It is an aluminosilicate-based cesium retention concept for HTGR fuel.
Aluminosilicate is dispersed in the fuel matrix surrounding TRISO particles to capture cesium and immobilize it as pollucite.
Enhancing Cesium Retention
Without Redesigning TRISO Particles
A matrix-integrated aluminosilicate Cs getter technology
for HTGR and advanced TRISO fuel systems.
Key Points
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No TRISO Particle
RedesignMatrix-side chemical retention
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Cs Retention Demonstrated
at 1600°CAr / air atmosphere testing
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Pollucite Formation
ConfirmedCsAlSi2O6 identified by FIB-TEM
Technical Summary
Matrix-Integrated Cs Getter Technology is an aluminosilicate-based cesium retention concept for HTGR and advanced TRISO fuel systems. The technology is designed to chemically capture cesium in the fuel matrix without redesigning TRISO particles. Laboratory-scale testing demonstrated cesium-bearing phases after 1600°C exposure under Ar and air atmospheres, and FIB-TEM identified CsAlSi2O6 / pollucite as the reaction product. Further fuel-form validation is required before practical application.
Problem
In conventional HTGR fuel, cesium may migrate from the fuel kernel through the TRISO coating and fuel matrix, potentially reaching the primary circuit.
Cs migration remains a key source-term challenge in HTGR fuel.
Fuel kernel
TRISO coating
Cs migration
Fuel matrix
Primary circuit deposition
Technology: Matrix-Side Cesium Capture
An aluminosilicate dispersed in the fuel matrix captures Cs and immobilizes it as pollucite.
Advantages
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Minimal Impact on TRISO Particle Design
Adds functionality to the fuel matrix without modifying TRISO particles.
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Additional Chemical Retention Layer
Complements the physical barrier function of TRISO coatings.
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High-Temperature Evidence
Cs-bearing phases were observed after 1600°C exposure.
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Applicable to Multiple Fuel Forms
Potentially applicable to pebble and compact fuel forms.
Experimental Evidence at 1600°C
Experimental validation at 1600°C
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What was tested
Graphite–aluminosilicate mixture exposed to Cs
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Test conditions
1600°C under Ar and air atmospheres
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What was observed
Cs-bearing phases remained after heating
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What was identified
CsAlSi2O6 / pollucite by FIB-TEM
Development Roadmap Toward Fuel-Form Validation
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Step 1
Fuel Matrix Fabrication
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Step 2
Quantitative Cs Retention Testing
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Step 3
Irradiation Stability Evaluation
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Step 4
Fuel Performance Modeling
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Step 5
Fuel-Form Validation
Collaborative Development Framework
Collaboration Opportunities
We are seeking partners for fuel-form validation and future application studies.
Possible collaboration areas:
- Getter-loaded fuel matrix fabrication
- Thermal and mechanical property evaluation
- Quantitative Cs retention testing
- Irradiation stability evaluation
- Fuel performance evaluation
- Reactor-specific applicability studies
- Initial discussion
- Fuel-specific validation plan
- Joint testing / modeling
- Technology assessment
Potential Applications
Potential application areas include:
- HTGR pebble fuel
- HTGR compact fuel
- Advanced TRISO fuel systems
- Fuel-form validation studies
- Cs retention enhancement studies
FAQ
Frequently Asked Questions
In HTGR fuel, a fraction of cesium may migrate from TRISO particles into the surrounding fuel matrix and potentially reach the primary circuit.
This technology is designed to add a chemical retention function within the fuel matrix to reduce cesium migration at the fuel-form level.
No.
The concept is designed to add cesium retention functionality to the surrounding fuel matrix without modifying the TRISO particle itself.
Aluminosilicate reacts with cesium to form cesium aluminosilicate, known as pollucite.
This reaction immobilizes cesium as a stable solid phase within the fuel matrix.
Cesium-bearing phases were observed after exposure at 1600°C under both Ar and air atmospheres.
FIB-TEM analysis identified CsAlSi2O6, or pollucite, as the cesium-bearing reaction product.
Further validation is needed before practical application.
Key next steps include fuel-form fabrication, quantitative cesium retention testing, thermal and mechanical property evaluation, irradiation stability evaluation, and reactor-specific applicability studies.
Potential collaboration areas include getter-loaded fuel matrix fabrication, thermal and mechanical property evaluation, quantitative cesium retention testing, irradiation stability evaluation, fuel performance evaluation, and reactor-specific applicability studies.
Publications & Patents
- Conference paper
- Journal publication
- Japanese patent granted
- PCT application filed
- MEXT Innovative Nuclear R&D Program
Research Team
Principal Investigator
Koei Sasaki, JAEA
Contact
For technical discussion, collaborative research, licensing, or conference-related inquiries, please contact us through the inquiry form.
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