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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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Latest News
NNSA awards BWXT $1.5B defense fuels contract
The Department of Energy’s National Nuclear Security Administration has awarded BWX Technologies a contract valued at $1.5 billion to build a Domestic Uranium Enrichment Centrifuge Experiment (DUECE) pilot plant in Tennessee in support of the administration’s efforts to build out a domestic supply of unobligated enriched uranium for defense-related nuclear fuel.
Kenneth Hoar, Piotr Nowinski, Vernon Hodge, James Cizdziel
Nuclear Technology | Volume 175 | Number 1 | July 2011 | Pages 351-359
Technical Paper | Special Issue on the 16th Biennial Topical Meeting of the Radiation Protection and Shielding Division / Environmental Effects of Nuclear Technology | doi.org/10.13182/NT11-A12307
Articles are hosted by Taylor and Francis Online.
Rock varnish samples were collected near three point sources of air pollution to determine if the varnish contained a record of recent air pollution. Samples were collected as follows: downwind of the Nevada Test Site (NTS); in the fallout pattern of the shuttered Mohave Power Plant, located in Laughlin, Nevada; and, near the operating Reid-Gardner Power Plant, just east of Las Vegas, Nevada. Analysis of the NTS rock varnish shows 240Pu/239Pu mass ratios as low as 0.0592 ± 0.0003 and 241Pu/239Pu ratios as low as 0.00063 ± 0.00004, compared to worldwide values of 0.18 ± 0.01 and 0.009 ± 0.002, respectively, clearly indicating that the varnish can be used as a forensic tool for identifying the source of air pollution, in this case the NTS. The samples collected in the plumes of the coal-fired power plants contain thorium and uranium, and have 232Th/238U mass ratios from 1 to 30, and concentrations from 5 to 755 ppm for Th and 1 to 578 ppm for U. The highest concentrations of these elements occur together at locations that implicate the power plants; however, additional samples would be required to demonstrate unequivocally that the power plants are the sources. Overall, it is apparent that rock varnish can be utilized as a passive monitor to investigate recent air pollution.
