Fuel Integrity Monitoring System for Lead-Cooled Reactor Applications 1

Job description

Background and Motivation Fuel integrity is a fundamental safety requirement in nuclear systems. Early detection of fuel cladding failure is crucial to ensure operational safety, extend component lifetime, and support accident management strategies. In advanced lead-cooled reactor concepts, detection of fission gas release from failed fuel rods is one of the most promising monitoring strategies. The HELIOS-3 experimental facility, currently used for research on lead chemistry and thermal-hydraulics, offers a unique opportunity to test innovative fuel integrity monitoring systems (FIMS) under representative liquid lead conditions. This project aims to design and experimentally assess possible leak-detection concepts for integration in lead-cooled fast reactors (LFR). Objectives The goal of the master thesis is to design, experimentally evaluate a fuel leak detection system compatible with lead-cooled environments. Specific objectives are: Adaptation of the current approach: Modify the HELIOS-3 bubbling system by adding a newly designed bubble sparger. Demonstrate that leaked fission-gas simulants can be collected by buoyancy and transferred to a mass spectrometer for analysis. Include a new bubble capture system Evaluation of the capture tube: Characterisation: Define advantages, limitations and integration constraints Methodology The work will include: Literature review: previous thesis and papers produced at SCKCEN; survey fuel integrity monitoring approaches in LFR concepts (BREST, SEALER, MYRRHA). Conceptual design: Develop system layouts adapted to HELIOS-3 (geometry, tubing, sensor integration). Experimental setup: Propose modifications to existing HELIOS-3 instrumentation (e.g. bubbling injector, hollow pipe) . Testing and analysis: Simulate gas leakage (e.g., Ar/N2 injection) and evaluate capture efficiency, bubble transport, and detection reliability. Expected Outcomes A conceptual design for a fuel integrity monitoring system adapted to HELIOS-3. Proof-of-concept results on gas bubble detection and transport. Recommendations for scaling up to an LFR prototype or demo reactor. Relevance This project aligns with the strategic objectives of LFR technology development , where compact and reliable monitoring solutions are required. Its results will contribute to improved safety case demonstration for fuel integrity, as well as to the validation of innovative instrumentation for operation in liquid lead. Profile The successful candidate will have a bachelor’s in engineering or physics or similar with focus on thermal/fluid management/interaction. Prior knowledge in ANSYS-FLUENT as well as MATLAB/PYTHON is not fundamental, but it is a plus. She/He is willing to take up responsibilities and able to work independently in a multinational environment.