scholarly journals Mining Process and Product Information From Pressure Fluctuations Within a Fuel Particle Coater

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Douglas W. Marshall ◽  
Charles M. Barnes
Keyword(s):  
Nuclear Power ◽  
Product Information ◽  
Pressure Fluctuations ◽  
Scale Up ◽  
Differential Pressure ◽  
Fuel Particle ◽  
Triso Fuel ◽  
Product And Process ◽  
Operation Pressure ◽  
Particle Bed

The next generation nuclear power/advanced gas reactor (NGNP/AGR) fuel development and qualification program included the design, installation, and testing of a 6-in. diameter nuclear fuel particle coater to demonstrate quality tri-structural isotropic (TRISO) fuel production on a small industrial scale. Scale-up from the laboratory-scale coater faced challenges associated with an increase in the kernel charge mass, kernel diameter, and a redesign of the gas distributor to achieve adequate fluidization throughout the deposition of the four TRISO coating layers. TRISO coatings are applied at very high temperatures in atmospheres of dense particulate clouds, corrosive gases, and hydrogen concentrations over 45% by volume. The severe environment, stringent product and process requirements, and the fragility of partially-formed coatings limit the insertion of probes or instruments into the coater vessel during operation. Pressure instrumentation were installed on the gas inlet line and exhaust line of the 6-in. coater to monitor the bed differential pressure and internal pressure fluctuations emanating from the fuel bed as a result of bed and gas “bubble” movements. These instruments are external to the particle bed and provide a glimpse into the dynamics of fuel particle bed during the coating process and data that could be used to help ascertain the adequacy of fluidization and, potentially, the dominant fluidization regimes. Pressure fluctuation and differential pressure data are not presently useful as process control instruments, but data suggest a link between the pressure signal structure and some measurable product attributes that could be exploited to get an early estimate of the attribute values.

scholarly journals Mining Process and Product Information From Pressure Fluctuations Within a Fuel Particle Coater

2008 ◽  
Author(s):  
Douglas W. Marshall ◽  
Charles M. Barnes
Keyword(s):  
Nuclear Power ◽  
Product Information ◽  
Pressure Fluctuations ◽  
Scale Up ◽  
Differential Pressure ◽  
Fuel Particle ◽  
Triso Fuel ◽  
Product And Process ◽  
Operation Pressure ◽  
Particle Bed

The Next Generation Nuclear Power/Advanced Gas Reactor (NGNP/AGR) Fuel Development and Qualification Program included the design, installation, and testing of a 6-inch diameter nuclear fuel particle coater to demonstrate quality TRISO fuel production on a small industrial scale. Scale-up from the laboratory-scale coater faced challenges associated with an increase in the kernel charge mass, kernel diameter, and a redesign of the gas distributor to achieve adequate fluidization throughout the deposition of the four TRISO coating layers. TRISO coatings are applied at very high temperatures in atmospheres of dense particulate clouds, corrosive gases, and hydrogen concentrations over 45% by volume. The severe environment, stringent product and process requirements, and the fragility of partially-formed coatings limit the insertion of probes or instruments into the coater vessel during operation. Pressure instrumentation were installed on the gas inlet line and exhaust line of the 6-inch coater to monitor the bed differential pressure and internal pressure fluctuations emanating from the fuel bed as a result of bed and gas “bubble” movement. These instruments are external to the particle bed and provide a glimpse into the dynamics of fuel particle bed during the coating process and data that could be used to help ascertain the adequacy of fluidization and, potentially, the dominant fluidization regimes. Pressure fluctuation and differential pressure data are not presently useful as process control instruments, but data suggest a link between the pressure signal structure and some measurable product attributes that could be exploited to get an early estimate of the attribute values.

scholarly journals Uniformity Assessment of TRISO Fuel Particle Distribution in Spherical HTGR Fuel Element Using Voronoi Tessellation and Delaunay Triangulation

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Libing Zhu ◽  
Xincheng Xiang ◽  
Yi Du ◽  
Gongyi Yu ◽  
Ziqiang Li ◽  
...  
Keyword(s):  
Fuel Element ◽  
Delaunay Triangulation ◽  
Nearest Neighbor ◽  
Voronoi Tessellation ◽  
Fission Products ◽  
Fuel Particle ◽  
Volume Distribution ◽  
Triso Fuel ◽  
Triso Particles ◽  
Log Normal

Nonuniform distribution of tri-structural-isotropic (TRISO) fuel particles in a spherical fuel element (SFE) may increase the failure probability of the SFE in the high-temperature gas-cooled reactor, leading to the release of fission products. To evaluate the uniformity of the TRISO particles nondestructively, 3-dimensional cone-beam computed tomography is used to image the SFE, and TRISO particles are segmented. After TRISO particle positions are identified, the Voronoi tessellation and Delaunay triangulation are used to extract several geometric metrics. Results indicate that both the Voronoi volume distribution and the nearest neighbor-distance distribution follow the log-normal distributions, which provide strong evidence that the TRISO particles are approximately randomly uniformly distributed. Further study will be focused on validating the conclusion with more SFE data.

scholarly journals Management of Radioactive Waste Containing Graphite: Overview of Methods

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4638
Author(s):  
Leon Fuks ◽  
Irena Herdzik-Koniecko ◽  
Katarzyna Kiegiel ◽  
Grazyna Zakrzewska-Koltuniewicz
Keyword(s):  
High Temperature ◽  
Radioactive Waste ◽  
Nuclear Power ◽  
Information Service ◽  
Nuclear Industry ◽  
Current Status ◽  
Triso Fuel ◽  
Irradiated Graphite ◽  
High Temperature Gas

Since the beginning of the nuclear industry, graphite has been widely used as a moderator and reflector of neutrons in nuclear power reactors. Some reactors are relatively old and have already been shut down. As a result, a large amount of irradiated graphite has been generated. Although several thousand papers in the International Nuclear Information Service (INIS) database have discussed the management of radioactive waste containing graphite, knowledge of this problem is not common. The aim of the paper is to present the current status of the methods used in different countries to manage graphite-containing radioactive waste. Attention has been paid to the methods of handling spent TRISO fuel after its discharge from high-temperature gas-cooled reactors (HTGR) reactors.

scholarly journals Spatial Distribution of Pd, Ag & U in the SiC Layer of an Irradiated TRISO Fuel Particle

2014 ◽  
Vol 20 (S3) ◽  
pp. 1810-1811 ◽  
Author(s):  
Thomas M. Lillo ◽  
Isabella J. van Rooyen Idaho
Keyword(s):  
Spatial Distribution ◽  
Fuel Particle ◽  
Triso Fuel

Spatio–temporal analysis of hydrodynamic forces on the particle bed in an oscillatory flow environment

2018 ◽  
Vol 841 ◽  
pp. 167-202 ◽  
Author(s):  
Chaitanya D. Ghodke ◽  
Sourabh V. Apte
Keyword(s):  
Oscillatory Flow ◽  
Large Diameter ◽  
Pressure Fluctuations ◽  
Temporal Analysis ◽  
Hydrodynamic Forces ◽  
Generalized Extreme Value Distribution ◽  
Flow Environment ◽  
Lift Forces ◽  
Drag And Lift ◽  
Particle Bed

A numerical investigation of unsteady hydrodynamic forces on the particle bed in an oscillatory flow environment is performed by means of direct numerical simulations. Statistical descriptions of drag and lift forces for two particle sizes of diameter 372 and 125 in wall units in a very rough turbulent flow regime are reported. Characterization of unsteady forces in terms of spatial distribution, temporal autocorrelation, force spectrum as well as cross-correlations with measurable flow variables is carried out. Based on the concept of impulse, intermittency in the drag and lift forces is also investigated. Temporal correlations show drag and lift to be positively correlated with a time delay that is approximately equal to the Taylor micro-scale related to the drag/lift fluctuations. The force spectra for drag and lift reveal roughly two scaling regions, $-11/3$ and $-7/3$; the former typically represents turbulence–mean-shear interactions, whereas the latter indicates dominance of turbulence–turbulence interactions. Particle forces are strongly correlated with streamwise velocity and pressure fluctuations in the near-bed region for both flow cases. In comparison to the large-diameter particle case, the spatial extent of these correlations is 2–3 times larger in homogeneous directions for the small sized particle, a feature that is reminiscent of longer near-bed structures. For both large- and small-particle cases, it is shown that the distributions of drag (lift) fluctuations, in particular, peakedness and long tails, match remarkably well with fourth-order Gram–Charlier distributions of velocity (pressure) fluctuations. Furthermore, it is demonstrated that the intermittency is larger in the case of the lift force compared to that for the drag in both flow cases. Distributions of impulse events are heavily and positively skewed and are well described by a generalized extreme value distribution.

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