Long-Lived Waste Radionuclides

Ojovan, Michael I.; Lee, W.E.

doi:10.1016/b978-0-08-099392-8.00010-3

Cited by 1 publication

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 Among those radionuclides, iodine-129 is particularly challenging to handle due to its long halflife (15.7 million years), high yield (0.7% yield per fission of uranium-235), 3 and weak interactions with common materials in repository environments such as engineering barrier and rock in geology formation. 4,5 Iodide (I -) is the most stable form of iodine in an environment with pH and redox potential typically found in nature. [6][7][8] Under highly oxidizing conditions, iodide can be oxidized to iodine (I2) and/or iodate (IO3 -).…”

Section: Introductionmentioning

confidence: 99%

“…11 Therefore, iodine-129 is a primary contributor of the radiation dosage when analyzing the safety of disposal environments. 4 The immobilization of iodine-129 is one of the critical research subjects for nuclear waste management. 4,[13][14][15][16][17][18] The most probable scenarios that compromise nuclear waste forms in a repository environment are the contact with aqueous solutions.…”

Section: Introductionmentioning

confidence: 99%

“…4 The immobilization of iodine-129 is one of the critical research subjects for nuclear waste management. 4,[13][14][15][16][17][18] The most probable scenarios that compromise nuclear waste forms in a repository environment are the contact with aqueous solutions. 19,20 In a typical repository, nuclear waste forms are packed into corrosion resistant metallic canisters underground.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of solution chemistry on the iodine release from iodoapatite in aqueous environments

Zhang¹,

Gustin²,

Xie³

et al. 2019

Preprint

View full text Add to dashboard Cite

To ensure the safe disposal of nuclear waste, understanding the release process of radionuclides retained in the nuclear waste forms is of vital importance. Iodoapatite Pb9.85(VO4)6I1.7, a potential waste form for iodine-129, was selected as a model system for ceramic waste forms in this study to understand the effect of aqueous species on iodine release. Semi-dynamic leaching tests were conducted on bulk samples in cap-sealed Teflon vessels with 0.1 mol/L NaCl, Na2CO3, Na3PO4, and Na2SO4 solutions under 90 °C, fixed sample surface area to solution volume ratio of 5/m, and periodic replacement of leaching solutions. The reacted solutions were then analyzed by Inductively Coupled Plasma-Mass Spectrometry and Inductively Coupled Plasma-Optical Emission Spectrometry; the leached surfaces were characterized by X-ray diﬀraction, scanning electron microscopy, and infrared spectroscopy. The result shows that, compared to deionized water, the ion-rich solutions enhanced the iodine release as a result of the increased ionic strength, reduced activity coefficient of dissolved species, and increased solution pH. Surface reactions can lead to the formations of secondary phases by ion-exchange and precipitation. These findings suggest that an ion-rich environment in the geological repository can be detrimental to the disposal safety of the apatite waste form.

show abstract