Scientists discover type of ceramic that safely contains radiation

Monday, Aug. 7, 2000 | 11:15 a.m.

Scripps Howard News Service contributed to this report.

A new ceramic material that resists damage from radiation over long periods may relieve the pressure on nuclear power plants that want to bury spent reactor fuel inside Yucca Mountain.

An international team of researchers discovered a special blend of ceramics that could keep deadly radiation contained for thousands of years.

The discovery is significant because it could relieve pressure on dumping more than 77,000 tons of high-level nuclear waste at Yucca Mountain, 90 miles northwest of Las Vegas, by 2010.

Nuclear utilities at 73 sites across the country have stored highly radioactive spent fuel rods either in pools of water or dry casks on site because Yucca Mountain has not been proven as scientifically sound to contain the wastes.

If the team that included scientists from the Department of Energy's Los Alamos National Laboratory in New Mexico, the Imperial College in Britain and Osaka University in Japan, can confirm its results, containing radioactive wastes could be extended 100 years or longer.

Kurt Sickafus of Los Alamos led the team. The research results were published in the journal Science on Friday.

"We have Yucca Mountain being the place of choice, but it is not approved yet," Sickafus said.

The researchers said when fluorite is blended with other ceramic materials it can contain extreme radiation.

Sickafus said that the fluorite ceramic works because it resists damage from the high levels of radiation that occur over thousands of years. The research team urged further development.

"You have several waste streams (from military and commercial sources) that would go to Yucca," he said.

The nuclear industry is under fire for failing to care for its radioactive wastes from cradle to grave, Sickafus said. Such a durable material would help restore confidence in nuclear power.

Nuclear utilities in other countries reprocess the radioactive material, recovering 80 percent of the uranium for reuse. Originally the United States also planned to reprocess the fuel.

However, the government now fears that a rogue nation or a terrorist group might steal nuclear fuel from a power plant and use it to make a weapon.

The United States has no long-term storage policy. The new containment material might be able to shift the strategy away from storing the high-level nuclear waste at Yucca Mountain, he said.

The international research also may be important for long-term disposal of surplus plutonium nestled inside the cores of disassembled nuclear weapons.

When radioactive materials are blended with the fluorite ceramic, a crystal lattice grabs and traps radioactivity, withstands the radiation and resists the damage from the nuclear energy, Sickafus said.

In simple terms, the chemical bonds between the fluorite and the ceramic do not break down despite radioactive particles bombarding the material.

The research also may help the nuclear industry because it would provide a way to safely store radioactive wastes much longer than conventional approaches, Sickafus said.

To test other nuclear materials, such as radioactive wastes from Navy submarines or highly radioactive remains from developing nuclear weapons, more research is needed.

"We'll have to do more work to be sure," Sickafus said in the current Science article.