Yoonhee Lee

Chonbuk National University | cbnu · Department of Quantum System Engineering

Fully ceramic microencapsulated (FCM) fuel, a type of accident-tolerant fuel (ATF), consists of TRISO particles randomly dispersed in a SiC matrix. In this study, for a thermal analysis of the FCM fuel with such a high heterogeneity, a two-temperature homogenized thermal-conductivity model was applied by the authors. This model provides separate te...

The fully ceramic microencapsulated (FCM) fuel, one of the accident tolerant fuel (ATF) concepts, consists of TRISO particles randomly dispersed in SiC matrix. This high heterogeneity in compositions leads to difficulty in explicit thermal calculation of such a fuel. For thermal analysis of a fuel element of very high temperature reactors (VHTRs) w...

A new method of depletion calculation is introduced by decomposing nuclide concentration vector into two blocks (short-lived nuclide block and long-lived nuclide block). For short-lived nuclide block calculation, general Bateman solution of each short-lived nuclide is used. An “importance” concept is introduced for selecting important parents for p...

In this paper, with the experimental data on the chemical behavior of iodine under the conditions of severe accident in nuclear power plant, first, we perform numerical analyses on the iodine chemistry model in AnCheBi (Analysis on Chemical Behavior of Iodine Species in the Containment) code for validation. Then, we perform analyses on the importan...

In this paper, we select important fission products for the estimation of the source term during a severe accident of a PWR. The selection is based on the numerical results obtained from depletion calculations for the typical PWR fuel via the in-house code named DEGETION (Depletion, Generation, and Transmutation of Isotopes on Nuclear Application),...

When damaged core materials are relocated to the reactor lower head with penetrations during a severe accident, the loss integrity of the reactor pressure vessel caused by ejection of a penetration tube will occur earlier than the global failure of the reactor lower head. The overall aim of this study is to review and improve the previous contact p...

In this paper, first, MELCOR calculations for a conventional high power pressurized water reactor are performed to obtain the geometrical configurations and remaining fraction of the fission products in the degraded reactor core during the early phase of a severe accident. Then, based on the coupling between MELCOR and Serpent 2 code, sensitivity a...

In this paper, from a review of the size distribution of the bubbles during pool scrubbing obtained from experiments by EPRI, we apply the bubble size distributions to analyses on the decontamination factors of pool scrubbing via I-COSTA (In-Containment Source Term Analysis). We perform sensitivity studies of the bubble size on the various mechanis...

Most fission products are released into the containment as aerosol particles during severe accidents. In the conventional codes, two sets of equations are used to analyze the aerosol behaviors in the containment. The first set of equations are multicomponent sectional equations, solutions of which are given with the mass concentrations in each disc...

During a severe accident in a nuclear power plant, most of fission products are released into the containment as aerosol particles. The analyses on the aerosol behaviors in the containment are performed via solving two governing equations. The first equations are multicomponent sectional equations for coagulations and deposition, solutions of which...

Conventional codes for analyzing pool scrubbing of aerosol particles, such as SPARC-90 , BUSCA (Ramsdel et al., 1994), MELCOR based on SPARC-90, and etc. have been made based on the experimental results performed in a globular regime. However, such conventional codes do not give accurate decontamination factors (DFs) when the injection velocity is...

In Part I of this paper, the two-temperature homogenized model for the FCM fuel, in which TRISO particles are randomly dispersed in a fine lattice stochastic (FLS) structure, was discussed. In this model, the fuel-kernel and SiC matrix temperatures are distinguished. Moreover, the obtained temperature profiles are more realistic than those from oth...

As a type of accident-tolerant fuel, fully ceramic microencapsulated (FCM) fuel was proposed after the Fukushima accident in Japan. The FCM fuel consists of tristructural isotropic particles randomly dispersed in a silicon carbide (SiC) matrix. For a fuel element with such high heterogeneity, we have proposed a two-temperature homogenized model usi...

The fully ceramic microencapsulated (FCM) fuel, one of the accident tolerant fuel (ATF) concepts, consists of TRISO particles randomly dispersed in SiC matrix. This high heterogeneity in compositions leads to difficulty in explicit thermal calculation of such a fuel. For thermal analysis of a fuel element in very high temperature reactors (VHTRs) w...

Due to randomly distributed fuel particles in the compact fuel, block type VHTRs present a significant challenge for geometric modeling. Such a complicated structure will definitely affect temperature profiles in the fuel element. Recently, a two-temperature homogenized model developed by the particle transport Monte Carlo method was proposed that...