Double walled or double containment piping is considered for use in the ITER international project and other next-generation fusion device designs to provide an extra barrier for tritium gas and other radioactive materials. The extra barrier improves confinement of these materials and enhances safety of the facility. This paper describes some of the design challenges in designing double containment piping systems. There is also a brief review of a few operating experiences of double walled piping used with hazardous chemicals in different industries. The authors recommend approaches for the reliability analyst to use to quantify leakage from a double containment piping system in conceptual and more advanced designs. The paper also cites quantitative data that can be used to support such reliability analyses.
