Maximum Temperature Calculation and Operational Characteristics of Fuel Follower Control Rods for the AFRRI TRIGA Reactor Facility

1991 ◽  
Author(s):  
M. Forsbacka ◽  
M. Moore
Keyword(s):  
Maximum Temperature ◽  
Reactor Facility ◽  
Triga Reactor ◽  
Temperature Calculation ◽  
Operational Characteristics ◽  
Control Rods

Production of 37Ar in The University of Texas TRIGA reactor facility

2011 ◽  
Vol 291 (1) ◽  
pp. 257-260 ◽  
Author(s):  
Christine M. Egnatuk ◽  
Justin Lowrey ◽  
Steven R. Biegalski ◽  
Theodore Bowyer ◽  
Derek Haas ◽  
...  
Keyword(s):  
Reactor Facility ◽  
Triga Reactor ◽  
University Of Texas ◽  
The University

Numerical Study on Multiscale Heat Conduction Problems in Very High Temperature Reactor Fuel Pebble Based on OpenFOAM

2021 ◽  
Author(s):  
Jincheng Wang ◽  
Ming Ding
Keyword(s):  
Heat Conduction ◽  
High Temperature ◽  
Numerical Study ◽  
Maximum Temperature ◽  
Conduction Model ◽  
Heat Conduction Model ◽  
Temperature Calculation ◽  
Very High Temperature Reactor ◽  
High Temperature Reactor ◽  
Very High

Abstract Pebble bed very high temperature reactor (VHTR) has been identified as one of six Generation-IV (Gen-IV) types of reactor which could operate at a high thermal power. The calculation of the temperature in the fuel pebble is a key part of VHTR thermal hydraulics numerical simulation. However, due to the special structure of the VHTR fuel pebble, the temperature calculation involves a multiscale problem. The multiscale heat conduction model includes mesoscale temperature of fuel pebble and microscale temperature of TRISO fuel particles calculation. To deal with the particularity of temperature calculation of the fuel pebble, this paper presents a multiscale heat conduction model based on an open source CFD package OpenFOAM. Firstly, the quasi steady state heat conduction method (QSSHC) and homogeneous layers method (HL) was verified by a simple multiscale model. The results show that the QSSHC method has a good ability of multiscale temperature prediction. Secondly, the mesoscale temperature distribution and the maximum temperature in the microscale of VHTR fuel pebbled are calculated with QSSHC method based on OpenFOAM. This multiscale solver will be couple with other solvers of OpenFOAM, to provide a new perspective of VHTR simulation.

scholarly journals Usage of multiple fission cells for neutron flux measurements during rod-insertion method

2020 ◽  
Vol 225 ◽  
pp. 04024
Author(s):  
Igor Lengar ◽  
Sebastjan Rupnik ◽  
Andrej Žohar ◽  
Vid Merljak ◽  
Marjan Kromar ◽  
...  
Keyword(s):  
Neutron Flux ◽  
Nuclear Power ◽  
Physical Parameters ◽  
Ionization Chambers ◽  
Triga Reactor ◽  
Control Rod ◽  
Multiple Fission ◽  
Insertion Method ◽  
Flux Measurements ◽  
Control Rods

The measurements of physical parameters of the TRIGA reactor and Nuclear power plant Krško (NEK) reactor cores have been in the past performed on hand of the neutron flux signal obtained from uncompensated ionization cells and by employment of the a digital meter of reactivity (DMR). At the TRIGA reactor only one ionization cell is currently used for flux measurements. During the insertion of one control rod the neutron flux distribution is significantly altered affecting the flux measurements of inserting different control rods. The problem is presently solved by assigning a correction factor to each control rod what introduces an additional uncertainty. In the present paper the implementation of four fission cells for reactivity measurements is presented. In this way determining the correct gamma background and its subtraction, performed by DMR algorithms, becomes less important as previously by using ionization chambers. The larger number of detectors also reduces the flux redistribution effects on the signal during individual control rod movements.

Analysis of Characteristics of LED Lamps with T8 Bulb by Various Manufacturers

2019 ◽  
pp. 82-87
Author(s):  
Nina P. Nestyorkina ◽  
Olga Yu. Kovalenko ◽  
Yulia A. Zhuravlyova
Keyword(s):  
Supply Voltage ◽  
Luminous Flux ◽  
Supply Network ◽  
Operational Characteristics ◽  
Nominal Voltage ◽  
Electric Parameters ◽  
The Moment ◽  
Colour Rendering

The article analyses the operational characteristics of 10W LED lamps with T8 bulb manufactured by ASD (Russia), Smartbuy (Taiwan), and VOLPE (PRC) and 18W FL with T8 bulb manufactured by PHILIPS (Poland) including the dependence of these lamps on the supply voltage. The results of measurements show that: a) the period of stabilisation of electric parameters and luminous flux of LED lamps does not cause discomfort of illumination unlike the said FL, the luminous flux of which at the moment of switching on is 70 % of the nominal value, which is reached after 13 minutes; b) with nominal voltage of supply network, the value of luminous flux of 10W ASD LED-T8R-STD LED lamp (Russia) is 6 % less than the declared one, and that of Smartbuy SBL-T8-10-64K-A (Taiwan) and VOLPE LED-T8-10W/DW/G13/FR/FIX/N (PRC) is even less; c) the general colour rendering index of all studied LED lamps is less than the declared one (72 instead of 80); d) the flicker index of all studied LED lamps does not exceed the declared value of 5 %; e) the characteristics of LED lamps almost do not depend on changes of the supply voltage within the range of ±10 %. The recommendations regarding the application of the studied LED lamps are given.

Reconstruction of maximum temperature on Zhegu Mountain, western Sichuan Plateau (China)

2020 ◽  
Vol 81 ◽  
pp. 1-14
Author(s):  
M Keyimu ◽  
Z Li ◽  
Y Zhao ◽  
Y Dong ◽  
B Fu ◽  
...  
Keyword(s):  
Tree Growth ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Southwestern China ◽  
Maximum Temperature ◽  
Driving Mechanism ◽  
Western Sichuan ◽  
Relationship Analysis ◽  
Decadal Scale ◽  
Thermal Variability

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon fir Abies fargesii var. faxoniana at the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.

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