Hydrogen Isotope Research Center - Toyama Univ.
Data Base for Tritium Solid Breeding Materials (Li2O, Li2TiO3, Li2ZrO3 and Li4SiO4) of Fusion Reactor Blankets --- Yoshiaki FUTAMURA
7. Database for Li4SiO4 (αLi4SiO4)
7.5 Irradiation effects
7.5.1 Physical integrity
| No. | Data and remark | Fig. | Refs. |
| 1 | Poor at 500, 700, 900°C (< 3 at. % burn-up) | - | 23, 35 |
7.5.2 Swelling
| No. | Data and remark | Fig. | Refs. | ||||||||||||||||||||
| 1 |
|
- | 30 | ||||||||||||||||||||
| 2 | Volumetric Swelling of Li2ZrO3 at 700°C. | 7.2 | 49 | ||||||||||||||||||||
| 3 | Diameter Swelling of Li2ZrO3 at 500°C, 700°C, 900°C. | 7.3 | 70 | ||||||||||||||||||||
7.5.3 Grain growth
| No. | Data and remark | Fig. | Refs. |
| 1 | None, at ~1 atom % 6Li burn-up, for 500°C, 700°C
1→2μm, at ~1 atom % 6Li burn-up at 900°C |
- | 36 |
7.5.4 Li transport
| No. | Data and remark | Fig. | Refs. |
| 1 | Burn-up dependence of Li-transfer for Li2O, Li2ZrO3 and Li4SiO4. | 4.28 | 56 |
7.5.5 Thermal conductivity
| No. | Data and remark | Fig. | Refs. |
| 1 | No data (But it is given by thermal conductivity.) | - | - |
| Notes1 | Thermal conductivity κ=α·Cp·ρ (W/m-K)
α : Thermal diffusivity (m2/s) Cp : Specific heat (J/g-K) ρ : Density (g/m3) |
- | - |
7.5.6 Young's modulus --- No data
7.5.7 Tensile strength --- No data
7.5.8 Compressive strength --- No data
7.5.9 Bending strength --- No data
7.5.10 Tritium diffusivity (cm2/s)
| No. | Data and remark | Fig. | Refs. |
| 1 | No single crystal data
D=1.37×10-7exp(–63 kJ/mol/RT) Based on grain size of polycrystalline samples. |
- | 71 |
| 2 | Diffusion Coefficient of Tritium in Oxide Ceramic Breeder Materials is shown in the following Appendix 7.5.10. | - | 42, 43, 44, 45 |
| 3 | Summary of Tritium Diffusion Coef. in Li4SiO4, Li2O, Li2TiO3 and Li2ZrO3. | 7.4 | 18 |
Appendix 7.5.10 Diffusion Coefficient of Tritium in Oxide Ceramic Breeder Materials.6, 42, 43, 44, 45)
| Material | Neutron fluence (cm-2) |
LogD0 (cm2-s-1) |
Q (kJ-mol-1) |
Temp. range (K) |
| Li2O | 8.1×1016 | –4.1±0.5 | 77.4±5.6 | 570~690 |
| Li2ZrO3 | 2.5×1016 | –4.9±0.2 | 75.0±2.2 | 540~730 |
| Li4SiO4 | 2.5×1016 | –6.7±0.1 | 43.8±0.9 | 530~850 |
7.5.11 Tritium residence time (hr)
| No. | Data and remark | Fig. | Refs. |
| 1 | τ=2.24×10-7exp(–63 kJ·mol-1/RT)
dg : ~20 μm, p : ~0.08, 560≦T≦770K, He+0.1 % He purge |
- | 12, 29 |
| 2 | Tritium Residence Times for Li4SiO4. | 7.5 | 12, 29 |
7.5.12 Tritium release
| No. | Data and remark | Fig. | Refs. |
| 1 | Refer to tritium retention and tritium residence time. | - | - |
7.5.13 Tritium retention
| No. | Data and remark | Fig. | Refs. |
| 1 | Tritium retention in Li2ZrO3, Li2O and Li4SiO4 at 700°C. | 6.10 | 49, 50, 48 |
7.5.14 Helium retention
| No. | Data and remark | Fig. | Refs. | ||||||||
| 1 | At 1 atom % 6Li burn-up
|
- | 48 | ||||||||
| 2 | Helium Retention in Li4SiO4 after irradiation. | 7.6 | 48 |
7.5.15 After heat (W/cm3)
| No. | Data and remark | Fig. | Refs. |
| 1 | 0.003 W/cm3, 15 MW. yr/m2 fluence, 1-hr cooling, 85%TD
no impurities : tritium retained in breeder |
- | 62, 65, 90 |
| 2 | 0.0001 W/cm3, 12.5 MW. yr/m2 fluence, 1-hr cooling, 85%TD
no impurities or tritium |
- | 62, 65, 91 |
7.5.16 Class C waste disposal rate
| No. | Data and remark | Fig. | Refs. |
| 1 | 0.14%, at 15 MW. yr/m2 fluence, 10-yr cooling, 85%TD | - | 62, 90 |
| Notes1 | For the base case with no impurities, the U.S. Class C waste disposal rating for Li2TiO3 is roughly equal to that for Li2O and Li4SiO4, and more than 10 times lower than for Li2ZrO3. | - | 65 |
