Conference Agenda

An Annular Linear Induction Pump (ALIP) was designed for driving Lead Bismuth Eutectic (LBE). The basic parameters of the ALIP were calculated by the multi-physics coupling software COMSOL. The ALIP have 4 pole pairs, a frequency of 50 Hz, an input line current ranging from 0 to 80 A, and a corresponding output head ranging from 0 to 500 kPa, with a flow rate of 0 to 10m³/h. Experiments were conducted within the current range from 28 to 52A, the results showed that the experimental values matched well with the calculated values. Experiments on the output head of the ALIP was conducted with LBE at temperatures of 250, 300, and 350℃. The results showed that the output head of the ALIP varied little under the same electromagnetic parameters. This is due to the small change in the resistivity of the LBE with temperature, which is significantly different from sodium. The head curve of the ALIP was tested at a LBE temperature of 300℃ by adjusting the input electromagnetic parameters. The results indicate that the output head and LBE flow rate of the ALIP increase with the increase of input current, voltage, and power. However, under the same input electromagnetic parameters, the output head of the ALIP decreases as the flow rate increases.

The development of pool-type reactor MYRRHA, utilizing heavy liquid metal coolant necessitates primary pumps with extended massive shafts supported below the coolant free-surface level. Hydrostatic bearings are the most suitable choice for these specific conditions. However, conventional calculation methods for hydrostatic bearings are inadequate for the unique operational parameters presented by this application. This study focuses on the computational fluid dynamics (CFD) analysis and optimization of hydrostatic bearing designs for primary pumps in MYRRHA. Three bearing design candidates with different numbers of pockets were initially evaluated using CFD simulations on a scaled-down test model of the primary pump. The most promising design underwent iterative refinement to meet specific performance requirements, including pressure drop, load capacity, pressure ratio, and frictional torque. A comprehensive parametric analysis was conducted on the optimized design to characterize its performance across various operational scenarios, including the study of the influence of rotational speed and eccentricity. The CFD model developed for this analysis incorporated mesh optimization and turbulence modelling, simulating heavy liquid metal flows in the restrictors, the pockets, and the narrow gap of the hydrostatic bearing. The outcome of this research is a hydrostatic bearing design that satisfies all specified requirements for use in the scaled-down test model of the primary pump of MYRRHA. The CFD modelling approach provides a robust and reliable framework for future design and optimization efforts in this field, contributing to the advancement of primary pump hydrostatic bearing technology in heavy liquid metal-cooled reactors.

Amongst Generation IV reactor designs, liquid metal-cooled reactors boast high power density owing to the high thermal conductivity of metals. The thermo-hydraulic phenomena that occur in the reactor pool in different scenarios (steady operation, accidents, non-critical transients, etc.) are a topic of great interest in the research community. One such reactor concept is MYRRHA, a flexible fast-spectrum research reactor cooled by lead-bismuth eutectic (LBE) under design at SCK CEN. To support the design of MYRRHA and provide data that gives insight into such phenomena and for numerical code validation, a 1/6th scale model called European SCAled Pool Experiment (E-SCAPE) was developed.

As part of the European project PASCAL, NRG aims to perform multi-scale simulations of E-SCAPE subjected to asymmetric accident scenarios of Heat Exchanger and Single Pump Failure coupling the in-house System Thermal Hydraulic (STH) code SPECTRA to the commercial Computational Fluid Dynamics (CFD) code STAR-CCM+ via the in-house coupling tool myMUSCLE: MultiphYsics MUltiscale Simulation CoupLing Environment.

In previous articles, the standalone as well as coupled models of E-SCAPE have been validated against a steady state isothermal scenario. In this article, the next step is taken by performing coupled calculations of the steady active operation at a mass flow rate of 93.2 kg/s and 80% power, i.e 73kW, that serves as the pre-accident state to the Heat Exchanger Failure scenario, and comparing to the standalone STH and experimental results. The calculations reveal stable solutions that are well in agreement with the standalone STH as well as the experimental results.

Lead(Pb) and lead bismuth(Pbbi) reactors are potential types of fourth generation reactors. Lead reactors have higher thermal efficiency and natural circulation capabilities. At present, there are almost no publicly reported experimental data on the heat transfer characteristics of liquid lead, especially the data under natural circulation mode. In this study, a pool-type natural circulation experimental platform was first designed, which includes a simulated core(simulated with 37 heating rods with a length of 1200mm, and P/D of 1.3), a hot pool, a cold pool, upper and lower channels, and four symmetrical lead-oil heat exchangers. During the experiment, liquid lead undergoes endothermic expansion in the simulated core and flows into the top lead-oil heat exchangers through a hot pool. After heat exchange, the liquid lead flows downwards along the cold pool into the bottom of the simulated core, completing natural circulation. The T/H characteristics of liquid lead at simulated core, hot pool, cold pool, etc. were analyzed and studied. At the same time, experimental modeling based on system code was also carried out, and the experiments were compared and verified with the code. The research results can provide support for the design of liquid lead pool-type natural circulation reactors.

System codes can efficiently handle system-level problems and obtain transient characteristics of whole system. However, they lack the ability to analyze the local flow and heat transfer characteristics of components. CFD codes have the ability to perform highly precise analysis of local components, but cannot analyze the whole system. Therefore, it is an important direction of current research that achieving the coupling calculation of system and CFD codes. To obtain the flow and heat transfer characteristics of the core and transient response of the lead-bismuth fast reactor, a coupling code between system code and CFD was developed. Through a data transferring platform based and explicit coupling method, the simulation of the primary loop of lead-bismuth fast reactor core was achieved. To verify the coupling code, system code and coupling code under the same operating conditions were performed. The flow rate and coolant temperature in the primary loop of the lead-bismuth fast reactor were compared. It was found that the coupling simulation results were consistent with the results of system code, indicating that the coupling code can accurately predict the flow and heat transfer characteristics and system response of the lead-bismuth fast reactor core, and verify the feasibility and rationality of the coupling method. This study provides a coupling method for the thermal hydraulic analysis of lead-bismuth fast reactors.