Posts Tagged ‘Japan’

UMD panel: U.S. Safe from Fukushima Fallout

Wednesday, March 30th, 2011

A panel of University of Maryland nuclear experts said the United States is safe from radiation leaking out of Japan’s Fukushima Daiichi plant, but disagreed on what the disaster would mean to the environment surrounding the facility.

Jeff Stehr, an atmospheric and oceanic sciences researcher, has helped form projections of the path of the plume of radioactive particles coming from the plant, which was damaged by a 9.0 earthquake and the resulting tsunami on March 11. He said Alaska’s Aleutian Islands might see slightly higher levels of radiation than normal, but in the continental U.S. even the West Coast was at very little risk.

“We’re not really looking at a big deal for us,” Stehr said. “We’re very, very far away.”

The discussion came on the heels of news of high levels of radiation in the seawater around the damaged Fukushima plant. Mohamad Al-Sheikhly, an engineering professor, said that was not cause for panic because the vastness of the Pacific Ocean would dilute radiation and the Japanese have method for retrieving uranium from water.

But Donald Milton, a professor at the Maryland Institute for Applied Environmental Health, warned of “bio-concentration.” He said some radioactive elements, like Cesium, tend to concentrate in water and move up the food chain rather than dissipating.

“What’s going to be really important is the monitoring of fish and mollusks,” Milton said.

The panel was moderated by Carol Rogers, professor of journalism, and also included Bill Dorland, professor of physics, Nate Hultman, professor of public policy, and John Steinbruner, professor of public policy.

The panel agreed that the U.S. nuclear community could learn from the Fukushima crisis.

Dorland said that Tepco, which operated the Fukushima plant, was warned years earlier that the area around the plant had a history of tsunamis. He said the plant had been built to withstand a tsunami of 6.5 meters but the one that took out its backup power March 11 reached 14 meters.

Maryland’s only nuclear power plant, Calvert Cliffs, is likely safe from earthquakes and tsunamis. The U.S. Geological survey reports that there has never been an earthquake centered in Washington, D.C., in recorded history.

But more mundane weather conditions have caused problems at Calvert Cliffs. Last year, the plant’s general manager, Thomas Trepanier, warned employees about declining maintenance after melting snow leaked through the roof and shorted out one of the reactor’s electrical distribution boxes. One of the plant’s five backup generators then failed, causing the Nuclear Regulatory Commission to issue a rare “white” finding.

Dorland said he was unfamiliar with the incident, but that any reactor should be built so that both the primary and secondary power  sources for cooling could not be knocked out by the same event.

“If snow is an issue there, and both the primary and secondary power are vulnerable to snow, then that’s a design flaw,” he said.

Hultman said the incident in Japan would likely affect U.S. nuclear policy and regulation and noted that Germany had shut down several of its older nuclear plants in light of the crisis.

Steinbruner said that all nuclear plants could be made safer than they are now by sacrificing some efficiency, but it would require an “entirely different configuration of the industry.”

New, safer reactor designs are on the way, Al-Sheikhly said, including a Westinghouse AP 1000 model with a passive safety system that eliminates the possibility of a meltdown due to operator error. He also touted advanced gas-cooled reactors that are smaller and safer, relying on liquid helium for cooling, rather than water.

But Dorland noted that many of the problems at Fukushima came not from the reactors themselves, but from spent nuclear fuel sitting outside the containment units in cooling ponds. That led Milton to note that the U.S. had not found any viable solutions for storing nuclear waste in the long term, despite setting aside $24 billion to build a permanent facility.

“Even if we come up with reactors that are inherently safe, can we deal with the waste they produce?” Milton asked.

By Capital News Service’s Andy Marso