29th Symposium on Fusion Technology (SOFT 2016)

P4.190 Experimental loop and purification system design for corrosion in flowing PbLi

8 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 190

Poster I. Materials Technology P4 Poster session

Speaker

Daniele Martelli (Department of Civil and Industrial Engineering)

Description

The use of PbLi and RAFM steels in blanket applications requires a better understanding of material compatibility related to physical/chemical corrosion phenomena in the 450-550°C temperature range. The impact of corrosion includes deterioration of the mechanical integrity of the blanket structure due to the wall thinning. Furthermore, serious concerns are associated with the transport of corrosion products by the Pb-Li coolant constituting strong limitations for the blanket design where the requested high temperatures must be compatible with acceptable corrosion behaviour. Available experimental data on the mass loss for ferritic/martensitic steels in the flowing PbLi spread over a wide range, predicting possible wall thinning (at temperatures higher than 450 °C) from 5 mm/yr up to a few hundred mm/yr. In order to improve the knowledge of corrosion behaviour, further experiments are needed. In this frame, the present work aims to illustrate the design of a new experimental facility named LIFUS II (LIthium for FUSion II) intended to extensively investigate corrosion mechanisms related on coated (Al2O3 based) and uncoated EUROFER samples at constant temperature of 550°C, for three different velocities (0.01, 0.1, 1 m/s) and four different exposure times (1000, 2000, 4000, 8000 h). Furthermore, a “cold trap” purification system is designed in order to remove impurities and corrosion product (resulting from the corrosion of the samples and the steel structures themselves) dissolved in the liquid metal via upper concentration limits imposed by temperature-dependent solubility constrains. The proposed design basically consists in a heat and mass transfer device, where supersaturated solution of impurity is generated as a result of coolant cooling. The performances and efficiency of the purification system will be also assessed in the LIFUS II experimental campaign.