Heat wave: EDF could further reduce its nuclear production

Hard hit for EDF. While more than half of the 56 nuclear reactors are already shut down due to maintenance or corrosion problems, the electrician could be forced to further reduce its nuclear power production in the coming days and even halt one of the four reactors at the Tricastin (Drôme) power station. due to the high temperatures of the rivers. This is during the production of nuclear power Today, “with 290 terawatt hours at the lowest level in years” (compared to a capacity of 460 TW in normal times), Economics Minister Bruno Le Maire recently recalled.

Restrictions from August 6th

“Due to the high temperatures forecast on the Rhône, production restrictions at the Tricastin nuclear power plant are likely to occur from August 6, 2022, up to and including the shutdown of a block,” says the electricity producer. “However, a production of at least 400 MW must be ensured with the maintenance of 2 units coupled for grid reasons”, specifies 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 discharge heated water bound by temperature limits to preserve aquatic biodiversity. EDF sometimes reduces the power of its reactors – or even shuts them down – to conserve the temperature of the waterways.

Since last Friday, EDF has been sounding the alarm, warning that the plant’s production could be affected by the heating of the waterways used to cool the reactors.

“So far, only Tricastin Reactor #2 has modulated its power to meet its discharge order (twice for a few hours on July 29 and 31),” an AFP spokesman said Tuesday after noon.

Other plants could be affected

In addition, EDF also warned of possible “cuts in production” at the Saint-Alban (Isère) power plant, also on the banks of the Rhône, although minimum production is also planned. Such restrictions are also being considered at the Golfech power station (Tarn-et-Garonne), this time due to high temperature forecasts for another river, the Garonne.

Since 2006, each power plant has had its own official water discharge temperature limits, which must not be exceeded in order not to overheat the surrounding water bodies and to protect their fauna and flora. The power plants actually pump water to cool the reactors before rejecting it. The regulations provide for possible temporary exceptions in certain locations to allow them to operate at high temperatures and ensure the operation of the infrastructures.

Restrictions will accelerate in 2022

So far they have only been used once, in 2018 for the Golfech power plant, and that for 36 hours, but such deviations from the environmental regulations are skyrocketing this year. Due to the heat early this year, EDF had to reduce the power of a reactor for a few hours already in May in Blayais and then in June in Saint-Alban. In mid-July, derogations were granted until July 24 for the Golfech, Blayais (Gironde), Saint-Alban and Bugey power stations in Ain.

The power stations most at risk of exceeding thermal water discharge limits are Golfech, Le Blayais, and Bugey, Saint-Alban and Tricastin on the Rhône. Added to this is Chooz in the Ardennes thanks to a Franco-Belgian agreement on the Meuse river, which EDF announced in early July.

In mid-June, EDF said that losses due to high temperatures or low river flow have averaged 0.3% of the park’s annual production since 2000. However, according to RTE, heat waves have already resulted in the simultaneous unavailability of reactors reaching almost 6 GW, or about 10% of installed capacity, and this problem is expected to increase in the coming years.

In addition to their impact on biodiversity, the debate over exemptions calls into question the use of fuel oil combustion turbines to meet rising demand, rather than nuclear power, as has been done recently.

Heating oil instead of nuclear power to generate electricity in times of heat waves: a challenging choice