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The
Las Vegas Review Journal
www.lvrj.com
YUCCA MOUNTAIN: State, federal scientists in hot water
debate
Nevada researcher says geothermal flows could hit nuclear
waste at proposed site
By Keith Rogers
Tuesday, May 01, 2001
As
the U.S. energy secretary waits to receive a report on the
proposed Yucca Mountain nuclear waste dump, a scientist
for Nevada said Monday it's clear that thermal water rose
upward in the distant past and could do so again, a sign
the site should be disqualified.
But
a team of federal scientists for the U.S. Geological Survey
said they are equally convinced that's not the case. They
say the minerals formed slowly as the mountain cooled after
it was formed by volcanic ash showering down 13 million
years ago.
The
federal team's finding is expected to weigh heavily in final
scientific reports that Energy Secretary Spencer Abraham
will use later this year to recommend whether the mountain,
100 miles northwest of Las Vegas, is suitable for safely
entombing 77,000 tons of highly radioactive waste for at
least 10,000 years.
Despite
the federal team's conclusion, Nevada consultant Yuri Dublyansky,
of the Russian Academy of Sciences Siberian Branch, told
colleagues at an international nuclear waste conference
that the process he claims formed the mineral features --
hot water rising upward -- should be considered as a possible
disqualifying factor in the Yucca Mountain performance assessment.
"This
has to be called thermal," he said about evidence of
relatively high temperatures locked in tiny bubbles held
by the calcite minerals.
"They
have to carry heat from somewhere. I am taking very strong
issue with that," he said, referring to the federal
scientists' belief that rainwater percolated downward from
the mountain's surface and slowly formed mineral crystals
over millions of years.
If
the water shot upward before, chances are it could happen
again and flood the area where the waste is stored, carrying
off its potentially deadly radioactive contaminants into
the environment, according to state scientists. If the water
percolated downward from the surface, it would be far less
likely to disperse the waste because of the low amount of
rainfall involved, they said.
Nick
Wilson, a University of Nevada, Las Vegas researcher who
made a presentation Monday at the Ninth International High-Level
Radioactive Waste Management Conference, said results of
a UNLV study into the minerals are consistent with the conclusions
of the federal team. The conference was held at the Alexis
Park Hotel.
Joseph
Whelan, a geochemist from the U.S. Geological Survey's Denver
office, said there is strong evidence that mineral crystals
were formed in the presence of films from water that trickled
downward through the mountain, and not by upwelling flooding
that filled cavities in the mineral features.
"There
is no evidence to support flooding of the unsaturated zone,"
he told the session attended by three dozen scientists.
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