Abstract
AbstractLeaching of uranium from uranium oxide fuel in contact with water can be a radiation hazard problem in the case of fuel cladding failure, either during nuclear reactor operation or in an interim storage, as well as in a final repository. One way to mitigate this is to reduce the solubility of the fuel matrix by the mixing uranium oxide with a compound which is less soluble but otherwise of similar properties. In this paper, the effect of thorium oxide content on the leaching of the uranium oxide matrix is investigated. The method was to study the leaching of the uranium oxide fuel matrix as a function of a varying content of thorium oxide, using materials manufactured by powder co-milling. It was found that the substitution of more than 25% UO2 with ThO2 reduces the matrix leaching by more than one order of magnitude in most of the different leaching solutions investigated. The substitution of 7% UO2 with ThO2 results in a reduction of matrix leaching by 10–90%, depending on the concentration of borate and dissolved oxygen in the leaching solution.
Funder
Norges Forskningsråd
Kungl. Vetenskaps- och Vitterhets-Samhället i Göteborg
Karl och Annie Leons minnesfond
University of Gothenburg
Publisher
Springer Science and Business Media LLC
Subject
Health, Toxicology and Mutagenesis,Public Health, Environmental and Occupational Health,Spectroscopy,Pollution,Radiology, Nuclear Medicine and imaging,Nuclear Energy and Engineering,Analytical Chemistry
Reference30 articles.
1. OECD-NEA (2015) Introduction of thorium in the nuclear fuel cycle: NEA No. 7224. Organisation for Economic Co-operation and Development Nuclear Energy Agency, Paris
2. Dekoussar V, Dyck GR, Galperin A, Ganguly C, Todosow M, Yamawaki M (2005) Thorium fuel cycle — Potential benefits and challenges. Technical report IAEA-TECDOC-1450, International Atomic Energy Agency, Vienna, Austria
3. Lau CW, Nylén H, Demazière C, Sandberg U (2014) Reducing axial offset and improving stability in PWRs by using uranium–thorium fuel. Prog Nucl Energ 76:137–147
4. Insulander Björk K, Netterbrant C (2018) Thorium as an additive for improved neutronic properties in boiling water reactor fuel. Ann Nucl Energ 113:470–475
5. Åstrand P-G, Ekström P-A, Hjerpe T, Keesmann S, Jaeschke B (2015) Radionuclide transport and dose calculations for the safety assessment SR-PSU. Technical report TR-14-09, Svensk Kärnbränslehantering AB, Stockholm, Sweden