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Initial Activation Assessment for ARIES Compact Stellarator Power Plant. L. El-Guebaly, P. Wilson, D. Paige and the ARIES Team Fusion Technology Institute University of Wisconsin - Madison 16 th TOFE Meeting September 14-16, 2004 Madison, WI. Objectives .
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Initial Activation Assessment for ARIES Compact Stellarator Power Plant L. El-Guebaly, P. Wilson, D. Paige and the ARIES Team Fusion Technology Institute University of Wisconsin - Madison 16th TOFE Meeting September 14-16, 2004 Madison, WI
Objectives • Perform systematic activation assessment for interim ARIES-CS design. • Evaluate: • Activity • Decay Heat • Address waste-related issues: • Waste Disposal Rating • Breakdown of Class A and Class C waste • Any cleared materials?
SiC- and FS-Based Systems Selected for Initial Activation Analysis BreederMultiplierStructureFW/Blanket ShieldVVCoolantCoolantCoolant Internal VV: Flibe Be FS Flibe Flibe H2O LiPb – SiC LiPb LiPb H2O LiPb – FS He/LiPb He H2O External VV: LiPb – FS He/LiPb He/B-H2O He LiPb – FS He/LiPb He He Li – FS He/Li He He
Analysis Performed at Two Radial Cross Sections Magnet Xn through nominal blanket/shield/VV Shield/VV Plasma Blanket Xn through WC-Shield @ min ARIES Compact Stellarator 3 Field Period Configuration
LiPb/SiC Radial Build 5 Thickness (cm) 25 1 25 ≥ 2 25 2.2 18 37 31 2 Blanket Zones SOL FW / Blanket-I (LiPb/SiC) Plasma Gap Winding Pack Blanket-II (LiPb/SiC) FS Shield Gap Gap + Th. Insulator Coil Case & Insulator External Structure Vacuum Vessel | ≥ 140 cm | Thickness (cm) 18 2.2 31 1 2 25 25 25 2 11 5 Shield Only Zones SOL WC Shield Plasma WC Shield Gap Vacuum Vessel Winding Pack Coil Case & Insulator Gap Gap + Th. Insulator External Structure WC Shield min = 114 cm | |
LiPb/FS/He Radial Build 5 1 Thickness (cm) 32 ≥ 2 18 28 2.2 20 2 9 47 4.8 Blanket Zones SOL Blanket (LiPb/FS/He) Plasma Winding Pack FS Shield Gap Gap FW Gap + Th. Insulator Coil Case & Insulator External Structure Back Wall Vacuum Vessel | ≥ 149 cm | 5 Thickness (cm) 18 2.2 20 2 2 28 11 47 4.8 Shield Only Zones SOL Plasma FW Back Wall Vacuum Vessel Winding Pack Coil Case & Insulator Gap Gap + Th. Insulator External Structure WC Shield min = 118 cm | |
Key Parameters for Activation Assessment Average Neutron Wall Loading 2 MW/m2 Replaceable Component Lifetime 6 FPY for SiC 5 FPY for FS Permanent Component Lifetime 40 FPY System Availability 85%
Activity • At intermediate time following shutdown (1 d - 10 y), SiC offers 3-4 orders of magnitude lower activity compared to FS. • WC filler generates highest activity.
Decay Heat • SiC decay heat drops sharply after shutdown, a salient feature. • WC-shield generates 10 - 1000 times higher decay heat than FW/blanket @ 1 d after shutdown. • If temperature during LOCA/LOFA exceeds limit, install special loop to transport decay heat from WC-shield to surroundings.
Waste Disposal Rating(for Compacted Waste @ 100 y After Shutdown) SiC SystemFS System Replaceable Components: FW/Blanket-I 0.03 0.4 WC-Shield 0.8 0.6 Permanent Components: Blanket-II 0.06 --- Shield 0.5 0.7 Vacuum Vessel 0.02 0.05 Magnet < 0.1 < 0.1 • WDR < 1 Class C Low Level Waste (LLW). • SiC-FW/blanket, VV, and magnet qualify as Class A LLW.
Breakdown of Class A and Class C Low Level Waste 34% Class A 66% Class C 63% Class A 37% Class C
Concrete Building can be Cleared Shortly after Plant Decommissioning • Steel structure of building can be released after 20 y storage period. • None of the internal components can be cleared from regulatory control.
Conclusions • No major activation problems identified for SiC and FS systems. • High decay heat identified for WC-shield • Special loop will be installed to transfer decay heat to surroundings if temperature during accident exceeds limit. • All radioactive wastes qualify as Class A and Class C LLW. • None of ARIES-CS components can be cleared from regulatory control except building. Concrete and reinforced steel structure can be released to commercial market after ~0.5 y and ~20 y, respectively.