Sentences with phrase «uranium concentrations»

UNL researchers Karrie Weber and Jason Nolan found that the High Plains aquifer contains uranium concentrations up to 89 times the EPA standard and nitrate concentrations up to 189 times greater.

«Uranium dissolved in groundwater flows slowly into nearby rivers, where it becomes diluted below the uranium concentrations naturally present in river water,» says John Bargar, SLAC's project lead and researcher at the lab's Stanford Synchrotron Radiation Lightsource (SSRL), a DOE Office of Science User Facility.

«We want to understand the way uranium gets from the ground into the groundwater, creating a plume of contamination in which uranium concentrations stay above regulatory safety requirements.»

Not exact matches

As I explain in my book, «Strange Glow: The Story of Radiation,» the U.S. atomic bomb effort used enriched uranium — uranium that has an increased concentration of the easily split uranium - 235 — while the Germans used unenriched uranium.

This is why, by measuring the concentrations of uranium and lead, it was possible for us to date a sediment layer to an accuracy of 35,000 years, which is already fairly precise for periods over 250 million years.»

In addition, only about one tenth of the mined uranium ore is converted into fuel in the enrichment process (during which the concentration of uranium 235 is increased considerably), so less than a hundredth of the ore's total energy content is used to generate power in today's plants.

This will permit the average terrestrial concentrations of uranium and thorium to be 2 to 4.7 times higher than that observed in chondrites.

But uranium - lead dating, in which researchers estimate the age of a rock by comparing its concentrations of radioactive uranium and the lead it decays into, tells a different story.

The concentration of this isotope must therefore be boosted in natural uranium before it can function as nuclear power plant fuel.

Renaissance requirements The search for more uranium has already begun in earnest but nothing approaching the concentration of McArthur River has been discovered since 1988.

He then used the concentration of naturally occurring but unstable uranium in the calcite to estimate how much time had passed since the popcorn formed, giving him a minimum age for the art.

If the concentration of hydrogen rises high enough, flammable uranium hydride (UH3) will start to form instead of the oxide.»

Particularly lively debates take place on how the concentration of oxygen in the atmosphere evolved; after all, it is associated with many other geological weathering processes, including the fate of uranium.

Scientists had previously witnessed decreasing concentrations of uranium in groundwater when iron - breathing bacteria were active, but they have yet to show that those iron - breathing bacteria were directly respiring the uranium.

According to Weber, peer - reviewed studies have also indicated that food crops can accumulate uranium when irrigated by water containing high concentrations of it.

The researchers looked for signs of bacterial activity when they gradually added small amounts of dissolved uranium at the right concentration back to the samples where uranium had become immobilized.

A measure of the effort expended in a uranium enrichment plant to separate uranium of a given U235 content into two components, one having a higher percentage of U235 and the other a lower concentration.

The concentration of U235, expressed by percentage of weight in uranium, in a given quantity of uranium ore, uranium hexafluoride or uranium metal.

Uranium enrichment is sold as separative work units (SWU), which represent the level of effort required to increase the concentration of U235 in natural uUranium enrichment is sold as separative work units (SWU), which represent the level of effort required to increase the concentration of U235 in natural uraniumuranium.

But the fuel assemblies that power a commercial nuclear reactor at an electric utility generally need uranium with a 4 % — 5 % concentration of U235.

HEU can be blended with other forms of uranium in a series of complex technologies that result in dilution of the concentration of U-235 from the 90 % range in HEU down to the three to five percent used in reactor fuel.

Radon and Radon Decay Product Concentrations in New Mexico's Uranium Mining and Milling District, Thomas Buhl, Jere Millard, David Baggett, Sue Trevathan, Radiation Protection Bureau, Environmental Improvement Division, New Mexico Health and Environment Department, Final Report, March 1985.

To produce this fuel, companies enrich the concentration of U235 in natural uranium hexafluoride (UF6) to the appropriate level and sell the fuel to utility customers.

This is due to the reason that the concentration of U-235 is very low in naturally occurring Uranium.

In contrast, super-Earths with a similar concentration but larger absolute amount of radioactive heat sources (i.e., uranium and thorium) than Earth would produce more internal heat, more vigorous mantle convection, and faster plate tectonic action involving thinner plates, which may promote planetary habitability with lower mountain ranges but higher volcanic activity and an atmosphere with a greater relative composition of volcanic and lighter gases (Sasselov and Valencia, Scientific American, August 2010; Valencia and O'Connell, 2009; and Valencia et al, 2007).

The amount of uranium at present and future mineable concentrations in the Earth's continental Crust means uranium resources are effectively unlimited.

Known reserves of uranium (other than low concentrations in granite and seawater) are actually roughly equivalent in energy content to estimated fossil fuel reserves.

Whereas uranium ore could have a significant concentration of uranium.

Unfortunately, any country that can enrich natural uranium to 2 to 3 percent (the concentration needed to fuel a power plant) can easily use those same machines to enrich the U-235 to 80 or 90 percent, the concentration needed for a nuclear bomb.

286 Brian Dodge: «average concentration of Uranium in coal ash is ~ 1.3 ppm» Wrong.

According to http://www.wise-uranium.org/uwai.html, the minimum economically processable Uranium ore concentration is on the order of 700 - 1000ppm.

[The average concentration of uranium in coal is 1 or 2 parts per million.