Golfech Shuts Down Reactor Again Due to Warm Garonne

Golfech – 30 July 2026: French energy group EDF has again disconnected Reactor 2 at the Golfech nuclear power plant in the Tarn-et-Garonne department from the power grid. It is already the third interruption of the only reactor most recently available at the site in summer 2026. The reason is once again the high temperatures of the Garonne, from which the plant draws cooling water.

The shutdown came only a few days after the reactor had been restarted. Reactor 2 had been reconnected to the national power grid at 03:47 on 26 July after being offline due to the heat since 9 July. The plant had already been out of operation for the same reason between 23 June and 3 July. Repeated, sometimes longer interruptions have therefore characterized the reactor’s operations so far this summer.

Water-law requirements for the site are decisive. EDF must limit the plant’s output or temporarily shut down the reactor when the average daily temperature of the Garonne downstream of the plant exceeds 28 degrees Celsius. The requirement stems from an authorization issued on 18 September 2006. It is intended to prevent the discharge of cooling water heated during operation from placing an additional burden on the river beyond permissible limits.

The plant draws water from the Garonne for cooling and subsequently discharges a large portion of it back into the river. According to EDF, the returned water raises the Garonne’s temperature by an average of 0.2 degrees Celsius. Between 1 June and 30 September, the additional warming at the discharge point may not exceed 1.25 degrees Celsius. High baseline river temperatures therefore reduce the operational margin available to the plant.

The renewed shutdown affects the site during a period of high summer electricity demand. Reactor 1 is also not generating electricity: it has been offline since 8 May for a scheduled partial overhaul. During such maintenance periods, fuel elements are replaced and technical inspections and maintenance work are carried out, among other measures. Golfech has two pressurized-water reactors, each with an electrical capacity of 1,300 megawatts. The site is therefore currently unable to feed electricity into the French grid.

According to the published information, the shutdown is a mandatory measure to protect the river, rather than a reported technical incident. French nuclear regulator ASNR notes that nuclear reactors located on rivers must reduce output or be shut down completely when water temperatures are high in order to protect aquatic ecosystems. EDF initiated the first shutdown in June as a precaution, before the relevant temperature threshold had been reached.