scholarly journals Dry air oxidation kinetics of K-Basin spent nuclear fuel

1998 ◽  
Author(s):  
J. Abrefah ◽  
H.C. Buchanan ◽  
W.M. Gerry ◽  
W.J. Gray ◽  
S.C. Marschman
2021 ◽  
Vol 13 (3) ◽  
pp. 1442
Author(s):  
Sanggil Park ◽  
Jaeyoung Lee ◽  
Min Bum Park

The temperature of zirconium alloy cladding on the postulated spent nuclear fuel pool complete loss of coolant accident is abruptly increased at a certain time and the cladding is almost fully oxidized to weak ZrO2 in the air. This abrupt temperature escalation phenomenon induced by the air-oxidation breakaway is called a zirconium fire. Although an air-oxidation breakaway kinetic model correlated between time and temperature has been implemented in the MELCOR code, it is likely to bring about unexpected large errors because of many limitations of model derivation. This study suggests an improved time–temperature correlated kinetic model using the Johnson–Mehl equation. It is based on that the air-oxidation breakaway is initiated by the phase transformation from the tetragonal to monoclinic ZrO2 at the oxide–metal interface in the cladding. This new model equation is also evaluated with the Zry-4 air-oxidation literature data. This equation resulted in the almost similar air-oxidation breakaway timing to the actual experimental data at 800 °C. However, at 1000 °C, it showed an error of about 8 min. This could be inferred from the influence of the ZrN phase change due to the nitrogen existing in air.


2016 ◽  
Vol 86 (3-4) ◽  
pp. 165-177
Author(s):  
S. P. Roy ◽  
N. K. Gupta ◽  
Ram Avtar Jat ◽  
S. C. Parida ◽  
S. K. Mukerjee

2016 ◽  
Vol 35 (4) ◽  
pp. 353-359
Author(s):  
S. Liu ◽  
Q. Q. Guo ◽  
L. L. Liu ◽  
L. Xu ◽  
Y. Y. Liu

AbstractThe oxidation behavior of Ti-5Al-2.5Sn and Ti-6Al-4V produced by hot isostatic pressing (HIP) has been studied at 650–850°C in air for 24 h. The oxidation kinetics of both alloys followed the parabolic law with good approximation, except for Ti-5Al-2.5Sn oxidized at 850°C. Multi-layered scales formed on both alloys at 750°C and 850°C. Ternary additions of Sn and V accounted for the different morphology of the scales formed on these two alloys. In addition, the oxidation behavior of HIP alloys is compared with that of the corresponding cast alloys and the scaling mechanism is discussed.


Author(s):  
Suverna Trivedi ◽  
Ram Prasad ◽  
S. Chadha

This paper describes the kinetics of catalytic air oxidation of propane. The kinetics data were collected in a plug flow tubular reactor. The experiments were performed over the NiCo2O4 catalyst prepared by co-precipitation method followed by calcination at 400 oC. The kinetic data were collected under the following conditions: 200 mg of catalyst, 2.5 % of propane in air, total flow rate of 60 mL/min, and temperature ranges of 130-170 oC. The data were fitted to the power law rate equation. The activation    energy and frequency factor were found to be 59.3 kJ/g mol and 2.9×108 (mol)0.47.L0.53/g cat.h, respectively. Copyright © 2017 BCREC Group. All rights reservedReceived: 20th November 2016; Revised: 26th February 2017; Accepted: 26th February 2017How to Cite: Trivedi, S., Prasad, R., Chadha, S. (2017). Oxidation Kinetics of Propane-Air Mixture over NiCo2O4 Catalyst Emitted from LPG Vehicles. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2): 191-196 (doi:10.9767/bcrec.12.2.798.191-196)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.798.191-196 


2009 ◽  
Vol 283-286 ◽  
pp. 209-213 ◽  
Author(s):  
Dong Ya Huang ◽  
Xiang Jin Zhao ◽  
Tao Zhang ◽  
Vincent Ji

The isothermal oxidation behavior of Zr58Nb3Cu16Ni13Al10 bulk metallic glass (BMG) under dry air in the glassy state and the supercooled liquid state (SLS) was studied by the thermogravimetric method. The oxidation rate and thickness growth speed in the SLS were both hugely higher than in the glassy state. The oxidation kinetics of BMG in both states for 1.5 hours was different, the parabolic law was followed in the glassy state at 300°C and 350°C, contrarily the linear law was followed in SLS at 400 °C. After the oxidation for 126 hours in SLS, the oxidation kinetics possessed two stages, the linear stage and the parabolic stage. The diffusion of the Cu2+ ion and CuZr intermetallic alloys were detected by GIXRD.


2019 ◽  
Vol 11 (22) ◽  
pp. 6364
Author(s):  
Sanggil Park ◽  
Min Bum Park

The OECD/NEA Spent Fuel Pool (SFP) project was conducted to investigate consequences of spent nuclear fuel pool accident scenarios. From the project, it was observed that cladding temperature could abruptly increase at a certain point and the cladding was completely oxidized. This phenomenon was called a “zirconium fire”. This zirconium fire is one of the crucial concerns for spent fuel pool safety under a postulated loss of coolant accident scenario, since it would lead to an uncontrolled mass release of fission products into the environment. To capture this critical phenomenon, an air-oxidation breakaway model has been implemented in the MELCOR code. This study examines this air-oxidation breakaway model by comparing the SFP project test data with a series of MELCOR code sensitivity calculation results. The air-oxidation model parameters are slightly altered to investigate their sensitivities on the occurrence of the zirconium fire. Through such sensitivity analysis, limitations of the air-oxidation breakaway model are identified, and needs for model improvement is recommended.


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