Hydrogen Distribution, Combustion and Detonation for H2 Risk Analysis in Large Facilities

2002 ◽  
Author(s):  
A. Beccantini ◽  
N. Coulon ◽  
F. Dabbene ◽  
S. Gounand ◽  
S. Kudriakov ◽  
...  
Keyword(s):  
Risk Analysis ◽  
Atomic Energy Commission ◽  
Atomic Energy ◽  
Governing Equations ◽  
Hydrogen Distribution ◽  
Numerical Studies ◽  
Lumped Parameter ◽  
Safety Code ◽  
Parameter Approach ◽  
Numerical Strategy

The French Atomic Energy Commission (C.E.A.) is developing a hydrogen risk analysis code (safety code) which incorporates both lumped-parameter and multi-dimensional formulations. In this paper we present the governing equations, numerical strategy and schemes used for the lumped parameter approach as well as for the multi-dimensional one. Typical numerical studies will be presented for hydrogen distribution and combustion applications in realistic large geometries.

Containment Thermal-Hydraulic Simulations With an LP-CFD Approach: Qualification Matrix of the TONUS Code

2006 ◽  
Author(s):  
A. Bentaib ◽  
A. Bleyer ◽  
J. Malet ◽  
C. Caroli ◽  
J. Vendel ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Risk Analysis ◽  
Atomic Energy Commission ◽  
Physical Models ◽  
Radiological Protection ◽  
Hydrogen Distribution ◽  
Lumped Parameter ◽  
Safety Code ◽  
Computational Fluid Dynamics Cfd

The French Atomic Energy Commission (CEA) and the Institute for Radiological Protection and Nuclear Safety (IRSN) are developing a hydrogen risk analysis code (safety code) which incorporates both lumped parameter (LP) and computational fluid dynamics (CFD) formulations. In this paper we present briefly the main physical models for containment thermal-hydraulics. Validation and typical numerical results will be presented for hydrogen distribution and combustion applications in small and realistic large geometries.

Radiological safety and assessment of the performance of X-ray systems in veterinary facilities

2020 ◽  
Author(s):  
S. Economides ◽  
C.J. Hourdakis ◽  
C. Pafilis ◽  
G. Simantirakis ◽  
P. Tritakis ◽  
...  
Keyword(s):  
Decision Making ◽  
Radiation Protection ◽  
Atomic Energy Commission ◽  
Atomic Energy ◽  
Regulatory Control ◽  
Continuous Training ◽  
X Ray ◽  
The Public ◽  
Radiological Safety ◽  
High Level

This paper concerns an analysis regarding the performance of X-ray equipment as well as the radiological safety in veterinary facilities. Data were collected from 380 X-ray veterinary facilities countrywide during the on-site regulatory inspections carried out by the Greek Atomic Energy Commission. The analysis of the results shows that the majority of the veterinary radiographic systems perform within the acceptable limits; moreover, the design and shielding of X-ray rooms as well as the applied procedures ensure a high level of radiological safety for the practitioners, operators and the members of the public. An issue that requires specific attention in the optimization process for the proper implementation of veterinary radiology practices in terms of radiological safety is the continuous training of the personnel. The above findings and the regulatory experience gained were valuable decision-making elements regarding the type of the regulatory control of veterinary radiology practices in the new radiation protection framework.

U. S. Atomic Energy Commission

AIBS Bulletin ◽  
1963 ◽  
Vol 13 (5) ◽  
pp. 29 ◽  
Author(s):  
Arnold Joseph
Keyword(s):  
Atomic Energy Commission ◽  
Atomic Energy

scholarly journals Hydrogen Mixing Analyses for a VVER Containment

2002 ◽  
Author(s):  
Pal Kostka ◽  
Zsolt Techy ◽  
James J. Sienicki
Keyword(s):  
Three Dimensional ◽  
Primary System ◽  
Hydrogen Distribution ◽  
Lumped Parameter ◽  
Circulation Patterns ◽  
Contour Plots ◽  
Design Basis Accident ◽  
Input Model ◽  
Block Models ◽  
Containment Integrity

Hydrogen combustion may represent a threat to containment integrity in a VVER-440/213 plant owing to the combination of high pressure and high temperature. A study has been carried out using the GASFLOW 2.1 three-dimensional CFD code to evaluate the hydrogen distribution in the containment during a beyond design basis accident. The VVER-440/213 containment input model consists of two 3D blocks connected via one-dimensional (1D) ducts. One 3D block contains the reactor building and the accident localization tower with the suppression pools. Another 3D block models the air traps. 1D ducts represent the check valves connecting the accident localization tower with the air traps. The VVER pressure suppression system, called “bubbler condenser,” was modeled as a distributed heat sink with water thermodynamic properties. This model accounts for the energy balance. However, it is not currently possible to model dynamic phenomena associated with the water pools (e.g., vent clearing, level change). The GASFLOW 2.1 calculation gave detailed results for the spatial distribution of thermal-hydraulic parameters and gas concentrations. The range and trend of the parameters are reasonable and valuable. There are particularly interesting circulation patterns around the steam generators, in the bubbler tower and other primary system compartments. In case of the bubbler tower, concentration and temperature contour plots show an inhomogeneous distribution along the height and width, changing during the accident. Hydrogen concentrations also vary within primary system compartments displaying lower as well as higher (up to 13–20% and higher) values in some nodes. Prediction of such concentration distributions was not previously possible with lumped parameter codes. GASFLOW 2.1 calculations were compared with CONTAIN 1.2 (lumped parameter code) results. Apart from the qualitatively similar trends, there are, for the time being, quantitative differences between the results concerning, for example, pressure histories, or the total amount of steam available in the containment. The results confirm the importance of detailed modeling of the containment, as well as of the bubbler condenser and sump water pools. The study showed that modeling of hydrogen distribution in the VVER-440/213 containment was possible using the GASFLOW 2.1 code with reasonable results and remarkable physical insights.

Uranium Mining and the AEC: The Birth Pangs of a New Industry

1962 ◽  
Vol 36 (3) ◽  
pp. 325-333
Author(s):  
Herbert H. Lang
Keyword(s):  
National Security ◽  
Financial Support ◽  
Atomic Energy Commission ◽  
Uranium Mining ◽  
Atomic Energy ◽  
New Industry

The interrelationship of national security, the Atomic Energy Commission, government financial support, and the birth pangs of a new and growing industry with unusual competitive characteristics are examined in this article.

scholarly journals Evaluation of passive autocatalytic recombiners operation efficiency by means of the lumped parameter approach

Nukleonika ◽  
2015 ◽  
Vol 60 (2) ◽  
pp. 339-345 ◽  
Author(s):  
Tomasz Bury
Keyword(s):  
Hydrogen Generation ◽  
Cooling System ◽  
Component Mixture ◽  
Pressurized Water ◽  
Water Reactor ◽  
Safety Issues ◽  
Loss Of Coolant Accident ◽  
Lumped Parameter ◽  
Core Cooling ◽  
Parameter Approach

Abstract The problem of hydrogen behavior in containment buildings of nuclear reactors belongs to thermal-hydraulic area. Taking into account the size of systems under consideration and, first of all, safety issues, such type of analyses cannot be done by means of full-scale experiments. Therefore, mathematical modeling and numerical simulations are widely used for these purposes. A lumped parameter approach based code HEPCAL has been elaborated in the Institute of Thermal Technology of the Silesian University of Technology for simulations of pressurized water reactor containment transient response. The VVER-440/213 and European pressurised water reactor (EPR) reactors containments are the subjects of analysis within the framework of this paper. Simulations have been realized for the loss-of-coolant accident scenarios with emergency core cooling system failure. These scenarios include core overheating and hydrogen generation. Passive autocatalytic recombiners installed for removal of hydrogen has been taken into account. The operational efficiency of the hydrogen removal system has been evaluated by comparing with an actual hydrogen concentration and flammability limit. This limit has been determined for the three-component mixture of air, steam and hydrogen. Some problems related to the lumped parameter approach application have been also identified.

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