LIPSIE device: Pb-17Li irradiation in water loop with on-line tritium measurements

Due to the low solubility and high diffusivity of tritium in Pb-17Li, tritium permeation through the walls of a water-cooled Pb-17Li blanket has to be investigated. This has been done in Lipsie irradiation performed by CEA in the OSIRIS reactor. The Isabelle 4 PWR loop, in the OSIRIS reactor pool, has been adapted to allow us to irradiate in demineralized water at 15 MPa and 300°C a 316L stainless steel capsule of 0.025 m diameter, containing about 0, 450 kg of Pb-17Li manufactured with natural lithium. Two tritium measurements systems have been specially developed around radioactivity scintillation counting devices: one for tritium in cooling water out of the capsule and one for tritium in helium gas after sweeping or sparging in Pb-17Li inside the capsule. This paper describes the loop used for this irradiation and the tritium measurement systems. The experiment will enable us to estimate tritium permeation rate through the capsule wall in Demo-representative conditions of tritium in Pb-17Li and also study the effect of oxidation of the external capsule wall on tritium permeation by oxygen injection near the capsule.