Compatibility of a Zircaloy in Lead-bismuth Eutectic Heavyliquid Metal

Liquid Lead-Bismuth Eutectic (LBE) is a coolant of one of main candidates for the future nuclear reactor in the world (Generation IV reactors) i.e. LFR (Lead alloy-cooled Fast Reactor), and also a spallation target material for ADS (Accelerator Driven Transmutation System). The liquid has several advantages from neutronic, thermal-hydraulic, and inert characteristic with water and air. Nevertheless, the liquid LBE has the corrosive characteristic to metals as constituent materials of fuel cladding and structural of the reactors. Therefore, development of fuel cladding and structural materials in lead-bismuth eutectic environment is one of key issues for the deployment of LFR and ADS. A zirconium alloy material i.e. ZrNbMoGe has been developed in the Center for Technology of Nuclear IndustryMaterials (PTBIN)-BATAN. In order to explore the characteristics of the zircaloy, investigation of compatibility of ZrNbMoGe in liquid LBE has been done using COSTA apparatus facility at Pulsed Power and Microwave Technology, Karlsruhe Institute of Technology Germany. The test was done at 550 ºC of temperature with an oxygen concentration of 1x10-6 wt.% for 312 hours. The result showed the trace of zirconium oxide formation on the surface of the sample. This phenomenon revealed that in a relatively short time the zirconium alloy consumed a lot of oxygen in liquid LBE to form zirconium oxide on the surface of the sample. However, the zirconium oxide was spalled off from the surface of the sample because of fast formation with relatively thick of the zirconium oxide. Therefore, the zircaloy is not compatible with lead-bismuth eutectic heavy liquid metal that is used in the nuclear reactor system

Langfristiger Verlauf der Nierenfunktion nierentransplantierter Patienten unter hohen bzw. niedrigen Cyclosporinspiegeln

Die Nephrotoxizität von Cyclosporin A ist hinreichend bekannt. Interessant bleiben die prognostische Relevanz und die Dosisabhängigkeit des Langzeittransplantatüberlebens. Die Fragestellung dieser Studie war, ob der langfristige Verlauf der Nierenfunktion nierentransplantierter Patienten über fünf Jahre unter niedrigen (150ng/ml) Cyclosporinspiegeln unterschiedlich ist. Die Retentionswerte und die Kreatinin-Clearance zeigten zwischen den Gruppen keinen signifikanten Unterschied, im Gegensatz zum Verlauf des Serumphosphats: Hier fielen in Gruppe A anfangs erniedrigte Werte auf, die sich im Verlauf in den Normbereich einstellten, in Gruppe B war ein Abfall von zunächst erhöhten auf zuletzt hochnormale Werte zu beobachten, was durch eine im Verlauf schlechtere tubuläre Reabsorption erklärbar ist. Dies zeigt, dass unterschiedliche Cyclosporinspiegel nicht zwangsläufig die Gesamtprognose des Transplantates im Langzeitverlauf verschlechtern müssen. Nephrotoxicity of cyclosporine is well known. Prognostic relevance and dose-dependance of long term graft survival remain interesting. The question of this study was, wether the long term outcome over five years of renal function in patients with renal transplant is different under low (150ng/ml) levels of cyclosporine. The laboratory test results concerning renal retention and the clearance of creatinine didn’t differ significantly, in contrast to the serum-phosphate-levels. Group A first showed reduced serum-phosphate, that increased to normal in the end, whereas in group B there was a decrease from first exalted serum-phosphate to finaly high normal levels. This can be explained by an impaired tubular reabsorption. It shows, that different cyclosporine-levels do not have to worsen long term graft outcome

Corrosion Investigations of Materials in Antimony–Tin and Antimony–Bismuth Alloys for Liquid Metal Batteries

Liquid metal batteries are discussed as stationary electrical energy storage for renewable energies, in order to compensate their fluctuating supply of energy. A liquid metal battery consists of three different liquids, which stay segregated due to density differences and mutual immiscibility. The negative electrode is the low-density liquid metal, and in our case sodium, a medium density molten salt, is the electrolyte and positive electrode is a high-density liquid metal. For the latter, Sb–Sn and Sb–Bi alloys are selected. However, one issue is the compatibility of structural materials with the used liquids. In a first step, the behavior of potential structural materials in Sb3Sn7 and SbBi9 at the temperature of 450 °C up to 750 h was tested. The results showed that the corrosion in SbBi9 was significantly less than in Sb3Sn7 and the most promising materials were molybdenum meta and Max-phase coatings

Liquid metal technology for concentrated solar power systems: Contributions by the German research program

Concentrated solar power (CSP) systems can play a major role as a renewable energy source with the inherent possibility of including a thermal energy storage subsystem for improving the plant dispatchability. Next-generation CSP systems have to provide an increased overall efficiency at reduced specific costs and they will require higher operating temperatures and larger heat flux densities. In that context, liquid metals are proposed as advanced high temperature heat transfer fluids, particularly for central receiver systems. Their main advantages are chemical stability at temperatures up to 900 ℃ and even beyond, as well as largely improved heat transfer when compared to conventional fluids like oil or salt mixtures, primarily due to their superior thermal conductivity. However, major issues here are the corrosion protection of structural materials and the development of technology components and control systems, as well as the development of indirect storage solutions, to circumvent the relatively small heat capacity of liquid metals. On the other hand, using liquid metals might enable alternative technologies like direct thermal-electric conversion or use of solar high-tem­perature heat in chemical processes. This article aims at describing research areas and research needs to be addressed for fully evaluating and subsequently utilizing the potential of liquid metals in CSP systems. A second aim of the article is a brief overview of the liquid metal research capabilities of Karlsruhe Institute of Technology (KIT), their background and their relation to CSP and the aforementioned research pathways

Corrosion tests on austenitic samples with alumina and alumina-forming coatings in oxygen-containing stagnant Pb and turbulently flowing PbBi

Two differently produced alumina coatings (by pulsed laser deposition (PLD) and detonation gun (DG)) and one alumina-forming coating realised by pack cementation are proposed as a protection barrier against corrosion of austenitic steels in Pb and PbBi. Samples were tested in oxygen-controlled stagnant Pb (10$^{−7}$ wt.%) at 480 °C and 550 °C for up to 10,000 h and in turbulently flowing (up to 1.6 m/s) PbBi eutectic at 490 °C with 10$^{−9}$–10$^{−8}$ wt.% oxygen for about 500 h. All exposed coatings showed a good behaviour in flowing PbBi and in stagnant Pb at around 480 °C independent of the oxygen content. At 550 °C, the PLD coating failed most probably due to incomplete coating of the sample, while the DG sample protected the base material

Influence of Si addition on the corrosion behaviour of 9 wt% Cr ferritic/martensitic steels exposed to oxygen-controlled molten Pb-Bi eutectic at 550 and 600 °C

Three 9 wt% Cr ferrite/martensite steels (two alloyed with Si) have been exposed to oxygen-controlled LBE at 550 and 600 °C, respectively. The passivating oxide scale consists of a spinel layer plus internal oxidation zone (IOZ). By adding Si, the thickness of spinel layer is decreased while the IOZ is enhanced. Moreover, a Si-rich oxide layer is observed underneath the spinel layer on Si-containing samples after 2000 h exposure at 600 °C. Besides, the less visible cracks/exfoliations on Si-containing samples indicate the positive role of Si addition on scale adherence

KOMPATIBILITAS PADUAN ZIRKONIUM PAD ACAIRAN LOGAM BERAT LEAD-BISMUTH EUTECTIC

KOMPATIBILITAS PADUAN ZIRKONIUM PAD ACAIRAN LOGAM BERAT LEAD-BISMUTH EUTECTIC. Cairan Lead Bismuth Eutectic (LBE) merupakan pendingin salah satu kandidat utama reaktor masa depan di dunia (Generation IV reactors) yaitu Lead alloy-cooled Fast Reactor (LFR) sekaligusmerupakan material target spalasi untuk Accelerator Driven Transmutation System (ADS). Cairan ini memiliki berbagai keunggulan dari segi netronik, termalhidrolik maupun sifat yang inert terhadap air dan udara. Namun cairan LBE ini bersifat korosif pada logam-logam yang menjadi penyusun material kelongsong bahan bakar dan struktur reaktor. Oleh karena itu pengembangan material kelongsong bahan bakar dan struktur reaktor dalamlingkungan LBE merupakan salah satu kunci utama dalam pengembangan LFR dan ADS. Telah dikembangkan paduan zirkonium yaitu ZrNbMoGe di Pusat Teknologi Bahan Industri Nuklir (PTBIN)-BATAN. Dalam rangka untuk mengeksplorasi karakteristik paduan zirkonium ini dilakukan investigasi kompatibilitas bahan paduan zirkonium ZrNbMoGe di dalam lingkungan cairan LBE dengan menggunakan fasilitas aparatus COSTA di Pulsed Power and Microwave Technology-Karlsruhe Institute of Technology Germany. Pengujian dilakukan pada suhu 550 °C dengan konsentrasi oksigen 1 x 10-6 %berat selama 312 jam. Hasil pengujian memperlihatkan jejak pembentukan lapisan oksida zirkonium di atas permukaan sampel yang kemudian terlepas. Hal ini menunjukkan bahwa dalam waktu yang relatif singkat paduan zirkonium telah mengkonsumsi cukup banyak oksigen di dalam cairan LBE dengan membentuk lapisan oksida zirkonium di atas permukaan sampel. Namun pembentukan lapisan oksida zirkoniumyang cepat dan relatif tebal di atas permukaan sampel ini menyebabkan dalamwaktu relatif singkat lapisan oksida ini terlepas dari permukaan bahan. Oleh sebab itu paduan zirkonium ini tidak kompatibel dengan cairan logam berat LBE yang digunakan dalam sistem reaktor nuklir