The major layout of the nuclear reactor, the power generating building, and the cooling tower are shown here.
What Happened at Three Mile Island in March also gives a quick summary of the event.
The accident at Chernobyl Unit 4 gives a rather detailed account.
|Reactor type||Location||Accident type||Year||Iodine-131 release, curies||Comments|
|Graphite-moderated, gas-cooled||Sellafield, Britain||graphite fire||1957||20,000|
|Graphite-moderated, water cooled||Chernobyl, Ukraine||supercriticality, steam explosion and graphite fire||1986||7 million, perhaps far greater (see text)||Safety experiment went awry; total release 50 to 80 million curies or more; potential for continuing large releases exists|
|Sodium-cooled fast breeder||Lagoona Beach (near Detroit) U.S.||cooling system block, partial meltdown||1966||release confined to the secondary containment||reactor was being tested for full power, but did not reach it; four minutes from indication of negative reactivity to meltdown|
|Sodium-cooled fast breeder||Monju, Japan||major secondary sodium leak||1995||secondary sodium was not radioactive; reactor was in test phase; extensive sodium contamination in plant|
|Light water reactor, PWR type||Three Mile Island, near Harrisburg, U.S.||cooling system failure, partial meltdown||1979||13 to 17||secondary containment prevented release of millions of curies of I-131; accident developed over several hours|
|Light water reactor, BWR||near Idaho Falls, U.S.||accidental supercriticality followed by explosion and destruction of the reactor||1961||80||small U.S. Army experimental reactor using HEU fuel; 3 operators were killed|
|Heavy water cooled and moderated reactor||Chalk River, Canada||lack of coolant for a fuel element||1958||radioactivity apparently contained within building||Highest worker dose 19 rem|
|Heavy water moderated, light water cooled, experimental reactor||Chalk River, Canada||inadvertent supercriticality and partial meltdown||1952||"There was some release of radioactivity"||President Jimmy Carter helped in the clean-up|
|Heavy water moderated and cooled, CANDU type||Narora, Rajasthan, India||turbine fire; emergency core cooling system operated to prevent meltdown system||1993||apparently no release of radioactivity|