Nuclear and Hydroelectric Power Generation Systems

Nuclear Thermal Power Plants

In nuclear thermal power plants, the traditional thermal power boiler is replaced by a nuclear reactor. Water vapor pressure occurs due to the heat generated by the fission (splitting) of the atomic nuclei of radioactive elements, primarily uranium. The uranium isotopes U-235 and U-238 are most commonly used.

The capacity of nuclear power plants installed in Spain includes the 466 MW Santa María de Garoña plant and the 1,087 MW Vandellòs II plant in Tarragona. The main advantage of nuclear power is its high energy production capacity. Its drawbacks include the management and storage of radioactive waste, as well as public concern regarding potential nuclear accidents.

The Problem of Waste and Pollution

• Non-nuclear power stations: These contribute to air pollution by generating particulate matter, heavy metals, and carbon molecules. They release large quantities of CO2, which increases the greenhouse effect, leading to serious and unpredictable weather consequences. Finally, thermal power plants emit nitrogen and sulfur oxides, the gases that cause acid rain, which can be devastating to forests, rivers, lakes, and monuments.
• Nuclear thermal power: These plants do not emit CO2 or other polluting gases; however, they produce nuclear waste, some of which remains potentially hazardous for thousands of years.

Waste Treatment and Mitigation

• Installing special filters in the power turbines to trap polluting gases, including nitrogen and sulfur oxides.
• Using low-sulfur fuel to reduce oxide emissions.
• Maintaining and increasing forest coverage to act as a carbon dioxide sink.
• Storing nuclear plant waste in thick-walled drums. These are stored in trenches (though use is minimized) and deep underground.

Hydroelectric Power Plants

Hydroelectric plants take advantage of the high potential energy of water impounded by dams. As the water falls, its energy is converted into kinetic energy. This moves the curved blades of a turbine connected to a generator rotor, which is responsible for transforming kinetic energy into electricity.

Types of Hydraulic Plants

• Gravity-based hydraulic plants: The water used is returned to the river bed to be used again.
• Pumped-storage hydraulic plants: Water falls to a lower reservoir and is then pumped back to the upper reservoir to be used again.