Xicheng Wang

KTH Royal Institute of Technology | KTH · Department of Physics

Pressure Suppression Pool (PSP) is employed in Boiling Water Reactor (BWR) as a heat sink to suppress pressurization of the containment and reactor vessel by discharging steam into the water pool. Modelling of Direct Contact Condensation (DCC) with the explicit resolution of both Mirco (condensation) and Macro (pool circulation) scales is computati...

Direct contact condensation (DCC) of steam in the pressure suppression pool (PSP) is used to control containment pressure in Boiling Water Reactors (BWRs) and Advanced Pressurized Water Reactors (APWRs). The competition between momentum and heat sources induced by steam injection through multi-hole spargers and blowdown pipes determines whether the...

Measurement of the velocity field in thermal-hydraulic experiments is of great importance for phenomena interpretation and code validation. Direct measurement by means of Particle Image Velocimetry (PIV) is challenging in some multiphase's tests where the measurement system would be strongly affected by the phase interaction. A typical example can...

Boiling Water Reactors (BWR) and Advanced Pressurized Water Reactors (APWR) often use spargers to release steam from the primary coolant system into a pool with subcooled water to prevent containment overpressure. Direct contact Condensation (DCC) creates sources of mass, heat, and momentum determined by the condensation regimes in a subcooled pool...

Transportation of fresh fuel assemblies requires the utilization of transport casks to ensure the internal radioactive material does not affect the environment. In this work, we introduce an innovative design of a transport cask for the fresh fuel assembly of a Small Module Reactor (SMR). The cask is constituted by two containers, supports and vari...

Transportation of fresh fuel assemblies requires the utilization of transport casks to ensure the internal radioactive material does not affect the environment. In this work, we introduce an innovative design of a transport cask for the fresh fuel assembly of a Small Module Reactor (SMR). The cask is constituted by two containers, supports and vari...

A R T I C L E I N F O Keywords: Fuel rod Flow-induced vibration Particle finite element method Partitioned paradigm A B S T R A C T As a newly designed 200 MW nuclear heating reactor (NHR200-II), flow-induced vibration (FIV) of the fuel rod has attracted extensive attention due to its slender shape and the hydrodynamic loads arose from the turbulen...

Steam discharging through spargers and blowdown pipes into the Pressure Suppression Pool (PSP) is employed in Boiling Water Reactor (BWR) to prevent overpressure of the reactor vessel and containment. The capability of suppression can be reduced during the operation when the thermal stratification is developed. Direct modeling of steam injection in...

Advanced Pressurized Water Reactors (APWRs) and Boiling Water Reactors (BWRs) employ a suppression pool as a heat sink to prevent overpressure of the reactor vessel and containment. Steam can be discharged into the pool through multi-hole spargers or blowdown pipes in both normal and accident conditions. Direct Contact Condensation (DCC) releases s...

Extended Abstract Containment served as the final physical barrier to prevent the release of fission products is of great significance for reactor safety. Depressurization by discharging steam into the Pressure Suppression Pool (PSP) through multi-hole spargers and blowdown pipes is a safety design for Boiling Water Reactors (BWRs) during normal an...

Propose steam condensation region (SCR) approach for implementation of the Effective Heat Source (EHS) and Effective Momentum Source (EMS) provides accurate prediction of the pool behaviour. The models are used for pre- and post-test analysis of the PANDA H2P3 and H2P4 experiments. Approach for estimation of liquid velocity in SEF-POOL tests based...

Boiling Water Reactor (BWR) uses the Pressure Suppression Pool (PSP) as a heat sink to prevent overpressure of the reactor vessel and containment. Steam can be released into the PSP through spargers in normal conditions and blowdown pipes during the Loss-Of-Coolant Accident (LOCA). The capacity of PSP and operation of the systems with the PSP as a...

Multi-hole spargers are used in Boiling Water Reactor (BWR) and advanced Pressurized Water Reactor (PWR) to condense the steam in large water pools. Thermal stratification that can lead to increased pool surface temperature and thus reduction of the pressure suppression capacity of the pool is of safety concern. Effective Heat Source (EHS) and Effe...

Boiling Water Reactors (BWRs) employ direct contact condensation in larger water pools to suppress pressurization of the containment in case of steam release from the primary coolant system. Effectiveness of the pressure suppression pool (PSP) can be negatively affected if thermal stratification develops during steam injection. Higher temperature o...

Pressure Suppression Pool (PSP) is a passive safety feature in Boiling Water Reactors (BWR) and Advanced Pressurized (AP) reactors. Steam released from the primary coolant system is condensed in a large water pool to prevent containment overpressure. Injected steam induces sources of heat (buoyancy force) and momentum (inertia). The competition bet...

Direct contact condensation (DCC) of steam in the pressure suppression pool (PSP) is used to control the pressure in the containment after steam release from the primary coolant system. Modeling of large-scale pool behavior induced by steam injection through multi-hole sparger is necessary to evaluate the capacity of the PSP, which can be affected...

Effective Momentum Source and the Effective Heat Source (EMS/EHS) models for spargers are further developed using source terms, boundary conditions and “unit cell” approaches. The models implemented in Fluent and GOTHIC have been used to support design of the sparger (H2P3) and integral (H2P4) tests series in PANDA facility in HYMERES-2 project. Th...

The Steam injection through multi-hole spargers into the pressure suppression pool (PSP) is used in light water reactors to prevent containment over-pressure. The development of thermal stratification in the PSP can reduce its cooling capacity and results in higher containment pressures compared to completely mixed pool conditions. Explicit modelli...

NHR200-Ⅱ is a 200 MW nuclear heating reactor. The integrity of the fuel assembly should be ensured during the normal operations and design basis accidents. In the latter cases (e.g. earthquake), its deformation or damage should not prevent the insertion of control rods to shut down the reactor. Meanwhile, during the operating time, there are two as...

A simplified modelling method for the spacer grid of NHR200-II fuel assembly is proposed to increase the computational efficiency in the dynamic analysis. It includes the replacement of the grid inside the dimples and three-arc springs with the non-linear connectors, and the replacement of the fuel rods with beam elements. The stiffness of connecto...

Extended Abstract Containment is a significant part of the reactor safety design and is served as the last physical barrier to prevent the release of radioactive fission products into the environment. The injection of steam into the Pressure Suppression Pool (PSP) is a passive safety design to control the pressure in the containment. The performanc...

The Pressure Suppression Pool (PSP) in a Boiling Water Reactor (BWR) is served as a heat sink to prevent containment over-pressure. The steam can be injected through the multi-hole spargers. The development of thermal stratification where a thermocline with a large temperature gradient appears in the pool can lead to the higher pressure in the dry...

KTH reports further development and validation of the Effective Momentum Source and the Effective Heat Source (EMS/EHS) models for spargers using source terms and boundary conditions approaches. Fluent and GOTHIC codes have been applied in the analysis to design sparger (H2P3) and integral (H2P4) test series in PANDA facility. Results of the analys...

Steam condensation in a large pool is often used in light water reactors to prevent containment over-pressure. In boiling water reactors, steam from the primary system can be released into a pressure suppression pool (PSP) in normal operation and during accidents through multi-hole spargers to control the pressure in the reactor vessel. Steam injec...

Steam condensation in a pool of water is often used in light water reactors. Steam injection provides sources of heat and momentum, which can lead to the development of thermal stratification or mixing of the pool. Modelling of the direct steam condensation is computationally challenging, especially considering the complex geometry of the pool and...

NHR200-Ⅱ is a kind of nuclear heating reactor designed by Institute of Nuclear and New Energy Technology, Tsinghua University. The fuel assembly (FA) is similar to PWRs but with a zircaloy channel. The purpose of this paper is to propose a detailed finite element (FE) model of NHR200-Ⅱ FA which can be used in the dynamic analysis (seismic, impact,...

统计能量法是解决复杂结构高频动力学问题的主要方法之一，限于其分析特性，过于细致 化的建模会引发其计算量大、计算精度低等问题。针对典型的船体板架结构，提出基于统计能量法的船体板架结构简化建模方法，并结合数值计算加以验证。根据实际需求，提出简化建模的等效原则，给出多平板的简化建模方法；通过研究给出周期加筋板的简化建模方法；提出一种双层底结构的简化建模方法，并进行误差分析 Statistical energy analysis is one of the main methods to solve the high frequency dynamics problem of complex structure. For its analysis limitation, excessively de...