Fully Ceramic Microencapsulated fuel in prismatic high-temperature gas-cooled reactors: Sensitivity of reactor behavior during design basis accidents to fuel properties and the potential impact of the SiC defect annealing process
| Autor: | Yutai Katoh, Nicholas R. Brown, Gerhard Strydom, Kurt A. Terrani, Takaaki Koyanagi, Cihang Lu |
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| Rok vydání: | 2019 |
| Předmět: |
Nuclear and High Energy Physics
Potential impact Materials science Annealing (metallurgy) 020209 energy Mechanical Engineering Nuclear engineering Control rod 02 engineering and technology 01 natural sciences 010305 fluids & plasmas Thermal conductivity Nuclear Energy and Engineering visual_art 0103 physical sciences Thermal 0202 electrical engineering electronic engineering information engineering visual_art.visual_art_medium General Materials Science Ceramic Irradiation Wigner effect Safety Risk Reliability and Quality Waste Management and Disposal |
| Zdroj: | Nuclear Engineering and Design. 345:125-147 |
| ISSN: | 0029-5493 |
| Popis: | We conducted reactor performance calculations to assess the potential design basis accident performance of HTGR fuel designs. Three Fully Ceramic Microencapsulated (FCM) fueled HTGR designs were developed in a previous work (Lu et al., 2018). The maximum fuel temperature in the cores fueled by these three FCM fuels was predicted to be higher than that in the reference 350-MWt mHTGR core in both normal operating conditions and during representative design basis accidents (Lu and Brown, 2019). To better understand the potential safety margins in mHTGR design basis accidents, we performed thermal-hydraulics sensitivity studies to investigate how maximum fuel temperature varies considering various parameters, e.g. thermal properties, within the ranges corresponding to the differences between the FCM-fueled prismatic mHTGR cores and the reference core with conventional fuel compacts. We found that the difference in the steady-state axial power distribution contributed the most to the difference in the maximum fuel temperature, in both normal operation and design basis accidents. Experimental data suggested that the annealing process of irradiation defects in SiC would be rapid at mHTGR relevant fuel temperatures. The bounding potential impact of the SiC annealing on the maximum fuel temperature was analyzed considering both the thermal conductivity recovery and the Wigner energy release due to the annealing of SiC. We found that the defect annealing process in SiC would at most increase the peak maximum fuel temperature of an FCM-fueled core by 40 K in loss of forced cooling accidents and by 10 K in a control rod withdrawal accident. Additional experiments on the SiC defect annealing kinetics and Wigner energy release in more relevant conditions are needed. |
| Databáze: | OpenAIRE |
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