China
Africa
Explore chapters and articles related to this topic
Radionuclides and heavy metals
Published in Rym Salah-Tazdaït, Djaber Tazdaït, Phyto and Microbial Remediation of Heavy Metals and Radionuclides in the Environment, 2022
Rym Salah-Tazdaït, Djaber Tazdaït
The three different types of decay can occur naturally or anthropogenically. So far, 83 radionuclides (radioactive elements) are known in nature, including primordial (existed since the Earth creation) and cosmogenic (from extraterrestrial sources), and over 3,000 artificial (anthropogenic) radionuclides have been identified (L’Annunziata 2016, 68). The naturally occurring radiations result from spontaneous decay of isotopes of various elements present in nature, while the artificial radioactivity results from isotopes created artificially mainly from the fission of uranium-235 used as fuel to produce energy. The fission process is triggered by neutrons called slow neutrons with low energy and results in the production of another type of neutrons called fast neutrons (with high energy) along with isotopes of different elements, including certain new artificial radioactive nuclei such as Technetium-95 (Tc) or Promethium-147 (Pm) (not occurring on Earth) (Guillaumont 2019, 617).
Combination of DGA and LN Columns: A Versatile Option for Isotope Production and Purification at Oak Ridge National Laboratory
Published in Solvent Extraction and Ion Exchange, 2021
Richard T. Mayes, Shelley M. VanCleve, Jay S. Kehn, Jordan Delashmitt, Josh T. Langley, Brian P. Lester, Miting Du, L. Kevin Felker, Lætitia H. Delmau
Additionally, the sequential usage of DGA resin followed by LN resin is also being considered for use in an even harsher radiolytic environment (i.e., the hot cell bank). Some valuable radioisotopes can be harvested from the fission products (FPs) obtained during the neutron irradiation of 237Np target to produce 238Pu. After recovering plutonium and neptunium, the fission products are considered as waste and are subsequently disposed. Two aspects were considered for this study. First, the presence of promethium-147 in the fission products makes the waste solution very attractive since Pm can be used for several applications, including nuclear batteries. Second, although extracting plutonium and neptunium is essentially quantitative, traces of 238Pu can increase the constraints associated with disposing of large amounts of solution. Reducing the amount of plutonium in the waste solutions to less than 5 μg/L would significantly affect the waste disposal path.