• 제목/요약/키워드: annulus

검색결과 487건 처리시간 0.023초

An Experimental Study on Heat Transfer Characteristics Just Before Critical Heat Flux in Uniformly Heated Vertical Annulus Under a Wide Range of Pressures

  • Chun, Se-Young;Moon, Sang-Ki;Chung, Heung-June;Chung, Moon-Ki
    • Nuclear Engineering and Technology
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    • 제34권4호
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    • pp.269-285
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    • 2002

  • Water heat transfer experiments were carried out in a uniformly heated annulus with a wide range of pressure conditions. The local heat transfer coefficients for saturated water (low boiling have been measured just before the occurrence of the critical heat flux (CHF) along the length of the heated section. The trends of the measured heat transfer coefficients were quite different from the conventional understanding for the heat transfer of saturated flow boiling. This discrepancy was explained from the nucleate boiling in the liquid film of annular flow under high heat flux conditions. The well-known correlations were compared with the measured heat transfer coefficients. The Shah and Kandlikar correlations gave better prediction than the Chen correlation. However, the modified Chen correlation proposed in the present work showed the best agreement with the present data among correlations examined .

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Radiation damage to Ni-based alloys in Wolsong CANDU reactor environments

  • Kwon, Junhyun;Jin, Hyung-Ha;Lee, Gyeong-Geun;Park, Dong-Hwan
    • Nuclear Engineering and Technology
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    • 제51권3호
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    • pp.915-921
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    • 2019

  • Radiation damage due to neutrons has been calculated in Ni-based alloys in Wolsong CANDU reactor environments. Two damage parameters are considered: displacement damage, and transmutation gas production. We used the SPECTER and SRIM computer codes in quantifying radiation damage. In addition, damage caused by Ni two-step reactions was considered. Estimations were made for the annulus spacers in a CANDU reactor that are located axially along a fuel channel and made of Inconel X-750. The calculation results indicate that the transmutation gas production from the Ni two-step reactions is predominant as the effective full power year increases. The displacement damage due to recoil atoms produced from Ni two-step reactions accounts for over 30% out of the total displacement damage.

  • https://doi.org/10.1016/j.net.2018.11.015 인용 PDF KSCI