Cooling systems at reactors 5 and 6 at the earthquake-stricken Fukushima nuclear power plant resumed their work on Saturday morning. Reactors 1 and 2 have been reconnected to electricity; their cooling systems might be restored on Sunday.
Restoring a stable source of electric power is a key step to prevent further complications at Fukushima-1 nuclear power plant. It is crucial to reactivate the cooling system down in the reactor cores and in water tanks storing the spent fuel rods.
Tokyo Electric Power Company (TEPCO), the operator of the plant, completed reconnection of reactors 1 and 2 on Saturday. The company will check if the electricity goes through safely and in case of no further complications reactivate the cooling system of the reactors and the pumps on Sunday.
Reconnection works on reactor 4 are also expected to be finalized on Sunday. TEPCO has pledged to make all-out efforts to connect outside power to all of the six reactors at the plant. However, the cooling function will not be recovered immediately, as some equipment has been soaked by seawater from tsunami waves that hit the plant on March 11.
The alert level at Fukushima-1 plant was raised from 4 to 5 on the international 7-level scale of nuclear accidents by the Nuclear and Industry Safety Agency on Friday. The 1985 Chernobyl meltdown has been the only grade 7 accident.
Grade 5 means that wider consequences are expected and the accident is no longer regarded as a localized problem. The operators of the nuclear plant had to raise the alert level as the cores of reactors 2 and 3 are believed to be damaged. The exact expected consequences are as yet unknown.
The Self-Defense forces continue using water cannon, helicopters and fire trucks to spray water through cracks in the walls and roofs of the reactor buildings. Priority is being given to reactors 3 and 4, where the water level in the pool with spent fuel rods is believed to be dangerously low. If the water in the pools gets too low, it will trigger the exposure of the fuel rods which might result in radioactive substances leaking out. Tokyo Fire Department forces have also joined the operation.
After all the cooling efforts, the temperatures on the surface of the four damaged reactors at Fukushima-1 have decreased to lower than 100 degrees Celsius, which shows the reactors are more stable than expected, Japan’s defense minister said on Saturday. He added that water spraying proved to be effective in cooling down the temperature of the spent fuel rod pool of reactor 3, Japan’s NHK broadcaster reported.
Radiation level high within 30km radius of nuke plant
The Japanese government has attempted to reassure the population living over 30km away from the plant that their radiation risk is estimated to be zero per cent. The ministry observed radiation levels of 0.5 to 52 microsieverts per hour within a 30 to 60 kilometer radius of the Fukushima-1 plant. These levels are all higher than normal, but not an immediate threat to health.
However, readings of radiation inside the 30km perimeter are high: 70 microsieverts per hour on Thursday and 150 microsieverts on Friday. Experts say exposure to this amount of radiation for six hours would result in absorption of the maximum level considered safe for one year. Chief Cabinet Secretary Edano has promised the government will take appropriate measures if this level of contamination continues in the area for a long period.
Radiation fluctuations at the Fukushima-1 plant itself are very unstable with peaks over 130 microsieverts per hour and lows of 3.74 microsieverts per hour as measured on Saturday morning.
Meanwhile, several farm products from areas near the nuclear power plant have been checked by the government for radiation levels, Vice Health Minister Kohei Otsuka said Saturday. Three to four items, including spinach and milk, have come out with radiation levels over local standards of safety, but pose no immediate risk to human health, Otsuka stated. Traces of radioactive iodine have also been found in tap water in Tokyo, according to Japan’s Kyodo news agency.
Japan’s Prime Minister Naoto Kan has refuted the allegations that the Japanese government is holding back any information regarding the crisis at Fukushima-1 nuclear power plant. “Concerning the nuclear power facility problem, we have been unveiling all the facts the Chief Cabinet Secretary and I were aware of,” he said. “I must tell you that the situation of the Fukushima nuclear power plant does not allow optimism.”
The Japanese government has admitted it was slow to respond to the nuclear troubles, which added another crisis on top of the natural disasters that hit the country on March 11. The powerful 9.0 earthquake and 23m tsunami left over 7,200 people dead and displaced more than 400,000 others. Over 11,000 people are still missing, according to Saturday’s reports from Japan’s police.
However, an expert on environmental and energy policies Robert Alvarez says there are many dangers lying within the stricken Fukushima station, making the situation there difficult to control. The efforts, Alvarez said, were ”improvisations on the playbook” for stopping a nuclear meltdown.
“The Japanese authorities appear to not still have control over this situation. They are taking measures that are desperate in nature… And it does not appear at this time they are working. The concern that I have had about this is the hazard of the spent fuel storage pools. The water has either completely or partially drained. And it is likely that the spent fuel will catch fire, and it has already caught fire.”
The devastated country continues to be shaken by earthquakes. Over ten quakes have been registered in Japan on Saturday only. The strongest one at 6.1 magnitude hit Ibaraki prefecture, which is North of Tokyo and South of Fukushima prefecture. Local authorities have reported that nuclear facilities situated within the prefecture have remained intact.