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.

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.

Properties of Chemical Vapor Deposited ZrC coating layer for TRISO Coated Fuel Particle

2007 ◽  
Vol 44 (10) ◽  
pp. 580-584
Author(s):  
Jun-Gyu Kim ◽  
E-Sul Kum ◽  
Doo-Jin Choi ◽  
Young-Woo Lee ◽  
Ji-Yeon Park
Keyword(s):  
Coating Layer ◽  
Chemical Vapor ◽  
Fuel Particle ◽  
Chemical Vapor Deposited ◽  
Coated Fuel Particle ◽  
Zrc Coating

Preparation of Silicon Carbide Coating Layer by Fluidized Bed Chemical Vapor Deposition Using a Halogen-Free Precursor

2016 ◽  
Vol 697 ◽  
pp. 846-851 ◽  
Author(s):  
Ma Lin Liu ◽  
Rong Zheng Liu ◽  
Jia Xing Chang ◽  
You Lin Shao
Keyword(s):  
Silicon Carbide ◽  
Chemical Vapor Deposition ◽  
Fluidized Bed ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Pyrolytic Carbon ◽  
Chemical Vapor Deposition Method ◽  
Fuel Particle ◽  
Coated Materials

Tristructural-isotropic (TRISO) particle, with spherical ceramic fuel particle kernels followed by three layers of pyrolytic carbon and one layer of silicon carbide (SiC), has been successful now in high temperature gas cooled reactor (HTGR). The silicon carbide (SiC) layer used in TRISO coated fuel particles is normally produced at high temperatures (~1600°C) via fluidized bed chemical vapor deposition from methyltrichlorosilane (MTS) in a hydrogen environment. The precursor is strong corrosive and the process is not environmentally friendly. In this work, hexamethyldisilane (HMDS) was used instead of MTS and the deposition behavior was investigated via fluidized bed chemical vapor deposition method. Different experimental parameters were tested, such as deposition temperature (800~1450°C) and gas flow ratio of Ar: H2. The deposition rates were obtained and compared. It was found that the optimization parameters of highest deposition rate is 1000°C with the ratio of Ar: H2 of 1:1. The microstructures of the products were further investigated by SEM, XRD and Raman scattering. From the X-ray diffraction pattern it could be inferred that the β-SiC phase was obtained, and free carbon was also found in deposition products. Different types of SiC layer, including dense and porous layer can be prepared. The experimental results validated that HMDS was an alternative precursor for preparing the SiC layer in producing the TRISO particle and other SiC-coated materials in lower temperatures

Three Dimensional Modeling of the Thermo-Mechanical Performance of the Fuel Rods of a PWR

2017 ◽  
Author(s):  
Wang Zhu ◽  
Zhang Chunyu ◽  
Li Aolin ◽  
Yuan Cenxi
Keyword(s):  
Mechanical Performance ◽  
Three Dimensional ◽  
Fission Products ◽  
General Purpose ◽  
Fuel Temperature ◽  
Pressurized Water ◽  
Fuel Rods ◽  
Fuel Rod ◽  
Three Dimensional Modeling ◽  
Water Reactors

The fuel rods of pressurized water reactors operate under complex radioactive, thermal and mechanical conditions. Multiphysics has to be taken into account in order to evaluate their performance. Many existing fuel rod codes make great simplifications on analyzing the behavior of fuel rods. The present study develops a three dimensional module within the framework of a general-purpose finite element solver, i.e. ABAQUS, for modeling the thermo-mechanical performance of the fuel rods. A typical fuel rod is modeled and the temperature as well as the stress within the pellets are computed. The results show that the burnup levels have an important influence on the fuel temperature. The swelling of fission products cause dramatically increasing of pellet strain. The change of the cladding stress and radial displacement with the axial length can be reasonably predicted. It is shown that a quick power ramp or a reactivity insertion accident can induce high tensile stress to the outer regime of the pellet and may cause further fragmentation to the pellets.

Deterioration of ZrC-coated fuel particle caused by failure of pyrolytic carbon layer

1998 ◽  
Vol 252 (1-2) ◽  
pp. 13-21 ◽  
Author(s):  
Kazuo Minato ◽  
Kousaku Fukuda ◽  
Hajime Sekino ◽  
Akiyoshi Ishikawa ◽  
Etsuro Oeda
Keyword(s):  
Pyrolytic Carbon ◽  
Carbon Layer ◽  
Fuel Particle ◽  
Coated Fuel Particle

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

Effect of gap design pressure on the LWR fuel rods lifetime

Kerntechnik ◽  
2021 ◽  
Vol 86 (3) ◽  
pp. 202-209
Author(s):  
M. Ghasabian ◽  
F. Mofidnakhaei ◽  
S. Talebi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Mechanical Performance ◽  
Fission Products ◽  
Fuel Temperature ◽  
Fuel Rods ◽  
Fuel Rod ◽  
Fuel Burn ◽  
Water Reactors ◽  
Centerline Temperature

Abstract The fuel burn-up rate has been raised in recent years to improve the efficiency of nuclear LWRs (light water reactors). Therefore, surveying and estimating changes in fuel properties and structural materials during radiation exposure is of paramount importance. In the present study, the researchers focused on analyzing the role of LWR fuel rod initial gap pressure (initial gas pressure when a fuel rod is fabricated) on the rod’s thermal and mechanical performance. FRAPCON-4.0 steady-state fuel performance code was used to simulate the effect of initial gap pressure on the behavior of a specific BWR-type fuel rod that was irradiated under the HALDEN research program. This fuel rod is similar to commercial BWR fuel rods in all respects, except that the research reactors have a height limit. The important fuel design criteria, such as the centerline temperature, effective stresses, total released fission gas to the fuel rod’s void volumes, and the cladding strains, were included in the analysis. According to the present study, a potential initial gap pressure range could be suggested to increase fuel rods’ lifetime by improving the safety criteria margins, especially fuel centerline temperature and the released amount of gaseous fission products. As we know, lower fuel temperature leads to having a reactor with a higher power density and, consequently, a maximum fuel burn-up rate, which can affect the economy and safety of nuclear power plants.

Effect of Temperature and Gas Flow on Bi2Se3 Nanoplates Grown by Chemical Vapor Deposition

2018 ◽  
Vol 18 (11) ◽  
pp. 7590-7594 ◽  
Author(s):  
Peng Gu ◽  
Jinling Yu ◽  
Xiaolin Zeng ◽  
Shuying Cheng ◽  
Yunfeng Lai ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Effect Of Temperature
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