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Liquid Metals as Heat Transfer Fluids for Science and Technology
Published in Alina Adriana Minea, Advances in New Heat Transfer Fluids, 2017
Alexandru Onea, Sara Perez-Martin, Wadim Jäger, Wolfgang Hering, Robert Stieglitz
Liquid lead–bismuth (44.5%–55.5% in weight) eutectic (LBE) mixture has a large operating temperature range of more than 1200°K ranging from 125°C to 1533°C. It has been extensively investigated in the context of nuclear waste transmutation. Compared to sodium, the chemical interaction with water and air results only in a slow and weak exothermal oxidation, but the corrosion rates with steels are significantly larger (>250 μm/year), requiring special protective layers. However, extensive research has been performed in this field (Engelko et al. 2001; Weisenburger et al. 2012; Müller et al. 2015), and ceramic protective layers composed of SiC and Ti3SiC2 have been reported to prevent corrosion up to 750°C (Rivai and Takahashi 2008). The handling of LBE represents demands dedicated measures, since it shows a biotoxic behavior; moreover, it is available at significantly larger cost only (more than 6 times compared to sodium). Further, the density is almost 12 times larger than that of sodium, necessitating a density adapted static seismic and pipe network design.
Subchannel Analysis of LFR Wire-Wrapped Fuel Bundle with RELAP5-3D
Published in Nuclear Technology, 2023
Cristiano Ciurluini, Vincenzo Narcisi, Ivan Di Piazza, Fabio Giannetti
Among the others, one of the most promising technologies is represented by lead-cooled fast reactors (LFRs). They foresee the adoption of lead or lead-bismuth eutectic (LBE) as primary coolant, ensuring several advantages in terms of reactor performance and safety. Indeed, this fluid is characterized by a very high boiling temperature and nonhazardous reactions with both air and water. However, to accomplish the GEN IV policy goals (i.e., enhanced actinide management, nuclear power plant economic competitiveness), reliable fuel operation at high burnup and high-power density must be guaranteed. Consequently, LFRs are characterized by high fuel and cladding temperatures.[2] In these conditions, some concerns arise related to the interaction of the liquid metal with the reactor structural materials. Considering all these aspects, an affordable core design must include effective thermal-hydraulic characterization of the fuel bundle at the subchannel level.
Oxygen concentration measurement and control of lead-bismuth eutectic in a small, static experimental facility
Published in Journal of Nuclear Science and Technology, 2020
Xian Zeng, Qinsheng Wang, Xie Meng, Zhao Chen, Yong Zhang, Qinzhi Yan, Yuezhou Wei
LBE and pure lead are usually used as the coolant in LFR and ADS. Pure lead/LBE has good neutron characteristics, safety performance, natural circulation abilities, and so on. However, the pure lead/LBE coolant also has drawbacks that include corrosion, generation of polonium (a highly poisonous substance), and structural instability [1,2]. The corrosion of LBE and pure lead is a physical or a physicochemical process involving species dissolution, oxidation and transport, chemical reactions, and new phase formation. To protect the structures from corrosion, oxygen should infiltrate the coolant, but the oxygen concentration should not be too high since high oxygen concentration can generate lead oxide that can block the channel. Thus, it is necessary to maintain the oxygen concentration within a range between the dissolution limit of the protective oxide film to avoid fast dissolution of the metal and the solubility limit of oxygen to avoid the formation of lead oxide [3]. Therefore, we should control the oxygen concentration in order to ensure the safety of the reactor. Oxygen-control includes the gas phase method and the solid phase method [4].
Effect of wall wettability condition on drift-flux parameters in lead–bismuth two-phase flow in circular and annular bubble columns
Published in Journal of Nuclear Science and Technology, 2018
Gen Ariyoshi, Ryota Inatomi, Daisuke Ito, Yasushi Saito
Lead–bismuth eutectic (LBE), one of the heavy liquid metals, is going to be applied to the ADS. The advantage of LBE as a coolant for the ADS attributes to its physical, chemical and thermodynamic properties such as high boiling temperature, low melting temperature, high thermal conductivity and chemical stability. Especially, due to its high boiling temperature (1670 °C), it is allowable to have a low pressure in the primary circuit when the outlet coolant temperature is equal to 400–500 °C. This simplifies the reactor design and enhances its reliability [1–3]. One of the fast-developing areas of the nuclear engineering is associated with using high-current proton accelerators for realization of the ADS [4,5]. The expediency of using heavy metals as a target material for proton beam is caused by a high neutron yield in spallation reactions between these materials. This necessity to apply a liquid metal target is associated also with the heat removal problem at a high energy release density. Hence, LBE and lead seem to be the best materials for liquid metal targets because of their high thermal conductivity [6,7].