Plutonium in soil
March 29, 2011
Fukushima plant operator Tokyo Electric Power Co. (TEPCO) has said plutonium was found at low-risk levels in five places at the nuclear facility, which was crippled by the massive earthquake and tsunami on March 11. This has heightened alarm over Japan's battle to contain the world's worst atomic crisis in 25 years.
Japan's Nuclear and Industrial Safety Agency said the plutonium levels were not harmful to human health. "Plutonium is a substance that's emitted when the temperature is high, and it's also heavy and so does not leak out easily," agency deputy director Hidehiko Nishiyama told a news conference.
But the discovery could mean the reactor's containment mechanism has been breached. "So if plutonium has emerged from the reactor that tells us something about the damage to the fuel. And if it has breached the original containment system, it underlines the gravity and seriousness of this accident," Nishiyama was quoted by the Reuters news agency.
Pressure mounted on Japanese prime minister
Some opposition lawmakers lambasted Japanese Prime Minister in parliament for his handling of the disaster and for not widening the exclusion zone around the plant.
Naoto Kan said he was seeking advice on such a step, as widening an evacuation zone would force 130,000 people to move in addition to 70,000 who are already displaced. Kan has said the situation at the coastal atomic power station remained "unpredictable" and pledged his government would "tackle the problem while in a state of maximum alert."
Plutonium, a by-product of atomic reactions and an ingredient used in nuclear bombs, is highly carcinogenic and one of the most dangerous substances on the planet. Experts say they believe some of the plutonium may have come from damage to reactor 3, which was the only reactor to use plutonium in its fuel mix.
"I apologize for making people worried," said Sakae Muto, vice-president of TEPCO, but reassured that the traces of plutonium-238, 239 and 240 were in keeping with levels found in Japan in the past due to particles in the atmosphere from nuclear testing abroad. "We believe the level is not serious enough to harm human health," Muto was quoted by AFP.
However, the US environmental protection agency says internal exposure to plutonium "is an extremely serious health hazard" as it stays in the body for decades, exposing organs and tissue to radiation and increasing the risk of cancer.
Partial meltdown
Conditions at the Fukushima nuclear plant site are making it too dangerous for workers to go near several of the reactor buildings, which are already charred by explosions, to repair the cooling systems needed to stabilize the plant. But for now they have no choice but to keep pumping water into the stricken reactors to stop the fuel rods from overheating and drying up.
"We must avoid a situation in which the temperature (of the fuel rods) rises and the water boils off. So this cooling is a priority," chief cabinet secretary Yukio Edano said on Tuesday in a televised press conference. "On the other hand, on the standing water, under the circumstances, work must proceed to remove it as quickly as possible."
Nuclear experts fear that if the rods were fully exposed to the air, they would rapidly heat up, melt down and spew out far greater plumes of radiation at the site, located approximately 250 kilometres northeast of the capital Tokyo.
Tokyo Electric Power Co., which faces a long and uncertain operation, has sought help from French firms and the Japanese government is also consulting Washington. The crisis, which has been deemed the worst nuclear accident since Chernobyl in 1986, has contaminated vegetables and milk from the area, as well as the surrounding sea. US experts are saying that groundwater, reservoirs and the sea all face "significant contamination."
Author: Sherpem Sherpa (Reuters/AFP)
Editor: Sarah Berning