Japan Has Just 'Hours' to Prevent Nuclear Meltdown

Fears of nuclear meltdown are spreading throughout Japan after five nuclear reactors have malfunctioned. Now, reports suggest Japanese officials may have only hours to cool reactors disabled by Friday’s massive 8.9 earthquake or face nuclear meltdown.

According to Reuters, Tokyo’s Electric Power Co. is struggling to cool down the reactor core after the plant lost power necessary to keep water circulating through the plant to prevent overheating.

Daiichi Units 1, 2 and 3 reactors shut down automatically at 2:46 p.m. local time due to the earthquake. But about an hour later, the on-site diesel back-up generators also shut, leaving the reactors without alternating current (AC) power.

That caused Tepco to declare an emergency and the government to evacuate thousands of people from near the plant. Such a blackout is “one of the most serious conditions that can affect a nuclear plant,” according to experts at the Union of Concerned Scientists, a U.S. based nuclear watchdog group.

“If all AC power is lost, the options to cool the core are limited,” the group warned.

TEPCO also said it has lost ability to control pressure at some of the reactors at its Daini plant nearby.

The reactors at Fukushima can operate without AC power because they are steam-driven and therefore do not require electric pumps, but the reactors do require direct current (DC) power from batteries for its valves and controls to function.

If battery power is depleted before AC power is restored, the plant would stop supplying water to the core and the cooling water level in the reactor core could drop.

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