Workers were pumping more than 3 million gallons of contaminated water from Japan's tsunami-ravaged nuclear power complex into the Pacific Ocean on Tuesday, freeing storage space for even more highly radioactive water that has hampered efforts to stabilize the plant's reactors.
The government also asked nuclear superpower Russia to send a special radiation treatment ship used to decommission nuclear submarines as it fights to contain the world's worst atomic crisis since Chernobyl, Japanese media said late on Monday. The plant also plans to bring in a floating storage facility.
But these other storage options have been slow to materialize, so the pumping began late Monday. It was expected to take about two days to get most of the less-radioactive water out.
"The measure was to prevent highly radioactive water from spreading. But we are dumping radioactive water, and we feel very sorry about this," Chief Cabinet Secretary Yukio Edano told a news conference Tuesday.
Radioactivity is quickly diluted in the ocean, and government officials said the dump should not affect the safety of seafood in the area.
The crisis has unfolded as Japan deals with the aftermath of twin natural disasters that devastated much of its northeastern coast. Up to 25,000 people are believed to have died and tens of thousands lost their homes.
Since the disaster, water with different levels of radioactivity has been pooling throughout the plant. People who live within 12 miles (20 kilometers) have been evacuated and have not been allowed to return.
The pooling water has damaged systems and the radiation hazard has prevented workers from getting close enough to power up cooling systems needed to stabilize dangerously vulnerable fuel rods.
The world's costliest natural disaster has caused power blackouts and cuts to supply chains and business hours. It is threatening economic growth and the yen, while a recent opinion poll suggested voters want embattled Prime Minister Naoto Kan to form a coalition in order to steer Japan through its worst crisis since World War Two.
Earlier Monday, workers used a milky white dye to try to trace the path of highly radioactive water gushing from the crippled nuclear plant into the ocean.
Suspecting they might be targeting the wrong channel to the pit, workers tried to see if they could trace the leak's pathway by dumping into the system several pounds of salts used to give bathwater a milky hue, plant operator Tokyo Electric Power Co. (TEPCO) said.
On Saturday, they discovered a leak where radioactive water was pouring into the ocean.
Radiation exceeding the legal limit has been measured in seawater over the past few weeks, though calculating the exact contamination has vexed the plant's operator, Tokyo Electric Power Co. Japan's nuclear safety agency ordered the utility last week to reanalyze samples; new results released Monday showed unchanged or lower levels of radiation than previously reported.
The less-radioactive water that officials are purposely dumping into the sea is up to 500 times the legal limit for radiation.
"We think releasing water with low levels of radiation is preferable to allowing water with high levels of radiation to be released into the environment," said Junichi Matsumoto, a TEPCO official.
The need to make room for the highly radioactive water became more urgent when TEPCO discovered the extent to which it was leaking into the ocean, Matsumoto said.
Workers need to get rid of the highly radioactive water, but first they need somewhere safe to put it. Much of the less-radioactive water being dumped into the sea is from the tsunami and had accumulated in a nuclear waste storage building.
The building is not meant to hold water, but it's also not leaking, so engineers decided to empty it so they can pump in the more-radioactive water. The rest of the water going into the sea is coming from a trench beneath two of the plant's six reactors.
Japan has also asked Russia for the "Suzuran", a ship which treats radioactive liquids, Kyodo and Jiji news agencies said.
The ship, a joint venture between Japan and Russia, was designed to help decommission nuclear submarines in Russia's Pacific fleet in Vladivostock, ensuring radioactive waste was not dumped into the Sea of Japan, Kyodo said.
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.
"We need to stop the spread of (contaminated water) into the ocean as soon as possible. With that strong determination, we are asking Tokyo Electric Power Co to act quickly," Chief Cabinet Secretary Yukio Edano told a news conference before TEPCO said it would release radioactive water into the Pacific.
"We are strongly urging TEPCO that they have to take immediate action to deal with this," he said, warning that accumulating radiation from the leak that has defied desperate efforts to halt it "will have a huge impact on the ocean."
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 radius around the plant because of the radiation.
Attempts to seal leak
Over the weekend, the 8-inch-long crack was discovered in a maintenance pit. The area is normally blocked off by a seawall, but a crack was also discovered in that outer barrier Monday.
TEPCO 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.
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 before restoring the cooling system. 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.
Some of the reactors are made by General Electric, and the company's CEO met Sunday with TEPCO's chairman. Jeffrey Immelt told reporters Monday that more than 1,000 engineers from GE and its partner Hitachi are helping to analyze the problems at the plant.
Immelt also offered assistance in dealing with the electricity shortage brought on by damage to Dai-ichi and other power plants. Japan is expecting a shortfall of at least 10 million kilowatts come summer.
Gas turbines are on their way from the U.S. with both long- and short-term capabilities, Immelt said.