TY - JOUR
T1 - Osmosis-induced swelling of Eurobitum bituminized radioactive waste in constant total stress conditions
AU - Valcke, Elie
AU - Mariën, An
AU - Smets, Steven
AU - Li, Xiang Ling
AU - Mokni, Nadia
AU - Olivella, S.
AU - Sillen, X.
N1 - Score = 10
PY - 2010/11
Y1 - 2010/11
N2 - In geological disposal conditions, contact of Eurobitum bituminized radioactive waste, which contains high amounts of the hygroscopic and highly soluble NaNO3, with groundwater will result in water uptake and swelling of the waste, and in subsequent leaching of the embedded NaNO3 and radionuclides. The swelling of and the NaNO3 leaching from non-radioactive Eurobitum samples, comprized between two stainless steel filters and in contact with 0.1 M KOH, was studied in restricted (semi-confined) swelling conditions, i.e. under a constant total stress, or counterpressure, of 2.2, 3.3, or 4.4 MPa (i.e. oedometer conditions). Four tests were stopped after hydration times between 800 and 1500 days, and the samples were analyzed by micro-focus X-ray Computer Tomography (µCT) and by Environmental Scanning Electron Microscopy (ESEM). The complete set of data enabled a consistent interpretation of the observations and lead to an improved understanding of the phenomenology of the water uptake, swelling, and NaNO3 leaching in restricted swelling conditions.
AB - In geological disposal conditions, contact of Eurobitum bituminized radioactive waste, which contains high amounts of the hygroscopic and highly soluble NaNO3, with groundwater will result in water uptake and swelling of the waste, and in subsequent leaching of the embedded NaNO3 and radionuclides. The swelling of and the NaNO3 leaching from non-radioactive Eurobitum samples, comprized between two stainless steel filters and in contact with 0.1 M KOH, was studied in restricted (semi-confined) swelling conditions, i.e. under a constant total stress, or counterpressure, of 2.2, 3.3, or 4.4 MPa (i.e. oedometer conditions). Four tests were stopped after hydration times between 800 and 1500 days, and the samples were analyzed by micro-focus X-ray Computer Tomography (µCT) and by Environmental Scanning Electron Microscopy (ESEM). The complete set of data enabled a consistent interpretation of the observations and lead to an improved understanding of the phenomenology of the water uptake, swelling, and NaNO3 leaching in restricted swelling conditions.
KW - Eurobitum
KW - bituminized radioactive waste
KW - intermediate level radioactive waste
KW - osmosis
KW - swelling
KW - pressure increase
KW - NaNO3
KW - NaNO3 leaching
KW - Boom Clay
KW - geological disposal
UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_108745
UR - http://knowledgecentre.sckcen.be/so2/bibref/7282
U2 - 10.1016/j.jnucmat.2010.08.060
DO - 10.1016/j.jnucmat.2010.08.060
M3 - Article
SN - 0022-3115
VL - 406
SP - 304
EP - 316
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
IS - 3
ER -