Nagasaki Bomb Maker Offers Lessons for Fukushima CleanupShigeru Sato and Yuji Okada
Hanford Engineer Works produced the 20 pounds of plutonium for the bomb dropped on Nagasaki. It’s among the most toxic nuclear waste sites and the place Japan is turning to for help dealing with melted reactors in Fukushima.
Tokyo Electric Power Co. has sent engineers on visits to the Hanford site in Washington state this year to learn from decades of work treating millions of gallons of radioactive waste. Hanford also has a method to seal off reactors known as concrete cocooning that could reduce the 11 trillion yen ($112 billion) estimated cost for cleaning up Fukushima.
Hanford stretches over 586 square miles of scrubland southeast of Seattle where thousands of technicians are decommissioning the nine reactors in operation from 1944 to 1987. Its laboratories and plutonium facilities were integral to the Manhattan Project to make the first atomic bomb.
“The U.S. has vast experience in nuclear technology with their military activity, including decontaminating soil and managing river contamination,” Masumi Ishikawa, general manager of Tokyo Electric’s radioactive waste management, said in an interview. “There’s a lot we can learn from them.”
Japan Prime Minister Shinzo Abe agreed with that last week when he told his fellow citizens for the first time that Tokyo Electric alone isn’t able to handle the disaster at the Dai-Ichi plant. He promised more government funds for the cleanup without saying how they’d be used.
Abe’s comments followed a long series of mishaps by the utility known as Tepco, resulting in its admission last month that hundreds of tons of radioactive water is flowing into the Pacific Ocean more than two years after three reactor cores melted down at the plant.
Hanford has its own share of containment challenges. Six underground tanks leaking radioactive waste may offer lessons to Tepco in dealing with substances that contaminate everything they come in contact with. The tanks are among 177 buried at Hanford, about 200 miles (320 kilometers) southeast of Seattle along the Columbia River.
The U.S. Department of Energy has spent more than $16 billion since 1989 to clean up Hanford. The weapons production generated 56 million gallons of radioactive waste, enough to fill a vessel the size of a football field to a depth of 150 feet, according to a December report by the U.S. Government Accountability Office.
Tepco’s Ishikawa said visits by him and other company engineers to Hanford are part of an agreement with the Department of Energy to evaluate the technology for possible use at Fukushima.
Ishikawa, 46, studied nuclear engineering at Tohoku University in Sendai City, northeast Japan, and is one of the Fukushima Fifty.
The name refers to a group of engineers who stayed in the Japanese plant to fight the disaster as power was lost and reactor buildings exploded. Ishikawa was the right-hand man of Masao Yoshida, who led the group. Yoshida died on July 9 of esophageal cancer. He was 58.
At Hanford, the energy department finished a $65 million cocooning project in June last year, the DOE said in a statement. That involved demolishing the last one of the nine reactor buildings down to the four-foot- (1.2 meter) thick concrete shield around the reactor core.
More concrete was added to the shield, along with a new concrete roof to put the reactor into so-called safe storage for 75 years. This allows radiation levels to decay to safer levels in the core and gives the operator time to determine the final disposal method, according to the statement.
There are three ways to decommission nuclear reactors, said Ishikawa. One is immediate dismantling. Another, used at the wrecked Chernobyl plant in Ukraine, entombed the whole building in concrete. The third is cocooning used at Hanford. Entombing and cocooning cost less than immediate dismantling as it reduces the expense for handling and moving highly radiated material, Ishikawa said.
Tepco is talking with the DOE on whether cocooning could work for the crippled reactors in Fukushima. Sealing them off in concrete for 75 years would allow more focus on cleaning up surrounding areas so that residents could return, said Ishikawa.
Around 160,000 people were forced to evacuate from towns and villages when the Dai-Ichi plant released clouds of radiation after it was hit by an earthquake and tsunami on March 11, 2011.
“Decommissioning is vital for the areas around Fukushima Dai-Ichi to move ahead with restoration,” Ishikawa said.
Officials from the DOE involved with Hanford have visited the Fukushima Dai-Ichi plant three times as part of a six-month agreement with Tepco to investigate the conditions there and what solutions they can offer, he said.
“We identified seven areas of U.S. expertise that can be tapped,” said Ishikawa. “That includes decommissioning, nuclear waste disposal, removal of melted fuel, and restoration of surrounding areas.”
Ishikawa said talks with the DOE continue and he couldn’t provide a date on when any agreement may be reached for using expertise and technology developed at Hanford.
“The United States remains committed to working with Japan in their remediation efforts and believes that Japan can continue to leverage U.S. knowledge and experience in the environmental management area,” said Lindsey Geisler, a DOE spokesperson.
“The Energy Department’s environmental cleanup mission is one of the world’s largest programs of its type,” Geisler said in an e-mail response to questions.
Ishikawa said in his visits to Hanford he’s seen decontaminated areas coming back to life, noting for example a winery that’s been built. That, he said, is what he wants to see in Fukushima.