Japanese authorities continued their frantic attempts to cool spent fuel rods and restore electric power to quake-struck Fukushima Daiichi nuclear power plant on Friday even as the country raised rating of a crisis from level four to five.
The rise in the assessment of severity of the disaster, that was triggered by last Friday?s 9.0 magnitude earthquake and ensuing tsunami, from four to five on a seven-level scale heightened international alarm as the UN?s nuclear watchdog called the situation ?extremely serious?.
The new rating, which denotes a disaster with consequences beyond local, puts at par with the Three Mile Island incident in 1979 at Pennsylvania and two levels below the 1986 Chernobyl disaster in Ukraine.
Japanese engineers are now virtually risking lives in attempts to cool used fuel rods in a storage pond in the Reactor 3 of the plant, 240 km north of Tokyo, even as the second reactor spewed possibly radioactive smoke into the atmosphere.
Three explosions have rocked the Daiichi facility and a fire had engulfed the fourth reactor, damaging its spent-fuel pond and making it difficult to cool by dousing in water. The crisis with fourth reactor has been separately rated as level three.
Experts have tried dousing the reactors with cold water from helicopters and even flooding them seawater but to not much avail. Unless power is restored to the site maintaining a constant flow of coolant or water is proving to be difficult.
Sealing the entire site in sand and concrete, a makeshift measure, like the one used in Chernobyl, may be the last resort in dealing with the crisis but the solution might amputate the part of the country by creating a large radioactive sore.
Japanese officials however said desperate fix could would feature much later on the timeline.
Meanwhile, International Atomic Energy Agency (IAEA) chief Yukiya Amano said on Friday that Japan?s crisis was an ?extremely serious? incident and international cooperation was needed to crack it.