Strong blow for EDF. While more than half of the country’s 56 nuclear reactors have been shut down for maintenance or corrosion problems, the utility may be forced to further reduce its nuclear production in the coming days and even shut down one in four. reactors of the Tricastin power plant (Drôme) due to the high temperature of the rivers. This is while the production of nuclear electricity is now “at the lowest in years with 290 terawatt hours” (against a capacity of 460 TW in normal times), recently recalled Bruno Le Maire, the Minister of Economy.
Restrictions from August 6
“Due to forecasts of high temperatures in the Rhône, production restrictions are likely to affect the Tricastin nuclear production site from August 6, 2022, possibly until the closure of a unit”, indicates the producer of electricity. “However, a production of at least 400 MW must be ensured with the maintenance of 2 units coupled for network constraints”, specified the group.
Tricastin has 4 reactors of 900 MW each.
As a reminder, nuclear reactors pump water into rivers or seas to cool them, and release hot water, discharges under temperature limits to preserve aquatic biodiversity. Sometimes EDF reduces the power of its reactors – or even shuts them down – to preserve the temperature of the water channels.
Since last Friday, EDF has sounded the alarm by warning that the production of the plant may be affected due to the heat of the water channels used to cool the reactors.
“At the moment, only the Tricastin reactor no. 2 is modulating its power to fulfill its discharge order (twice within a few hours on July 29 and July 31),” a spokesperson told AFP on Tuesday after noon.
Other plants may be affected
In addition, EDF has also warned of possible “production restrictions” at the power plant in Saint-Alban (Isère), also on the banks of the Rhône, although there is a planned minimum production. Such restrictions are also considered at the Golfech (Tarn-et-Garonne) power plant due, at this time, to high temperature forecasts for another river, the Garonne.
Since 2006, each power plant has its own regulatory water discharge temperature limits that must not be exceeded, in order not to heat up the surrounding waterways and protect their fauna and flora. Power plants actually pump water into reactors to cool them down, before turning them off. The regulations provide for possible temporary derogations in some sites so that they can operate during high temperatures and guarantee the operation of the infrastructures.
The restrictions are intensifying in 2022
While they have so far only been used once, in 2018 for the Golfech power plant, and it was for 36 hours, such derogations from environmental regulations are skyrocketing this year. With the early heat this year, EDF had to reduce the power of a reactor for a few hours in May in Blayais, then in June in Saint-Alban. In mid-July, exemptions were granted until July 24 at the power plants in Golfech, Blayais (Gironde), Saint-Alban, and Bugey in Ain.
The power plants most exposed to the risk of exceeding the thermal water flow limits are Golfech, Le Blayais, and Bugey, Saint-Alban and Tricastin in the Rhône. Added to this is Chooz, in the Ardennes, due to a Franco-Belgian agreement on the flow of the Meuse, EDF showed in early July.
In mid-June, EDF explained that since 2000, losses due to high temperatures or low river flows represent an average of 0.3% of the park’s annual production. However, according to RTE, heat waves have already caused the simultaneous incapacitation of reactors reaching almost 6 GW, or about 10% of the installed capacity, and this problem is expected to increase in the future. years.
In addition to their impact on biodiversity, the debate on derogations raises the question when fuel oil combustion turbines are called to meet the increase in demand and not nuclear electricity, as has happened recently.