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Yim, Sung Paal

Publications and source records attributed to Yim, Sung Paal.

Determination of Elastic Coefficients for a Composite with Crossing Steel - 20086

For a composite material with an embedding of crossing reinforcement bars, the elastic coefficients are calculated by solving a boundary-value problem (elastostatic problem). The background material is concrete whereas the bars are made of steel. The bars cross each other horizontally at a right angle. The boundary-value problem is solved numerically by using 3-D quadratic basis functions in ABAQUS{sup R}. Under external shear loading conditions, the effective elastic coefficients on the macroscale are quite larger for a cross-section in which the bars are immediately below the ones in the cross-section normal to it. The shear modulus in the off-plane direction is about one and half times larger than that in the in-plane direction. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Stabilization/Solidification of Tritiated Water - 20135

Tritiated water was stabilized/solidified by using calcium oxide and a polymer. First, tritiated water was changed into the powder form of calcium hydroxide by addition of tritiated water into calcium oxide. Then the produced calcium hydroxide was solidified in waste form by using a polymer binder. The specimens of waste form prepared by surrogate calcium hydroxide were subjected to compressive strength testing and water immersion testing. In addition, the specimens of waste form prepared by tritiated calcium hydroxide were subjected to leach testing. The mean compressive strength of the specimens containing 40 wt % of the surrogate calcium hydroxide was about 98.5 MPa (14,300 psi). After water immersion testing, there was no distinct change in the appearance of the specimens. The mean compressive strength of the specimens after water immersion was 79.1 MPa (11,470 psi). The mean diffusion coefficient of tritium for the specimens containing 40 wt% of tritiated calcium hydroxide was 5.4 x 10-10 cm{sup 2}/s. These findings indicate that the waste form has enough mechanical integrity and durability for final disposal and releases tritium very slowly. (authors)

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