Fukushima Disaster: Tsunami, Nuclear Failure, and Impact

Potential Energy Examples: Chemical (burning fossil fuels), Nuclear (fission), Gravitational (boulder on a cliff), Elastic (coil spring).
Kinetic Energy Examples: Motion (tree in wind), Sound (whistling), Electrical (lighting), Radiant (x-ray), Thermal (cooking).

Causes: Underwater earthquake, undersea volcanic explosion, undersea landslide, asteroid impact.
Speed: Very fast, over 500 ext{ mph} (805 ext{ km/h}) in open ocean, slowing and increasing in height in shallow water.
Nature: Barely visible at sea, waves may reach the coast every 10-60 ext{ minutes}, much faster than a person can run.
Distinction from Wind Waves: Tsunamis influence the entire water depth, have wavelengths of 10 ext{s}- ext{100s of km}, velocities up to 100 ext{s of kph}, and come ashore as a raised plateau of water that submerges land. Wind waves influence only the upper \sim 100 ext{ m}, have shorter wavelengths, lower velocities, and break to expend energy.

Event: A 9.1 magnitude earthquake, the most powerful recorded in Japan, triggered a massive tsunami.
Impact: Waves up to 30-50 ext{ feet} (9-15 ext{ meters}) high traveled at 435 ext{ mph} (700 ext{ km/h}), surging up to 3 ext{ miles} (4.8 ext{ km}) inland.

Initial Event: Earthquake caused the nuclear reactor to go offline; fuel rods were in cooling tanks.
Tsunami's Role: 50 ext{ ft} tsunami waves inundated and disabled the backup generators, which were crucial for circulating water in the cooling tanks. This led to a "station blackout failure."
Consequence: Without cooling, reactors overheated. There was a buildup of hydrogen, causing an explosion in an upper building, not an explosion of the reactor itself. Uranium was not released from a reactor explosion.

Isotopes Released: Primarily I-131 (half-life of 8 ext{ days}) and Cs-137 (half-life of 30 ext{ years}).
Health Concerns: Inhaled I-131 can cause thyroid cancer. Radiation damage is measured in "rem."
Exposure Levels: No one experienced 100 ext{ rem} or more (causing radiation sickness). A dose of 25 ext{ rem} carries a 1\% chance of later cancer. Measurements showed 22 ext{ rem} at 14 ext{ miles} (22.5 ext{ km}) and 2 ext{ rem} over most of the exposed area (22,000 people). This suggested approximately 194 likely additional cancer cases over time, compared to an average of \sim4400 natural cases.
Misinformation: Media reports often exaggerated radiation levels and spread, falsely claiming widespread high fallout far from the plant. Actual radioactive pollution was limited to 12-25 ext{ miles} (19-40 ext{ km}) from the power plant, with levels thousands of times weaker than natural background radiation in distant areas like Denver.

Overall Impact: The tsunami and earthquake caused significantly more damage and loss of life than the nuclear disaster.
Tsunami's Devastation: Impacted 1200 ext{ miles} (1930 ext{ km}) of Japan's coast, with waves reaching up to 6 ext{ miles} (9.6 ext{ km}) inland. Resulted in nearly 18,500 deaths and 2,500 missing.

Nuclear Safety: Nuclear power reactors worldwide should be assessed for backup system failures to prevent similar incidents. Modern reactor designs can incorporate enhanced safety features.
Tragedy vs. Prevention: While natural disasters like tsunamis cannot be prevented, human-caused nuclear mishaps can be mitigated through improved safety protocols and technology.