Workers used a milky white dye Monday as they frantically tried to trace the path of highly radioactive water that is gushing from a tsunami-damaged Japanese nuclear plant and leaking into the ocean.
A crack in a maintenance pit was found over the weekend — the latest confirmation that radioactivity continues to spill into the environment. The leak is a symptom of the primary difficulty at the Fukushima Dai-ichi complex: Radioactive water is pooling around the plant and preventing workers from powering up cooling systems that would stabilize overheating reactors.
Government officials conceded Sunday that it will likely be several months before the cooling systems are completely restored. And even after that happens, there will be years of work ahead to clean up the area around the complex and figure out what to do with it.
Until all the pools of contaminated water are pumped to storage tanks and the cooling system restored, the makeshift methods of pumping water into the reactors and allowing it to gush out wherever it can are the only way to bring down temperatures and pressure in the reactor cores, where fuel rods continue to produce massive amounts of heat even though nuclear reactions have stopped.
"We must keep putting water into the reactors to cool to prevent further fuel damage, even though we know that there is a side effect, which is the leakage," Hidehiko Nishiyama, a spokesman for the Nuclear Safety and Industrial Agency, said. "We want to get rid of the stagnant water and decontaminate the place so that we can return to our primary task to restore the sustainable cooling capacity as quickly as possible."
That makeshift system also complicates plant operator Tokyo Electric Power Co.'s other goal: containing the spread of radiation.
Radioactivity has spewed from the plant since March 11, when a 9.0-magnitude earthquake spawned a massive tsunami that decimated large swaths of Japan's northeastern coast. Up to 25,000 people are believed to have died in the disaster, and tens of thousands lost their homes. Thousands more were forced to flee a 12-mile (20-kilometer) radius around the plant because of the radiation.
Over the weekend, an 8-inch-long (20-centimeter-long) crack was discovered in a maintenance pit, sending a stream of water into the sea. The area is normally blocked off by a seawall, but a crack was also discovered in that outer barrier Monday.
While radioactivity is quickly diluted in the ocean, a government spokesman said Monday that the sheer volume of contamination is becoming a concern. It is not clear how much water has leaked from the pit so far.
"Even if they say the contamination will be diluted in the ocean, the longer this continues, the more radioactive particles will be released and the greater the impact on the ocean," said Chief Cabinet Secretary Yukio Edano. "We are strongly urging TEPCO that they have to take immediate action to deal with this."
The operator said Monday it is ordering fencing that is typically used to contain oil spills. The screens are not designed to trap radioactivity but might curtail the flow of water and thus reduce the spread of contamination, said TEPCO manager Teruaki Kobayashi. It was not clear when they would arrive.
In the meantime, the company has tried to seal the leak with concrete and then by injecting a mixture of polymer, sawdust and shredded newspaper farther up a system of trenches, closer to where they believed the source was.
The failure of these efforts appeared to signal that officials were targeting the wrong channel to the maintenance pit. Then, workers threw several pounds (kilograms) of a milky white bath cleaner into the system, to see if they could trace the water's path.
The dye has yet to hit the ocean.
"There could be other possible passages that the water may be traveling. We must watch carefully and contain it as quickly as possible," Nishiyama said.
Before restoring the cooling system, workers must rid the plant of the pools of radioactive water that have collected under each of the three troubled reactors' turbine buildings and have spilled into various trenches around the complex. TEPCO has proposed pumping it into tankers, barges and is now considering sending it to a storage facility on site.
Work on those problems continue to make progress, even as workers try to stop the latest leak, Nishiyama said.
"We have to apply stopgap measures to day-to-day problems, like the pit water leakage, but we are continuing on our effort to achieve the goal," he said.
Associated Press writers Ryan Nakashima in Tokyo contributed to this report.