Sea water and boric acid is being injected into the primary containment vessel at unit 1 of the Fukushima Daiichi nuclear power plant in Japan to try and cool the reactor following a failure of the pumping systems.
The level of radioactive material measured at the nuclear power plant has been recorded as higher than normal, even though there is understood to be no leakage of reactor coolant. Tokyo Electric Power Co said:
“We will continue to monitor in detail the possibility of radioactive material being discharged from exhaust stack or discharge canal.”
A major earthquake and tsunami on Friday 11th March 2011 caused primary and backup cooling systems at the plant to fail. A nuclear emergency was declared at the plant at 19:03 local time on Friday 11th March 2011. Four workers were injured after the earthquake and TEPCO confirmed that one employee has been exposed to radiation exceeding 100mSv (106.3mSv), he has been sent to hospital for diagnosis.
The power plant experienced an explosion early in the morning on 12th March 2011 after workers tried to reactivate a pumping system. The outer concrete building around Unit 1 has been damaged, but the International Atomic Energy Agency Director General, Yukiya Amano, said that the Japanese authorities informed him that the primary containment vessel is still intact.
Workers at Fukushima Daiichi are monitoring water levels in all the units and trying to keep pressure levels under control until the full capability of the plant can be restored.
Japanese authorities have extended the evacuation zone around the Fukushima Daiichi plant to a 20-kilometre radius from the previous 10 kilometres. At the nearby Fukushima Daini nuclear power plant, the evacuation zone has been extended to a 10-kilometre radius from the previous three kilometres.
The authorities also say they are making preparations to distribute iodine to residents in the area of both the plants.