scholarly journals CALCULATION OF THE MODERATOR TEMPERATURE COEFFICIENT OF REACTIVITY FOR MINIATURE NEUTRON SOURCE REACTORS

2012 ◽  
Vol 15 (2) ◽  
pp. 5-14
Author(s):  
Binh Quang Do ◽  
Hai Hoang Nguyen
Keyword(s):  
Temperature Coefficient ◽  
Neutron Source ◽  
Safety Assessment ◽  
Analytical Representation ◽  
Reactor Safety ◽  
Reactor Kinetics ◽  
Average Value ◽  
Different Temperatures ◽  
Reactor Calculation ◽  
Coefficient Of Reactivity

This paper presents results of the evaluated group constants for fuel and other important materials of the Miniature Neutron Source Reactor (MNSR) and the moderator temperature coefficient of reactivity through global reactor calculation. In this study, the group constants were calculated with the WIMSD code and the global reactor calculation is accomplished by the CITATION code. This work also presents a method for evaluation of the moderator temperature coefficient of reactivity at different temperatures and it’s average value in a range of temperatures directly through the values of moderator temperature for MNSRs. This method provides simple analytical representation convenient for reactor kinetics calculation and reactor safety assessment.

scholarly journals CALCULATION OF THE MODERATOR TEMPERATURE COEFFICIENT OF REACTIVITY FOR MINIATURE NEUTRON SOURCE REACTORS

2012 ◽  
Vol 15 (3) ◽  
pp. 26-35
Author(s):  
Binh Quang Do ◽  
Hai Hoang Nguyen
Keyword(s):  
Temperature Coefficient ◽  
Neutron Source ◽  
Safety Assessment ◽  
Analytical Representation ◽  
Reactor Safety ◽  
Reactor Kinetics ◽  
Reactor Calculation ◽  
Coefficient Of Reactivity

This paper presents results of the evaluated group constants for fuel and other important materials of the Miniature Neutron Source Reactor (MNSR) and the moderator temperature coefficient of reactivity through global reactor calculation. In this study, the group constants were calculated with the WIMSD code and the global reactor calculation is accomplished by the CITATION code. This work also presents a method for evaluation of the moderator temperatures directly through the values of moderator temperature for MNSRs. This method provides simple analytical representation convenient for reactor kinetics calculation and reactor safety assessment.

Finite Element Analysis of the Stress on Cylinder of the Fluidized Bed Reactor for Fast Pyrolysis

2011 ◽  
Vol 201-203 ◽  
pp. 660-663
Author(s):  
Qing Ruo Xie ◽  
Yi Sun ◽  
Li Wen Zheng ◽  
Hu Qi Wang ◽  
Zhang Fa Tong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fluidized Bed ◽  
Safety Assessment ◽  
Scale Up ◽  
Fast Pyrolysis ◽  
Fluidized Bed Reactor ◽  
Element Analysis ◽  
Ansys Analysis ◽  
Different Temperatures

A new experimental fluidized bed reactor was investigated and designed which has been widely utilized for fast pyrolysis under different temperatures (T=727–973 K).The stresses of the reactor cylinder are analyzed using finite element method(FEM, ANSYS Inc., U.S.A ) based on the safety assessment, and the cylinder is designed for installing scheme. The result of ANSYS analysis shows that the stress unstable positions are nearby both ends of the cylinder. The results of analysis are shown that the designing stresses are not beyond the allow able ones. So the designing parameters can possess sufficient reliability, and the design scheme can completely satisfy the strength requirement. Certainty of the stress could offered the valuable instruction for the application of the equipment on industrial scale-up.

Transcutaneous carbon dioxide and oxygen tension measured at different temperatures in healthy adults.

1985 ◽  
Vol 31 (10) ◽  
pp. 1611-1615 ◽  
Author(s):  
P D Wimberley ◽  
K Grønlund Pedersen ◽  
J Olsson ◽  
O Siggaard-Andersen
Keyword(s):  
Carbon Dioxide ◽  
Temperature Coefficient ◽  
Oxygen Tension ◽  
Carbon Dioxide Tension ◽  
Healthy Adults ◽  
Transcutaneous Oxygen ◽  
Transcutaneous Carbon Dioxide ◽  
Different Temperatures ◽  
Gas Measurements ◽  
Increasing Temperature

Abstract Transcutaneous carbon dioxide tension (tc-pco2) at 37, 39, 41, 43, and 45 degrees C, and transcutaneous oxygen tension (tc-po2) at 41, 43, and 45 degrees C were measured simultaneously in 10 healthy adults during hyperventilation and inhalation of O2/CO2 gas. Nine electrodes were applied to each subject: Five CO2 electrodes, one O2 electrode, and three combined O2/CO2 electrodes. The CO2 electrodes had negligible temperature coefficients in the calibration gases, but the O2 electrodes showed an increase in po2 of 4.5% per degree C. With skin application, tc-pco2 increased approximately 4% per degrees C between 37 and 45 degrees C, which is close to the anaerobic temperature coefficient of pco2 in blood. The tc-po2 increases on the skin with increasing temperature appeared to be more dependent on changes in blood flow in skin, but in the temperature range 43 to 45 degrees C, tc-po2 showed the expected decrease in the temperature coefficient with increasing po2. The correlation between transcutaneous and capillary pco2 was close at all transcutaneous electrode temperatures, even 37 degrees C, provided the skin was preheated (via the electrode) to 45 degrees C. For tc-po2, an electrode temperature of at least 43 degrees C was necessary to produce a reasonable correlation between tc-po2 and capillary po2. The combined O2/CO2 electrodes measured slightly higher pco2 values than the single CO2 electrodes, but there were no differences in po2 readings, stabilization time, imprecision, or electrode drift between the two electrode types. The imprecision (CV, %) of tc-pco2 and tc-po2 measurements was approximately twice that of the corresponding capillary blood-gas measurements.

Heat Transfer Problems in Nuclear Reactor Safety

1976 ◽  
Vol 190 (1) ◽  
pp. 215-224
Author(s):  
W. B. Hall
Keyword(s):  
Heat Transfer ◽  
Safety Assessment ◽  
Nuclear Reactor ◽  
Reactor Safety ◽  
Operating Characteristics ◽  
Nuclear Reactor Safety ◽  
Thermal Explosions ◽  
Transient Boiling ◽  
Transfer Problems

Reactor safety assessment is a highly specialized topic which, in many of its aspects, depends heavily on a satisfactory understanding of a wide variety of heat transfer phenomena. It is the aim of the paper to air some of these problems outside the ranks of the reactor safety specialists. Typical liquid-cooled reactors, their operating characteristics, and some heat transfer aspects of their safety assessment are discussed: for example, transient boiling, quenching of hot surfaces and thermal explosions.

Analytical representation of the solution of the point reactor kinetics equations with adaptive time step

2014 ◽  
Vol 70 ◽  
pp. 112-118 ◽  
Author(s):  
Sérgio Q. Bogado Leite ◽  
Daniel A.P. Palma ◽  
Marco Tullio de Vilhena ◽  
Bardo E.J. Bodmann
Keyword(s):  
Analytical Representation ◽  
Time Step ◽  
Reactor Kinetics ◽  
Adaptive Time Step ◽  
Adaptive Time ◽  
Point Reactor Kinetics
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