scholarly journals The Possibilities of Fission Material Reproduction Increase in Thermal Reactor with the Assemblies with a Hard Neutron Spectrum

2011 ◽  
Vol 2011 ◽  
pp. 1-4
Author(s):  
Vladimir M. Kotov ◽  
Anna S. Sergeeva ◽  
Ruslan A. Irkimbekov ◽  
Vladislav I. Suprunov
Keyword(s):  
Energy Distribution ◽  
Major Part ◽  
Construction Materials ◽  
Reactor Core ◽  
Thermal Reactor ◽  
Fast Neutrons ◽  
Neutron Sources ◽  
Fission Spectrum ◽  
Reactor Criticality ◽  
Neutron Leakage

This paper addresses the problem of fission material reproduction increase in thermal reactors. Reproduction increase is achieved while decreasing the fission material content in the fuel. In that case, a decrease of neutron loss in construction materials and a neutron leakage decrease are required for obtaining reactor criticality. Effectiveness of the reactor functioning can be increased by the use of additional neutron sources, for example, n-2n reaction in beryllium framing. The possibility of additional neutron source development with the use of fast neutrons with an energy distribution close to the fission spectrum in the major part of thermal reactor core is researched in this paper.

Calculation studies of coated particles performance in sodium-cooled fast reactor

Kerntechnik ◽  
2021 ◽  
Vol 86 (1) ◽  
pp. 45-49
Author(s):  
N. V. Maslov ◽  
E. I. Grishanin ◽  
P. N. Alekseev
Keyword(s):  
Fast Reactor ◽  
Reactor Core ◽  
Heat Removal ◽  
Design Solution ◽  
Fast Neutrons ◽  
Steel Shell ◽  
Primary Circuit ◽  
Coated Particles ◽  
The Core ◽  
Fuel Assemblies

Abstract This paper presents results of calculation studies of the viability of coated particles in the conditions of the reactor core on fast neutrons with sodium cooling, justifying the development of the concept of the reactor BN with microspherical fuel. Traditional rod fuel assemblies with pellet MOX fuel in the core of a fast sodium reactor are directly replaced by fuel assemblies with micro-spherical mixed (U,Pu)C-fuel. Due to the fact that the micro-spherical (U, Pu)C fuel has a developed heat removal surface and that the design solution for the fuel assembly with coated particles is horizontal cooling of the microspherical fuel, the core has additional possibilities of increasing inherent (passive) safety and improve the competitiveness of BN type of reactors. It is obvious from obtained results that the microspherical (U, Pu)C fuel is limited with the maximal burn-up depth of ∼11% of heavy atoms in conditions of the sodium-cooled fast reactor core at the conservative approach; it gives the possibility of reaching stated thermal-hydraulic and neutron-physical characteristics. Such a tolerant fuel makes it less likely that fission products will enter the primary circuit in case of accidents with loss of coolant and the introduction of positive reactivity, since the coating of microspherical fuel withstands higher temperatures than the steel shell of traditional rod-type fuel elements.

Integral measurement of spectrum-averaged cross sections of a few threshold reactions induced by fast neutrons of a TRIGA reactor: comparison with integrated data from excitation functions given in various data libraries

2020 ◽  
Vol 108 (7) ◽  
pp. 511-516
Author(s):  
Md. Shuza Uddin ◽  
K. A. Rafee ◽  
S. M. Hossain ◽  
R. Khan ◽  
S. M. Qaim
Keyword(s):  
Excitation Function ◽  
Cross Sections ◽  
Fast Neutrons ◽  
Integral Test ◽  
Triga Reactor ◽  
Fission Spectrum ◽  
Data Libraries ◽  
First Time ◽  
Prompt Fission ◽  
Fast Neutron Spectrum

AbstractIntegral cross sections of the reactions 24Mg(n,p)24Na, 27Al(n,p)27Mg, 27Al(n,α)24Na, 58Ni(n,d + np)57Co and 60Ni(n,p)60Co were measured for the first time using the fast neutron spectrum of a TRIGA reactor extending from 0.5 to 20 MeV. The values obtained in this work were comparable with the recommended values for a pure 235U prompt fission spectrum. The measured integral value was utilized for integral test of excitation function of each reaction given in some data libraries, namely ENDF/B-VIII.0, TENDL-2017, IRDFF-1.05 and ROSFOND-2010. The integral measurements are generally consistent with the integrated values within 5 %, except for a few cases, e. g. the reaction 60Ni(n,p)60Co, where the data libraries appear to need improvement.

Electronics for Instrumentation and Controls in Accelerator Driven Sub-Critical System

2016 ◽  
Author(s):  
Wenjuan Cui ◽  
Zhiyong He ◽  
Qiang Zhao ◽  
Yichuan He ◽  
Yuxi Luo
Keyword(s):  
Radiation Effects ◽  
Reactor Core ◽  
High Energy ◽  
Nuclear Industry ◽  
Fast Neutrons ◽  
Critical System ◽  
Energy Beam ◽  
Single Event Upsets ◽  
Commercial Off The Shelf ◽  
Critical Reactor

In this paper, we study the electronics in the instrumentation and control (I&C) systems for an accelerator driven sub-critical (ADS) system, where a target located at the centre of a sub-critical reactor core is bombarded by the protons from an accelerator. In comparison with a commercial reactor used in nuclear industry, more control electronics are required to exactly couple the high-energy beam from the accelerator to the spallation target in the reactor core. There is a strong drive to utilize standard commercial-off-the-shelf devices to minimize cost and development time. In order to improve the reliability of I&C systems, redundancy architecture has been considered by adding more electronic devices. In comparison with I&C system without redundancy, the dual redundancy architecture improves the reliability of the system by 20000 times. Then, we study the potential application of electronics devices, such as the preamplifiers for detectors, in the reactor building by shielding them with shielding materials. Since the most effective neutrons in creating radiation damages are those fast neutrons with the energy of more than 0.1 MeV, we have proposed a sandwich shielding method to reduce the neutron-induced radiation effects, in which the first and third layers are made of polyethylene and the second layer is made of heavy metal, e.g. tungsten. Simulation results with GEANT4 code have indicated that the shielding with a 30 cm-thick sandwich can increase the expected lifetime of electronics by 1258 times, and can reduce the soft errors caused by single event upsets by 5400 times.

scholarly journals Fast neutron spectrum unfolding of a TRIGA Mark II reactor and measurement of spectrum-averaged cross sections: integral tests of differential cross sections of neutron threshold reactions

2013 ◽  
Vol 101 (10) ◽  
pp. 613-620 ◽  
Author(s):  
M. S. Uddin ◽  
S. Sudár ◽  
S. M. Hossain ◽  
R. Khan ◽  
M. A. Zulquarnain ◽  
...  
Keyword(s):  
Fast Neutron ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Neutron Field ◽  
Fast Neutrons ◽  
Metal Foils ◽  
Spectrum Unfolding ◽  
Fission Spectrum ◽  
Data Files ◽  
Triga Mark Ii

Summary The spectrum of fast neutrons having energies from 0.5 to 20 MeV in the core of the 3MW TRIGA Mark II reactor at Savar, Dhaka, Bangladesh, was unfolded by activating several metal foils to induce threshold nuclear reactions covering the whole spectrum, and then doing necessary iterative calculations utilizing the activation results and the code SULSA. The analysed shape of the spectrum in the TRIGA core was found to be similar to that of the pure 235U-fission spectrum, except for the energies between 0.5 and 1.5 MeV, where it was slightly higher than the fission spectrum. Spectrum-averaged cross sections were determined by integral measurements. The integral values measured in this work were compared with the recommended values for a pure fission spectrum as well as with the integrated data deduced from measured and evaluated excitation functions of a few reactions given in some data files. The good agreement between integral measurements and integrated data in case of well-investigated reactions shows that the fast neutron field at the TRIGA Mark II reactor can be used for validation of evaluated data of neutron threshold reactions.

PREPARATION AND CHARACTERISTICS OF A POLONIUM–BERYLLIUM NEUTRON SOURCE

1950 ◽  
Vol 28a (1) ◽  
pp. 60-66 ◽  
Author(s):  
J. W. T. Spinks ◽  
G. A. R. Graham
Keyword(s):  
Angular Distribution ◽  
Neutron Source ◽  
Fast Neutrons ◽  
Emission Data ◽  
Γ Radiation ◽  
Neutron Sources ◽  
Decay Products

The preparation of a polonium–beryllium sandwich containing 2.1 c. of polonium is described. The source emits 2 × 106 neutrons per second and its γ radiation is approximately equivalent to that of 0.2 mgm. radium in equilibrium with its decay products. Polar diagrams for the angular distribution of the fast neutrons are given. Emission data for two similar neutron sources, containing 3.2 and 3.5 c. polonium respectively, are given.

Energy distribution of fast neutrons in the F-1 uranium-graphite reactor

1980 ◽  
Vol 48 (3) ◽  
pp. 219-220
Author(s):  
V. A. Kanareikin ◽  
V. M. Tyryshkin ◽  
V. S. Yuzgin
Keyword(s):  
Energy Distribution ◽  
Fast Neutrons ◽  
Graphite Reactor
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