Foto: Peter Woodman from flickr / https://creativecommons.org/licenses/by-sa/2.0/
A report released by the French Court of Auditors highlighted the issues regarding the safety and operation of nuclear power plants because of the increasingly unstable supply of the water necessary for cooling reactors. Drought and low water levels caused some plants to be turned off temporarily last summer. The auditors warned that the 56 existing reactors, as well as the planned ones, must be analyzed in the context of climate extremes such as prolonged droughts and rising water temperatures in rivers.
The auditors found that the consequences of climate change would affect the operation and safety of French nuclear power plants in various ways but that the impact would advance. The fleet consists of 56 reactors in 18 power plants across the country, and water availability is a major issue as it is necessary for cooling, the report reads.
Water availability is a major issue as it is necessary for cooling reactors
The consequences of climate change jeopardize the equipment but also affect the surroundings, water flow, river temperatures, air, flooding, and sea level. All other risks and the most extreme projections must be considered and a precise adaptation plan is necessary, the report reads.
Risks will become more frequent in the future
Over the past several years, France has been hit by severe droughts, causing a fall in water levels. Last year’s events prompted the conditions for reactor safety and operation to be reconsidered. Last summer, France’s nuclear safety agency ASN allowed temperature limits to be exceeded for some reactors to continue generating electricity.
Forced shutdowns of nuclear reactors due to low water levels are brief for now and occur only in the summer. However, the court warns that such events are set to become three to four times more frequent by 2050.
In the reactor cooling process, water is discharged back to the river, which increases its temperature. In another system, based on evaporation, less water is used.
EDF needs assess water availability
Électricité de France (EDF) must prepare nuclear power plants for the effects of global warming, but also the reactors it plans to build, the first of which is scheduled to come online in 2035. The state-owned utility must make water availability and water level projections for the next 10-15 years, the auditors added.
The court recommended not to commission the six planned EPR2 reactors without significant technological improvement and a cooling system that uses less water. EDF also needs to determine the locations of future reactors as soon as possible to secure water supply.
In the next 15 years, the company plans to invest EUR 619 million in reactor maintenance, embankment construction, and the renovation of cooling towers. The court said the budget is modest and that it requires additional comprehensive analysis.
The court based the report on the models and projections from the Intergovernmental Panel on Climate Change (IPCC).
If water is short, dry cooling has long been considered a viable alternative. It adds several percent to the capital costs, takes up a small but significant amount of land and the fans generally makes a bit of noise.
Proposals for new power stations should always be required to consider dry cooling as an alternative to evaporative cooling in the early design stages.