Tuesday, August 16, 2005
Copyright © Las Vegas Review-Journal

YUCCA MOUNTAIN: Fuel assembly plan in works, official says

Engineers' study pointed to possibility of radioactive leaks at nuclear repository

A facility or process for handling damaged spent fuel assemblies at the planned Yucca Mountain nuclear waste repository will be added to the site's design in the coming weeks, a Department of Energy spokesman said Monday.

"Over the next several weeks that's going to be closed and solved," said Allen Benson, a spokesman for the department's Office of Repository Development.

He was responding to questions raised by a Review-Journal story Saturday about a study by department contractor engineers who were hired to troubleshoot the repository's design.

The engineers conducted the study so there wouldn't be any surprises when a license application is submitted to the Nuclear Regulatory Commission, Benson said.

"We are in the process of refining the design to accommodate the issue identified in the report. It will be dealt with through refinement of design or operational techniques," he said, referring to the contractor's report.

Benson said Yucca Mountain project scientists and engineers are working to finalize the design but the department is not ready to release the blueprint in its current stage.

Contractor engineers reported in March that thousands of highly radioactive fuel assemblies are expected to arrive damaged at the site's surface facilities, 100 miles northwest of Las Vegas.

There the fuel assemblies will be removed from transportation casks, inspected and sent to above-ground facilities for aging and repackaging before they are put in maze of tunnels deep inside the mountain for permanent storage.

The study found that 4 percent, or roughly 8,880, are expected to have varying amounts of damage to the zirconium-alloy cladding that surrounds spent fuel pellets.

Unless precautionary measures are taken to repackage the fuel assemblies in an oxygen-free environment, engineers believe cracks or undetected leaks could result in oxidation of the fuel and contamination released in the form of highly-radioactive powders. This in turn would pose potential risks to workers and the public.

Benson said there will be a complete surface facility design for the NRC staff to review in the license application for the repository. "All operational facilities will be designed to handle damaged fuel assemblies" if there are any, he said.

He said the NRC is aware of the oxidation potential "and it is up to the Department of Energy to address it in the license application."

In the past, critics of the project including consultants for Nevada's Nuclear Projects Agency have expressed concerns about the potential for accidents at the surface facilities.

As much as 20,000 tons of spent fuel casks could be left on pads outside the repository where the decaying waste will age before it is put below ground. While being handled or stored above ground, the waste could be vulnerable to shaking from strong earthquakes or damage and fire from aircraft crashes, critics have said.