5 Juin 2016
June 5, 2016
The operator of the damaged Fukushima Daiichi nuclear power plant says a water leak in the number 2 reactor emergency cooling system may have contributed to its meltdown.
The plant lost power following a massive earthquake and tsunami on March 11th 2011.
The emergency cooling system began operating right away, driven by steam generated in the reactors. The system's pumps were designed to inject coolant into the reactors during an emergency.
The number 2 reactor's emergency cooling equipment lost its function on March 14th, 3 days after the disaster.
The exact cause of the failure remains unknown more than 5 years after the accident.
Workers tried to inject water from outside, but were unsuccessful in cooling it down. This led to the nuclear fuel meltdown and release of radioactive substances into the air that spread across the region.
Experts at Tokyo Electric Power Company analyzed the level of contaminated water inside the number 2 reactor, as well as the amount of leaked water.
They believe that water is leaking from a hole near the cooling system.
The experts suspect that cooling water began leaking from the system after the pumps had operated beyond the 8 hours for which they were designed.
They believe the water leakage was the major cause of the reactor heating up.
Water injected to cool the melted nuclear fuel continues to leak into the reactor building. This contaminated water is hampering decommissioning work at the plant.