THERMODYNAMIC AND MASS BALANCE ANALYSIS OF EXPANSIVE PHASE PRECIPITATION IN SALTSTONE

Fletcher, D

关键词: AR FACILITIES;    WASTE FORMS;    RADIOACTIVE WASTE DISPOSAL;    WATER INFLUX;    EXPANSION;    PHASE STUDIES;    MASS BALANCE;    MINERALOGY;    POROSITY;    PRECIPITATION;    THERMODYNAMICS;   

DOI  :  10.2172/929104
RP-ID  :  WSRC-STI-2008-00236
PID  :  OSTI ID: 929104
Others  :  TRN: US0803678

学科分类：核能源与工程

美国|英语

来源: SciTech Connect

【 摘 要 】

This report assesses the potential for future precipitation of expansive phases that could cause fracturing in saltstone. It examines the equilibrium case using The Geochemist's Workbench{reg_sign} reaction path model. The scenarios simulated examine the effects of different possible infiltrating fluids, different saltstone formulations, and different amounts of minerals available for reaction. Mineralogy of the vault cement and saltstone were estimated using reported chemical compositions of each. The infiltrating fluid was assumed to be either rainwater equilibrated with vault cement or rainwater itself. The simulations assumed that minerals were homogeneously distributed in saltstone and that each pore volume of infiltration reached equilibrium with the mineral assemblage. Fracturing that initiates in pores by expansive phase precipitation is unlikely to occur in saltstone because the maximum amount of porosity filled is 34%. If less than 100% of the saltstone minerals are available for reaction, less porosity will be lost to expansive phases. Likewise, the formulation of saltstone used will affect the amount of porosity filled by expansive phases.