Radioactive material

A former professor's research
could have been used in a bomb

Radioactive material loaned to the University of Hawaii-Manoa since the 1960s was safely removed and disposed of through a program designed to prevent it from ending up in terrorists' hands.

In a news release, the National Nuclear Security Administration said it removed a "substantial quantity" of radioactive cobalt-60 from a research irradiator at UH-Manoa.

The NNSA said the material could have been used in a "dirty bomb," a combination of explosive and radioactive material that could spread and contaminate a large area with radioactive material.

The removal was part of a nationwide effort to secure radioactive materials, the federal agency said in the news release.

UH-Manoa radiation safety officer Irene Sakimoto said the material was safely secured and kept under 12 feet of water to prevent any threat of exposure to people who worked with it. She said there are no other such materials on campus.

The material had been used by a UH-Manoa professor who recently retired. His experiments focused on irradiating tropical fruits to kill fruit flies, said UH-Manoa spokesman Jim Manke.

Sakimoto said the irradiator was also used over the years to sterilize fruit flies and in genetic experiments to isolate DNA, and by astronomy and physics researchers to test how radiation affects certain materials that could be used in space.

The radioactivity of the material has also been declining, and once the professor retired, no one had any use for the irradiator, Sakimoto said.

She said UH-Manoa asked the NNSA to take care of the disposal, since the Department of Energy owned the material. Funds were available to remove and dispose of the material through the new anti-terrorism program, which is part of the Bush administration's Global Threat Reduction Initiative.

If the university had to dispose of the material, "it would have been very expensive," Sakimoto said. She estimates the cost would have been about $1 million.

The university had about 1,000 curies of cobalt-60, a measurement that is also an indication of its radioactivity, Sakimoto said. Cobalt-60 has a half-life of about five years, meaning its radioactivity and mass declines in half every five years. Originally, the material was about 42,000 curies, she said.

The material was removed by a contractor on March 25 and disposed of at a secure NNSA facility on Tuesday, the agency said.

Sakimoto said about 100 pieces of material fit into a 2-by-3-foot lead box.

National Nuclear Security Administration
University of Hawaii

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