actu/0201232126158.htm?xtor=RSS-2077 Les Echos - 18/03/11 - A Saint-Laurent, EDF a renoncé à construire une digue contre les inondations] Les Echos, published 2011-03-18, accessed 30 March 2011</ref>

On 13 March 1980, there was some [[Engineering:Annealing (metallurgy)|annealing]] that occurred in the [[Chemistry:Graphite|graphite]] of one of the reactors, causing a brief heat excursion.  This was also classified as 4 on the INES and has been called another worst nuclear accident in France.  Much later, the Institute of Marine Geochemistry at the ''École normale supérieure'' claimed that they found traces of [[Chemistry:Plutonium|plutonium]] in the river they believed was released in the 1980 or 1969 accident.<ref name=IRSN2015>{{Cite news|url=https://www.irsn.fr/fr/actualites_presse/actualites/pages/20150518_accidents-1980-1969-reacteurs-saint-laurent-des-eaux.aspx#.XaXaN-hKiUm|title=Accidents survenus en 1969 et 1980 à la centrale nucléaire de Saint-Laurent-des-Eaux (Loir-et-Cher) : l'IRSN publie une note d'information|date=18 May 2015|work=Institut de radioprotection et de sûreté nucléaire|access-date=15 October 2019|language=fr}}</ref><ref>[http://www.asn.fr/sections/rubriquesprincipales/publications/dossiers-controle/dossiers-controle-2000/rejet-installations/downloadFile/attachedFile_unvisible_f0/dossier_137_bis.pdf?nocache=1159191918.86  Contrôle 137, novembre 2000]{{dead link|date=May 2018 |bot=InternetArchiveBot |fix-attempted=yes }} [http://wikiwix.com/cache/?url=http://www.asn.fr/sections/rubriquesprincipales/publications/dossiers-controle/dossiers-controle-2000/rejet-installations/downloadFile/attachedFile_unvisible_f0/dossier_137_bis.pdf?nocache=1159191918.86&title=Contr%C3%B4le%20137%2C%20novembre%202000 archive] Les rejets des installations nucléaires (page 77, in French)</ref> However, tests conducted in 1993 by the IPSN and in 2003 by the IRSN determined that the levels of plutonium measured upstream and downstream from the power plant were similar and of the same order of magnitude, concluding that the presence of the plutonium was due to the fallout of aerial nuclear tests and not due to either the 1980 or 1969 accidents.<ref name=IRSN2015 />

On the morning of 12 January 1987 at 9 h 30, due to the exceptional frost of Loire, ice clogged the water intakes from the central A1 (GCR) and resulted in the loss of normal cooling. This caused the automatic shutdown of the gas-graphite reactor. The cooling system needed to remove the residual power failed as the diesel generators failed to start. It was necessary to feed it by the western power grid of France. The generators were eventually returned to service, just before the collapse of the power grid which took place around noon after a failure of the thermal power plant at Cordemais.<ref>Les jeux de l'atome et du hasard, Jean-Pierre Pharabod et Jean-Paul Schapira, Éditions Calmann-Lévy, 1988.</ref> The army was then called in<!--not a mistake--> to use explosives and destroy the ice blocking the water intakes.<ref>Le canard enchainé, 23 March 2011 : Petits pépins deviendront grands</ref>

On 12 May 2004, radioactive sodium was released into the atmosphere during a leak test of new steam generators of one of the reactors at the B plant. The incident, which resulted in the automatic shutdown of the reactor, was of no consequence for the environment according to EDF. [[Organization:Sortir du nucléaire (France)|Sortir du nucléaire]] noted however that when the automatic shutdown of the reactor happened, the control rods remained blocked for unknown reasons.<ref>radioactive Rejection at St-Laurent-des-Eaux, AFP of 13 May 2004</ref>

On 19 August 2011, reactor #1 stopped after a failure.<ref>[http://www.tradingsat.com/edf-FR0010242511/actualites/arret-inattendu-du-reacteur-1-de-la-centrale-de-saint-laurent-des-eaux-238290.html  '' unexpected shutdown of the reactor 1 of the St-Laurent-des-Eaux ''] Trading on Sat 19 August 2011</ref>

==Flood risk==
The initial report following the 1999 Blayais Nuclear Power Plant flood, identified the Saint-Laurent plant as being at risk of flooding, and called for its safety measures to be re-examined.<ref name=IPNS-02-02-01>[http://www.irsn.fr/FR/expertise/rapports_expertise/Documents/surete/rapport_sur_l_inondation_du_site_du_blayais.pdf Rapport sur l'inondation du site du Blayais survenue le 27 décembre 1999] Institute for Nuclear Protection and Safety, published 2000-01-17, accessed 21 March 2011</ref> Plans to build a flood wall around the site were made but abandoned, it is thought, due to the cost.<ref name=echos-11-03-18 />

==Gallery==
<gallery>
Image:Centrale-nucleaire-Saint-Laurent-des-Eaux.jpg|Sunflowers and the nuclear power station
Image:A1 A2 saint laurent.JPG|The two GGRs
Image:Saint-Laurent des Eaux Centrale (2).jpg|The two GGRs
Image:Saint-Laurent des Eaux Centrale (1).jpg|The nuclear power plant
</gallery>

==References==
{{Reflist}}

==External links==
*[http://econtent.unm.edu/cdm4/item_viewer.php?CISOROOT=/nuceng&CISOPTR=58&CISOBOX=1&REC=1 St Laurent des eaux (UNGG reactors)], Nuclear Engineering International wall chart, August 1969

{{French nuclear power plants}}

[[Category:Graphite moderated reactors]]

{{Sourceattribution|Saint-Laurent Nuclear Power Plant}}