Officials are racing to restore electricity to Japan’s leaking nuclear plant, but getting the power flowing will hardly be the end of their battle: with its mangled machinery and partly melted reactor cores, bringing the complex under control is a monstrous job.
Restoring the power to all six units at the tsunami-damaged complex is key, because it will, in theory, drive the maze of motors, valves and switches that help deliver cooling water to the overheated reactor cores and spent fuel pools that are leaking radiation.
Ideally, officials believe it should only take a day to get the Fukushima Dai-ichi nuclear under control once the cooling systems are up and running. But it could take days or weeks to get those systems working.
“We have experienced a very huge disaster that has caused very large damage at a nuclear power generation plant on a scale that we had not expected,” Japan’s Nuclear and Industrial Safety Agency deputy director general Hidehiko Nishiyama told reporters.
The nuclear plant’s cooling systems were wrecked by the massive earthquake and tsunami that devastated north eastern Japan on March 11.
Since then, conditions at the plant have been volatile, and plumes of smoke rose from two reactor units yesterday, prompting workers to evacuate units 1-4.
The crews resumed the work early today, plant spokesman Motoyasu Tamaki said.
In another setback, the plant’s operator said it had just discovered that some of the cooling system’s key pumps at the complex’s troubled Unit 2 are no longer functional - meaning replacements have to be brought in.
Tokyo Electric Power said it placed emergency orders for new pumps, but it was unclear how long it would take for them to arrive.
If officials can get the power turned on, get the replacement pumps working and get enough seawater into the reactors and spent fuel pools, it would only take a day to bring the temperatures back to a safe, cooling stage, said Ryohei Shiomi, an official with the Nuclear and Industrial Safety Agency.
Asked what the alternative would be, Shiomi said: “There is nothing else we can do but keep doing what we’ve been doing.”
In other words, officials would continue dousing the plant in seawater - and hope for the best.
An official of the US Nuclear Regulatory Commission said in Washington that Units 1, 2 and 3 have all seen damage to their reactor cores, but that containment is intact.
The assessment dispels some concerns about Unit 2, where an explosion damaged a pressure-reducing chamber around the bottom of the reactor core.
“I would say optimistically that things appear to be on the verge of stabilising,” said the commission’s executive director for operations Bill Borchardt.
What caused the smoke to billow first from Unit 3 and then from Unit 2 yesterday was under investigation, nuclear safety agency officials said. In the days since the earthquake and tsunami, both units have overheated and seen explosions outside their reactor cores.
Workers were evacuated from the area to buildings nearby, though radiation levels remained steady, the officials said. It was a setback in efforts to rewire the plant, where officials had hoped to finish connecting all six reactor units to the grid on Tuesday.
Problems set off by the disasters have ranged far beyond the shattered north east coast and the wrecked nuclear plant, handing the government what it has called Japan’s worst crisis since the Second World War. Rebuilding may cost as much as $235bn. Police estimate the death toll will surpass 18,000.