Individual pebble temperature peaking factor due to local pebble arrangement in a pebble bed reactor core
Name
Sobes-Journal Paper v4.pdf
Description
Accepted version
Size
449.82 KB
Format
Adobe PDF
Checksum (MD5)
67766e02e35f64935a7a4e1988e80cf3
Author(s)
Sobes, Vladimir
Forget, Benoit
Kadak, Andrew
Date Issued
2011
Journal
Nuclear Engineering and Design
Publisher
Elsevier BV
Citation
Sobes, V., B. Forget, and A. Kadak. "Individual Pebble Temperature Peaking Factor Due to Local Pebble Arrangement in a Pebble Bed Reactor Core." Nuclear Engineering and Design 241 1 (2011): 124-33.
Version
Author's final manuscript
Abstract
Scientists at the German AVR pebble bed nuclear reactor discovered that the surface temperature of some of the pebbles in the AVR core were at least 200 K higher than previously predicted by reactor core analysis calculations. The goal of this research paper is to determine whether a similar unexpected fuel temperature increase of 200 K can be attributed solely or mostly to elevated power production resulting from exceptional configurations of pebbles. If it were caused by excessive pebble-to-pebble local power peaking, there could be implications for the need for core physics monitoring which is not now being considered for pebble bed reactors. The PBMR-400 core design was used as the basis for evaluating pebble bed reactor safety. Through exhaustive Monte Carlo modeling of a PBMR-400 pebble environment, no simple pebble-to-pebble burn-up conditions were found to cause a sufficiently high local power peaking to lead to a 200 K temperature increase. Simple thermal hydraulics analysis was performed which showed that a significant core coolant flow anomalies such as higher than expected core bypass flows, local pebble flow variation or even local flow blockage would be needed to account for such an increase in fuel temperature. The identified worst case scenarios are presented and discussed in detail. The conclusion of this work is that the stochastic nature of the pebble bed cannot lead to highly elevated fuel temperatures but rather local or core-wide coolant flow reductions are the likely cause. © 2010 Elsevier B.V. All rights reserved.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/j.nucengdes.2010.10.032
