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Ohgama, Kazuya; Hazama, Taira; Katagiri, Hiroki*; Takegoshi, Atsushi*; Mori, Tetsuya
Nuclear Technology, 210(8), p.1336 - 1353, 2024/08
Times Cited Count：1 Percentile：57.00(Nuclear Science & Technology)In the prototype fast breeder reactor Monju, reaction rate distributions of fission reaction rates of 
Pu, 
U and 
U, and capture reaction rate of U were measured by using activation foils during its system startup test. The measurements in the core and radial blanket regions were evaluated in detail, and their reliability and usefulness as the validation data for fast reactor neutronics design methodologies were examined through a comparison with calculations. The reaction rate data measured in Monju were confirmed all reliable and useful as the validation data. The fission reactions of Pu, U, and U can be validated with an accuracy of a few percent in the core and blanket regions. The capture reaction of U in the core region also can be validated with a similar accuracy, whereas a precise calculation of the foil cross section is necessary to consider resonance shielding effects of surrounding fuel pins and a foil.
Ohgama, Kazuya; Takegoshi, Atsushi*; Katagiri, Hiroki; Hazama, Taira
Nuclear Technology, 208(10), p.1619 - 1633, 2022/10
Times Cited Count：4 Percentile：53.26(Nuclear Science & Technology)Ohgama, Kazuya; Katagiri, Hiroki; Takegoshi, Atsushi*; Hazama, Taira
Nuclear Technology, 207(12), p.1810 - 1820, 2021/12
Times Cited Count：4 Percentile：40.86(Nuclear Science & Technology)Ohgama, Kazuya; Takegoshi, Atsushi; Katagiri, Hiroki*; Hazama, Taira
Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 8 Pages, 2019/05
Taninaka, Hiroshi; Takegoshi, Atsushi; Kishimoto, Yasufumi*; Mori, Tetsuya; Usami, Shin
Progress in Nuclear Energy, 101(Part C), p.329 - 337, 2017/11
Times Cited Count：4 Percentile：25.44(Nuclear Science & Technology)The present paper describes the evaluation of the power reactivity loss data obtained in the Japanese prototype fast breeder reactor Monju. The most recent analysis on the power reactivity loss measurement (Takano, et al., 2008) is updated considering the following findings: (a) in-core temperature distribution effect, (b) crystalline binding effect, (c) logarithmic averaging of the fuel temperature, (d) localized fuel thermal elongation effect, (e) updated Japanese Evaluated Nuclear Data Library, JENDL-4.0, and (f) refined corrections on the measured value. The influences of the updates are quantitatively identified and the most precise and probable C/E value is derived together with a thorough uncertainty evaluation. As a result, it is revealed that the analysis overestimates the measurement by 4.6% for the measurement uncertainty of 2.0%. The discrepancy is reduced to as small as 1.1% when the core bowing effect is considered, which implies the importance of the core bowing effect in the calculation of the power reactivity loss.
Kitano, Akihiro; Takegoshi, Atsushi*; Hazama, Taira
Journal of Nuclear Science and Technology, 53(7), p.992 - 1008, 2016/07
Times Cited Count：10 Percentile：60.04(Nuclear Science & Technology)A feedback reactivity measurement technique was developed based on a reactivity model featuring components that depend on the reactivity coefficients, denoted as reactor power (K
) and reactor vessel inlet temperature (K
). This technique was applied to the feedback reactivity experiment conducted in the Monju system start-up test in May 2010. A thorough evaluation considering all possible biases and uncertainties revealed that the reactivity coefficients can be evaluated with a measurement uncertainty smaller than 3%. The evaluated reactivity coefficients were simulated considering the temperature distribution in the core. The C/E value of K showed good agreement between calculated and measured values within the established uncertainty, and the value of K was consistent with that reported in a previous isothermal temperature coefficient experiment. The measured and calculated fuel subassembly outlet temperatures also agreed well within 0.2
C.
Ohgama, Kazuya; Takegoshi, Atsushi*; Hamase, Erina; Doda, Norihiro; Yamano, Hidemasa; Tanaka, Masaaki
no journal, ,
no abstracts in English
Ohgama, Kazuya; Takegoshi, Atsushi; Katagiri, Hiroki*; Hazama, Taira
no journal, ,
no abstracts in English
