scholarly journals Fission Product Transport in TRISO Particles and Pebbles

2021 ◽  
Author(s):  
Wen Jiang ◽  
Aysenur Toptan ◽  
Jason Hales ◽  
Benjamin Spencer ◽  
Albert Casagranda ◽  
...  
2021 ◽  
pp. 153468
Author(s):  
Karen E. Wright ◽  
John Stempien ◽  
Wen Jiang ◽  
Isabella J. van Rooyen

Author(s):  
Isabel J. van Rooyen ◽  
Jan H. Neethling ◽  
Johannes Mahlangu

The PBMR fuel consists of TRISO Coated Particles (CPs) in a graphite matrix. The three layer system, IPyC-SiC-OPyC, forms the primary barrier to fission product release, with the SiC layer acting as the main pressure boundary of the particle. The containment of fission products inside the CPs is however a function of the operating temperature and microstructure of the SiC layer. During accident conditions, the CPs will reach higher temperatures than normal operating conditions. The Fuel Design department of PBMR is therefore investigating various characteristics of the SiC layer, especially nano characteristics at variant conditions. The integrity of the interface between the SiC and Inner PyC layers is also important for fission product retention and therefore interesting TEM images of this region of the experimental PBMR TRISO particles will be shown. Transmission electron microscope (TEM) images of the microstructure of TRISO coated particles of three different experimental batches after annealing will be discussed. Particles annealed at 1980°C for 1 hour revealed that the inner PyC layer debonded from the SiC layer. Changes observed in the diffraction rings are evidence that the PyC structure is becoming organized or anisotropic. The SiC layer, on the other hand, did not show any changes as a result of annealing. Only the cubic 3C-SiC phase was observed for a limited number of grains analyzed. The nano hardness and elasticity measurements of the three test batches were done using a CSM Nano Hardness Tester. These results are compared to indicate possible differences between the 1 hour and 5 hour annealing time as a function of annealing temperature from 1000°C to 1980°C. The variation of hardness and elasticity as a function of temperature for the three experimental batches are identified and discussed. This preliminary TEM investigation and nano hardness measurements have contributed new knowledge about the effect of high temperature annealing on the microstructure of TRISO CPs produced by PBMR.


1958 ◽  
Author(s):  
W. T. Ward ◽  
R. A. Strehlow ◽  
W. R. Grimes ◽  
G. M. Watson
Keyword(s):  

1998 ◽  
Author(s):  
V. A. Rubchenya ◽  
J. Äystö ◽  
P. Dendooven ◽  
S. Hankonen ◽  
A. Jokinen ◽  
...  

Separations ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 104
Author(s):  
Leah M. Arrigo ◽  
Jun Jiang ◽  
Zachary S. Finch ◽  
James M. Bowen ◽  
Staci M. Herman ◽  
...  

The measurement of radioactive fission products from nuclear events has important implications for nuclear data production, environmental monitoring, and nuclear forensics. In a previous paper, the authors reported the optimization of an intra-group lanthanide separation using LN extraction resin from Eichrom Technologies®, Inc. and a nitric acid gradient. In this work, the method was demonstrated for the separation and quantification of multiple short-lived fission product lanthanide isotopes from a fission product sample produced from the thermal irradiation of highly enriched uranium. The separations were performed in parallel in quadruplicate with reproducible results and high decontamination factors for 153Sm, 156Eu, and 161Tb. Based on the results obtained here, the fission yields for 144Ce, 153Sm, 156Eu, and 161Tb are consistent with published fission yields. This work demonstrates the effectiveness of the separations for the intended application of short-lived lanthanide fission product analysis requiring high decontamination factors.


RSC Advances ◽  
2021 ◽  
Vol 11 (35) ◽  
pp. 21323-21331
Author(s):  
Kankan Patra ◽  
Biswajit Sadhu ◽  
Arijit Sengupta ◽  
C. B. Patil ◽  
R. K. Mishra ◽  
...  

Separation scheme was developed for selective extraction of long-lived fission product 137Cs using substituted calix crown 6 ether from aqueous acidic solution.


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