STP1123: Cementation of Borate Waste by Adding Slaked Lime

    Kim, J-H
    Head, Korea Atomic Energy Research Institute, Taejon,

    Kim, H-Y
    Principal researcher, Korea Atomic Energy Research Institute, Taejon,

    Park, H-H
    Director, Korea Atomic Energy Research Institute, Taejon,

    Suh, I-S
    Vice-president, Korea Atomic Energy Research Institute, Taejon,

    Pages: 10    Published: Jan 1992


    With regard to the cementation of the evaporator concentrate from pressurized water reactors, this study identifies the operating conditions giving properly coherent waste forms of a high volume reduction factor, high compressive strength, and good workability without the development of freestanding water. Simulated waste specimens prepared by varying the mixing ratios of simulated borate waste [boric acid (H3BO3) 12% by weight, pH 9], Portland cement, and slaked lime were tested. The results appear in a three-phase diagram depicting the proper blending necessary to yield final products possessing a compressive strength of over 15 MPa and a volume reduction factor above 0.65.

    The solubility of sodium borate is higher than that of H3BO3, and cementation of a concentrated borate solution (24 wt% H3BO3, pH 9) was therefore also tested. The region of over 15 MPa of compressive strength with a volume reduction factor of over 0.6 based on the waste volume was identified. By increasing the H3BO3 concentration in the waste from 12 to 24 wt%, the actual volume was reduced by an additional factor of about two.


    boric acid, pressurized water reactor, cementation, slaked lime, borate waste

    Paper ID: STP19562S

    Committee/Subcommittee: D34.01

    DOI: 10.1520/STP19562S

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