• Title/Summary/Keyword: mcnp

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Gamma Ray Shielding Study of Barium-Bismuth-Borosilicate Glasses as Transparent Shielding Materials using MCNP-4C Code, XCOM Program, and Available Experimental Data

  • Bagheri, Reza;Moghaddam, Alireza Khorrami;Yousefnia, Hassan
    • Nuclear Engineering and Technology
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    • v.49 no.1
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    • pp.216-223
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    • 2017
  • In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and $10^{th}$ value layer values of barium-bismuth-borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium-bismuth-borosilicate glasses have good gamma ray shielding properties from the shielding point of view.

Assessment of Dose Distribution using the MIRD Phantom at Uterine Cervix and Surrounding Organs in High Doserate Brachytheraphy (자궁주위 방사선 근접치료시 MIRD 팬텀을 이용한 주변장기의 피폭환경평가)

  • Lee, Yun-Jong;Nho, Young-Chang;Lee, Jai-Ki
    • Korean Journal of Environmental Biology
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    • v.24 no.4
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    • pp.387-391
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    • 2006
  • Computational and experimental dosimetry of Henschke applicator with respect to high dose rate brachytherapy using the MIRD phantom and a remote control afterloader were performed. A comparison of computational dosimetry was made between the simulated Monte Carlo dosimetry and GAMMADOT brachytherapy Planning system's dosimetry. Dose measurements was performed using ion chamber in a water phantom. Dose rates are calculated using Monte Carlo code MCNP4B and the GAMMADOT. Thecomputational models include the detailed geometry of Ir-192 source, tandem tube, and shielded ovoids for accurate estimation. And transit dose delivered during source extension to and retraction from a given dwell position was estimated by Monte Carlo simulations. Point doses at ICRU bladder/rectal pointswhich have been recommened by ICRU 38 was assessed. Calculated and measured dose distribution data agreed within 4% each other. The shielding effect of ovoids leads to 19% and 20% dose reduction at bladder surface and rectal points.

Response characterization of slim-hole density sonde using Monte Carlo method (Monte Carlo 방법을 이용한 소구경용 밀도 존데의 반응 특성)

  • Won, Byeongho;Hwang, Seho;Shin, Jehyun;Park, Chang Je;Kim, Jongman;Hamm, Se-Yeong
    • Geophysics and Geophysical Exploration
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    • v.17 no.3
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    • pp.155-162
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    • 2014
  • We performed MCNP modeling for density log, and examined its reliability and validity comparing the correction curves from physical borehole model. Based on the constructed numerical model, numerical modelings of density sonde in three-inch borehole were carried out under the various conditions such as the existence and type of casing or fluid, and also the stand-off between the sonde and borehole wall. These results of numerical modeling quantitatively reflect effects of casing and fluid in borehole, and moreover, demonstrate constant patterns with interval change from borehole wall. From this study, numerical modeling using MCNP shows a good applicability for well logging, and therefore, can be efficiently used for the calibration of well logging data under the various borehole conditions.

Kinetics calculation of fast periodic pulsed reactors using MCNP6

  • Zhon, Z.;Gohar, Y.;Talamo, A.;Cao, Y.;Bolshinsky, I.;Pepelyshev, Yu N.;Vinogradov, Alexander
    • Nuclear Engineering and Technology
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    • v.50 no.7
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    • pp.1051-1059
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    • 2018
  • Fast periodic pulsed reactor is a type of reactor in which the fission bursts are formed entirely with external reactivity modulation with a specified time periodicity. This type of reactors could generate much larger intensity of neutron beams for experimental use, compared with the steady state reactors. In the design of fast periodic pulsed reactors, the time dependent simulation of the power pulse is majorly based on a point kinetic model, which is known to have limitations. A more accurate calculation method is desired for the design analyses of fast periodic pulsed reactors. Monte Carlo computer code MCNP6 is used for this task due to its three dimensional transport capability with a continuous energy library. Some new routines were added to simulate the rotation of the movable reflector parts in the time dependent calculation. Fast periodic pulsed reactor IBR-2M was utilized to validate the new routines. This reactor is periodically in prompt supercritical state, which lasts for ${\sim}400{\mu}s$, during the equilibrium state. This generates long neutron fission chains, which requires tremendously large amount of computation time during Monte Carlo simulations. Russian Roulette was applied for these very long neutron chains in MCNP6 calculation, combined with other approaches to improve the efficiency of the simulations. In the power pulse of the IBR-2M at equilibrium state, there is some discrepancy between the experimental measurements and the calculated results using the point kinetics model. MCNP6 results matches better the experimental measurements, which shows the merit of using MCNP6 calculation relative to the point kinetics model.