STEM与日常科技·英语30篇（3）

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核裂变与核电站热能转换过程

Inside a nuclear reactor, uranium-235 atoms split when struck by slow-moving neutrons.
Each fission event releases energy mostly as kinetic energy of fragments and intense heat.
This heat warms pressurized water circulating through the reactor core in a closed loop.
The hot water then transfers its thermal energy to a secondary water loop via a steam generator.
In that second loop, water boils into high-pressure steam that spins a turbine connected to a generator.
The spinning turbine produces electricity through electromagnetic induction, just like in coal or gas plants.
Control rods made of boron or cadmium absorb excess neutrons to keep the chain reaction stable.
Spent fuel remains highly radioactive and requires decades of cooling in water pools before dry storage.
Unlike fossil fuels, nuclear fission emits no CO₂ during operation but produces long-lived waste.
Engineers constantly monitor neutron flux, temperature, and pressure to ensure safe, steady power output.