New burial design may be more dangerous

Monday, May 7, 2001 | 10:52 a.m.

Workers burying waste in a proposed repository at Yucca Mountain could be exposed to more radiation if a "cooler" design is used, a supplement to last year's draft environmental impact statement says.

The 86-page supplement, released Friday with a 1,000-page scientific report on the project, adds a possible design that would place the canisters of spent nuclear fuel farther apart -- one that scientists say would keep the mountain's rock cooler over time.

That design would change calculations of how much radiation workers might be exposed to as they bury the waste over the 60 years it should take to build and fill the repository, 90 miles northwest of Las Vegas.

Workers could be exposed to a fraction of a higher radiation dose under the cooler design, the supplemental report says.

The current repository design allows the rock temperature to exceed the boiling point and result in two worker deaths. A cooler, more spacious repository would keep the temperature below boiling but result in 2.8 worker deaths, the Energy Department calculated.

The greater danger to workers comes from longer exposure to the waste as they build and monitor more tunnels. Robots would handle the waste containers, the report says.

DOE scientists have calculated that no radiation is expected to escape into the environment for up to 10,000 years, the supplement says. That conclusion reflects the original draft environmental impact statement.

The supplemental report also allows for a larger waste-handling area on the surface of the mountain to prepare for burial of four types of nuclear waste arriving from commercial reactors and defense sites.

The types include commercial spent nuclear fuel -- up to 70,000 tons, most of it uranium metal pellets -- and another 7,000 tons of military wastes such as Navy reactors, liquid wastes transformed into glass blocks and weapons wastes.

The DOE has already received 11,000 public comments on its original draft environmental impact statement, released last August. Comments on the supplement may be submitted at a public hearing, in writing, by fax or via the Internet by June 25:

May 31 -- 6 to 9 p.m., Longstreet Inn & Casino, Amargosa Valley.

June 5 -- 6 to 9 p.m., Suncoast Hotel & Casino, 9090 Alta Drive.

June 7 -- 6 to 9 p.m., Bob Ruud Community Center, Pahrump.