While two-thirds of the water tables in mainland France are still below normal, the operation of nuclear power plants can be disrupted when watercourse temperature criteria are exceeded. This is explained by Karine Herviou, director general at the Institute of radiation protection and nuclear safety on franceinfo.
Operation of nuclear power plants “can be disturbed when temperature or flow criteria in these rivers are crossed as was the case last year”, explained on Wednesday on franceinfo Karine Herviou, deputy director general in charge of the nuclear safety pole at the Institute for radiation protection and nuclear safety (IRSN), while two thirds of the water tables in mainland France are still below normal. According to the Bureau of Geological and Mining Research (BRGM), responsible for monitoring groundwater, the state of these groundwater “changes only slightly and remains generally unsatisfactory”.
Can the operation of nuclear power plants be disrupted this summer due to drought?
The power stations draw water directly from the rivers. We have 38 reactors that are located along rivers. Their operation can be disrupted when temperature or flow criteria in these waterways are exceeded, as was the case last year. But it’s not for security reasons. It is essentially, initially, for reasons of protection of fauna and flora. On the Bugey plant, for example, if the temperature of the water after the plant exceeds 26 degrees, EDF must limit the power of the reactors or shut them down so as not to heat up the environment for reasons of environmental constraints.
For plants that operate in open circuit, they release water into the river, water that must not exceed a certain temperature. For this summer, should we expect exemptions?
Yes, depending on the evolution of the temperature. Then, it is the Safety Authority that decides on exemptions, in particular according to electricity needs. These are not safety reasons, but there are criteria to be met with regard to the protection of the environment. And there may be, if there is a need for high voltage on the electrical network, exemptions issued by the Nuclear Safety Authority.
Should these standards be reviewed?
EDF is working on it and has already made modifications to limit the heating of the water source. There are many studies on the subject. I don’t know if these criteria will be relaxed. In any case, EDF is working to limit the increase in water temperature between upstream and downstream of these plants.
For the Rhône, which has a sufficiently powerful flow, does this allow for slightly different restrictions?
In terms of safety, we always have sufficient flow on the Rhône power stations. It’s still reassuring. Temperatures are monitored, but again not for safety reasons.
If a central cannot reject, what would that mean?
This means a production stoppage. There are quantities of thermal effluents to be discharged. It can be constrained and if it can’t store them, it can’t function anymore.