Nuclear Energy – History, Science, and Impacts

1. Brief History of Nuclear Energy

  • 1890s–1900s: Discovery of radioactivity (Becquerel, Curie) and atomic structure (Rutherford).

  • 1938: Nuclear fission discovered in Germany.

  • 1942–1945: Manhattan Project developed atomic bombs (WWII).

  • 1954: First grid-connected nuclear power plant (NPP) in Obninsk, USSR.

  • Post-WWII: Focus shifted to peaceful energy production.

2. What is Nuclear Energy? How Does It Work?

  • Nuclear Fission: Splitting heavy atoms (e.g., uranium-235) releases energy.

    • Chain Reaction: Neutrons from fission trigger more splits, producing heat → electricity.

  • Strong Nuclear Force: Binds protons/neutrons in the nucleus; overcome in fission.

3. Key Definitions

  • Isotope: Atoms of the same element with different neutron counts (e.g., U-235 vs. U-238).

  • Radioactivity: Spontaneous decay of unstable nuclei (alpha, beta, gamma emissions).

  • Fuel Rods: Contain enriched uranium (3–10% U-235) for fission.

  • Control Rods (Boron): Absorb neutrons to regulate reaction speed.

  • Moderators (Water/Graphite): Slow neutrons to sustain fission.

4. Reactor Fuel: Uranium-235 vs. Uranium-238

  • U-235: Fissile (splits easily); used in reactors.

  • U-238: Fertile (converts to plutonium in reactors); less reactive.

  • Why Enrich? Natural uranium is 99.3% U-238; enrichment increases U-235 for efficient fission.

5. Advantages & Disadvantages

Category

Pros

Cons

Environmental

Zero CO₂ emissions; high energy density.

Radioactive waste (long-term storage).

Economic

Low fuel costs; stable energy output.

High construction/decommissioning costs.

Safety

Safest energy source per kWh*.

Catastrophic accident risks (Chernobyl, Fukushima).

6. Impacts & Risks

  • Mining: Low volume but radioactive dust risks.

  • Waste: Spent fuel remains toxic for millennia (geologic storage needed).

  • Accidents: Rare but severe (e.g., meltdowns, radiation leaks).

7. Future of Nuclear Energy

  • Uncertain: High costs and public fear limit expansion.

  • Innovations: Small modular reactors (SMRs), fusion research.