29 EDF nuclear reactors risk complete or partial loss of cooling systems –ASN
The French Nuclear Safety Authority (ASN) has issued an INES level 2 alert (scale of 0-7) due to the risk of loss of cooling systems for 20 of the reactors “of concern” operated by EDF.
The 29 reactors, with capacities ranging from 900 – 1300 MWe, are located at 12 nuclear power plants in the Belleville-sur-Loire, Cattenom, Chinon, Cruas, Dampierre-en-Burly, Golfech, Nogent-sur-Seine, Paluel, Saint-Alban and Saint-Laurent-des-Eaux NPPs, ASN reported.
The reactor heat sink could be lost owing to the unavailability of the pumps of the reactor essential service water system (SEC) as a result of internal flooding following an earthquake-induced rupture of the piping supplying water to the fire protection network (JPP system) and the raw water filtration network (SFI or CFI systems).
Vulnerability to Earthquakes
“The insufficient earthquake resistance of a JPP pipe was initially detected by EDF in the Belleville-sur-Loire NPP. Additional investigations requested by ASN and performed by EDF in early June 2017 revealed that several sections of these pipes were degraded, with thicknesses less than the minimum thickness required for earthquake resistance. This degradation is the result of corrosion which may have developed because of a lack of appropriate preventive maintenance. This event was provisionally rated level 1 on the INES scale on 2nd August 2017,” ASN reported.
Risk of Total Loss of Heat Sink
“EDF then took thickness measurements on piping sections of other systems (SFI and CFI) situated in the same areas as the JPP pipes, from early July to the end of September 2017, on all the EDF NPP reactors potentially concerned. Following this measurement campaign and then the earthquake resistance analysis of the piping concerned, EDF declared on 10th October 2017 that 20 reactors were concerned by a risk of total loss of heat sink (loss of both trains of the SEC system). This event is therefore rated level 2 on the INES…”
20 Reactors Subject to the INES Level 2 Alert (“Incident”)
- Belleville-sur-Loire NPP: reactors 1 and 2
- Cattenom NPP: reactors 1, 2, 3 and 4
- Chinon NPP: reactors B3 and B4
- Cruas NPP: reactors 1 and 4
- Dampierre-en Burly NPP: reactors 1, 2, 3 and 4
- Golfech NPP: reactors 1 and 2
- Nogent-sur-Seine NPP: reactors 1 and 2
- Saint-Laurent-des-Eaux NPP: reactors B1 and B2
9 Reactors subject to the INES Level 0 Alert (“Deviation”)
- Cruas NPP: reactors 2 and 3
- Paluel NPP: reactors 3 and 4
- Saint-Alban NPP: reactors 1 and 2
- Tricastin NPP: reactors 1, 3 and 4
EDF
Électricité de France (EDF) is the country’s main electricity generation and distribution company, managing 58 reactors. French Government owns about 85% of EDF shares.
Nuclear power forms 40% of France’s energy consumption, and is the largest source of electricity generation in the country, accounting for more than 76% of the total production of 546 TWh in 2015, the highest percentage in the world.
Fire Earth 