Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Effect of bentonite on radiation induced dissolution of UO2 in an aqueous system
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.ORCID iD: 0000-0003-0552-6282
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.ORCID iD: 0000-0003-0663-0751
2014 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 447, no 1-3, 73-76 p.Article in journal (Refereed) Published
Abstract [en]

In order to elucidate the impact of bentonite on the process of radiation induced oxidative dissolution of UO2 in an aqueous system, the dissolution of U(VI) and consumption of H2O2 over time has been studied. In addition, γ-irradiation experiments were performed to study a more relevant and complex system, serving as a comparison with the previously stated system. In both cases, the experiments revealed that the presence of bentonite in water could either delay or prevent in part the release of uranium to the environment. The cause is mainly attributed to the scavenging of radiolytic oxidants rather than to the adsorption of uranium onto bentonite.

Place, publisher, year, edition, pages
2014. Vol. 447, no 1-3, 73-76 p.
Keyword [en]
Spent Nuclear-Fuel, Induced Oxidative Dissolution, Radiolysis Products, Hydrogen-Peroxide, Relative Impact, H2o2, Montmorillonite, Water, Reactivity, Kinetics
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-142319DOI: 10.1016/j.jnucmat.2013.12.012ISI: 000334134600010Scopus ID: 2-s2.0-84893123145OAI: oai:DiVA.org:kth-142319DiVA: diva2:702992
Note

QC 20140305

Available from: 2014-03-05 Created: 2014-02-28 Last updated: 2017-04-21Bibliographically approved
In thesis
1. Experimental studies of radiation-induced dissolution of UO2: The effect of intrinsic solid phase properties and external factors
Open this publication in new window or tab >>Experimental studies of radiation-induced dissolution of UO2: The effect of intrinsic solid phase properties and external factors
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Dissolution of the UO2 matrix is one of the potential routes for radionuclide release in a future deep geological repository for spent nuclear fuel. This doctoral thesis focuses on interfacial reactions of relevance in radiation-induced dissolution of UO2 and is divided in two parts:

In the first part, we sought to explore the effects of solid phase composition:

The impact of surface stoichiometry on the reactivity of UO2 towards aqueous radiolytic oxidants was studied. H2O2 reacts substantially faster with stoichiometric UO2 than with hyperstoichiometric UO2. In addition, the release of uranium from stoichiometric UO2 is lower than from hyperstoichiometric UO2. The behavior of stoichiometric powder changes with exposure to H2O2, approaching the behavior of hyperstoichiometric UO2 with the number of consecutive H2O2 additions.

The impact of Gd-doping on the oxidative dissolution of UO2 in an aqueous system was investigated. A significant decrease in uranium dissolution and higher stability towards H2O2 for (U,Gd)O2 pellets compared to standard UO2 was found.

In the second part, we sought to look at the effect of external factors:

The surface reactivity of H2 and O2 was studied to understand the overall oxide surface reactivity of aqueous molecular radiolysis products. The results showed that hydrogen-abstracting radicals and H2O2 are formed in these systems. Identical experiments performed in aqueous systems containing UO2 powder showed that the simultaneous presence of H2 and O2 enhances the oxidative dissolution of UO2 compared to a system not containing H2.

The effect of groundwater components such as bentonite and sulfide on the oxidative dissolution of UO2 was also explored. The presence of bentonite and sulfide in water could either delay or prevent in part the release of uranium to the environment. The Pd catalyzed H2 effect is more powerful than the sulfide effect. The poisoning of Pd catalyst is not observed under the conditions studied.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2017. 77 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2017:23
Keyword
Oxidation, dissolution, uranium dioxide, gadolinium, bentonite, sulfide, hydrogen, gamma radiation, radiolysis, hydrogen peroxide, hydroxyl radical, repository
National Category
Physical Chemistry
Research subject
Chemistry
Identifiers
urn:nbn:se:kth:diva-205605 (URN)978-91-7729-343-9 (ISBN)
Public defence
2017-05-12, Kollegiesalen, Brinellvägen 8, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20170421

Available from: 2017-04-21 Created: 2017-04-20 Last updated: 2017-04-21Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Barreiro Fidalgo, AlexandreJonsson, Mats

Search in DiVA

By author/editor
Barreiro Fidalgo, AlexandreSundin, SaraJonsson, Mats
By organisation
Applied Physical Chemistry
In the same journal
Journal of Nuclear Materials
Physical Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 241 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf