Marine
11-26-2002, 6:40am
http://images.zwire.com/local/z/zwire2144/zwire/images/DC-L.gifos Alamos County and U.S. Forest Service personnel who are thinning trees in Bayo Canyon east of Los Alamos have been warned by Los Alamos National Laboratory not to remove trees they cut in various parts of the canyon because the trees might be radioactive.
Small sections at the bottom of Bayo Canyon - formerly known as Technical Area 10 - were used from the 1940s until 1961 as test sites by scientists studying explosions, said LANL spokesman James Rickman.
The Forest Service is assisting Los Alamos County with various thinning projects on county lands. The crews are thinning dense ponderosa stands to try to reduce the danger of a large-scale fire in various canyons near the town.
Before work began earlier this week, LANL officials told thinning crews not to remove trees from certain areas within former test sites, which total less than 30 acres of the 160-acre thinning project, Rickman said.
"It's not because it presents any reasonable risk. It's just a precaution," Rickman said. "There's a negligible amount of trees in those areas anyway. But, never the less, we wanted to point that out in those areas."
As an added precaution, Forest Service and county crews have opted not to remove any vegetation from the entire canyon. Instead, crews are grinding the trees into mulch with a machine.
"There were a series of tests conducted at the site called the RaLa Experiments," Rickman said. "They were named that because they involved radioactive lanthanum, which has a half-life of 40 hours."
Lanthanum was used as a tracer material in tests that studied explosions.
"So, since it has such a short half-life of 40 hours, most of the radioactivity from those tests would be nearly zero after two weeks."
But impurities in the lanthanum also produced small amounts of Strontium 90, a radioactive material prevalent in nuclear fallout that has a half-life of 28 years, he said.
"The reason that is a concern is because it acts similar to calcium," Rickman said. "If you would ingest it, it would tend to appear in your bones and teeth."
Bayo Canyon is a popular spot for hiking and horseback riding.
"Normal recreational use, the activities that are done in that area, don't present any risks to the public," Rickman said. "Because we've asked the Forest Service to leave those trees in that area does not mean people need to be afraid of that area. We have placards (in Bayo Canyon) that say 'No excavating,' but normal recreational use is not a problem."
Bill Armstrong, forester for the Santa Fe National Forest, said crews are staying out of the canyon bottoms and are trying not to disturb the soil because they have been told that buried hazardous materials can be pushed to the surface by plants.
The thinning project has an added importance now because of the contaminants, Armstrong said. Erosion and flooding are likely to occur if an intense forest fire burns in the canyon. The water could carry hazardous material toward homes in Los Alamos, he said.
Crews plan to finish the thinning project by early next year, Armstrong said.
http://santafenewmexican.com/site/news.cfm?newsid=6162927&BRD=2144&PAG=461&dept_id=367954&rfi=6
Small sections at the bottom of Bayo Canyon - formerly known as Technical Area 10 - were used from the 1940s until 1961 as test sites by scientists studying explosions, said LANL spokesman James Rickman.
The Forest Service is assisting Los Alamos County with various thinning projects on county lands. The crews are thinning dense ponderosa stands to try to reduce the danger of a large-scale fire in various canyons near the town.
Before work began earlier this week, LANL officials told thinning crews not to remove trees from certain areas within former test sites, which total less than 30 acres of the 160-acre thinning project, Rickman said.
"It's not because it presents any reasonable risk. It's just a precaution," Rickman said. "There's a negligible amount of trees in those areas anyway. But, never the less, we wanted to point that out in those areas."
As an added precaution, Forest Service and county crews have opted not to remove any vegetation from the entire canyon. Instead, crews are grinding the trees into mulch with a machine.
"There were a series of tests conducted at the site called the RaLa Experiments," Rickman said. "They were named that because they involved radioactive lanthanum, which has a half-life of 40 hours."
Lanthanum was used as a tracer material in tests that studied explosions.
"So, since it has such a short half-life of 40 hours, most of the radioactivity from those tests would be nearly zero after two weeks."
But impurities in the lanthanum also produced small amounts of Strontium 90, a radioactive material prevalent in nuclear fallout that has a half-life of 28 years, he said.
"The reason that is a concern is because it acts similar to calcium," Rickman said. "If you would ingest it, it would tend to appear in your bones and teeth."
Bayo Canyon is a popular spot for hiking and horseback riding.
"Normal recreational use, the activities that are done in that area, don't present any risks to the public," Rickman said. "Because we've asked the Forest Service to leave those trees in that area does not mean people need to be afraid of that area. We have placards (in Bayo Canyon) that say 'No excavating,' but normal recreational use is not a problem."
Bill Armstrong, forester for the Santa Fe National Forest, said crews are staying out of the canyon bottoms and are trying not to disturb the soil because they have been told that buried hazardous materials can be pushed to the surface by plants.
The thinning project has an added importance now because of the contaminants, Armstrong said. Erosion and flooding are likely to occur if an intense forest fire burns in the canyon. The water could carry hazardous material toward homes in Los Alamos, he said.
Crews plan to finish the thinning project by early next year, Armstrong said.
http://santafenewmexican.com/site/news.cfm?newsid=6162927&BRD=2144&PAG=461&dept_id=367954&rfi=6