The LIquid Lead LAboratory (LILLA) is situated at the Joint Research Centre in Petten, The Netherlands. LILLA offers testing of mechanical and corrosion properties of materials in liquid lead with controlled dissolved oxygen concentrations at temperatures up to 650°C. It gives the possibility to study liquid metal embrittlement phenomena / environmentally assisted cracking, and the effect of stress, temperature and oxygen concentration on corrosion mechanisms, as well as to test lead chemistry instrumentation in liquid lead.The facilityThe facility features four pneumatically operated testing apparatus (Test Sections TS), which can operate simultaneously. After a major refurbishment, the facility now features two TS designed to perform Small Punch Tensile (SPT) tests (illustration, left), while the other two perform Slow Strain Rate Tensile (SSRT) tests (illustration right). Illustration of the types of Test Sections: On the left the Small Punch test (SPT) with a close up on the specimen disk holder; at the right the Slow Strain Rate test (SSRT) with the tensile specimen holder.EU,2025 The SPT test setup allows an axial movement of 3mm in total with a maximum applied force of 6kN. The small punch specimens are circular disks of 8 x 0.5 mm dimensions, in accordance with the SPT standard EN 10371-2021. The SSRT test setup allows axial movement of up to 7mm at forces up to 6kN. The SSRT specimens can be either flat or cylindrical in accordance with the ISO 7539-7-2005 standard. In the measurement tank, high temperature mechanical test can also be conducted without lead, to perform reference tests in inert high temperature environment (Ar or Ar/H2).The setup hosts about 350 kg of high purity Pb. The Pb bath is allowed to reach temperatures up to 650°C. In the dump tank (DT, where the Pb is stored, Figure 1a) the lead is melted and pre-conditioned. The pre-conditioning is performed through additions of two different gasses, a mixture of 4% H2 in argon and pure argon (Ar 5.0). The former is used to reduce the oxygen content absorbed in the liquid Pb bath, while the latter is used to increase the concentration of oxygen. Throughout the process the O2 concentration is actively monitored by specific oxygen sensors. Once the Pb bath has reached the target temperature and the required O2 concentration, it is transferred to the measurement tank (MT, Figure 1b). Also the MT is equipped with O2 sensors, and the O2 is actively controlled through additions of Ar/H2, Ar, while air can be used to give a rapid increase of oxygen if needed. LILLA features a software that automatically controls the addition of gases to keep the O2 concentration quasi-constant within close margins. Photograph and schematic illustration of the LILLA setup: Left) Dump Tank (DT), Right) Measurement Tank (MT) with four Test Sections.EU 2025 Priority topicsPriority topics of LILLA are: the safety and reliability of nuclear components for future nuclear systems,the characterisation of the mechanical properties of candidate and new materials, included surface modifications and welded joints,the development of test and assessment methods as well as instrumentation to achieve reliable material properties using sub-size or miniaturised specimens, and,the support to the development and adaptation of European Codes and Standards.Supporting 3D profilometry, microstructural analysis (light optical microscopy, scanning electron microscopy with energy dispersive X-ray spectrometry), as well as nano-indentation (1 mN – 100 mN) and micro hardness (0.1 kg – 20 kg) testing are offered by the Environmental Mechanical Materials Assessment (EMMA) laboratories MCL Micro-Characterization Laboratory and SMPA Structural Materials Performance Assessment Laboratoriy at JRC Petten. All laboratories are part of JRC’s Open Access to research infrastructure scheme.
