The Radiation Chemistry of CMPO: Part 2. Alpha Radiolysis

Mincher, Bruce J.; Mezyk, Stephen P.; Elias, Gracy; Groenewold, Gary S.; Riddle, Catherine L.; Olson, Lonnie G.

doi:10.1080/07366299.2013.850300

Cited by 20 publications

(10 citation statements)

References 11 publications

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“…Alpha radiation induced ligand degradation is generally studied to a lesser extent, as it poses additional challenges towards the determination of the absorbed dose by the solvent and especially the analysis of the irradiated samples. [46][47][48][49] This is because samples exposed to strong alpha radionuclides remain highly radioactive. Previously, it was shown that high linear energy transfer (LET) irradiation with alpha radiation leads to a slower degradation of TODGA, probably because recombination of the formed radical species occurs more oen.…”

Section: Introductionmentioning

confidence: 99%

Gamma radiolytic stability of the novel modified diglycolamide 2,2′-oxybis(N,N-didecylpropanamide) (mTDDGA) for grouped actinide extraction

et al. 2022

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Section: Introductionmentioning

confidence: 99%

Gamma radiolytic stability of the novel modified diglycolamide 2,2′-oxybis(N,N-didecylpropanamide) (mTDDGA) for grouped actinide extraction

et al. 2022

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“…For example, there were new 31 P NMR peaks with similar chemical shifts to m- CMPO (see the Methods section and Supporting Information (SI)). Based on NMR chemical shifts, GCMS data, IR spectroscopy, and previous reports, we suspect amide hydrolysis of m- CMPO to be the culprit. , Regardless, the 31 P NMR analyses showed that the m- CMPO DAAP resin was ∼85% pure in m- CMPO and the m- CMPO TBP resin was ∼90% pure in m- CMPO. At this point, it seems appropriate to remind the reader that despite impurities present in these m- CMPO TBP and m- CMPO DAAP resins it remains important to evaluate their 241 Am-extracting ability because they are the current industry standard and are representative of what is used operationally today.…”

Section: Resultsmentioning

confidence: 68%

“…These variables include better defining the role of the phase transfer catalysts, the impact of metal contaminants present in solution on 241 Am extraction, extraction capacity for the CMPO , and DGA , extraction resins, etc. This study, and those preceding in the literature, ,,,,− ,− will hopefully inspire innovative research in the future that improves our general understanding of extraction chromatography. If successful, further optimizing large-scale separations for 241 Am recovery, and for processing other important analytes, will be more easily realized.…”

Section: Discussionmentioning

confidence: 70%

Characterizing Extraction Chromatography for Large-Scale Americium-241 Processing

Arko

Dan

Adelman

et al. 2021

Ind. Eng. Chem. Res.

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The americium-241 ( 241 Am) radioisotope has valuable nuclear properties that find broad industrial usage. Ensuring stable supplies of 241 Am is critical for supporting (and expanding) the existing 241 Am-application space and enabling emerging 241 Amtechnologies that are important for economic growth, energy, and national security. Unfortunately, the United States halted 241 Am production in 1984 and the existing inventory was depleted in the early 2000s. This situation recently changed when the U.S. Department of Energy Isotope Program established 241 Am recovery at Los Alamos National Laboratory. Today, large-scale quantities of 241 Am are now obtained using the Chloride Extraction and Actinide Recovery (CLEAR) process. This method uses a resin that has the di-(4-t-butylphenyl)-N,N-di-iso-butylcarbamoylmethylphosphine oxide (m-CMPO) extractant adsorbed on a resin bead to harvest 241 Am from plutonium-containing waste streams. To maintain and improve CLEAR processing of 241 Am, we have evaluated the extraction of 241 Am by m-CMPO as a function of three important processing relevant variables: (1) HCl concentration, (2) metal contaminant concentration, and (3) contact time. The performance of the m-CMPO resin was additionally compared against commercially available resins, namely, rare earth (RE) resin and a selected series of diglycolamide (DGA) resins. Our results suggested that the m-CMPO resin outperformed most of the commercially available alternatives. However, tetraoctyl-DGA (TODGA) and tetraethyl-hexyl-DGA (TEHDGA) prevailed on several fronts. The TODGA and TEHDGA resins quantitatively released 241 Am at low HCl concentrations (<0.5 M), were less susceptible to deleterious side effects from metal contaminants in the mobile phase and bound 241 Am faster. Based on these results, we concluded that 241 Am recovery yields have the potential to improve if TODGA or TEHDGA is used in place of m-CMPO for large-scale CLEAR processing of 241 Am.

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“…However, the concentrated tracks containing these reactive species ensure that most recombine rather than reacting with other solutes, and alpha radiolysis typically has less damaging effects on organic species in solution than gamma radiolysis. [Mincher 2014] Possible radiolytic reactions include the radiolysis of water, nitrate, and organic compounds. In addition to the organic sorbent and TEA/TEAN, the waste drums contain plastic materials, primarily polyethylene (PE) and polyvinyl chloride (PVC).…”

Section: Radiolysis Reactionsmentioning

confidence: 99%