Numerical investigation of the random arrangement effect of coated fuel particles on the criticality of HTTR fuel compact using MCNP6

2017 ◽  
Vol 103 ◽  
pp. 114-121 ◽  
Author(s):  
Hai Quan Ho ◽  
Yuki Honda ◽  
Minoru Goto ◽  
Shoji Takada
2016 ◽  
Author(s):  
D. A. Vnuchkov ◽  
D. G. Nalivaychenko ◽  
A. V. Starov ◽  
V. I. Zvegintsev

2018 ◽  
Vol 112 ◽  
pp. 42-47 ◽  
Author(s):  
Hai Quan Ho ◽  
Yuki Honda ◽  
Minoru Goto ◽  
Shoji Takada

Author(s):  
R. J. Lauf

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.


Author(s):  
J. M. Cowley

Recently a number of authors have reported detail in dark-field images obtained from diffuse-scattering regions of electron diffraction patterns. Bright spots in images from short-range order diffuse peaks of disordered binary alloys have been interpreted as evidence for the existence of microdomains of ordered lattice or of segragated clusters of one component. Spotty contrast in dark field images of near-amorphous materials has been interpreted as evidence for the existense of microcrystals. Without a careful analysis of the imaging conditions such conclusions may be invalid. Usually the conditions of the experiment have not been specified in sufficient detail to allow evaluation of the conclusions.Elementary considerations show that even for a completely random arrangement of atoms the statistical fluctuations of density will give a spotty contrast with spots of minimum diameter determined by the dark field aperture size and other factors influencing the minimum resolvable distance under darkfield imaging conditions, including fluctuations and drift over long exposure times (resolution usually 10Å or more).


2016 ◽  
Vol 136 (3) ◽  
pp. 141-146 ◽  
Author(s):  
Akira Kawasaki ◽  
Kenichi Kubota ◽  
Ikkoh Funaki ◽  
Yoshihiro Okuno

Sign in / Sign up

Export Citation Format

Share Document