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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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No impact from Savannah River radioactive wasps
The news is abuzz with recent news stories about four radioactive wasp nests found at the Department of Energy’s Savannah River Site in South Carolina. The site has been undergoing cleanup operations since the 1990s related to the production of plutonium and tritium for defense purposes during the Cold War. Cleanup activities are expected to continue into the 2060s.
K. Wisshak, J. Wickenhauser, F. Käppeler, G. Reffo, F. Fabbri
Nuclear Science and Engineering | Volume 81 | Number 3 | July 1982 | Pages 396-417
Technical Paper | doi.org/10.13182/NSE82-6
Articles are hosted by Taylor and Francis Online.
A new experimental method has been used to determine the isomeric ratio (IR) in neutron capture of 241Am in a differential experiment. Thin 241Am samples have been activated with subthermal monoenergetic neutrons of 14.75 meV and quasi-monoenergetic neutrons of ∼30 keV. The decay of the 242Am nuclei produced has been determined by observing the emitted beta spectrum in a mini-orange spectrometer. The measurements have been performed relative to gold. The ratio R1 = σγ (241Am→ 242gAm)/σγ(Au) was found to be R1 = 5.79 ± 0.33 at 14.75 meV and R1 = 2.73 ± 0.16 at ∼30 keV. The corresponding IRs, σγ(241Am→ 242gAm)/σγ(Am), are 0.92. ± 0.06 at 14.75 meV and 0.65 ± 0.05 at ∼30 keV. Detailed theoretical calculations of the total capture cross section, the IR, and the capture gamma-ray spectra were performed in the energy range from 1 to 1000 keV taking advantage of recently available information on the discrete level scheme of 242Am. With the present knowledge on the level scheme of 242Am, it seems to be difficult to reproduce the strong energy dependence of IR as indicated by the experimental results.