Park Ho Jin

The purpose of this paper is to present the Monte Carlo (MC) method augmented by the B1 spectrum to generate few-group diffusion theory constants, to assess their qualification in terms of the core depletion analysis, and thus to validate the MC method implemented into the Seoul National University MC code, McCARD, as a few-group diffusion theory constant generator. To do so, two-step core neutronics analyses are conducted for two types of power reactors, pressurized water reactors and very high

We examined the temperature ($T$) evolution of the optical conductivity spectra of ${Sr}_{3}$${Ir}_{2}$${O}_{7}$ over a wide range of 10--400 K. The system was barely insulating, exhibiting a small indirect bandgap of $\ensuremath{\le}$0.1 eV. The low-energy features of the optical d-d excitation ($\ensuremath{\hbar}\ensuremath{\omega}$ 0.3 eV) evolved drastically, whereas such evolution was not observed for the O $K$-edge x-ray-absorption spectra. This suggests that the $T$ evolution in optical

A new formulation aimed at quantifying uncertainties of Monte Carlo (MC) tallies such as keff and the microscopic reaction rates as well as nuclide number density estimates in MC depletion analysis is presented. It is shown that when the two major MC inputs - the microscopic cross sections and nuclide number densities - are assumed to have uncertainties, the variance of a given MC tally used as a measure of its uncertainty in this formulation arises from four sources: the statistical uncertainty

We report an optical spectroscopic study of $\mathrm{SrMnS}{\mathrm{b}}_{2}$, a low-carrier-density metal. As temperature is decreased, our measurements reveal a large increase in the quasiparticle plasma frequency, which is highly unusual for a metal. This seemingly anomalous behavior can be accounted for using a ``three-band'' model of the multiband electronic structure of $\mathrm{SrMnS}{\mathrm{b}}_{2}$ that includes two conduction bands and one valence band. The second conduction band is as

The BEAVRS (Benchmark for Evaluation and Validation of Reactor Simulation) benchmark calculations were performed by DeCART stand-alone and DeCART/MATRA multi-physics coupled code system to verify their accuracy. The solutions of DeCART stand-alone calculations for the control rod bank worth, detector signal, isothermal temperature coefficient, and critical boron concentration agreed very well with the measurements. The root-mean-square errors of the boron letdown curves for two-cycles were less

For an efficient Monte Carlo (MC) burnup analysis, an accurate high-order depletion scheme to consider the nonlinear flux variation in a coarse burnup-step interval is crucial accompanied with an accurate depletion equation solver. In a Seoul National University MC code, McCARD, the high-order depletion schemes of the quadratic depletion method (QDM) and the linear extrapolation/quadratic interpolation (LEQI) method and a depletion equation solver by the Chebyshev rational approximation method (

The electrodynamics of free carriers in the semimetallic Dirac material $\mathrm{SrMnB}{\mathrm{i}}_{2}$ was investigated using optical spectroscopy and first-principles calculations. Using a two-carrier-model analysis, the total free-carrier response was successfully decomposed into individual contributions from Dirac fermions and non-Dirac free carriers. Possible roles of chiral pseudospin, spin-orbit interaction (SOI), antiferromagnetism, and electron-phonon $(e\text{\ensuremath{-}}ph)$ coupl

In this study, a cross section stochastic sampling (S.S.) capability is implemented into both the McCARD continuous energy Monte Carlo code and MIG multiple-correlated data sampling code. The ENDF/B-VII.1 covariance data based 30 group cross section sets and the SCALE6 covariance data based 44 group cross section sets are sampled by the MIG code. Through various uncertainty quantification (UQ) benchmark calculations, the McCARD/MIG results are verified to be consistent with the McCARD stand-alon

In the Monte Carlo (MC) burnup analyses, the uncertainty of a tally estimate at a burnup step may be induced from four sources: the statistical uncertainty caused by a finite number of simulations, the nuclear covariance data, uncertainties of number densities, and cross-correlations between the nuclear data and the number densities. In this paper, the uncertainties of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:msub><mml:mi>k</mml:mi><mml:mrow><mml:mtext>inf</

AbstractThe B1 theory-augmented Monte Carlo (MC) method has been recently presented as a new MC method to generate homogenized few-group diffusion theory constants (FGCs) of nuclear systems such as a fuel pin cell or a fuel assembly (FA). It is demonstrated that it can produce FGCs that are well qualified for highly accurate two-step core neutronics analyses. However, it is unavoidable for FGCs from it to carry uncertainties that are ascribed to statistical uncertainties, as well as nuclear cros