TY - JOUR
T1 - Mechanisms of immobilization of nuclear waste elements by cement minerals, cement and mortar
AU - Komarneni, S.
AU - Roy, D. M.
N1 - Funding Information:
These hydroxides may combine with Ca and silica to form phases such as calcium uranyl (or plutonyl) silicates under radwaste repository conditions (ll). References I. "Alternatives for Long-Term Management of Defense High-Level Radioactive Waste," ERDA 77-42/I, Savannah River Plant (May 1977). 2. R.O. Lokken, "A Review of Radioactive Waste Immobilization in Concrete," PNL-2654 (June 1978). 3. A.H. Kibbey and H.W. Godbee, "A Critical Review of Solid Radioactive Waste Practices at Nuclear Power Plants," ORNL-4924 (March 1974). 4. H.O. Weeren, Nucl. Eng. Des., 44, 291 (1977). 5. W.E. Clark, Nucl. Tech., 36, 215 (1977). 6. M.T. Morgan, J.G. Moore, H.E. Devaney, G.C. Rogers, C. Williams and E. Newman, in "Scientific Basis for Nuclear Waste Management," (Ed. G.J. McCarthy) Vol. l, pp. 453-459, Plenum Press, New York (1979). 7. D.M. Roy and G.R. Gouda, Nucl. Tech. 4_9_0, 214 (1978). 8. D.M. Roy, ONWI-212, Proceedings, 1980 Natl. Waste Terminal Storage Program Information Meeting, Columbus, OH, 'Dec. 9-11, 1980, pp. 165-169. 9. S. Komarneni, W.P. Freeborn, and C.A. Smith, Am. Mineral., 6_4_4, 650 (1979). lO. D.M. Roy, B.E. Scheetz, L.D. Wakeley and M.W. Barnes, Leach Characteriza-tion of Cement Encapsulated Wastes, Conference on Leachability of Radio-active Solids, Gatlinburg, TN, Dec. 9-11, 1980, Nuclear and Chemical Waste Management (in press). llo This research was supported by the U.S. Department of Energy.
PY - 1981
Y1 - 1981
N2 - The mechanisms of immobilization of nuclear waste elements such as Cs, Sr, Ba, U, La and Nd (the latter two simulating Am and Cm) by three cement minerals, one cement and one mortar were investigated. Cement minerals did not immobilize Cs or Sr or Ba in the absence of CO2 but immobilized 62 to 91% of the added Cs and all of the added Sr by forming carbonates when CO2 was bubbled through the cement mineral suspensions. The elements La, Nd and U reacted significantly with various cement minerals, cement and mortar and precipitated as hydroxides. For example, C3S{black star} mineral immobilized 92, 73 and 99.2 of the added La, Nd and U respectively. Reaction of cement with U resulted in the formation of basic calcium uranyl silicate hydrate or uranophane under simulated repository conditions. These results suggest that cements serve as not only physical barriers but also act as chemical barriers for the migration of especially U and transuranic elements of nuclear waste.
AB - The mechanisms of immobilization of nuclear waste elements such as Cs, Sr, Ba, U, La and Nd (the latter two simulating Am and Cm) by three cement minerals, one cement and one mortar were investigated. Cement minerals did not immobilize Cs or Sr or Ba in the absence of CO2 but immobilized 62 to 91% of the added Cs and all of the added Sr by forming carbonates when CO2 was bubbled through the cement mineral suspensions. The elements La, Nd and U reacted significantly with various cement minerals, cement and mortar and precipitated as hydroxides. For example, C3S{black star} mineral immobilized 92, 73 and 99.2 of the added La, Nd and U respectively. Reaction of cement with U resulted in the formation of basic calcium uranyl silicate hydrate or uranophane under simulated repository conditions. These results suggest that cements serve as not only physical barriers but also act as chemical barriers for the migration of especially U and transuranic elements of nuclear waste.
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U2 - 10.1016/0008-8846(81)90038-7
DO - 10.1016/0008-8846(81)90038-7
M3 - Article
AN - SCOPUS:0019770073
SN - 0008-8846
VL - 11
SP - 789
EP - 794
JO - Cement and Concrete Research
JF - Cement and Concrete Research
IS - 5-6
ER -