The Japanese government has raised the severity of the ongoing nuclear emergency at Fukushima's nuclear power plants. Several of the reactors and at least one storage pool are in bad shape and releasing radiation due to failures in the coolant systems following the massive 9.0 earthquake.
Efforts to string up power lines to restore power to the backup systems are underway, as is efforts to manually pump water onto the stricken reactors to cool them down.
Japan on Friday increased the severity of the crisis at the Fukushima site from 4 to 5 on a 7-point international nuclear event scale.One of the possible solutions to prevent a significant release of radiation being proffered is that the Japanese and Tokyo Electric (TEPCO) may erect a concrete and sand sarcophagus, similar to the containment structure erected by the Soviets following the Chernobyl disaster.
Firefighters are dousing water on damaged reactor buildings with powerful hoses. But they have to limit their time inside the complex due to the high radiation levels.
Japanese engineers also are extending an emergency power cable to the nuclear reactor complex. A steady supply of power could enable workers at the Fukushima plant to get water pumps working again.
Meanwhile, the head of the International Atomic Energy Agency, Yukiya Amano, says Japan is racing against time to cool the overheating reactors. Amano arrived in Japan Friday to meet with top Japanese officials and learn how the IAEA can help with the crisis.
The increase in the nuclear accident's severity rating comes shortly after the chief secretary of Japan's cabinet, Yukio Edano, tried to calm fears about the radiation. He said elevated radiation levels detected kilometers away from the plant were not a health risk.
The International Atomic Energy Agency says that Japanese authorities have told them they have successfully laid a cable line to reactor number two at the nuclear plant. However, it is not clear how close workers are to actually restoring power.
The disaster is sure to spark a renewed look at Japan's nuclear industry and failures of oversight and recognition of risks based on site analysis. While the engineering of the containment facilities appears to have been vindicated as far as the reactor cores are concerned, risks from seismic events and tsunamis were underestimated and design decisions did not take the tsunami risk seriously enough:
Back-up diesel generators that might have averted the disaster were positioned in a basement, where they were overwhelmed by waves.UPDATE:
“This in the country that invented the word Tsunami,” said Brockman, who also worked at the U.S. Nuclear Regulatory Commission. “Japan is going to have a look again at its regulatory process and whether it’s intrusive enough.”
The cascade of events at Fukushima had been foretold in a report published in the U.S. two decades ago. The 1990 report by the U.S. Nuclear Regulatory Commission, an independent agency responsible for safety at the country’s power plants, identified earthquake-induced diesel generator failure and power outage leading to failure of cooling systems as one of the “most likely causes” of nuclear accidents from an external event.
While the report was cited in a 2004 statement by Japan’s Nuclear and Industrial Safety Agency, it seems adequate measures to address the risk were not taken by Tokyo Electric, said Jun Tateno, a former researcher at the Japan Atomic Energy Agency and professor at Chuo University.
“It’s questionable whether Tokyo Electric really studied the risks,” Tateno said in an interview. “That they weren’t prepared for a once in a thousand year occurrence will not go over as an acceptable excuse.”
Hajime Motojuku, a utility spokesman, said he couldn’t immediately confirm whether the company was aware of the report.
Among the latest measures the Japanese government has done in conjunction with raising the nuclear emergency alert level was purchase 150 tons of boron from South Korea and France to help tamp down the neutron reactions in the affected reactors. The boron would be mixed with the water being pumped on to the reactors to cool them down.
That raises questions as to the preparedness of Japan to deal with a nuclear emergency, why they didn't have sufficient stocks of boron on hand to deal with a potential disaster, and why they didn't move sooner to attempt to add boron to the water being poured on the reactors.
Also, the spent fuel pool at reactor 4 is among the priority concerns because there appears to be damage to the pool itself, allowing water to leak and affecting the ability to keep the fuel rods submerged and cool. It's a danger because the spent fuel pools aren't designed with containment to the same level as the reactor core is.