Higher-order modes of the neutron diffusion/transport equation can be used to study the temporal behavior of nuclear reactors and can be applied in modal analysis, transient analysis, and online monitoring of the reac...
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Higher-order modes of the neutron diffusion/transport equation can be used to study the temporal behavior of nuclear reactors and can be applied in modal analysis, transient analysis, and online monitoring of the reactor core. Both the deterministic method and the Monte Carlo(MC) method can be used to solve the higher-order modes. However, MC method, compared to the deterministic method, faces challenges in terms of computational efficiency and α mode calculation stability, whereas the deterministic method encounters issues arising from homogenization-related geometric and energy spectra *** on the higher-order mode diffusion calculation code HARMONY, we developed a new higher-order mode calculation code, HARMONY2.0, which retains the functionality of computing λ and α higher-order modes from HARMONY1.0, but enhances the ability to treat complex geometries and arbitrary energy spectra using the MC-deterministic hybrid two-step strategy. In HARMONY2.0, the mesh homogenized multigroup constants were obtained using OpenMC in the first step,and higher-order modes were then calculated with the mesh homogenized core diffusion model using the implicitly restarted Arnoldi method(IRAM), which was also adopted in the HARMONY1.0 code. In addition, to improve the calculation efficiency, particularly in large higher-order modes, event-driven parallelization/domain decomposition methods are embedded in the HARMONY2.0 code to accelerate the inner iteration of λ∕α mode using OpenMP. Furthermore, the higher-order modes of complex geometric models, such as Hoogenboom and ATR reactors for λ mode and the MUSE-4 experiment facility for the prompt α mode, were computed using diffusion theory.
Kalman filter (KF) is increasingly attracted for sensorless control of surface permanent magnet synchronous motors (SPMSMs) due to its strong robustness against measurement and system noise. However, conventional meth...
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The existing drive method of the main equipment transporter of the nuclear island makes the transporter have frequent jamming problems when the transporter going straight and turning, which affects the safety during t...
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In this work, an evaluation towards influence of high-dose gamma irradiation on surface acoustic wave (SAW) resonators, is reported. The single-port SAW resonators are fabricated using Lithium niobate (LiNbO3) and Cat...
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Borated stainless steels (BSSs) are extensively applied in the nuclear energy industry due to boron's excellent thermal neutron absorption capacity, but large and brittle borides formed during casting result in a ...
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The nuclear power SVDU in nuclear power plants is an important component of the nuclear reactor protection system. With the complete digitalization of the reactor protection system, the risks of cybersecurity attacks ...
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Monitoring key parameters in nuclear power plant control rooms is critical, as human errors can result in severe safety and operational consequences. This study proposes a hybrid framework for power prediction and fau...
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Existing studies identify the failure of turbulent heat flux modeling—particularly the constant turbulent Prandtl number (Prt) assumption—as the primary cause of inaccurate heat transfer deterioration (HTD) predicti...
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In this paper, a novel model is proposed to investigate the neutron transport in scattering and absorbing medium. This solution to the linear Boltzmann equation is expanded from the idea of lattice Boltzmann method(LB...
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In this paper, a novel model is proposed to investigate the neutron transport in scattering and absorbing medium. This solution to the linear Boltzmann equation is expanded from the idea of lattice Boltzmann method(LBM) with the collision and streaming process. The theoretical derivation of lattice Boltzmann model for transient neutron transport problem is proposed for the first *** fully implicit backward difference scheme is used to ensure the numerical stability, and relaxation time and equilibrium particle distribution function are obtained. To validate the new lattice Boltzmann model, the LBM formulation is tested for a homogenous media with different sources, and both transient and steady-state LBM results get a good agreement with the benchmark solutions.
In this paper,the evaluations of metal ablation processes under high temperature,i.e.,the Al plate ablated by a laser and a heat carrier and the reactor pressure vessel ablated by a core melt,are studied by a novel pe...
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In this paper,the evaluations of metal ablation processes under high temperature,i.e.,the Al plate ablated by a laser and a heat carrier and the reactor pressure vessel ablated by a core melt,are studied by a novel peridynamic *** all,the peridynamic formulation for the heat conduction problem is obtained by Taylor’s expansion ***,a simple and efficient moving boundary model in the peridynamic framework is proposed to handle the variable geometries,in which the ablated states of material points are described by an additional scalar ***,due to the automatic non-interpenetration properties of peridynamic method,a contact algorithm is established to determine the contact relationship between the ablated system and the additional heat *** addition,the corresponding computational procedure is listed in ***,several numerical examples are carried out and the results verify the validity and accuracy of the present method.
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