Uranium fever: why nuclear energy is safer than you thought
Nuclear power generation is a major source of synchronous electricity generation in power systems worldwide, providing reliable and continuous low-carbon baseload power with no direct greenhouse gas emissions during operation. In Great Britain, it accounted for 11.8% of generation in 2025 according to the National Energy System Operator.
Currently operational stations are: Torness (1.3 GW), Hartlepool (1.2 GW), Heysham (1 & 2 combined c. 2.5 GW), and Sizewell B (1.2 GW).
Nuclear power generation at present utilises nuclear fission, whereby enriched uranium within fuel rods undergoes atomic splitting, releasing large amounts of heat energy. In British advanced gas-cooled reactors (AGRs), graphite acts as the moderator and carbon dioxide as the coolant; in pressurised water reactors (such as Sizewell B), water acts as both coolant and moderator. The moderator slows neutrons to sustain the chain reaction, while control rods absorb neutrons to regulate or shut down the reaction when required.
The heat produced generates steam, which drives a turbine connected to an alternator to produce electricity.
Radiation safety and public exposure
Under normal operating conditions, nuclear power stations release only very small, regulated amounts of radioactive material. The resulting radiation doses to the public are extremely low and typically negligible compared to natural background radiation. Background radiation originates from cosmic rays, naturally occurring radionuclides in soil and building materials, and even from food.
In the UK, nuclear energy, industrial and defence activities together account for less than 1% of the average annual radiation dose to the public, with the vast majority coming from natural sources (UK Radioactive Waste Inventory; Public Health England).
Although conventional chemical explosions (for example, hydrogen explosions) can occur at nuclear power stations under severe accident conditions, these are fundamentally different from nuclear weapon detonations. Civil nuclear fuel is typically enriched up to 5%, whereas nuclear weapons require much higher enrichment levels and very specific configurations to produce an explosive chain reaction. Reactor fuel assemblies are not physically arranged or engineered in a way that would permit a nuclear detonation.
Radioactive waste and recycling
High-level waste (HLW) is often the most discussed category of radioactive waste. While it represents a small fraction of the total waste volume, it contains around 95% of the total radioactivity generated from nuclear power production. Some radionuclides within this waste have very long half-lives, meaning the material must be cooled, shielded, and isolated from the biosphere for extended periods. Deep geological disposal is widely considered the preferred long-term management solution.
Although this may appear to be a strong argument against nuclear power, up to around 96% of the material in spent nuclear fuel is technically recyclable for future fuel use, depending on national fuel cycle policy. The remaining fraction constitutes high-level waste requiring long-term management.
A 1 GW nuclear power station produces roughly 27 tonnes of spent nuclear fuel per year. Some studies have suggested that, under normal operation, fly ash from coal plants can expose 100 times more radiation into the surrounding environment than an equivalent nuclear power plant.
Major nuclear incidents
Public perception of nuclear energy has been strongly shaped by several major accidents, most notably those at Chernobyl, Fukushima Daiichi, and Three Mile Island.
Chernobyl (Ukraine) used RBMK reactors, and a catastrophic accident occurred in 1986 during a flawed safety test, resulting in a power surge, steam explosion, and graphite fire. A total of 237 workers were hospitalised for acute radiation sickness, and 28 died within three months. Longer-term cancer projections vary: a 2006 World Health Organisation report suggested that up to around 9,000 excess cancer deaths could eventually occur across affected regions, though estimates differ depending on methodology. The RBMK reactor design is not used in Britain, and British reactors have fundamentally different safety characteristics and containment structures.
Fukushima Daiichi (Japan) used boiling water reactors. In 2011, a magnitude 9.0 earthquake and subsequent tsunami disabled grid power and backup diesel generators, leading to loss of cooling and core damage in three reactors. Hydrogen explosions damaged reactor buildings. Two workers were hospitalised with radiation burns, two workers drowned in the tsunami, and additional workers sustained injuries. Numerous evacuation-related deaths occurred, particularly among vulnerable populations during the emergency response, though there were no confirmed immediate deaths from radiation exposure. The accident was driven by an extreme natural disaster; the seismic and tsunami risks in Britain are significantly lower, though modern safety standards are designed to account for severe external hazards.
Three Mile Island (Pennsylvania, United States) involved a pressurised water reactor and experienced a partial core meltdown in 1979 due to equipment malfunctions and operator error. Small amounts of radioactive gases, primarily noble gases such as xenon and krypton, were released. Investigations into long-term health impacts have generally found no statistically significant increase in cancer rates attributable to the accident. The average radiation dose to approximately two million nearby residents was estimated to be less than half that received from a standard chest X-ray.