How Nuclear Power Works

Understanding the technology behind nuclear energy generation

How Nuclear Power Plants Work

A nuclear power plant generates electricity through a controlled nuclear chain reaction. This process involves multiple interconnected systems working together to convert nuclear energy into electrical power.

⚛️ Nuclear Fission: Heat from Splitting Atoms

Inside a nuclear reactor, uranium fuel pellets are packed into metal rods within the reactor core. When a neutron strikes a uranium-235 atom, the nucleus splits apart in a process called fission. This releases a burst of heat energy and additional neutrons, which trigger more fissions, creating a self-sustaining chain reaction.

Simplified diagram of a nuclear power plant

Simplified diagram illustrating the operation of a pressurised water reactor. Source: World Nuclear Association


♨️ Primary Circuit: Containing the Heat

The heat from all the fission chain reactions is absorbed by water or another coolant flowing through the primary loop. This coolant is kept under high pressure, allowing it to stay extremely hot without boiling, much like a supercharged pressure cooker; only the pressure is about 150 times the atmospheric pressure. Meanwhile, control rods made of neutron-absorbing materials (such as boron or cadmium) adjust the reaction rate.

💨 Secondary Circuit: Steam from the Heat

The hot coolant passes through a steam generator, transferring its heat to a separate water system in the secondary loop. This water turns into high-pressure steam without ever mixing with the radioactive primary coolant.

⚡ Electricity Generation: From Steam to Power

The steam rushes through massive turbines, spinning them at incredible speeds. These turbines drive a generator, converting mechanical energy into the electricity that powers homes, industries, and technology.

Cooling System: Completing the Cycle

After passing through the turbines, the steam is cooled back into liquid water in a condenser. This cooling often relies on water from rivers, oceans, or the cooling towers that releases non-radioactive vapor. The water is then cycled back into the system.

Key Takeaway

A nuclear power plant consists of three key islands (sections):

  • Nuclear island - Is where fission takes place inside a reactor. The island also contains primary cooling system pumps, and safety systems including huge tanks containing water.
  • Turbine Island - Houses the steam turbines and generator
  • Balance of Plant - Includes secondary cooling systems, electrical switchyards, and support systems. Beyond the nuclear island, the process resembles conventional power plants that ultimately use heat to create steam that drives turbines and generators.

Overview of Nuclear Electricity Generation

A typical nuclear power generation capacity can have multiple reactors.

Flowchart of nuclear electricity generation process

Simplified diagram illustrating the operation of a nuclear power plant. Source: Foro Nuclear

Vision 2030, 2034: Kenya's Strategic Path to Nuclear Energy (Adapted from NuPEA)

Official data and strategic planning regarding Kenya's journey towards nuclear power adoption.

For official national progress updates and critical documentation, please refer to NuPEA at nuclear.co.ke.

Increasing Energy Demand

Kenya's economy is growing, and with it, the demand for electricity. Historic peaks in electricity demand reached 2,362.28 MW in July 2025.

Security of Supply

Nuclear power offers stable, continuous "baseload" energy that can run day and night, providing crucial reliability.

Cost Stability

The cost of uranium fuel is a small fraction of the total cost, offering protection against fossil fuel price volatility.

Environmental Sustainability

Nuclear power produces zero carbon emissions during operation, supporting Kenya's commitment to clean energy and climate goals.

Key Milestones on Kenya's Nuclear Journey (Source: NuPEA)

Detailed information on these milestones can be found on the official NuPEA website.

2010

National Priority Status

NESC recommends nuclear power as a national priority.

2019

Phase 1 Completion (Readiness)

Completed Phase 1 of the IAEA Milestone Approach (Ready to Make a Knowledgeable Commitment).

2027

Project Tender (Target)

Targeted date for issuing the tender for the first nuclear power plant (NPP).

2030

First Concrete/Construction (Target)

Key milestone for starting physical construction of the first NPP.

2034

First Grid Connection of 300 MW NPP (Target)

Key milestone for integrating nuclear power into national grid

2034

Commissioning of 300 MW NPP (Target)

Expected operationalization of the first nuclear power plant

Current Status: Phase 2 of IAEA Milestone Approach

At Phase 2 of IAEA's milestone approach for nuclear power development, Kenya is currently doing preparatory Work for Construction. For the latest official progress reports, please refer to NuPEA at nuclear.co.ke.

  • Industrial capacity assessment and development
  • Finalizing the legal framework
  • Conducting comprehensive site evaluations
  • Developing human resource capacity
  • Establishing robust regulatory systems
Kenya's Progress according to the IAEA milestone approach

Kenya's Progress according to the IAEA milestone approach, currently at Phase 2. (Adapted from NuPEA documentation)

Supply Chain Opportunities

Numerous specialized services will be required for Kenya's nuclear power program

Find out where your company fits in:

Explore detailed supply chain opportunities across nuclear island, turbine island, and balance of plant components.

Nuclear Island

Reactor Vessel, Control Rods, Core internals, Steam Generators, Primary Pumps

Turbine Island

Turbine Generator, Condenser, Feedwater Heaters, Cooling Water systems

Balance of Plant

Construction materials, Electrical equipment, HVAC, Instrumentation & Control, Site Services

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Contact the Researcher

Your feedback, expertise, and participation are crucial to the success of this study.

All responses are confidential and used solely for the Academic research study.

Researcher Contact

Desmond Trevor Nyalwanda Otieno

Collaborating Institutions

  • Nuclear Power and Energy Agency (NuPEA)
  • Tsinghua University
  • China National Nuclear Corporation