Nuclear Power Plant

Nuclear power plants are facilities that generate energy through the fission of atomic nuclei. The heat produced in this process converts water into steam, which drives turbines to generate electricity. Nuclear energy accounts for approximately 9-11% of global electricity production. It is a carbon-free energy source and is widely used, particularly in countries like the United States, France, and China.

Nuclear Fission and Energy Generation

Nuclear energy is obtained from energy released during splitting atomic nuclei. Typically, fissile isotopes like uranium-235 (U-235) are used. When a neutron strikes a U-235 nucleus, the nucleus splits into two smaller nuclei (fission products), releasing additional neutrons and a significant amount of energy. These neutrons impact other U-235 atoms, initiating a chain reaction. In reactors, this reaction is controlled by control rods (containing materials such as boron or cadmium) that absorb neutrons, regulating or stopping the reaction.

The heat produced in the reactor core is transferred by a coolant (usually water). This heat turns water into steam, which spins turbines that power generators to produce electricity. The two main reactor types widely used in the United States are Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). In BWRs, water boils directly in the reactor core to produce steam, whereas in PWRs, water under high pressure does not boil but instead transfers heat through a heat exchanger to a secondary water system, which then turns into steam.

Key Components and Operation

The main components of nuclear power plants include:

• Reactor Core: The region where fuel rods (usually made of uranium oxide pellets) are located, and fission occurs. A reactor can contain hundreds of fuel rods.
• Coolant: A liquid or gas that transfers heat from the core. Water is the most common coolant, but some reactors use helium, liquid sodium, or molten salt.
• Control Systems: Control rods and moderators (materials that slow neutrons to sustain the reaction, typically water or graphite).
• Steam Generator and Turbine: In PWRs, the steam generator transfers heat to a secondary water circuit, while the turbine converts steam energy into mechanical energy.
• Containment Structure: A reinforced concrete and steel structure designed to contain radiation in the event of an accident.

Fuel and Waste Management

The most commonly used fuel in nuclear power plants is uranium. More than 99% of naturally occurring uranium consists of non-fissile U-238, while less than 1% is fissile U-235. Therefore, uranium is enriched to increase its U-235 content to 3-5%. Each ceramic fuel pellet produces energy equivalent to about one ton of coal, and a reactor consumes an average of 27 tons of fuel annually. Uranium is the

The fission process generates radioactive waste. Low-level waste (e.g., contaminated equipment) is temporarily stored at the plant and typically disposed of in specialized facilities. High-level waste, such as spent fuel, is highly radioactive and is stored in special pools or dry casks. While the U.S. has yet to establish a permanent high-level waste repository, some countries recycle this waste for further energy production.

Efficiency and Technological Advancements

Nuclear power plants have a thermal efficiency of around 33-37%, similar to fossil fuel plants. However, next-generation reactors (e.g., Gen IV designs) promise efficiencies above 45%. Small Modular Reactors (SMRs), which generate 300 MW or less, stand out for their compact designs. Manufactured in factories and transported to sites, SMRs could shorten construction times and provide carbon-free energy to remote areas. Additionally, some advanced reactor designs use liquid metal or molten salt coolants, enabling operation at higher temperatures and facilitating applications such as hydrogen production.

Advantages and Challenges

As a low-carbon energy source, nuclear power plays a crucial role in combating climate change. Nuclear power plants, which account for approximately 10% of global electricity production, do not emit greenhouse gases like fossil fuel plants. Moreover, their ability to provide continuous (baseload) power makes them more reliable than some renewable energy sources.

However, nuclear power plants face several challenges. Construction costs are high, and projects often experience delays and budget overruns (e.g., the Vogtle plant in the U.S.). Radiation risks, particularly following major accidents (Chernobyl, Fukushima), have heightened safety concerns. Scientific models (such as the Linear No-Threshold Model - LNT) suggest that even low doses of radiation could increase cancer risk. Additionally, the long-term management of nuclear waste remains an unresolved issue, as some waste remains radioactive for thousands of years.

Nuclear Energy Worldwide

As of 2021, more than 413 commercial reactors are operating in 33 countries. The U.S. leads with 95 GW capacity and 778 billion kWh production, providing 19% of its electricity from nuclear power. France has the highest nuclear share at 68%. Emerging reactor technologies are actively being developed to meet growing energy demands, particularly in developing countries.

Nuclear power plants are a complex component of modern energy systems. While they offer low-carbon, high-capacity energy, they require careful consideration of safety, costs, and waste management. The potential and limitations of nuclear energy necessitate a balanced approach to energy policies.

Turkey’s Nuclear Energy Plan

Turkey’s nuclear energy plan aims to enhance energy security, reduce dependence on imports, and contribute to its 2053 net-zero emissions goal. The first concrete step has been the Akkuyu Nuclear Power Plant in Mersin. Built under a 2010 agreement with Russia, this plant will consist of four 1,200 MW VVER-1200 reactors and is expected to meet approximately 10% of the country’s electricity needs at full capacity. The first reactor is scheduled to be operational in 2025, with the remaining units expected to be completed by 2028. According to Turkey’s National Energy Plan, nuclear capacity is projected to increase from 2.4 GW in 2025 to 7.2 GW by 2035.

Additionally, plans are underway for second and third nuclear power plants in Sinop and İğneada. Negotiations with China, Russia, and South Korea for the Sinop Nuclear Power Plant began in 2023, while site selection and planning for the İğneada project are ongoing. Turkey has also joined the global “Declaration to Triple Nuclear Energy” initiative, aiming to reach 20 GW of nuclear capacity by 2050. This plan envisions nuclear energy playing a key role in Turkey’s energy transition alongside renewable sources.