THE CONCEPTUAL DESIGN FOR LIQUID EFFLUENT TREATMENT OF UO2 KERNEL FABRICATION

THE CONCEPTUAL DESIGN FOR LIQUID EFFLUENT TREATMENT OF UO2 KERNEL FABRICATION. The pebble fuel for HTGR is prepared through fabrication of UO2 kernel, coated particle and spherical element fuel. In the fabrication of UO2 kernel by external gelation method, a multicomponent of liquid effluent is generated. Therefore, the liquid effluent is required to be treated for safety reason before disposed to waste storage. In this paper, the conceptual design for the liquid effluent treatment of UO2 kernel fabrication is performed with the simulation process using CHEMCAD software. CHEMCAD is a software that can be utilized for chemical process design. The results showed that the proposed conceptual design is able to separate valuable components: isopropyl alcohol (IPA) and tetrahydrofurfuryl alcohol (THFA). The flowrate of IPA product is 5.28 kg/h with purity of 0.99 in mass fraction and the flowrate of THFA product is 1.01 kg/h with purity of 0.99 in mass fraction.Keywords: liquid effluent, UO2 kernel, CHEMCAD, HTGR.

EXPERIMENTAL STUDIES OF ROUGHNESS BY SURFACE PLASTIC DEFORMATION ON FLAT SURFACES

The article presents experimental studies of the roughness by surface plastic deformation (SPD) on flat surfaces of steel 45. A dispersion analysis was used to study the influence of various factors on the surface quality. From the experimental studies and the dispersion analysis made, a graphical interpretation of the main effects was obtained. Graphical visualizations of the roughness pattern after SPD on the processed surfaces were obtained. Overlapping sinusoidal movements of the deforming spherical element were realized.

A spherical element subdivision method for the numerical evaluation of nearly singular integrals in 3D BEM

Purpose The purpose of this paper is to preset a spherical element subdivision method for the numerical evaluation of nearly singular integrals in three-dimensional (3D) boundary element method (BEM). Design/methodology/approach In this method, the source point is first projected to the tangent plane of the element. Then two cases are considered: the projection point is either inside or outside the element. In both cases, the element is subdivided into a number of patches using a sequence of spheres with decreasing radius. Findings With the proposed method, the patches obtained are automatically refined as they approach the projection point and each patch of the integration element is “good” in shape and size for standard Gaussian quadrature. Therefore, all kinds of nearly singular boundary integrals on elements of any shape and size with arbitrary source point location related to the element can be evaluated accurately and efficiently. Originality/value Numerical examples for planar and slender elements with various relative location of the source point are presented. The results demonstrate that our method has much better accuracy, efficiency and stability than conventional methods.

Impact of Hammock Formations on Vertical Obstructions

The paper considers scenarios of head-on impact on vertical obstacles and destruction of hummock subsurface parts represented as a discrete spherical-element medium. The issues analyzed include the 2-phase nature of interaction and destruction of a loose and connected medium and also the cyclic pattern of loading and dynamic effects emerging in interaction with the hummock keel. The contact local stress in the subsurface part is determined by solving the Hertz equation which describes the indent of a sphere into a plane slab. Structural bonds are destructed when cohesion vanishes over the sliding plane. In the initial phase, a frozen ice ridge disintegrates as an perfectly plastic body with small angle of cohesion, while the second phase is viewed as dozing the sliding prism as a loose discrete body. This model allows for spatial effects in distortion of the subsurface part of an ice ridge. The dynamic effect is noted to increase with the size of hummock fragments, hummock speed and size.