Effect of PyC Thermal Behavior on the Stress of TRISO-Coated Fuel Particles

2016 ◽  
Vol 697 ◽  
pp. 852-857
Author(s):  
Rong Li ◽  
Bing Liu ◽  
Chun He Tang
Keyword(s):  
Pressure Vessel ◽  
Elastic Strain ◽  
Fission Products ◽  
Fuel Particle ◽  
Coated Particles ◽  
Inner Pressure ◽  
Higher Temperature ◽  
Fuel Particles ◽  
Coated Fuel Particle ◽  
Increasing Temperature

TRISO coated fuel particle is the most important component in HTR fuel, the silicon carbide (SiC) coating layer is regarded as the pressure vessel to contain the fission products. During reactor operation, the inner pressure resulting from fission products and pyrocarbon (PyC) thermal effect will contribute to the failure of TRISO-coated particles. The higher temperature will result in the increasing of inner pressure and PyC thermal expansion, which will then change the stress of SiC layer. Considering the effects of temperature on inner-pressure expansion and elastic strain into the pressure vessel failure model, thermal effects on the stress of TRISO-coated particles were studied with analytical solution. The results indicated that the effects of inner pressure on the particle stresses were increasingly highlighted at the late stage of irradiation. And the increasing temperature caused a slight effect on PyC elastic modulus while elastic strain is unaffected greatly, either. Therefore, CFP stresses remain unchanged basically.

scholarly journals Fission Products Distribution in TRISO Coated Fuel Particles Irradiated to 3.22 X 1021 n/cm2 Fast Fluence at 1092°C

2015 ◽  
Author(s):  
Haiming Wen ◽  
Isabella J. Van Rooyen ◽  
Connie M. Hill ◽  
Tammy L. Trowbridge ◽  
Ben D. Coryell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Beam ◽  
Fission Products ◽  
Fuel Particle ◽  
Next Generation ◽  
Research Activities ◽  
Transmission Electron ◽  
Fuel Particles ◽  
Coated Fuel Particle

Mechanisms by which fission products (especially silver [Ag]) migrate across the coating layers of tristructural isotropic (TRISO) coated fuel particles designed for next generation nuclear reactors have been the subject of a variety of research activities due to the complex nature of the migration mechanisms. This paper presents results obtained from the electron microscopic examination of selected irradiated TRISO coated particles from fuel compact 1-3-1 irradiated in the first Advanced Gas Reactor experiment (AGR-1) that was performed as part of the Next Generation Nuclear Plant (NGNP) project. It is of specific interest to study particles of this compact as they were fabricated using a different carrier gas composition ratio for the SiC layer deposition compared with the baseline coated fuel particles reported on previously. Basic scanning electron microscopy (SEM) and SEM montage investigations of the particles indicate a correlation between the distribution of fission product precipitates and the proximity of the inner pyrolytic carbon (IPyC)-silicon carbide (SiC) interface to the fuel kernel. Transmission electron microscopy (TEM) samples were sectioned by focused ion beam (FIB) technique from the IPyC layer, the SiC layer and the IPyC-SiC interlayer of the coated fuel particle. Detailed TEM and scanning transmission electron microscopy (STEM) coupled with energy dispersive X-ray spectroscopy (EDS) were performed to identify fission products and characterize their distribution across the IPyC and SiC layers in the areas examined. Results indicate the presence of palladium-silicon-uranium (Pd-Si-U), Pd-Si, Pd-U, Pd, U, U-Si precipitates in the SiC layer and the presence of Pd-Si-U, Pd-Si, U-Si, U precipitates in the IPyC layer. No Ag-containing precipitates are evident in the IPyC or SiC layers. With increased distance from the IPyC-SiC interface, there are less U-containing precipitates, however, such precipitates are present across nearly the entire SiC layer.

Understanding the 1600°C Fuel Temperature Limit of TRISO Coated Fuel Particles

2015 ◽  
Vol 1769 ◽  
Author(s):  
Félix Cancino Trejo ◽  
Mariana Sáenz Padilla ◽  
Eddie López-Honorato
Keyword(s):  
Fission Products ◽  
Chemical Vapor ◽  
Pyrolytic Carbon ◽  
Temperature Limit ◽  
Inert Atmosphere ◽  
Effect Of Temperature ◽  
Fuel Particle ◽  
Fuel Temperature ◽  
Water Reactors ◽  
Coated Fuel Particle

ABSTRACTThe TRISO (tristructural isotropic) coated fuel particle is made of a uranium oxide kernel coated with three layers of pyrolytic carbon and one of silicon carbide. This fuel, originally used in High Temperature Reactors, has been proposed as accident tolerant fuel for Light Water Reactors after the accident in Fukushima. Although this fuel is capable of retaining fission products within the particle up to 1600°C, little is known on the origin of this temperature limit. Therefore, in order to increase the safety of this type of fuel, it is necessary to understand the origin of the degradation of the materials that compose this fuel. We have studied the effect of temperature on the microstructure and diffusion of silver in pyrolytic carbon coatings produced by fluidized bed chemical vapor deposition. Samples were heat treated at 1000°C, 1400°C and 1700°C for 200 hrs. under inert atmosphere. The effect of temperature on the microstructure and silver diffusion behavior were analyzed by Raman spectroscopy, X-Ray diffraction, optical microscopy, SEM and TEM. We observed that the microstructure of PyC changed drastically above 1400°C, showing the increase in anisotropy and the re-orientation of the graphene planes. The diffusion of silver appears to be also correlated with this change in microstructure.

Thermodynamic Modelling of the Uranium-Carbon-Oxygen System in the Frame of the Uranium Oxide and Carbon Interaction in the TRISO Fuel Particle of High Temperature Reactor

2006 ◽  
Vol 45 ◽  
pp. 1944-1951 ◽  
Author(s):  
Jean Christophe Dumas ◽  
Jean Paul Piron ◽  
Sylvie Chatain ◽  
Christine Guéneau
Keyword(s):  
High Temperature ◽  
Fission Products ◽  
Nuclear Materials ◽  
Chemical Compositions ◽  
Fuel Particle ◽  
Chemical Systems ◽  
Triso Fuel ◽  
Physico Chemical ◽  
Chemical Studies ◽  
Fuel Particles

A thermodynamic approach is necessary in order to predict and understand physico-chemical phenomena occurring in nuclear materials under irradiation, involving large chemical systems with a lot of elements including both initial nuclides and fission products (FP). In the frame of thermo-chemical studies of the High Temperature Reactors fuel, a first step is to assess the (U-O-C) system in order to understand the interaction between the UO2 kernel and the pyrocarbon layers constituting such a fuel particle. Our model for irradiated oxide fuel, based on Lindemer’s analysis, has been improved by introducing the (U-O-C) model developed by C. Guéneau & al into the SAGE code. Chemical compositions and related carbon oxides pressures of irradiated TRISO fuel particles have been calculated with the data published by Minato & al. We discuss our results by comparison with their thermochemical calculations and with their experimental observations. This approach can be used to predict the behaviour of complex nuclear materials, especially for the different kind of fuel materials considered in the frame of Gas Fast Reactors.

Design Study of 300 MWt PWR Fueled With UO2 Coated Fuel Particle

2006 ◽  
Author(s):  
Abu Khalid Rivai ◽  
Ferhat Aziz ◽  
Minoru Takahashi
Keyword(s):  
Optimization Design ◽  
Computer Code ◽  
Cycle Period ◽  
Fuel Particle ◽  
Pressurized Water ◽  
Type Reactor ◽  
Ordinary Type ◽  
Fuel Particles ◽  
Safety Characteristic ◽  
Coated Fuel Particle

A neutronic design was performed for 300 MWt Pressurized Water Reactor (PWR) with UO2 compacts made of coated fuel particles (CFP) comparing that with sintered pellets made of UO2 powder as ordinary fuel type. UO2 CFP type was enriched 4.8% of 235U and UO2 ordinary type was enriched 5% of 235U. Both reactors were operated with single batch refueling system with a cycle period of 3 years. The purpose of the design was to investigate the applicability of UO2 CFP type to PWR comparing with UO2 ordinary type that commonly used for PWR. The calculation was done with SRAC (Standard Reactor Analysis Code) computer code and nuclear library of JENDL-33. The results of calculation showed that k-effective for both type of fuel could be maintained at critical condition for 3 years operation without refueling. The k-effective and the Doppler coefficients have been calculated for all types of fuel at 600 K and 900 K degrees. The results of calculation showed that for all types of fuel Doppler coefficient was negative, which was good for inherent safety characteristic. The size optimization design showed that the active core dimensions of UO2 CFP type reactor was about 2 times larger than the UO2 ordinary type reactor.

Release of metal fission products from UO2 kernel of coated fuel particle

1985 ◽  
Vol 135 (1) ◽  
pp. 18-31 ◽  
Author(s):  
T. Ogawa ◽  
K. Fukuda ◽  
H. Sekino ◽  
M. Numata ◽  
K. Ikawa
Keyword(s):  
Fission Products ◽  
Fuel Particle ◽  
Coated Fuel Particle

scholarly journals The Effects of the Number of Coated Fuel Particles on the Neutronic Aspects of 25 MWt Pebble Bed Reactor with Thorium Fuel

2021 ◽  
Vol 7 (1) ◽  
pp. 102
Author(s):  
Dwi Irwanto ◽  
Nining Yuningsih
Keyword(s):  
Fuel Particle ◽  
Fissile Material ◽  
Particle Fraction ◽  
Pebble Bed ◽  
Pebble Bed Reactor ◽  
Effective Multiplication Factor ◽  
Fuel Particles ◽  
Coated Fuel Particle ◽  
Neutronic Characteristics ◽  
Effective Multiplication

High-Temperature Gas Reactor (HTGR) is a type of reactor that continues to be developed because of its advantages in terms of economic aspects, proliferation resistance, and safety aspects. One of the safety aspect improvements is due to the use of the Coated Fuel Particle (CFP). A coated fuel particle is a fuel with a diameter smaller than 1 mm and is protected by several carbon layers. In the Pebble Bed Reactor (PBR) type of HTGR design, the CFP is placed in a 6 cm fuel ball. How much CFP is put into the fuel ball will determine the neutronic characteristics of the reactor. In this study, the effect of the amount of CFP in the fuel ball on the 25 MWt PBR design using Thorium fuel and its impact on several important neutronic aspects, such as the effective multiplication factor, the amount of fuel enrichment, the utilization of fissile material, and the density of the fissile material formed. The calculation was performed by the Monte Carlo MVP / MVP-BURN code. This study found that the coated fuel particle fraction of 15% was the optimum value for the studied neutronic parameters.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

Burnup characteristic of CERMET and TRISO fuel particles used in Boiling Water Reactor with Pebble-Bed Coated Particles

2014 ◽  
Vol 2014 (1) ◽  
pp. 17-22
Author(s):  
Abdelfettah Benchrif ◽  
◽  
Abdelouahed Chetaine ◽  
Hamid Amsil ◽  
◽  
...  
Keyword(s):  
Boiling Water ◽  
Boiling Water Reactor ◽  
Pebble Bed ◽  
Water Reactor ◽  
Coated Particles ◽  
Triso Fuel ◽  
Fuel Particles

scholarly journals Evaluation of the Possibility of Using 1.4462 and 1.4501 Steel as a Construction Material for Apparatus Operating at an Increased Temperature and with Corrosive Factors

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4014
Author(s):  
Karol Prałat ◽  
Andżelika Krupińska ◽  
Marek Ochowiak ◽  
Sylwia Włodarczak ◽  
Magdalena Matuszak ◽  
...  
Keyword(s):  
Construction Material ◽  
Construction Materials ◽  
Optical Microscope ◽  
Passive Layer ◽  
Initial State ◽  
Time Intervals ◽  
Significant Deterioration ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Steel Heat

The objective of this study was to determine the requirements for steels used as construction materials for chemical apparatus operating at an elevated temperature and to correlate them with the properties of the tested steels. The experimental part examined the influence of the annealing process on the structure and properties of X2CrNiMoN22-5-3 (1.4462) and X2CrNiMoCuWN25-7-4 (1.4501) steel. Heat treatment was carried out on the tested samples at a temperature of 600 °C and 800 °C. Changes were observed after the indicated time intervals of 250 and 500 h. In order to determine the differences between the initial state and after individual annealing stages, metallographic specimens were performed, the structure was analyzed using an optical microscope and the micro-hardness was measured using the Vickers method. Potentiostatic tests of the samples were carried out to assess the influence of thermal process parameters on the electrochemical properties of the passive layer. An increase in the hardness of the samples was observed with increasing temperature and annealing time, the disappearance of magnetic properties for both samples after annealing at the temperature of 800 °C, as well as a significant deterioration in corrosion resistance in the case of treatment at a higher temperature.

Effect on Cs removal of solid-phase metal oxidation in metal ferrocyanides

2017 ◽  
Vol 105 (12) ◽  
Author(s):  
Keun-Young Lee ◽  
Jimin Kim ◽  
Maengkyo Oh ◽  
Eil-Hee Lee ◽  
Kwang-Wook Kim ◽  
...  
Keyword(s):  
Treatment Process ◽  
Solid Phase ◽  
Storage Conditions ◽  
Radioactive Cesium ◽  
Metal Oxidation ◽  
Aging Period ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
And Storage ◽  
Cobalt And Nickel

AbstractMetal ferrocyanides (MFCs) have been studied for many years and are regarded as efficient adsorbents for the selective removal of radioactive cesium (Cs) from contaminated aqueous solutions. Although their efficiency has been demonstrated, various investigations on the physicochemical, thermal, and radiological stability of the solids of MFCs are required to enhance the applicability of MFCs in the treatment process. We observed that the Cs adsorption efficiencies of cobalt and nickel ferrocyanides decreased as their aging period increased, while the Cs adsorption efficiencies of copper and zinc ferrocyanides did not decrease. The tendencies of these ferrocyanides were accelerated by exposure of the solids at a higher temperature for a longer time. Our comprehensive analyses demonstrated that only the oxidizable metals in the MFCs can be oxidized by aging time and increasing temperature; also, this affects the Cs removal efficiency by decreasing the exchangeable sites in the solids. The chemical stability of MFCs is very important for the optimization of the synthesis and storage conditions.

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