Fiume Columbia: misero le scorie in barili senza fondo (29 settembre)

Containers Seen Contamination Source
http://www.newsday.com/ap/text/national/ap757.htm
by LINDA ASHTON
Associated Press Writer

YAKIMA, Wash. (AP) -- High-level nuclear waste at the Hanford nuclear reservation was buried decades ago in bottomless containers less than four miles from the Columbia River, the Energy Department said Friday.

The agency said that may be why the level of radioactive tritium in area groundwater is 400 times higher than the federal safety standard.

Wade Ballard, assistant manager for planning and integration, couldn't say why the agency used the containers. He said it might have been to prevent water from accumulating in them and then leaching radioactive material into the ground.

''It was 40 years ago,'' he said. ''Obviously, if we were designing it today, we would do it differently.''

Five bottomless caissons, or large corrugated metal pipes, and 50 bottomless drums are buried 3½ miles from the Columbia River in south-central Washington. It was unclear how much waste is stored there, but it includes 11 to 22 pounds of plutonium, which was manufactured at Hanford for nuclear weapons.

Low-level radioactive waste also was dumped into trenches for burial at the 8.6-acre site from 1962 to 1967. Hanford does not expect to begin cleaning up the site until at least 2010.

Tritium is a radioactive isotope of hydrogen that poses a cancer risk when ingested. It was produced at Hanford for use in nuclear warheads to boost their explosive yield.

Last January, the high level of tritium was detected in a Hanford monitoring well near the waste site. The well is also in the path of a huge tritium plume stretching from the central part of the 560-square-mile reservation to the river.

It is unclear whether the tritium levels in the area are from the waste site or groundwater 60 feet below the surface, Ballard said. But experts say the tritium will likely reach the river.

''The issue is how much is there,'' said Mike Thompson, the site's groundwater manager. ''At this point in time, we don't believe there's a very large tritium plume.''

If tests show the tritium is moving fast enough to be a threat to the river, action will be taken to stop its progress, Ballard said.

AP-NY-09-29-00 1914EDT<