In Fukishima province, north of Tokyo, a large nuclear reactor, damaged by the earthquake, has lost emergency cooling functions. The Wall Street Journal updates —
Wall Street Journal 0143 EST March 12
TOKYO—Japanese nuclear authorities said Saturday afternoon the Fukushima Daiichi No. 1 nuclear reactor was experiencing the threat of a meltdown after Friday’s massive earthquake damaged the cooling system and that outside water was being poured into the reactor to cool it down.
“If the water level remains at this level, the reactor core might be damaged, but we are now pouring water into the reactor to prevent it from happening,” a spokesman for Tokyo Electric Power Co. said. The company, known as Tepco, is the owner of the plant, which is located 150 miles, or 240 kilometers, away from Tokyo.
A portion of the reactor’s fuel rods, which create heat through a nuclear reaction, have become exposed due to the cooling-system failure. The spokesman for Tepco said 1.5 meters of the 4.5 meter long fuel rods were potentially exposed.
Loss of cooling water resulted in a near meltdown of the Three Mile Island reactor in Pennsylvania in 1979, the worst nuclear incident in U.S. history.
If coolant isn’t restored, the result could be what’s known as a meltdown — extreme heat can melt through the reactor vessel and result in a radioactive release. Reactors have containment domes to catch any release. But there is always the chance that an earthquake could create cracks or other breaches in that containment system.