Universal Registration Document 2021

3.2.3.1.2 Optimisation of water use and reducing pressure on environments

The optimisation of water used in EDF’s generation activities serves to ensure management of water resources and to honour the Group’s commitment to guarantee multipurpose water resources (drinking water, water for irrigation, tourism, etc.) and to meet the needs of local authorities. The EDF group is working on several factors to optimise its water use and reduce pressure on the environment, by reducing its water consumption, reusing and/or recycling it, and using seawater desalination processes.

Water quality and effluents

Monitoring around industrial sites	EDF monitors land and aquatic ecosystem quality parameters, including subterranean groundwater around its industrial sites, particularly by measuring, controlling and analysis effluents on all sites. Monitoring the temperature of water upstream and downstream from thermal power plants is an important parameter with regard to biodiversity. The pH of water, its conductivity, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), nitrogen and phosphorus are also controlled and measured according to a regulatory environmental monitoring plan.
Monitoring around industrial sites	In terms of subterranean water, piezometers set up around industrial facilities are used to monitor and control water quality via withdrawals specified in a regulatory control plan. The information collected is used to ensure the quality of subterranean water is preserved. These environmental monitoring programmes, combined with impact and incidence assessments carried out at each facility, are used to guarantee that surface and subterranean water resources are lastingly preserved.
Specific monitoring for nuclear power plants	Each nuclear power plant has a specific authorisation defining, based on its characteristics and its environment, the water withdrawal conditions, and chemical, thermal and radioactive effluent discharge limits (mainly tritium and carbon-14). All these effluents are collected, treated, then transported to storage tanks where they are analysed, before being disposed of, in accordance with regulations to prevent any potential impact on aquatic ecosystems. Annually, more than 10,000 control analyses are carried out at each nuclear power plant, by both EDF and non-EDF laboratories. The results of this monitoring are provided to the relevant local authorities and used in documents available to the public.

There were no significant water-related environmental events or fines in 2021.

Water consumption reduction and withdrawal limitation measures

Experimentation

Golfech	In 2021, the Golfech nuclear power plant closed a trial with a local EMS to reduce its water withdrawals (95,000m³/year) from the Garonne river, as well as use of chemicals (acids and sodium) to produce demineralised water (89,000kg/year).

Dry air cooling systems

Overseas department	EDF R&D teams have designed “dry air cooling” systems for engine cooling, which reduce water withdrawal. EDF IPE’s new plants are now no longer cooled with seawater, and the same will be true for the Larivot plant.
Brazil	A plan for a second combined cycle power plant after Norte Fluminense is under consideration, featuring an air- rather than water-based cooling system from the design phase.

Dry cleaning of photovoltaic panels

EDF Renewables	At photovoltaic power plants operated by EDF Renewables in France, rain is generally sufficient to clean the panels. However, the level of dirt and grime that builds up over the years on panels can require cleaning. Cleaning frequency may vary from plant to plant, but panels always require cleaning easily more than once a year. In these cases, no products are added to the water used. Dry cleaning solutions are available and can be considered for use in cleaning panels in overseas zones facing water stress.

EDF Renewables

At photovoltaic power plants operated by EDF Renewables in France, rain is generally sufficient to clean the panels. However, the level of dirt and grime that builds up over the years on panels can require cleaning. Cleaning frequency may vary from plant to plant, but panels always require cleaning easily more than once a year. In these cases, no products are added to the water used. Dry cleaning solutions are available and can be considered for use in cleaning panels in overseas zones facing water stress.

Modernising the demineralisation chain

Belgium	In Angleur (Belgium), demineralised water, extracted from the River Ourthe, is used to both reduce NO_x emissions and increase turbine output. By modernising the demineralisation process, the site’s water intensity has been reduced by approximately 20%.

Reducing process water needs

Chile	In Chile, following a long drought that caused the water table to fall by 1m in less than a year, specific measures were taken for the combined cycle power plant in Nueva Renca, enabling halving of process water, which plummeted from 12t/h to 6t/h.