• 제목/요약/키워드: Nuclear engineering

검색결과 9,856건 처리시간 0.058초

A new approach to determine batch size for the batch method in the Monte Carlo Eigenvalue calculation

  • Lee, Jae Yong;Kim, Do Hyun;Yim, Che Wook;Kim, Jae Chang;Kim, Jong Kyung
    • Nuclear Engineering and Technology
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    • 제51권4호
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    • pp.954-962
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    • 2019

  • It is well known that the variance of tally is biased in a Monte Carlo calculation based on the power iteration method. Several studies have been conducted to estimate the real variance. Among them, the batch method, which was proposed by Gelbard and Prael, has been utilized actively in many Monte Carlo codes because the method is straightforward, and it is easy to implement the method in the codes. However, there is a problem when utilizing the batch method because the estimated variance varies depending on batch size. Often, the appropriate batch size is not realized before the completion of several Monte Carlo calculations. This study recognizes this shortcoming and addresses it by permitting selection of an appropriate batch size.

  • https://doi.org/10.1016/j.net.2019.01.007 인용 PDF KSCI

A fast gamma-ray dose rate assessment method for complex geometries based on stylized model reconstruction

  • Yang, Li-qun;Liu, Yong-kuo;Peng, Min-jun;Li, Meng-kun;Chao, Nan
    • Nuclear Engineering and Technology
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    • 제51권5호
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    • pp.1436-1443
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    • 2019

  • A fast gamma-ray dose rate assessment method for complex geometries based on stylized model reconstruction and point-kernel method is proposed in this paper. The complex three-dimensional (3D) geometries are imported as a 3DS format file from 3dsMax software with material and radiometric attributes. Based on 3D stylized model reconstruction of solid mesh, the 3D-geometrical solids are automatically converted into stylized models. In point-kernel calculation, the stylized source models are divided into point kernels and the mean free paths (mfp) are calculated by the intersections between shield stylized models and tracing ray. Compared with MCNP, the proposed method can implement complex 3D geometries visually, and the dose rate calculation is accurate and fast.

  • https://doi.org/10.1016/j.net.2019.03.004 인용 PDF KSCI

Use of big data for estimation of impacts of meteorological variables on environmental radiation dose on Ulleung Island, Republic of Korea

  • Joo, Han Young;Kim, Jae Wook;Jeong, So Yun;Kim, Young Seo;Moon, Joo Hyun
    • Nuclear Engineering and Technology
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    • 제53권12호
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    • pp.4189-4200
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    • 2021

  • In this study, the relationship between the environmental radiation dose rate and meteorological variables was investigated with multiple regression analysis and big data of those variables. The environmental radiation dose rate and 36 different meteorological variables were measured on Ulleung Island, Republic of Korea, from 2011 to 2015. Not all meteorological variables were used in the regression analysis because the different meteorological variables significantly affect the environmental radiation dose rate during different periods, and the degree of influence changes with time. By applying the Pearson correlation analysis and stepwise selection methods to the big dataset, the major meteorological variables influencing the environmental radiation dose rate were identified, which were then used as the independent variables for the regression model. Subsequently, multiple regression models for the monthly datasets and dataset of the entire period were developed.

  • https://doi.org/10.1016/j.net.2021.07.001 인용 PDF KSCI

Dynamics and control of molten-salt breeder reactor

  • Singh, Vikram;Lish, Matthew R.;Chvala, Ondrej;Upadhyaya, Belle R.
    • Nuclear Engineering and Technology
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    • 제49권5호
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    • pp.887-895
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    • 2017

  • Preliminary results of the dynamic analysis of a two-fluid molten-salt breeder reactor (MSBR) system are presented. Based on an earlier work on the preliminary dynamic model of the concept, the model presented here is nonlinear and has been revised to accurately reflect the design exemplified in ORNL-4528. A brief overview of the model followed by results from simulations performed to validate the model is presented. Simulations illustrate stable behavior of the reactor dynamics and temperature feedback effects to reactivity excursions. Stable and smooth changes at various nodal temperatures are also observed. Control strategies for molten-salt reactor operation are discussed, followed by an illustration of the open-loop load-following capability of the molten-salt breeder reactor system. It is observed that the molten-salt breeder reactor system exhibits "self-regulating" behavior, minimizing the need for external controller action for load-following maneuvers.

  • https://doi.org/10.1016/j.net.2017.06.003 인용 PDF KSCI