Thursday, March 02, 2000

Las Vegas Review-Journal Radioactivity discovered in groundwater

Nye County is trying to pinpoint the source of contamination found just outside the Nevada Test Site.

-- Dee (T1Colt556@aol.com), March 02, 2000

Answers

There's no real puzzle here! Nye County officials won't have to scratch their heads too hard.

From Long- Term Stewardship at the Nevada Test Site this site, by John B. Walker and Paul J. Liebendorfer of the Nevada Division of Environmental Protection, we read

this

"The Nevada Test Site (NTS) is a U.S. Department of Energy (DOE) installation occupying approximately 1,350 square miles (882,332 acres) in southeastern Nye County, Nevada. NTS is larger than the State of Rhode Island. Site features includes deserts, playas, and mountainous terrain (see Figure 1). NTS was established in 1951 as the nation's proving ground for testing and development of nuclear weapons. Between 1951 and 1992, the federal government conducted just over 900 nuclear tests at the site; 100 of these tests were conducted above ground."

and

"DOE does acknowledge, however, that longer-lived radionuclides remain in the soil and physical structures at the site. The primary radioactive isotopes that remain from above ground testing include americium, plutonium, cobalt, cesium, strontium, and europium."

and

"Beginning in June 1957 and ending in September 1992, DOE (and its predecessor agencies) conducted over 800 underground nuclear tests at the NTS. The tests had yields ranging from zero to 1,000 kilotons. Underground testing left an estimated source term of 300 million curies in the environmental media (soil and groundwater). Because an estimated 38 percent of the tests were conducted under or within 75 meters (246 ft) of the water table, the groundwater beneath the site now contains an estimated 120 million curies of radioactivity.

"There were four basic types of underground tests: shallow, borehole, deep vertical, and tunnel tests. Collectively, these tests caused significant disruption to the geologic media. They resulted in hundreds of subsidence craters and caused contamination of the subsurface geologic media, surface soils, and groundwater over an estimated 300 square mile area. In terms of absolute volume, Nevada officials contend that the NTS contains more contaminated media than any other site in the DOE weapons complex."

-- Tom Carey (tomcarey@mindspring.com), March 02, 2000.

Hmmmn.

<< He said the sample is the first ever from the network to register more than the safe drinking water standard of 15 picocuries per liter.

A curie is a unit of radioactivity and a picocurie is one-trillionth of a curie. In all, scientists estimate there are 300 million curies, or units of radioactivity, left in the ground from the 908 nuclear detonations at the test site.

McKnight said the type of radioactive material found in the sample had not been determined late Wednesday, and he was uncertain whether any naturally occurring uranium or radon had been accounted for in the sample.

He said confirmation of what's in the sample and how much radioactivity it contains won't come before March 8.

State environmental officials are expected to visit the well site today, he said.

The sample was taken from a relatively shallow depth, 26 feet beneath the surface of Amargosa Valley, some 25 miles southeast of Beatty. >>

Couple of thoughts - preliminary, since we don't have the March 8 results yet. (At that small a sample level, it takes a l----o---n---g time to run the analysis just to get enough clicks to analyze!

Anyway - If the sample were taken at 25 feet (depending on topology between the test site and the sample well) it's almost impossible to see how the radioactivity could have gon "uphill" from the deep explosion sites to the surface that far away - indicates a surface contmination possibility.

Also, NV and UT are U mining areas - and local (natural) contamination is also possible.

Or, the fed's could have goofed - and somehow the particles migrated several dozen miles to get that far. Remember, these are little particles (imagine chalk dust or grains of sand split into a hundred pieces) that have to physically moved from one place to another. Most are chemically reactive, and so combine rapidly with local chemicals in the first rocks they come across....and then don't move much thereafter.

On the other hand, it ony takes a few to get measureable results from a Geiger counter.

---...---

I notice the congressmen (D) are up in arms about this, linking this to material in the Yucca Flats facility - didn't see them compaining when their land was stolen by the adminstration.

Let's see what the results are.

-- Robert A. Cook, PE (Marietta, GA) (cook.r@csaatl.com), March 02, 2000.

Thank you Tom and Robert for your excellent input on this topic.

-- Dee (T1Colt556@aol.com), March 03, 2000.