TY - GEN
T1 - Kinetics of aqueous alteration of P0798 simulated waste glass in the presence of bentonite
AU - Yamaguchi, K.
AU - Inagaki, Y.
AU - Saruwatari, T.
AU - Idemiteu, K.
AU - Arima, T.
AU - Yoshikawa, H.
AU - Yui, M.
PY - 2006
Y1 - 2006
N2 - Static aqueous alteration tests were performed with a Japanese simulated HLW glass, P0798, in the presence of bentonite in order to understand the effects of bentonite on the glass alteration kinetics and on the associated Cs release. Analogous alteration tests were performed in 0.001M NaOH solution without bentonite for comparison. The results indicated that; 1) at the initial stage of alteration up to 50 days, no remarkable difference was observed in the alteration rate between both cases "with" and "without" bentonite, 2) at the later stage beyond 50 days, however, the rate in the case "with" bentonite was larger than that in the case "without" bentonite. These results on the alteration rate were analyzed by use of a water-diffusion model. In the case "without" bentonite, a good agreement was observed between the model analysis and the experimental results at the initial stage of alteration up to 50 days, however, the model analysis deviated from the experimental results at the later stage beyond 50 days. In the case "with" bentonite, on the other hand, a good agreement was observed even at the later stage to give the value of the apparent diffusion coefficient, A of 3.5×10-21 m2/s. The comparison between both cases suggests that the alteration rate is controlled by the water diffusion in both cases "with" and "without" bentonite, however, the rate is depressed in the case "without" bentonite probably by the protective effects of the alteration layer developing at the glass surface. In the case "with" bentonite, on the other hand, the alteration layer is expected to be less protective. Cesium desorption tests performed for the altered glass and bentonite indicated that most of the cesium dissolved from the glass is retained in the secondary phase of smectite developing in the precipitated layer by sorption with ion-exchange in the case "without" bentonite. In the case "with" bentonite, however, it is likely to be sorbed at bentonite surface.
AB - Static aqueous alteration tests were performed with a Japanese simulated HLW glass, P0798, in the presence of bentonite in order to understand the effects of bentonite on the glass alteration kinetics and on the associated Cs release. Analogous alteration tests were performed in 0.001M NaOH solution without bentonite for comparison. The results indicated that; 1) at the initial stage of alteration up to 50 days, no remarkable difference was observed in the alteration rate between both cases "with" and "without" bentonite, 2) at the later stage beyond 50 days, however, the rate in the case "with" bentonite was larger than that in the case "without" bentonite. These results on the alteration rate were analyzed by use of a water-diffusion model. In the case "without" bentonite, a good agreement was observed between the model analysis and the experimental results at the initial stage of alteration up to 50 days, however, the model analysis deviated from the experimental results at the later stage beyond 50 days. In the case "with" bentonite, on the other hand, a good agreement was observed even at the later stage to give the value of the apparent diffusion coefficient, A of 3.5×10-21 m2/s. The comparison between both cases suggests that the alteration rate is controlled by the water diffusion in both cases "with" and "without" bentonite, however, the rate is depressed in the case "without" bentonite probably by the protective effects of the alteration layer developing at the glass surface. In the case "with" bentonite, on the other hand, the alteration layer is expected to be less protective. Cesium desorption tests performed for the altered glass and bentonite indicated that most of the cesium dissolved from the glass is retained in the secondary phase of smectite developing in the precipitated layer by sorption with ion-exchange in the case "without" bentonite. In the case "with" bentonite, however, it is likely to be sorbed at bentonite surface.
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U2 - 10.1557/proc-932-83.1
DO - 10.1557/proc-932-83.1
M3 - Conference contribution
AN - SCOPUS:33746076728
SN - 1558998896
SN - 9781558998896
T3 - Materials Research Society Symposium Proceedings
SP - 385
EP - 392
BT - 29th International Symposium on the Scientific Basis for Nuclear Waste Management XXIX
PB - Materials Research Society
T2 - 29th International Symposium on the Scientific Basis for Nuclear Waste Management XXIX
Y2 - 12 September 2005 through 16 September 2005
ER -