Risk-based multi-criteria design concept of the ITER SDS getter bed

The main objective of ITER tritium Storage and Delivery System (SDS) is contracted to develop an optimal metal hydride bed that can be reveal the unprecedented fueling performance for the Tokamak. One function of the hydride bed is to keep safety requirements in terms of confinement of tritium. The hydride material for storing the deuterium and tritium fuelling gases is being made narrow with depleted uranium (DU) by its good performance. DU also has its own uncertainties, however, in applying it to realize the getter bed system having an all-round capability, especially in aspect of safety. This paper deals with from bed design target to the design variables in terms of comparison of risk-based multi-criteria using HAZOP (risk matrix) analysis. In analysis of the risks, important variables that denotes safety-effective, or cost-effective, or maintainability-effective, or manufacturability-effective are sometimes mutually interrelated with each other. As a conclusion the authors could recommend the way to concentrate and minimize the bed design variables with most meaningful risk-containing components that can be applied to increase the performance of hydride bed. It needs, however, that further study of comparison of risk analyses should be proceeded to complete the hydride bed design.