A comparison of the alpha and gamma radiolysis of CMPO

Mincher, Bruce J. ; Mezyk, Stephen P. ; Groenewold, Gary ; Elias, Gracy

Idaho National Laboratory

关键词: Radiation Chemistry;    Radiolysis;    Free Radicals;    Irradiation;    Dose Rates;   

DOI  :  10.2172/1027928
RP-ID  :  INL/EXT-11-22543
RP-ID  :  DE-AC07-05ID14517
RP-ID  :  1027928

美国|英语

来源: UNT Digital Library

【 摘 要 】

The radiation chemistry of CMPO has been investigated using a combination of irradiation and analytical techniques. The {alpha}-, and {gamma}-irradiation of CMPO resulted in identical degradation rates (G-value, in {mu}mol Gy{sup -1}) for both radiation types, despite the difference in their linear energy transfer (LET). Similarly, variations in {gamma}-ray dose rates did not affect the degradation rate of CMPO. The solvent extraction behavior was different for the two radiation types, however. Gamma-irradiation resulted in steadily increasing distribution ratios for both forward and stripping extractions, with respect to increasing absorbed radiation dose. This was true for samples irradiated as a neat organic solution, or irradiated in contact with the acidic aqueous phase. In contrast, {alpha}-irradiated samples showed a rapid drop in distribution ratios for forward and stripping extractions, followed by essentially constant distribution ratios at higher absorbed doses. These differences in extraction behavior are reconciled by mass spectrometric examination of CMPO decomposition products under the different irradiation sources. Irradiation by {gamma}-rays resulted in the rupture of phosphoryl-methylene bonds with the production of phosphinic acid products. These species are expected to be complexing agents for americium that would result in higher distribution ratios. Irradiation by {alpha}-sources appeared to favor rupture of carbamoyl-methylene bonds with the production of less deleterious acetamide products.