THERMODYNAMIC AND MASS BALANCE ANALYSIS OF EXPANSIVE PHASE PRECIPITATION IN SALTSTONE

Fletcher, D

Savannah River Site (S.C.)

关键词: Mass Balance;    Radioactive Waste Disposal;    12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    Mineralogy;    Waste Forms;   

DOI  :  10.2172/929104
RP-ID  :  WSRC-STI-2008-00236
RP-ID  :  DE-AC09-96SR18500
RP-ID  :  929104

美国|英语

来源: UNT Digital Library

【 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.