Experimental Analyses of 243Am and 235U Fission Reaction Rates at Kyoto University Critical Assembly

The partition of the total excitation energy between the fission fragments for the n th +235 U and n(En = 5.55 MeV)+235 U fission reactions are analyzed with the experimental data available. Our results show that the total excitation energy is not shared by the fragments in proportion of their masses but support the so-called energy sorting-mechanism. The temperature of the heavy fragment is generally lower than that of the light one when the shell effect does not play a strong role. As soon as the mass of heavy fragment closes to 132, its temperature becomes higher than the complementary light one because of strong shell effect. Our results also show that the heavy fragments gain more energy than the complementary light ones when the incident neutron energy increases.

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Measurement of 237Np Fission Rate Ratio Relative to 235U Fission Rate in Cores with Various Thermal Neutron Spectrum at the Kyoto University Critical Assembly.

Journal of Nuclear Science and Technology ◽

10.3327/jnst.37.627 ◽

2000 ◽

Vol 37 (8) ◽

pp. 627-635 ◽

Cited By ~ 7

Author(s):

Hironobu UNESAKI ◽

Tomohiko IWASAKI ◽

Takanori KITADA ◽

Akio KOHASHI ◽

Daisuke FUJIWARA ◽

...

Keyword(s):

Thermal Neutron ◽

Neutron Spectrum ◽

Rate Ratio ◽

Critical Assembly ◽

Fission Rate ◽

235U Fission ◽

Thermal Neutron Spectrum

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Axial Distributions of Fission Reaction Rates in the Annular Core of the ASTRA Critical Facility with Poison Profiling Elements in the Internal Reflector

Physics of Atomic Nuclei ◽

10.1134/s1063778821080147 ◽

2021 ◽

Vol 84 (8) ◽

pp. 1397-1404

Author(s):

V. A. Nevinitsa ◽

V. F. Boyarinov ◽

P. A. Fomichenko ◽

A. A. Zimin ◽

A. E. Glushkov ◽

...

Keyword(s):

Reaction Rates ◽

Fission Reaction

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Determination of the relative fission reaction rates for different isotopes by recording the ?-radiation of La140 fission fragments

Soviet Atomic Energy ◽

10.1007/bf01116109 ◽

1965 ◽

Vol 18 (5) ◽

pp. 665-666

Author(s):

L. N. Yurova ◽

A. V. Bushuev

Keyword(s):

Reaction Rates ◽

Fission Reaction ◽

Fission Fragments

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Verification of the stationary module of the ShIPR software system for modelling experiments of the ASTRA HTGR type critical facility

Kerntechnik ◽

10.1515/kern-2020-850103 ◽

2020 ◽

Vol 85 (1) ◽

pp. 4-8

Author(s):

M. N. Zizin ◽

V. F. Boyarinov ◽

V. A. Nevinitsa ◽

P. A. Fomichenko ◽

Yu. N. Volkov ◽

...

Keyword(s):

Cross Sections ◽

Nuclear Reactors ◽

Reaction Rates ◽

Automatic Generation ◽

Hydraulic Calculation ◽

Monte Carlo Code ◽

Fission Reaction ◽

Development Environment ◽

Transient Conditions ◽

Control Rods

Abstract Coupled neutronic and thermal hydraulic calculation codes are verified for calculating the design of modern and prospective types of nuclear reactors. This verification is done by comparing experimental and calculated results for stationary and transient conditions. This paper presents ShIPR (Shell of Intelligent Package for Reactor) Integrated Development Environment with automatic generation of head programs based on the chain of computational modules. The aim of this study is to find the reason of a discrepancy in the modelling of sub-critical states that was found in previous work. The comparison of ShIPR stationary module with Monte-Carlo code (MCU) and experimental results on ASTRA HTGR critical facility was presented in the paper. To compare the detector readings and MCU calculation with the ShIPR module, the interpolation cross-section procedure was performed. This procedure allows simulating 235U fission reaction rates (detector readings) in the complicate, annular core, using the micro-cross sections prepared by the cell-lattice code. We found that the calculation accuracy of stationary ShIPR module is on an acceptable level but the macro constants for control rods need to be prepared independently, given with surroundings.

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Subcritical Multiplication Parameters of the Accelerator-Driven System with 100 MeV Protons at the Kyoto University Critical Assembly

Science and Technology of Nuclear Installations ◽

10.1155/2012/395878 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 5

Author(s):

Jae-Yong Lim ◽

Cheol Ho Pyeon ◽

Takahiro Yagi ◽

Tsuyoshi Misawa

Keyword(s):

Reaction Rate ◽

Reaction Rates ◽

Relative Difference ◽

Critical Assembly ◽

The Core ◽

Driven System ◽

Accelerator Driven System ◽

Special Mention ◽

Basic Experiments ◽

Mev Protons

Basic experiments on the accelerator-driven system (ADS) at the Kyoto University Critical Assembly are carried out by combining a solid-moderated and -reflected core with the fixed-field alternating gradient accelerator. The reaction rates are measured by the foil activation method to obtain the subcritical multiplication parameters. The numerical calculations are conducted with the use of MCNPX and JENDL/HE-2007 to evaluate the reaction rates of activation foils set in the core region and at the location of the target. Here, a comparison between the measured and calculated eigenvalues reveals a relative difference of around 10% in C/E values. A special mention is made of the fact that the reaction rate analyses in the subcritical systems demonstrate apparently the actual effect of moving the tungsten target into the core on neutron multiplication. A series of further ADS experiments with 100 MeV protons needs to be carried out to evaluate the accuracy of subcritical multiplication parameters.

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