Pictures: The Nuclear Cleanup Struggle at Fukushima

Battered by the Sea

Photograph courtesy Giovanni Verlini, IAEA

A damaged seawater intake pump sits outside the Fukushima plant, testimony to the frantic efforts to control the fuel decay heat last March after power was lost to the cooling system.

(Related: "Would a New Nuclear Plant Fare Better Than Fukushima?")

Water remains at the heart of the workers' efforts, but not in the same way as it was at the start of the crisis. "The real focus of activities has moved beyond the stabilization of the plant," says Neil Wilmshurst, vice president-nuclear for the electric industry's nonprofit research arm, the Electric Power Research Institute based in Palo Alto, California. "The challenge now facing TEPCO is the water cleanup."

Tens of thousands of tons of contaminated water collected in reactor and turbine buildings as a result of the tsunami, the injection of water to cool the reactor fuel, and rainfall through structures damaged by hydrogen explosions.

(Related: "Japan Reactor Crisis: Satellite Pictures Reveal Damage")

TEPCO dumped more than 10,000 tons of contaminated water into the sea before it was able to set up a large radioactive waste treatment facility in June. The system has had its ups and downs, and some worry about TEPCO's ability to treat water fast enough to avert additional overflow into the sea.

TEPCO also must work to desalinate the radioactive water--a complex and typically energy-intensive process--to reduce the potential for corrosion by the salt.

The safety of the treated water also is a public concern. One Japanese official recently went to the length of drinking water on live TV that had been treated after being taken from flooded basements of reactor buildings.

"They've started to partially decontaminate the water, but there is still a massive volume of water that needs to be decontaminated and stored for a long time," Lyman said.

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Published November 11, 2011

Helping Hands from Hiroshima

Photograph from Kyodo/Reuters

Volunteers from Hiroshima, the first city to be destroyed by a nuclear weapon, have traveled to Fukushima to aid their countrymen whose lives were upended by a peacetime atomic accident. Here, they work on October 24 to remove radioactive substances from a fishing boat in Minamisoma, Fukushima prefecture.

The group, formed in August, includes former nuclear power plant workers and survivors of the U.S. atomic bombing in 1945. Their goal in the project pictured here is to decontaminate the fishing boat, which was swept to land by the tsunami, so it can be taken back out to sea.

Wilmshurst said no one can say how long the Fukushima plant cleanup will take, but it certainly won't be done in the next year. "This is going to be a number of years before this cleanup is complete."

(Related: "Energy-Short Japan Eyes Renewable Future, Savings Now")

He noted a video that circulated a few weeks ago showing the challenge of TEPCO workers navigating the debris in order to inspect the condensers in the reactors. IAEA noted in a report this week that TEPCO has had success in removing obstacles to the robots that are surveying the damage in the Unit 3 Reactor building, which allows for greater access and more detailed surveys of dose rates, environmental conditions and temperatures.

Despite the various difficulties, Wilmshurst says progress is being made on building enclosures around the damaged reactors. That will help contain radiation.

"As the cleanup continues and the access improves, more things will be discovered and there will be more understanding," Wilmshurst said.  "It's a developing situation every day."

(Related:"How is Japan's Nuclear Crisis Different?")

Published November 11, 2011

Watchful, Even at Play

Photograph from Kyodo/AP

A man measures the radiation level before the start of the Fukushima prefectural high school baseball tournament in July in Koriyama,  about 37 miles (60 kilometers) from the power plant.

Some sites just outside the restricted zone now show radioactive readings in line with the global average for natural or background radiation.

Others readings are still elevated. For example, at one station about 20 miles (32 kilometers) northwest of the plant, 300 microsieverts (0.3 millisieverts) of radiation were recorded over a 24-hour period between October 31 and November 1, according to data posted by the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT).

While that's significantly less than the readings there in March, it is a higher dose than getting a chest X-ray every day and would be on pace to exceed the annual dose for which there is evidence of radiation-related cancer in adults.

(Related:  "Is Japan Reactor Crew Exposed to Fatal Radiation?")

Residents in areas with elevated levels of radiation have been advised to prepare for possible evacuation.

The fact that hot spots were detected last month as far away as Tokyo, 150 miles (240 km) to the south, "illustrates the very uncertain nature of the dispersal and deposition process of the isotopes," said Lyman of the Union of Concerned Scientists.

At least initially, the government didn't do enough monitoring to satisfy public concerns, and many of the hot spots have been discovered through surveys funded by citizen groups, Lyman noted.

"Because the dispersal is so highly variable, it takes a very intensive effort to survey every area," Lyman said. "I'm sure there are hot spots that haven't been discovered yet and there may be people at risk who don't realize it."

A recent Fukushima University survey of displaced households near the nuclear plant found that two-thirds don't trust government declarations that radiation levels are safe, and one-quarter don't want to return to their homes.

But the IAEA team report made a point to praise Japan's "impressive" system for tracking radiation levels. "The  extensive,  real-time monitoring system that is currently being set up and the transparent online availability of the resulting data are important measures to reassure the public and the international community," the IAEA report said.

(Related: "Ten Oldest U.S. Nuclear Plants-Post-Japan Risks")

Published November 11, 2011

A Deep Dig into Soil, and Coffers

Photograph by Tomohiro Ohsumi, Bloomberg/Getty Images

An excavator removes contaminated soil at a park in Koriyama, Fukushima prefecture, on October 17.

Japan's environment ministry will budget 1.1 trillion yen ($14 billion) for decontamination projects by the end of next fiscal year, an agency officials  recently said. Kyoto University researchers have estimated that decontaminating the soil alone in about a 200-square-mile (51,800-square-hectare) area will cost more than $13 billion.

The isotope Cesium 137 is the greatest worry because it takes 30 years for its radioactivity to halve. The Tokyo Institute of Technology has developed a method it hopes can be used for converting highly radioactive cesium in sewage sludge into a stable cesium oxide that could be stored in an intermediate-level facility.

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Published November 11, 2011

Surmounting the Waste Problem

Photograph from TEPCO via Reuters

Used radiation protection suits pile up last month at a radioactive waste dump at J-village, a soccer training center in Fukushima that has been converted into a command center in the cleanup effort.

Japanese officials announced that the national government will take responsibility of the disposal of waste with high levels of cesium in ash and sludge in Fukushima and several nearby prefectures.

Such high-radioactive ash already had been found in 42 waste disposal facilities in Tokyo, Fukushima and five other prefectures as of late August. An incinerator in Chiba prefecture 175 miles (282 kilometers) south of Fukushima was shut down because of high levels of radioactive cesium in incinerated ash.

Government officials said they would establish an interim storage facility in Fukushima prefecture within three years that has an estimated storage capacity of 19 million to 37 million cubic feet (15 to 28 million cubic meters). The government said contaminated soil, ash, and other radioactive materials would be stored at the temporary site for up to 30 years before they are moved to a final disposal site outside Fukushima prefecture.

"You can measure the environmental contamination; that is a known problem," said Lyman of the Union of Concerned Scientists. "The challenge is going to be how to set the appropriate levels to determine what areas to clean up and which areas to abandon. That could affect the long-term habitability of many of the areas."

At this point, he said, it appears that the public is leery of setting a high level  for acceptable radiation.

But the IAEA team of experts, in their summary report after visiting Fukushima last month, encouraged Japanese authorities to "avoid over-conservatism" in establishing such standards. The team praised Japan for allocating resources necessary to develop an efficient remediation and monitoring program, but encouraged officials to involve more radiation protection experts in efforts to reduce exposure.

Published November 11, 2011

Hoping for Safe Harvest

Photograph by Yasuhiro Takami, Yomiuri Shimbun/AP

Volunteers work to decontaminate the soil of a home garden near Fukushima on October 29.

The prefecture of Fukushima was Japan's fourth-largest agricultural area, a top producer of many fruits, vegetables, tobacco, and raw silk. But some samples of fish, mushrooms and meat from Fukushima prefecture continue to exceed regulatory standards for radioactive contaminants, according to Japan Ministry of Health data released earlier this month.

Restrictions were lifted as of November 7 on the distribution and consumption of leafy vegetables and turnips produced in specific areas of Fukushima prefecture. But tea leaves and beef from some nearby prefectures also remain on the restricted list.

Japanese officials told the recent IAEA team that the goal for farmland is to reduce the radioactive air dose level by 50 percent within the next two years.

Experiments have been conducted to determine the best way to remediate farmland. At one site, a layer of top soil with elevated levels of cesium was removed, and rice was planted. Deep plowing also has been tested.

The IAEA team said there is room for "removing some of the conservatism" during the next cropping season, based on research showing less transfer of radioactive cesium from soil to crops than Japanese officials are assuming. The IAEA singled out the limits that Japan had placed on cultivation of rice as an example of a standard that could be eased, once testing is complete.

The IAEA team said it's also crucial to focus on upland drainage areas, because radioactive trace elements can seep from hillsides to rice paddies and rivers through soil erosion or heavy rainfall.

Published November 11, 2011

Room for Greater Knowledge

Photograph by Masanori Genko, Yomiuri Shimbun/AP

Teachers and parents work to help decontaminate Omika Elementary School, just outside the evacuation zone in Minamisoma, Fukushima prefecture, last month.

Omika and four other schools in the area were allowed to reopen in mid-October after decontamination was completed and an evacuation standby zone designation lifted.

Minamisoma is roughly 15 miles (24 km) north of the nuclear plant; Omika Elementary is about 13 miles (21 km) from the plant. Japanese officials ordered residents within 12.4 miles (20 km) of the plant to leave soon after the March accident, and later recommended evacuation of residents living between 12 and 18 miles (20 km to 30 km) of the plant. But by then, residents of Minamisoma already had left the area. Residents continue to be wary, and school officials, concerned about possible radiation exposure, asked parents to drive rather than walk their children to the school.

The IAEA team was told during its recent mission that 400 school playgrounds also had been remediated as of September 30. Some school sites were worked on mostly by volunteers with technical support provided by the Japan Atomic Energy Agency. The IAEA team praised Japan for giving priority in its remediation efforts to areas where children typically spend most of their time.

The effects of low-level radiation exposure may take decades to manifest, and it remains "very unclear the number of children exposed to significant levels the first few days" after the accident, said Lyman of the Union of Concerned Scientists.

"There is a possibility," he said, "that there were populations that were exposed and, as in Chernobyl, the effects won't appear for at least a decade."

But Lyman said that Japan has moved beyond viewing any criticism about the level of safety of nuclear plants as a political attack. He sees a new level of self-examination by TEPCO and Japanese authorities as a positive that has emerged from the disaster.

(Related: 20 "unforgettable" pictures of the Japan tsunami and its aftermath.)

Published November 11, 2011