Journal Article

IMPULSE-2026-00043

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Assessment of the Influence of Secondary Sources on the Thermal-Hydraulic Behavior of FRM II Using Serpent 2 and Ansys CFX

Shehu, K.MLZ* ; Bonete-Wiese, D.MLZ* ; Reiter, C. (Corresponding author)MLZ*

2025
Soc. La Grange Park, Ill.

Please use a persistent id in citations: doi:10.1080/00295639.2025.2455348

Abstract: The Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II) reactor is utilized for active engagement in international efforts toward the goal of decreasing usage of highly enriched uranium in civil cycles. This goal can be achieved by changing the current fuel system with a high-density low-enriched uranium fuel. This work is part of a broad parameter study that aims to assess different potential conversion scenarios for FRM II, Germany’s most powerful neutron source. Several geometrical parameters of the core are the subject of the parameter study. Therefore, investigation of the core in terms of neutronics and thermal hydraulics is crucial. The components of the coupling between neutronics and thermal hydraulics are Serpent 2 and Ansys CFX, respectively. Because of the rotational symmetry of the FRM II core, the current thermal-hydraulic calculations are performed on one single plate. Despite the robust and efficient nature of this approach, in this work, the neutronics and computational fluid dynamics (CFD) calculations are taken a step further by taking into account the influence of the hot and cold source installations on the thermal-hydraulic behavior. Furthermore, a proof of concept of the CFD capabilities sequentially coupled to neutronics to model the full core is beneficial for future calculations. Two different cases representing a symmetric heating profile and an asymmetric profile are shown and discussed. The total power deposited in the core remains constant in both cases, while the maximum fuel temperature, cladding temperature, and water temperature calculated for the asymmetric heating case increase by 1.7%, 1.5%, and 1.5%, respectively. Therefore, power asymmetry has minor effects.

Keyword(s): Engineering, Industrial Materials and Processing (1st) ; Instrument and Method Development (2nd) ; Others (2nd)

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Contributing Institute(s):

1. CNSI-THEORY (CNSI-THEORY)
2. CNSI-LABS (HEUMEULAB ; CNSI-LABS)
3. CNSI (RPHYSICS ; CNSI)

Experiment(s):

1. No specific instrument

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Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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