Japan desperate to find radiation leak
TOKYO (AP) — Workers used a milky bathwater dye Monday as they frantically tried to trace the path of radioactive water seeping into the ocean from Japan's tsunami-damaged nuclear plant.
The crack in a maintenance pit discovered over the weekend was 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 needed to stabilize dangerously vulnerable fuel rods.
The plant operators also deliberately dumped 10,000 tons of tainted water — measuring about 500 times above the legal limit for radiactivity — into the ocean Monday to make space at a storage site for water that is even more highly radiactive.
Engineers have turned to a host of improvised and sometimes bizarre methods to tame the nuclear plant after it was crippled in Japan's magnitude 9.0 quake and tsunami March 11.
Efforts over the weekend to clog the leak with a special polymer, sawdust and even shredded newspapers failed to halt the flow at a cracked concrete maintenance pit near the shoreline. They still can't say for sure if the pit, where radioactive iodine was measured at 10,000 times the legal limit, is the source of the leak.
Suspecting they might be targeting the wrong channel to the pit, workers tried to confirm the leak's pathway by dumping several pounds (kilograms) of salts used to give bathwater a milky hue into the system, plant operator Tokyo Electric Power Co. said Monday.
"There could be other possible passages that the water may be traveling. We must watch carefully and contain it as quickly as possible," said Hidehiko Nishiyama, a spokesman for the Nuclear Safety and Industrial Agency.
Radioactive water has pooled throughout the plant because the operator has been forced to rely on makeshift ways of pumping water into the reactors — and allowing it to gush out wherever it can — to bring down temperatures and pressure in the cores.
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.
The makeshift system makes it difficult to contain the radiation leaks, but it is aimed a preventing fuel rods from going into a full meltdown that would release even more radiactivity into the environment.
"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," Nishiyama 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."
To that end, the plant's operator, Tokyo Electric Power Co., said it jettisoned the 10,000 tons of water Monday, clearing space in a waste-storage facility. The government decided to allow the step as "an unavoidable emergency measure," Chief Cabinet Secretary Yukio Edano said.
An additional 1,500 tons will be dumped from a trench under the plant's units 5 and 6. That water is threatening to interfere with the workings at those units, whose reactors are under control.
Radioactivity is quickly diluted in the ocean, and Edano 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 decimated large swaths of its 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.
The 8-inch-long crack was discovered in the maintenance pit over the weekend. It is sending radioactive water into area that is normally blocked off by a seawall, but a crack was also discovered in that outer barrier Monday.
Though it later authorized the dumping of slightly radioactive water, the government said Monday it was growing concerned about the sheer volume of contaminated materials spilling into the Pacific. It is not clear how much water has leaked from the pit so far.