Neutronic Assessment of Accident-Tolerant Cladding Concepts for Civil Nuclear Marine Propulsion Cores. Part Ii: Rim Effect and Reactivity Feedback Analysis
Abstract
In this reactor physics study, we examine the neutronic performance of accident-tolerant fuel (ATF) claddings - austenitic type 310 stainless steel (310SS), ferritic Fe-20Cr-5Al (FeCrAl), advanced powder metallurgic ferritic (APMT), and silicon carbide (SiC)-based materials - as alternative cladding materials compared with Zircaloy-4 (Zr) cladding. The cores considered in this study use 18% and 15% 235U enriched micro-heterogeneous ThO2-UO2duplex∗and homogeneously mixed all-UO2fuels, respectively, loaded into 13 x 13 pin arrays. A constant cladding coating thickness of 655 μm was assumed throughout this study. In a companion paper (Part I), we used the WIMS reactor physics code to analyse the associated reactivity, achievable discharge burnup and spectral variations to compare the different neutronic cases for the candidate cladding materials. In this paper (Part II), the relative fission power as a function of radius is evaluated. It is observed that the claddings with lower capture cross-section (SiC and Zr) exhibit higher relative fission power at the pellet periphery. It is evident that build-up of 239Pu is higher in the UO2fuel compared to the duplex fuel for all the candidate claddings. For both the candidate fuels, the end-of-life (EOL) 239Pu (for UO2fuel) and 233U (for duplex fuel) inventories are higher for the claddings with higher thermal capture cross-sections. Reactivity feedback parameters (moderator and fuel temperature coefficients) are also calculated, and values are more negative in the duplex fuel than the UO2fuel for all the candidate claddings. The candidate claddings with harder spectra exhibit more negative reactivity coefficient values than claddings with softer spectra.
Recommended Citation
S. B. Alam et al., "Neutronic Assessment of Accident-Tolerant Cladding Concepts for Civil Nuclear Marine Propulsion Cores. Part Ii: Rim Effect and Reactivity Feedback Analysis," International Conference on Physics of Reactors, PHYSOR 2018: Reactor Physics Paving the Way Towards More Efficient Systems, pp. 3154 - 3165, Curran Associates Inc., Jan 2018.
Department(s)
Nuclear Engineering and Radiation Science
Keywords and Phrases
Accident-tolerant cladding; Plutonium build-up; Reactivity feedback parameters; Relative fission power; Rim effect; Soluble-boron-free (SBF) design
International Standard Book Number (ISBN)
978-171380851-0
Document Type
Article - Conference proceedings
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Curran Associates Inc., All rights reserved.
Publication Date
01 Jan 2018