CH 29Engineering & technology
The light that said less
Three Mile Island Unit 2 accident
Three Mile Island, 1979: what the control room could not see
Dossier · 7 case files · 1979–2025
Power grid blackouts and energy disasters.
Continental blackouts, frozen power plants, reactor accidents and a blown-out well: how energy systems cascade from one failure into many.
Backdrop: The Three Mile Island nuclear power plant near Middletown, Pennsylvania, the site of the 28 March 1979 accident, shown from the air. Centers for Disease Control and Prevention · Public domain · Wikimedia Commons.
Power systems are built to survive the loss of any single part. Large failures happen when several protections act at once, when an alarm system stops working, when cold or flood reaches equipment that was assumed to be safe, or when a control scheme meant to steady the system cannot hold it.
These cases draw on grid operators' and regulators' reports and on international safety reviews. Each traces how a local problem spread across a network, and why the hardest question is often not what tripped first but why the system could not absorb it.
In date order of the event. Each file is a full investigation: briefing, source-linked evidence, reasoning steps and findings.
CH 60Engineering & technology
A test changed on the spot
Chernobyl accident (1986)
Soviet Union, 26 April 1986: why did the reactor become unstable during a test?
CH 07Engineering & technology
The grid that lost its warning signs
2003 Northeast blackout
Northeast blackout, 2003: local faults, regional consequences
CH 62Engineering & technology
The pressure test read as a seal
Deepwater Horizon blowout (2010)
Gulf of Mexico, 20 April 2010: why did the crew believe the well was sealed?
CH 61Engineering & technology
A seawall built to an older estimate
Fukushima Daiichi accident (2011)
Japan, 11 March 2011: why did the tsunami defeat the plant's cooling?
CH 79Systems & energy
Why so many plants stopped at once
Texas grid freeze (2021)
The Texas grid, 2021: which failures pushed the system to the edge of collapse?
CH 59Engineering & technology
Voltage the grid could not hold
Iberian blackout (2025)
Spain and Portugal, 28 April 2025: what caused the grid to collapse?
From the journal
The ideas behind these cases.
- Why power grids collapse: voltage, frequency and visibilityA grid collapses when voltage, frequency or margins pass their limits faster than operators and protection can respond. Three case files show how.
- Alarm floods and silent failures: signals that misleadWarnings fail in two ways: they flood operators, or fall silent while trouble grows. Learn to test whether an indicator shows a state or only a command.
Automation surprise: when a system does something elseWhen an automated system changes mode or acts on a bad input, the crew must work out what it is doing. Five cases show what made that hard.
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