Importance of self-shielding for improving sensitivity coefficients in light water nuclear reactors

2014 ◽  
Vol 63 ◽  
pp. 417-426 ◽  
Author(s):  
Basma Foad ◽  
Toshikazu Takeda
1998 ◽  
Vol 540 ◽  
Author(s):  
C. Degueldre ◽  
M. Pouchon ◽  
M. Doebli ◽  
G. Ledergerber

AbstractA zirconia based ceramic is foreseen as an inert matrix fuel for burning excess plutonium in light water nuclear reactors. For reactor safety reasons the behaviour of volatile fission products such as cesium and iodine must be studied since a retention of fission products is favourable for licensing the studied inert matrix fuel. In this study, implantation of Cs and I was performed into polycrystalline (Zr0.85, Y0.15)O1.925 samples. The implantation depth was selected on the basis of the ability to observe by Rutherford backscattering spectroscopy (RBS) the behaviour of Cs and I after treatment. With a 1 MeV incident energy, the ions are implanted at a depth of 200 nm as predicted by TRIM. After implantations full quantification of I and Cs concentration profiles was performed by RBS. The implantation profiles are measured as a function of sample temperature during stepwise heating programs. It is interesting to observe retention of Cs and I at relatively high temperature (e.g. for 2 h, below 900 K for Cs and below 1400 K for I). This behaviour is likely to be due to the size and interactions of these species in the zirconia solid solution.


JOM ◽  
2016 ◽  
Vol 68 (11) ◽  
pp. 2938-2943 ◽  
Author(s):  
P. J. Blau ◽  
J. Qu ◽  
R. Lu

JOM ◽  
2016 ◽  
Vol 68 (11) ◽  
pp. 2912-2921 ◽  
Author(s):  
Zs. Rak ◽  
C. J. O’Brien ◽  
D. W. Brenner ◽  
D. A. Andersson ◽  
C. R. Stanek

1987 ◽  
Vol 78 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Edward C. Beahm ◽  
Yun-Ming Wang ◽  
Simon J. Wisbey ◽  
William E. Shockley

Author(s):  
Henryk Anglart

Post-dryout heat transfer plays an important role in safe and economical operations of Light Water Reactors (LWR). This type of heat transfer is avoided under normal operational conditions of nuclear reactors; however, it may occur in transient or accidential situations. To estimate the risk of clad damages due to increase of temperature associated with the occurrence of post-dryout, it is necessary to properly model heat transfer processes under such conditions. The influence of various parameters on heat transfer downstream of spacer has been investigated. It is concluded that heat transfer enhancement due to spacers is largely under-predicted for flows with relatively low quality. For such flows the effect of droplets impinging heated walls is significant and must properly be taken into account. The phenomenological model presented in this paper shows a superior accuracy over correlations and presents a potential to capture the phenomenon of rewetting that occurs downstream of spacers.


Sign in / Sign up

Export Citation Format

Share Document