Japan's Creeping Meltdown

Initial optimism fades as engineers, scientists at Japan's scuttled Fukushima plant realize they've made no headway in cooling exposed fuel rods.

Gabe Kahn. , | updated: 6:23 PM

Fukushima Aftermath
Fukushima Aftermath

The Fukushima reactors have been releasing radiation for weeks, Der Spiegel reports.

According to some computer projections, the nuclear plant has released one-tenth of the radiation released during the Chernobyl disaster. Technicians worked for days to restore electricity to the stricken plant, but on Thursday two employees were hospitalized after just forty-five minutes in the No. 3 reactor turbine room. The men, working with cables while wading in water, sustained radiation burns and absorbed 180 millisievert of radiation - nine times the dose of a normal plant employee. This despite wearing helmets, masks, overcoats, and rubber boots and gloves over their radiation suits.

The incident underscores the very real question occupying the minds of health officials and radiological scientists: just how bad is it? No one expected radiation levels in the basement water to reach the levels it did. Yet, the radiation levels in the water in the No. 1, No. 2, and No. 3 reactors have set new records. The water in No. 2 measures 1,000 millisieverts per hour due to the partial core melt that reactor sustained. Japanese officials have also concluded that the containment vessel for the third reactor was breached. Last week's talk of hopeful progress and cautious optimism seems to have evaporated. Engineers have begun to accept that they are making no headway.

"We are experiencing an ongoing, massive release of radioactivity," Wolfram Koenig, head of Germany's Federal Office for Radiation Protection, told Der Spiegel.

"And everyone should know by now that this isn't over by a long shot," nuclear expert Helmut Hirsch, says, "All I hear is that people are wondering whether this will turn into a meltdown. But the thing is, it already is a partial meltdown."

The only difference is that Fukushima is a creeping disaster. The cooling system is not online, pumps are not working, and as much as forty-five tons of sea-salt has accumulated as a result of the desperate decision to flood the reactors with sea-water in the hopes of avoiding a worst-case scenario. The salts are crystallizing at hot-spots and forming a layer of insulation. There are also 3,450 still-fervid spent fuel rods sitting in half-empty pools and therefore exposed to the air. Compounding the issue, the wind changed on Friday.

Radioactive particles over the Pacific have drifted westward across Japan. High levels of radiation have been detected in produce, water and soil near the Fukushima plant. Japanese authorities have only evacuated a zone within 20 kilometers (12.4 miles ) of the plant, but risks of radiation are growing for people outside the zone. "It is high time Japanese authorities extend the 20- kilometer evacuation zone around the crippled nuclear-power plant at Fukushima," writes nuclear critic Mycle Schneider, lead author of the World Nuclear Industry Status Reports, adding that "...pregnant women and small children should immediately be evacuated from a progressively increasing area."

Embryos, fetuses, and infants are especially vulnerable because radiation targets cells that divide quickly. There are 77,000 people in ad hoc emergency shelters. Another 62,000 live within the 30-kilometer zone. The United States Regulatory Agency (NRC) had advised extending the evacuation zone to 80 kilometers, which would require relocating 2 million. This, in addition to hundreds of thousands of Japanese earthquake and tsunami victims. Japanese authorities, to date, have asked people to voluntarily evacuate the area.

The set-upon Japanese are also being bombarded with advice, demands, and speculation from United States, Russia, Finland, and Germany. Even France's nuclear agency IRSN, not known for its caution, issued disturbing projections last week. According to the French, the Fukushima plant has released 1/10th the radiation of the Chernobyl disaster in 1986. The International Atomic Energy Agency (IAEA), however, believes that the French are engaging in Gallic exaggeration. According to the IAEA, its calculations, based on readings at the site, is only a fraction of French estimates.

French projections were based on their knowledge of fissile material stored in the reactors, independent research on the condition of hot fuel rods, and readings taken in the vicinity of Fukushima. There are more than 2,500 tons of uranium and plutonium in Fukushima. And Japanese emergency release valves for radioactive steam generated for active fuel rods do not have filters like plants in Germany and the United States. The Japanese, due to radiation levels, have not released the steam in a week, but that can't go on forever. 

"This is not an exaggeration," German nuclear expert Helmut Hirsch says. "There is a gigantic radioactive inventory at Fukushima. At least 20 times as much as there was at Chernobyl."

But while French experts believe the worst radiation leaks may be behind the Japanese, other experts have gloomier theories. US expert Bill Borchart of the NRC blames high radiation levels around Fukushima on the spent fuel rods in the holding pools. These rods, normally kept underwater while shielded by the reactor roof, are now emitting radiation into the open air. Only cooling water prevents the rods from igniting, but the water is constantly being converted to radioactive steam. And it remains unclear whether the pools can be refilled at all as earthquake damage has not been assessed.

After the Three Mile Island meltdown 1979 it took six years before engineers could re-open the core to determine how far the meltdown progressed. The site remains closed today. And, even 25 years after the Chernobyl meltdown, which also resulted in a sealed plant, boar hunters in the affected region still have to discard meat because it is contaminated by radiation. The long-term effects of a radioactive core open to the atmosphere remain a worrisome enigma. In Japan, which endured the aftermath and health-consequences of Hiroshima and Nagasaki, that enigma is a nerve-jarring specter.

Borchart summed up Japan's crisis, "We don't have the slightest idea of what conditions are like in the reactor buildings."