Situation very grave, Japan official says

source: manila bulletin
TOKYO (AP) – Highly toxic plutonium is seeping from the damaged nuclear power plant in Japan's tsunami disaster zone into the soil outside, officials said Tuesday, further complicating the delicate operation to stabilize the overheated facility.



Plutonium, which experts say is highly carcinogenic and one of the most dangerous substances on the planet, has been detected in small amounts at several spots outside the Fukushima Dai-ichi power plant for the first time, plant operator Tokyo Electric Power Co. (TEPCO) said.

Safety officials said the amounts were not a risk to humans but support suspicions that dangerously radioactive water is leaking from damaged nuclear fuel rods – a worrying development in the race to bring the power plant under control.

“The situation is very grave,” Chief Cabinet Secretary Yukio Edano told reporters Tuesday. “We are doing our utmost efforts to contain the damage.”

A tsunami spawned by a magnitude-9.0 earthquake last March 11 destroyed the power systems needed to cool the nuclear fuel rods in the complex, 140 miles (220 kilometers) northeast of Tokyo.

Since then, three of the complex's six reactors are believed to have partially melted down, and emergency crews have grappled with everything from malfunctioning pumps to dangerous spikes in radiation that have sent workers fleeing.

Radiation seeping from the plant has made its way into produce, raw milk and even tap water as far away as Tokyo, prompting some nations to halt imports from the region. Residents within a 12-mile (20-kilometer) radius of the plant have been urged to leave or stay indoors.

The troubles have eclipsed Pennsylvania's 1979 crisis at Three Mile Island, when a partial meltdown raised fears of widespread radiation release. But it is still well short of the 1986 Chernobyl disaster, which killed at least 31 people with radiation sickness, raised long-term cancer rates and spewed radiation across much of the northern hemisphere.

A series of missteps and accidents, meanwhile, have raised questions about the handling of the disaster, with the government revealing growing frustration with TEPCO.

The Yomiuri daily newspaper reported that the government was considering temporarily nationalizing the troubled nuclear plant operator, but Edano and TEPCO officials denied holding any such discussions.

The nuclear crisis has complicated the government's ability to address the humanitarian situation facing hundreds of thousands left homeless by the twin disasters. The official number of dead surpassed 11,000 on Tuesday, police said, and the final figure is expected to top 18,000.

The urgent mission to stabilize the Fukushima plant has been fraught with setbacks.

The discovery of plutonium, released from fuel rods only when temperatures are extremely high, confirms the severity of the damage, Nishiyama said.

Of the five soil samples showing plutonium, two appeared to be coming from leaking reactors while the rest were likely the result of years of nuclear tests that left trace amounts of plutonium in many places around the world, TEPCO said.

Plutonium is a heavy element that doesn't readily combine with other elements, so it is less likely to spread than some of the lighter, more volatile radioactive materials detected around the site, such as the radioactive forms of cesium and iodine.

“The relative toxicity of plutonium is much higher than that of iodine or cesium but the chance of people getting a dose of it is much lower,” says Robert Henkin, professor emeritus of radiology at Loyola University's Stritch School of Medicine. “Plutonium just sits there and is a nasty actor.”

When plutonium decays, it emits what is known as an alpha particle, a relatively big particle that carries a lot of energy. When an alpha particle hits body tissue, it can damage the DNA of a cell and lead to a cancer-causing mutation.

Plutonium also breaks down very slowly, so it remains dangerously radioactive for hundreds of thousands of years.

“If you inhale it, it's there and it stays there forever,” said Alan Lockwood, a professor of Neurology and Nuclear Medicine at the University at Buffalo and a member of the board of directors of Physicians for Social Responsibility, an advocacy group.

All nuclear power plants that depend on electrical power for their safety systems are subject to meltdown and/or explosion if the electrical power is lost for an extended period. If a massive solar storm lasted for several days, power generation could be disrupted globally. Unless all of the vital equipment in nuclear power plants is absolutely shielded from disruption, the problems witnessed in Japan could be witnessed world wide.


source: manila bulletin