Explainers · data
How nuclear power works, one verified fact at a time
Five pages in reading order. Every figure on them is a fact from the explainer fact base, each with its source and the date it was read; nothing that could not be verified appears. Two cross-sections, a pressurised water reactor and an integral small modular reactor, open a sourced note for every part.
1How fission worksIsotopes, neutrons, control, coolant, enrichment, fuelWhat happens inside a reactor core: the isotopes, the neutrons that keep the chain reaction going, how it is controlled, what carries the heat, why fuel is enriched and what the fuel looks like.2Reactor familiesPWR, BWR, PHWR, VVER, gas-cooled, graphite, high-temperature, fast, molten saltThe nine reactor families in use or under development, what sets each apart, and the world fleet by type and status.With the world fleet by type and status from the reactor dataset3Generations and safetyGen I to Gen IV, defence in depth, passive safety, INES, the three accidentsHow reactor design generations differ, what defence in depth and passive safety mean, the INES scale, the three significant accidents as sourced facts, and the safety record in deaths per TWh and life-cycle emissions.4Small modular reactorsDefinition, rationale, floating plants, use cases, named designsWhat counts as a small modular reactor, why factory fabrication matters, the one floating plant in operation, the use cases, and the named designs with their status and dates.With the named designs from the SMR project dataset5Spent fuel and wasteComposition, volumes, pools, casks, repositories, reprocessing, half-livesWhat spent fuel is, how much there is, how it is stored, where the repositories stand, what reprocessing and fast reactors change, and how half-lives work.
The five pages draw on the 110 facts of the fission, reactor families, generations and safety, SMR and waste sections of the explainer fact base (docs/explainers/FACTS.md, built 9 Oct 2026). Related: the uranium journey for the fuel cycle step by step and the energy comparison for nuclear against the alternatives.