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Fwd: Plutonium Found in Nev. Groundwater

In a message dated 1/6/99 2:02:43 PM Eastern Standard Time, AOL News writes:

<< Plutonium Found in Nev. Groundwater
 
 .c The Associated Press
 
  By JEFF BARNARD
 
 Traces of plutonium from a test blast in the Nevada desert migrated nearly a
mile through groundwater, according to a study that prompted the government to
recalculate slightly the risks that would be posed by an underground nuclear
waste storage site.
 
 Scientists said the amount of radioactivity that can move this way is too
small to endanger the public, and the U.S. Energy Department, in reassessing
the risks of the government's proposed waste site beneath Nevada's Yucca
Mountain, agreed.
 
 Until recently, it was commonly believed that significant amounts of
plutonium would not move through groundwater because the element dissolves at
a very low rate and attaches strongly to any rocks it touches.
 
 But in a study published Wednesday in the journal Nature, researchers
confirmed suspicions that plutonium can hitch a ride on colloids, or particles
of debris suspended in water.
 
 Scientists from Lawrence Livermore National Laboratory in California and Los
Alamos National Laboratory in New Mexico looked at a 30-year-old nuclear blast
that reached below the water table on the Nevada Test Site, where the United
States has conducted 828 underground nuclear tests between 1956 and 1992. The
site is 70 miles northwest of Las Vegas.
 
 The scientists found minute amounts of plutonium -- measurable only by the
most sensitive equipment -- in test wells nearly a mile away from the blast,
and concluded that the plutonium had flowed downstream on colloids.
 
 ``We have shown there is a new potential pathway that has been suggested
before, but never definitely shown. The question is what the maximum amount is
that you could move. We don't know that,'' said Annie Kersting, a Lawrence
Livermore scientist.
 
 The Energy Department wants to build a nuclear waste repository at Yucca
Mountain, about 90 miles northeast of Las Vegas. The government has already
spent $2.2 billion in 15 years of research in hopes of entombing 80,000 tons
of used reactor fuel that will remain deadly 300,000 years.
 
 The department took the latest findings into account and concluded that the
seepage wouldn't happen for 10,000 to 100,000 years, and even then, the
escaped radiation would be less than the background amount.
 
 ``They are not rates that would bust any kind of standards. We see no
impact,'' said Abe Van Luik, senior technical advisor for performance
assessment for the Energy Department.
 
 Bruce Honeyman, a professor at the Colorado School of Mines, said the very
nature of colloids -- their extremely small size and low concentrations --
assure that they would never move large amounts of radiation.
 
 ``The radioactivity is so low that it probably is not of significance for
adverse human health effects,'' he said. ``Conceptually, you can think of
colloids being like a conveyor belt. The belt is really not turning very
quickly.''
 
 The Energy Department's conclusions did not satisfy Bob Loux, executive
director of the Nevada Agency for Nuclear Projects in the Nevada governor's
office. He said he believes containers holding the waste will fail much more
quickly than the government estimates and allow unknown quantities of
contaminants to escape within 500 years.
 
 AP-NY-01-06-99 1402EST
  >>



Plutonium Found in Nev. Groundwater

.c The Associated Press

 By JEFF BARNARD

Traces of plutonium from a test blast in the Nevada desert migrated nearly a
mile through groundwater, according to a study that prompted the government to
recalculate slightly the risks that would be posed by an underground nuclear
waste storage site.

Scientists said the amount of radioactivity that can move this way is too
small to endanger the public, and the U.S. Energy Department, in reassessing
the risks of the government's proposed waste site beneath Nevada's Yucca
Mountain, agreed.

Until recently, it was commonly believed that significant amounts of plutonium
would not move through groundwater because the element dissolves at a very low
rate and attaches strongly to any rocks it touches.

But in a study published Wednesday in the journal Nature, researchers
confirmed suspicions that plutonium can hitch a ride on colloids, or particles
of debris suspended in water.

Scientists from Lawrence Livermore National Laboratory in California and Los
Alamos National Laboratory in New Mexico looked at a 30-year-old nuclear blast
that reached below the water table on the Nevada Test Site, where the United
States has conducted 828 underground nuclear tests between 1956 and 1992. The
site is 70 miles northwest of Las Vegas.

The scientists found minute amounts of plutonium -- measurable only by the
most sensitive equipment -- in test wells nearly a mile away from the blast,
and concluded that the plutonium had flowed downstream on colloids.

``We have shown there is a new potential pathway that has been suggested
before, but never definitely shown. The question is what the maximum amount is
that you could move. We don't know that,'' said Annie Kersting, a Lawrence
Livermore scientist.

The Energy Department wants to build a nuclear waste repository at Yucca
Mountain, about 90 miles northeast of Las Vegas. The government has already
spent $2.2 billion in 15 years of research in hopes of entombing 80,000 tons
of used reactor fuel that will remain deadly 300,000 years.

The department took the latest findings into account and concluded that the
seepage wouldn't happen for 10,000 to 100,000 years, and even then, the
escaped radiation would be less than the background amount.

``They are not rates that would bust any kind of standards. We see no
impact,'' said Abe Van Luik, senior technical advisor for performance
assessment for the Energy Department.

Bruce Honeyman, a professor at the Colorado School of Mines, said the very
nature of colloids -- their extremely small size and low concentrations --
assure that they would never move large amounts of radiation.

``The radioactivity is so low that it probably is not of significance for
adverse human health effects,'' he said. ``Conceptually, you can think of
colloids being like a conveyor belt. The belt is really not turning very
quickly.''

The Energy Department's conclusions did not satisfy Bob Loux, executive
director of the Nevada Agency for Nuclear Projects in the Nevada governor's
office. He said he believes containers holding the waste will fail much more
quickly than the government estimates and allow unknown quantities of
contaminants to escape within 500 years.

AP-NY-01-06-99 1402EST

 Copyright 1998 The Associated Press.  The information  contained in the AP
news report may not be published,  broadcast, rewritten or otherwise
distributed without  prior written authority of The Associated Press. 

 

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