STUDY ON SEALING CHARACTERISTICS OF ELASTOMER 0-RINGS UNDER LOW TEMPERATURE

In the design of the packaging for radi oacti ve materials transport (casks), IAEA's transport regulations require considering, as a temperature condition for materials of the component, a temperature range down to -40~ on the low temperature side. Considered here as component materials for the cas k are cask body materials, shock absorber, and sealing mat e rials for ming the containment system, etc . Among these, cask body and shock absorber materials are often evaluated by comparing the materials ' properties ; however, the elastomer 0-ring, widely used as a sealing material, may become brittle at low temperatures. Although the material properties of elastomer 0-rings (such as the brittle point and tensile strength) are relatively known, many t hings regarding the elastic changes required for evaluating its sealing performance and design data related with the sealing performance remain unknown. This study considers four kinds of elastomers often employed in the containment system of a cask. Under various low temperature conditions the relation between load and displacement characteristics (spring constant) and that between load and sealing performance are shown as data related with the above points, using temperature as a parameter, to clarify the sealing performance and simultaneously propose points to consider as for low temperature characteristics in designing containment system.