Parametric study of the influence of $^{135}$Xe build-up on required excess reactivity for load-following operations

Žerovnik, Gašper (author), Levpušček, Blaž (author), Snoj, Luka (author)

An analytical model was used to study the effect of $^{135}$Xe build-up after reactor shutdown on reactor reactivity, with implications on possible restrictions for reactor operation in the load-following mode. The parameters of the analytical model were estimated using a 2D Serpent Monte Carlo unit-cell model of a typical pressurised water reactor and ENDF/B-VII.1 nuclear data library. Parametric studies to fuel composition, boron concentration in the moderator, and moderator-to-fuel volume ratio were performed. Mixed-oxide fuel has a smaller impact on reactivity decrease than UO$_2$ fuel due to $^{135}$Xe after reactor shutdown and is therefore more suitable for load-following operations. For UO$_2$, higher initial $^{235}$U enrichment is beneficial for the same reason. Similarly, higher boron concentration and less moderated neutron spectrum lead to a less pronounced $^{135}$Xe effect on reactivity. The methodology is general and may in principle be expanded to other operational parameters, fuel and reactor types.

• Language: English
• Keywords: excess reactivity, xenon-135, neutron absorption, Monte Carlo method
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 10 str.
• Numbering: Vol. 424, art. 113297
• PID: 20.500.12556/RUL-160099
• UDC: 539.1
• ISSN on article: 0029-5493
• DOI: 10.1016/j.nucengdes.2024.113297
• COBISS.SI-ID: 204158979
• Publication date in RUL: 20.08.2024

Record is a part of a journal

• Title: Nuclear engineering and design
• Shortened title: Nucl. eng. des.
• Publisher: Elsevier
• ISSN: 0029-5493
• COBISS.SI-ID: 5246730

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: jedrska fizika, poskusni reaktor

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: L2-2612
• Name: Stabilnost jedrskih reaktorjev pri obratovanju v načinu sledenja bremenu

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0073
• Name: Reaktorska fizika