Ascó has two nuclear reactors. The first unit (1032 MW) is owned by Endesa Generación and began commercial operation in 1984. The second unit (1027 MW) is owned by Endesa Generación (85%) and Iberdrola Generación (15%) and has been operating in the grid since 1986.

you can get more information
about each item from
the diagram or legend

CONTAINMENT
BUILDING

Domed building, built as a reinforced concrete and steel structure that houses the reactor, the steam generators and the pressuriser. The containment is designed as a safety barrier to confine radiation and, in turn, protect the primary circuit.

CONTAINMENT BUILDING

STEAM
GENERATORS

Heat exchanger where the primary circuit's cooling water transfers its energy to the secondary circuit water. This makes the secondary circuit water change state, from liquid water to steam. There are three steam generators per unit.

CONTAINMENT BUILDING

REACTOR

The reactor is the heart of a nuclear power plant, where fission takes place. Ascó has two PWR reactors, manufactured by Westinghouse. Inside the reactor, water reaches 315 °C. The reactor's power is controlled by means of the control rods, by decreasing the turbine's demand and by changing the concentration of boric acid in the primary circuit. Boron is an effective absorber of the neutrons released during fission.

CONTAINMENT BUILDING

PRIMARY CIRCUIT

Closed water system that removes and transports the heat generated in the reactor core. In PWR reactors, the water is heated up as it goes through the reactor and it is directed to the steam generators, where the heat is transferred, producing steam in the secondary circuit. A component called the pressuriser maintains the pressure and ensures the water is in liquid state, despite the high temperature.

CONTAINMENT BUILDING

SECONDARY CIRCUIT

Closed water system that transports the heat transferred by the reactor's primary circuit as steam. The high pressure steam in the secondary circuit drives the turbine, in order to move the electrical generator and produce electricity. After being used in the turbine, it is condensed (into water) to start the cycle again.

COOLING
TOWER

160 metres in height and 120 metres in diameter at the base, the natural draught tower is a distinct feature of Ascó. However, it was not included in its initial design. It was built in 1995 with the aim of having additional cooling capacity and of returning the water to the Ebro River in accordance with the set environmental requirements.

TURBINE

Rotating machine with a series of blades assembled on a shaft, which transforms the energy from the high pressure steam flow into rotating energy and drives the electrical generator. The turbine transforms the thermal energy of the steam into kinetic energy and, finally, into mechanical rotation energy. At Ascó, this equipment comprises a high-pressure turbine and two low-pressure turbines, in order to optimise its performance.

GENERATOR

Equipment that is connected to the turbine and generates electricity by transforming the mechanical rotation energy into medium voltage and high current electrical energy.

TRANSFORMER

Device that increases the voltage of electricity to minimise losses during long-distance transport.

SWITCHYARD

After being transformed into high voltage, the electricity arrives at the distribution points through the Distribution Grid, which is owned by Red Eléctrica de España.

COOLING CIRCUIT

The secondary circuit's steam that drives the turbine returns to the steam generators as liquid water, to once again capture the heat from the primary circuit. To turn the steam back into liquid state, a third circuit transports a large flow rate of cold water that is used as the condensing agent. The water is taken from the Ebro River, and must be cooled, using the natural draught tower and forced draught cooling equipment, before being returned to the environment.

FUEL
BUILDING

Facility that houses the pool where the irradiated fuel elements are stored under water after completing their operation cycle in the reactor. Since 2013, Ascó also has a temporary fuel storage facility known as ATI, enabling the dry storage of spent fuel.

CONTROL ROOM

The command bridge of a nuclear power plant, one room per unit. It provides continuous information on all the systems and enables their remote operation. Each room is staffed by a closed shift comprising a turbine operator, a reactor operator and a control room supervisor, led by a shift manager.

Vandellós II is a nuclear power plant with 1087 MW of power, owned by Endesa Generación (72%) and Iberdrola Generación (28%). The plant began commercial operation in 1988.

you can get more information
about each item from
the diagram or legend

CONTAINMENT
BUILDING

Domed building, built as a reinforced concrete and steel structure that houses the reactor, the steam generators and the pressuriser. The containment is designed as a safety barrier to confine radiation and, in turn, protect the primary circuit.

CONTAINMENT BUILDING

STEAM
GENERATORS

Heat exchanger where the primary circuit's cooling water transfers its energy to the secondary circuit water. This makes the secondary circuit water change state, from liquid water to steam. There are three steam generators per unit.

CONTAINMENT BUILDING

REACTOR

The reactor is the heart of a nuclear power plant, where fission takes place. Vandellós II has a PWR (light water) reactor, manufactured by Westinghouse. The reactor's power is controlled by means of the control rods, by decreasing the turbine's demand and by changing the concentration of boric acid in the primary circuit. Boron is an effective absorber of the neutrons released during fission.

CONTAINMENT BUILDING

PRIMARY CIRCUIT

Closed water system that removes and transports the heat generated in the reactor core. In PWR reactors, the water is heated up as it goes through the reactor and it is directed to the steam generators, where the heat is transferred, producing steam in the secondary circuit. A component called the pressuriser maintains the pressure and ensures the water is in liquid state, despite the high temperature.

CONTAINMENT BUILDING

SECONDARY CIRCUIT

Closed water system that transports the heat transferred by the reactor's primary circuit as steam. The high pressure steam in the secondary circuit drives the turbine, in order to move the electrical generator and produce electricity. After being used in the turbine, it is condensed (into water) to start the cycle again.

TURBINE

Rotating machine with a series of blades assembled on a shaft, which transforms the energy from the high pressure steam flow into rotating energy and drives the electrical generator. The turbine transforms the thermal energy of the steam into kinetic energy and, finally, into mechanical rotation energy. At Vandellós II, this equipment comprises one high-pressure turbine and three low-pressure turbines, in order to optimise its performance.

GENERATOR

Equipment that is connected to the turbine and generates electricity by transforming the mechanical rotation energy into medium voltage and high current electrical energy.

TRANSFORMER

Device that increases the voltage of electricity to minimise losses during long-distance transport.

SWITCHYARD

After being transformed into high voltage, the electricity arrives at the distribution points through the Distribution Grid, which is owned by Red Eléctrica de España.

COOLING CIRCUIT

The secondary circuit's steam that drives the turbine returns to the steam generators as liquid water, to once again capture the heat from the primary circuit. To turn the steam back into liquid state, a third circuit transports a large flow rate of cold water that is used as the condensing agent. Vandellós II is the only Spanish nuclear power plant that takes this water from the sea. Before returning it to the environment, it is cooled in the discharge channel.

FUEL
BUILDING

Facility that houses the pool where the irradiated fuel elements are stored under water after completing their operation cycle in the reactor.

CONTROL ROOM

The command bridge, the brain of the nuclear power plant. It provides continuous information on all the systems and enables their remote operation. The room is staffed by a closed shift comprising a turbine operator, a reactor operator and a control room supervisor, led by a shift manager.