Concept design analyses of an ITER radwaste system pipeline

Abstract

As a part of ITER research and development activities, concept design of a pipeline containing low-level liquid wastage is being carried out. Since failure of the radwaste pipeline can result in release of radioactive materials and threat the safety of penetrating Tokamak and annex buildings, the pipeline should satisfy requirements of faulted condition as well as normal operating condition. The objective of this study is to examine load-carrying capacity of the ITER radwaste pipeline through systematic numerical analyses. In this context, at first, simplified finite element analyses were performed for five candidate geometries under conservative seismic displacements. Subsequently, modal and response spectrum analyses were conducted for the same geometries to confirm whether the simplified approach is valid or not during the concept design stage. Based on these two kinds of analyses, a spiral-type configuration was derived as the optimum geometry for detailed design of the radwaste pipeline. Also, it was proven that the modal analyses results showed reasonable dynamic characteristics of the pipeline and the simplified analyses results such as maximum stresses and displacements were comparable to the response spectrum analyses results from the conservative standpoint.