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Thermo-hydraulic analysis on Korean helium cooled solid breeder TBM with updated back manifolds design
Fusion Engineering and Design 86 (2011) 2289–2292
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
Thermo-hydraulic analysis on Korean helium cooled solid breeder TBM with updated back manifolds design Mu-Young Ahn ∗ , Duck Young Ku, Seungyon Cho, In-Keun Yu National Fusion Research Institute, Daejeon, Republic of Korea
a r t i c l e
i n f o
Article history: Available online 6 January 2011 Keywords: TBM Thermo-hydraulic analysis Breeding blanket ITER
a b s t r a c t Thermo-hydraulic design of test blanket module (TBM) is challenging in that each component of TBM should be properly controlled within narrow temperature margins in the extreme conditions such as high heat flux from plasma and volumetric heat generation due to neutron irradiation. This paper presents thermo-hydraulic analysis results on the Korean helium cooled solid breeder (HCSB) TBM with the updated design. In the previous study, computation was performed on the TBM model with assumption that the coolant is uniformly distributed at back manifolds, without including the back manifolds in the computational model. In the present study, the updated configuration of the back manifolds is introduced. Flow distribution in each manifold is investigated as well as flow characteristics. Then, thermo-hydraulic analysis on the TBM model is carried out with flow distributions calculated from the flow analysis results on the back manifolds. It is found that the current manifolds are reasonably designed so that the TBM components are effectively cooled against associated thermal loads. © 2010 Elsevier B.V. All rights reserved.
1. Introduction Towards achieving objectives to demonstrate DEMO relevant breeding blanket concepts in ITER, various design and R&D activities are being carried out for the Korean HCSB TBM [1–4]. Although sound progress has been made, it is still challenging to develop the TBM due to its narrow margins with the extreme conditions. In particular it is challenging task from thermo-hydraulic design point of view since each component in the TBM has maximum allowable temperature from material limitation and at the same time the TBM should be operated at elevated temperature for the purpose of tritium release and heat extraction demonstration. Hence, the cooling scheme should be carefully adopted and the cooling capability should be validated through thermo-hydraulic analysis. In the previous study carried out by the authors, the three-dimensional steady state thermo-hydraulic and thermomechanical analysis was performed for the Korean HCSB TBM. The whole TBM was modeled, except the back manifolds of which design is under progress, with assumption that the coolant is uniformly distributed at the back manifolds [5]. After the study, design modification on the side wall was adopted based on the computational results and they also affected on the design evolution of BMs. In this paper, the updated design of the back manifolds is introduced. Flow analysis on the updated back manifolds is per-
∗ Corresponding author. Tel.: +82 42 879 5726; fax: +82 42 879 5799. E-mail address: [email protected] (M.-Y. Ahn). 0920-3796/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.fusengdes.2010.12.010
formed to investigate that the flow is distributed as expected. Then, thermo-hydraulic analysis on the same TBM model as the previous study, but with consideration of simulated coolant distribution from the flow analysis results, is presented. A commercial computational fluid dynamics code, CFX-11, which is a finite volume Navier–Stokes solver, is used for this study. 2. Design and thermo-hydraulic parameters The Korean HCSB TBM comprises the first wall (FW), the side wall (SW), the breeding zone (BZ) and the back manifolds (BMs) as shown in Fig. 1. Main configuration has been maintained. The FW is U-shaped structure with 100 channels of 8 mm × 8 mm size. In the BZ cooling plates, total 60 pipes of 7 mm diameter are piled up in the poloidal direction. The cooling line in the SW and BZ is coupled with the BZ cooling plates so that they are cooled simultaneously. In order to reduce thermal stress, counter-cooling scheme is adopted for the SW and BZ as well as the FW. For details, see Ref. [5]. At backside of the TBM, the BM which is a high pressure manifold system for 8 MPa helium coolant feeding to the TBM components is located. It closes the TBM box structure and provides the support for the mechanical attachment at the interface with ITER Port Plug. The schematic view of the BM is shown in Fig. 2. It will be equipped with flexible supports and shear keys to endure structural loads. The BMs consist of 4 plates of 15 mm thickness, i.e. three BMs. Between the plates, there are flow guides to control the coolant flow distribution. These guides are rib-like structure so that they
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M.-Y. Ahn et al. / Fusion Engineering and Design 86 (2011) 2289–2292
Fig. 1. Exploded view of HCSB TBM.
Fig. 3. Streamline with velocity in BM1.
collecting manifold, it is not included in the study. Then thermohydraulic analysis on the TBM model was carried out with inlet mass flow rate distribution calculated from the flow analysis. In all calculations, steady state conditions were assumed. Since the helium coolant is in turbulent regime, turbulence modeling should be considered in the calculations. Throughout this study, k–ε model was used with scalable wall function. In all cases, hexahedral mesh was constructed with y+ ranging from 20 to 120 near the wall, which is acceptable for the turbulence model with scalable wall function. 3.1. BM1
Fig. 2. Schematic view of BMs.
Table 1 Thermo-hydraulic parameters. Parameter
Values
Neutron wall loading
0.78 MW/m2
FW heat flux Average Peak
0.3 MW/m2 0.5 MW/m2
Thermal Power
1.01 MW
Coolant Pressure Mass flow rate Temperature
He 8 MPa 0.973 kg/s FW (300 ◦ C/390 ◦ C)SW&BZ (390 ◦ C/500 ◦ C)
Fig. 3 shows the configuration of the BM1 with the flow analysis result. The helium coolant of 8 MPa enters from the coolant outer pipe and is distributed to the FW in which there are 50 channels in the upper and lower part, respectively. Since their arrangement is in staggered way to adopt the counter-cooling scheme, the flow is not exactly symmetric on the horizontal guide. For this analysis, only continuity and momentum equations were solved. To control flow distribution, there are 8 flow guides in horizontal, vertical and diagonal directions, and their angles were delicately adjusted in order to flow more coolant to the side edge area. The calculated flow distribution is shown in Fig. 4. The average flow rate is 9.7 g/s. The maximum and minimum flow rates are 10.2 g/s and 8.3 g/s, respectively, and they correspond to 105% and 86% of the average. In overall the flow is uniformly distributed with more flow rates than the average in the side area, as expected. However, the minimum rate in the
could also provide more rigidity to the BMs. Since the maximum temperature was located on side edge area of the FW from the previous results [5], the flow guides were modified so that more flow enters to side edge region. The TBM experiences severe surface heat flux from the plasma and volumetric heat generation by the neutron loading. Although the latest surface heat flux given by ITER loading condition specification is 0.5 MW/m2 , in this study the former surface heat flux of 0.3 MW/m2 is applied. The updated boundary conditions will be imposed in a further design step. Table 1 depicts thermo-hydraulic parameters of the TBM for the present study. 3. Computational results CFX-11 which can solve conjugate heat transfer between fluid and structure as well as Navier–Stokes equations was used for the analysis. For the BM1 and the BM2, flow analysis was performed to investigate flow distribution in each BM. Since the BM3 is only
Fig. 4. Flow distribution in BM1.
M.-Y. Ahn et al. / Fusion Engineering and Design 86 (2011) 2289–2292
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Fig. 5. Streamline with velocity in BM2.
center area is a little bit lower due to the purge gas inlet and outlet. 3.2. BM2 The configuration of the BM2 is depicted in Fig. 5 with the flow analysis result. After cooling the FW, the coolant comes and is distributed to the SW cooling pipes in the BM2. There are total 60 pipes, 30 in right side and 30 in left side. Like BM1, the pipe arrangement is in staggered way to adopt the counter-cooling scheme. Therefore, the flow is not exactly symmetric on the vertical guide. Also only continuity and momentum equations were solved in this case. To control flow distribution, there are 8-shaped flow guides with horizontal and vertical guides. Due to perpendicular guide shapes, vortex and secondary flows are seen around the corner. However, the flow distribution is reasonably uniform except 4 peaks as shown in Fig. 6. The average flow rate is 16.2 g/s. The maximum and minimum flow rates are 18.1 g/s and 15.4 g/s, respectively, and they correspond to 112% and 95% of the average. The peaks take place at the inlet number 4, 9, 21 and 26 where small gaps exist between the guide tips and the SW. And the peaks are due to small portion of flow ingress to the next cooling pipe through the gaps. To prevent this, it is recommended that the guides are completely extended to meet the SW surface.
Fig. 6. Flow distribution in BM2.
Fig. 7. Temperature contour (a) Be armor and (b) structure.
3.3. TBM The thermo-hydraulic calculation was performed for the whole TBM module. In this simulation model, the BMs were not directly modeled. Instead, the inlet mass flow rate distribution in each manifold was taken from the calculated results from the flow analysis on the BM1 and the BM2. The same mesh with the previous study [5] was used, i.e., total mesh nodes 5.35 million with 1.95 million nodes for the coolant and 3.3 million nodes for beryllium armor, structural material (RAFM steel), breeder (Li4 SiO4 pebble), multiplier (beryllium pebble) and reflector (graphite pebble). In this case, full Navier–Stokes equations were solved with 4-node parallel computing. Fig. 7 shows the temperature contour on the beryllium armor and the structural material. As the BM1 result was included in the calculation, the maximum temperature decreases about 4 ◦ C each and area of hot spot in the side edge considerably reduces compared to the previous study. However, the maximum temperature of the structure is still slightly above the allowable temperature limit of RAFM steel, 550 ◦ C in the side edge area where no cooling exists, and new hot spot in the central part is observed due to the low flow rate around the purge line. In the case of the BZ and SW, not much difference was found compared with the previous result as shown in Fig. 8. Temperatures in all the layers composed of breeder, multiplier and reflector are bound to the proper temperature windows. As for the helium coolant, the results are also similar compared to the previous study. Table 2 summarizes the computational results.
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M.-Y. Ahn et al. / Fusion Engineering and Design 86 (2011) 2289–2292
Fig. 8. Temperature contour in breeding zone (a) on the top plane (b) on the middle plane and (c) on the bottom plane.
Table 2 Summary of the computational results. Zone Solid (max/min temperature) Be armor RAFM structural material Li4 SiO4 breeder Be multiplier Graphite reflector Coolant in BM1 Pressure drop Coolant in FW Inlet/outlet temperature Pressure drop Coolant in BM2 Pressure drop Coolant in SW and BZ Inlet/outlet temperature Pressure drop
Results 569 ◦ C/419 ◦ C 561 ◦ C/313 ◦ C 834 ◦ C/412 ◦ C 517 ◦ C/414 ◦ C 575 ◦ C/452 ◦ C 5 kPa 300 ◦ C/379 ◦ C 10 kPa
still slightly over the allowable temperature limit despite of overall improvement. As for the BZ and SW, all the layers are effectively cooled within the temperature window. While further thermohydraulic design optimization is necessary, thermo-mechanical analysis is being carried out using ANSYS-11 on the temperature data exported from the present study. Acknowledgments This research was supported by National R&D Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology and Ministry of Knowledge Economy (2010-0000556)
30 kPa 390 ◦ C/489 ◦ C 609 kPa
4. Conclusions The three-dimensional flow analysis and thermo-hydraulic analysis were performed on the BMs and the whole TBM, respectively. From the flow analysis, simulated flow distributions on the updated BMs were obtained and they were imposed as the inlet boundary conditions for the thermo-hydraulic simulation, rather than modeling the whole TBM with the BMs. The computational results show that temperature of the side edge region of the FW is
References [1] S. Cho, M.-Y. Ahn, D.H. Kim, E.-S. Lee, S. Yun, N.Z. Cho, et al., Current status of design and analysis of Korea helium-cooled solid breeder test blanket module, Fusion Engineering and Design 83 (2008). [2] M.-Y. Ahn, S. Cho, D.H. Kim, E.-S. Lee, H.-S. Kim, J.-S. Suh, et al., Preliminary safety analysis of Korea helium cooled solid breeder test blanket module, Fusion Engineering and Design 83 (2008). [3] S. Cho, M.-Y. Ahn, D.Y. Ku, D.H. Kim, I.-K. Yu, S. Han, et al., Current R&D activities on Korean helium cooled solid breeder test blanket module, Fusion Science and Technology 56 (2009). [4] M.-Y. Ahn, S. Cho, D.Y. Ku, H.-S. Kim, J.-S. Suh, LOCA analysis for Korean helium cooled solid breeder test blanket module, Fusion Engineering and Design 84 (2009). [5] M.-Y. Ahn, D.Y. Ku, S. Cho, I.-K. Yu, Thermo-hydraulic and thermo-mechanical analysis of Korean helium cooled solid breeder TBM, Fusion Engineering and Design 85 (2010), doi:10.1016/j.fusengdes.2010.05.009.
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
Thermo-hydraulic analysis on Korean helium cooled solid breeder TBM with updated back manifolds design Mu-Young Ahn ∗ , Duck Young Ku, Seungyon Cho, In-Keun Yu National Fusion Research Institute, Daejeon, Republic of Korea
a r t i c l e
i n f o
Article history: Available online 6 January 2011 Keywords: TBM Thermo-hydraulic analysis Breeding blanket ITER
a b s t r a c t Thermo-hydraulic design of test blanket module (TBM) is challenging in that each component of TBM should be properly controlled within narrow temperature margins in the extreme conditions such as high heat flux from plasma and volumetric heat generation due to neutron irradiation. This paper presents thermo-hydraulic analysis results on the Korean helium cooled solid breeder (HCSB) TBM with the updated design. In the previous study, computation was performed on the TBM model with assumption that the coolant is uniformly distributed at back manifolds, without including the back manifolds in the computational model. In the present study, the updated configuration of the back manifolds is introduced. Flow distribution in each manifold is investigated as well as flow characteristics. Then, thermo-hydraulic analysis on the TBM model is carried out with flow distributions calculated from the flow analysis results on the back manifolds. It is found that the current manifolds are reasonably designed so that the TBM components are effectively cooled against associated thermal loads. © 2010 Elsevier B.V. All rights reserved.
1. Introduction Towards achieving objectives to demonstrate DEMO relevant breeding blanket concepts in ITER, various design and R&D activities are being carried out for the Korean HCSB TBM [1–4]. Although sound progress has been made, it is still challenging to develop the TBM due to its narrow margins with the extreme conditions. In particular it is challenging task from thermo-hydraulic design point of view since each component in the TBM has maximum allowable temperature from material limitation and at the same time the TBM should be operated at elevated temperature for the purpose of tritium release and heat extraction demonstration. Hence, the cooling scheme should be carefully adopted and the cooling capability should be validated through thermo-hydraulic analysis. In the previous study carried out by the authors, the three-dimensional steady state thermo-hydraulic and thermomechanical analysis was performed for the Korean HCSB TBM. The whole TBM was modeled, except the back manifolds of which design is under progress, with assumption that the coolant is uniformly distributed at the back manifolds [5]. After the study, design modification on the side wall was adopted based on the computational results and they also affected on the design evolution of BMs. In this paper, the updated design of the back manifolds is introduced. Flow analysis on the updated back manifolds is per-
∗ Corresponding author. Tel.: +82 42 879 5726; fax: +82 42 879 5799. E-mail address: [email protected] (M.-Y. Ahn). 0920-3796/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.fusengdes.2010.12.010
formed to investigate that the flow is distributed as expected. Then, thermo-hydraulic analysis on the same TBM model as the previous study, but with consideration of simulated coolant distribution from the flow analysis results, is presented. A commercial computational fluid dynamics code, CFX-11, which is a finite volume Navier–Stokes solver, is used for this study. 2. Design and thermo-hydraulic parameters The Korean HCSB TBM comprises the first wall (FW), the side wall (SW), the breeding zone (BZ) and the back manifolds (BMs) as shown in Fig. 1. Main configuration has been maintained. The FW is U-shaped structure with 100 channels of 8 mm × 8 mm size. In the BZ cooling plates, total 60 pipes of 7 mm diameter are piled up in the poloidal direction. The cooling line in the SW and BZ is coupled with the BZ cooling plates so that they are cooled simultaneously. In order to reduce thermal stress, counter-cooling scheme is adopted for the SW and BZ as well as the FW. For details, see Ref. [5]. At backside of the TBM, the BM which is a high pressure manifold system for 8 MPa helium coolant feeding to the TBM components is located. It closes the TBM box structure and provides the support for the mechanical attachment at the interface with ITER Port Plug. The schematic view of the BM is shown in Fig. 2. It will be equipped with flexible supports and shear keys to endure structural loads. The BMs consist of 4 plates of 15 mm thickness, i.e. three BMs. Between the plates, there are flow guides to control the coolant flow distribution. These guides are rib-like structure so that they
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M.-Y. Ahn et al. / Fusion Engineering and Design 86 (2011) 2289–2292
Fig. 1. Exploded view of HCSB TBM.
Fig. 3. Streamline with velocity in BM1.
collecting manifold, it is not included in the study. Then thermohydraulic analysis on the TBM model was carried out with inlet mass flow rate distribution calculated from the flow analysis. In all calculations, steady state conditions were assumed. Since the helium coolant is in turbulent regime, turbulence modeling should be considered in the calculations. Throughout this study, k–ε model was used with scalable wall function. In all cases, hexahedral mesh was constructed with y+ ranging from 20 to 120 near the wall, which is acceptable for the turbulence model with scalable wall function. 3.1. BM1
Fig. 2. Schematic view of BMs.
Table 1 Thermo-hydraulic parameters. Parameter
Values
Neutron wall loading
0.78 MW/m2
FW heat flux Average Peak
0.3 MW/m2 0.5 MW/m2
Thermal Power
1.01 MW
Coolant Pressure Mass flow rate Temperature
He 8 MPa 0.973 kg/s FW (300 ◦ C/390 ◦ C)SW&BZ (390 ◦ C/500 ◦ C)
Fig. 3 shows the configuration of the BM1 with the flow analysis result. The helium coolant of 8 MPa enters from the coolant outer pipe and is distributed to the FW in which there are 50 channels in the upper and lower part, respectively. Since their arrangement is in staggered way to adopt the counter-cooling scheme, the flow is not exactly symmetric on the horizontal guide. For this analysis, only continuity and momentum equations were solved. To control flow distribution, there are 8 flow guides in horizontal, vertical and diagonal directions, and their angles were delicately adjusted in order to flow more coolant to the side edge area. The calculated flow distribution is shown in Fig. 4. The average flow rate is 9.7 g/s. The maximum and minimum flow rates are 10.2 g/s and 8.3 g/s, respectively, and they correspond to 105% and 86% of the average. In overall the flow is uniformly distributed with more flow rates than the average in the side area, as expected. However, the minimum rate in the
could also provide more rigidity to the BMs. Since the maximum temperature was located on side edge area of the FW from the previous results [5], the flow guides were modified so that more flow enters to side edge region. The TBM experiences severe surface heat flux from the plasma and volumetric heat generation by the neutron loading. Although the latest surface heat flux given by ITER loading condition specification is 0.5 MW/m2 , in this study the former surface heat flux of 0.3 MW/m2 is applied. The updated boundary conditions will be imposed in a further design step. Table 1 depicts thermo-hydraulic parameters of the TBM for the present study. 3. Computational results CFX-11 which can solve conjugate heat transfer between fluid and structure as well as Navier–Stokes equations was used for the analysis. For the BM1 and the BM2, flow analysis was performed to investigate flow distribution in each BM. Since the BM3 is only
Fig. 4. Flow distribution in BM1.
M.-Y. Ahn et al. / Fusion Engineering and Design 86 (2011) 2289–2292
2291
Fig. 5. Streamline with velocity in BM2.
center area is a little bit lower due to the purge gas inlet and outlet. 3.2. BM2 The configuration of the BM2 is depicted in Fig. 5 with the flow analysis result. After cooling the FW, the coolant comes and is distributed to the SW cooling pipes in the BM2. There are total 60 pipes, 30 in right side and 30 in left side. Like BM1, the pipe arrangement is in staggered way to adopt the counter-cooling scheme. Therefore, the flow is not exactly symmetric on the vertical guide. Also only continuity and momentum equations were solved in this case. To control flow distribution, there are 8-shaped flow guides with horizontal and vertical guides. Due to perpendicular guide shapes, vortex and secondary flows are seen around the corner. However, the flow distribution is reasonably uniform except 4 peaks as shown in Fig. 6. The average flow rate is 16.2 g/s. The maximum and minimum flow rates are 18.1 g/s and 15.4 g/s, respectively, and they correspond to 112% and 95% of the average. The peaks take place at the inlet number 4, 9, 21 and 26 where small gaps exist between the guide tips and the SW. And the peaks are due to small portion of flow ingress to the next cooling pipe through the gaps. To prevent this, it is recommended that the guides are completely extended to meet the SW surface.
Fig. 6. Flow distribution in BM2.
Fig. 7. Temperature contour (a) Be armor and (b) structure.
3.3. TBM The thermo-hydraulic calculation was performed for the whole TBM module. In this simulation model, the BMs were not directly modeled. Instead, the inlet mass flow rate distribution in each manifold was taken from the calculated results from the flow analysis on the BM1 and the BM2. The same mesh with the previous study [5] was used, i.e., total mesh nodes 5.35 million with 1.95 million nodes for the coolant and 3.3 million nodes for beryllium armor, structural material (RAFM steel), breeder (Li4 SiO4 pebble), multiplier (beryllium pebble) and reflector (graphite pebble). In this case, full Navier–Stokes equations were solved with 4-node parallel computing. Fig. 7 shows the temperature contour on the beryllium armor and the structural material. As the BM1 result was included in the calculation, the maximum temperature decreases about 4 ◦ C each and area of hot spot in the side edge considerably reduces compared to the previous study. However, the maximum temperature of the structure is still slightly above the allowable temperature limit of RAFM steel, 550 ◦ C in the side edge area where no cooling exists, and new hot spot in the central part is observed due to the low flow rate around the purge line. In the case of the BZ and SW, not much difference was found compared with the previous result as shown in Fig. 8. Temperatures in all the layers composed of breeder, multiplier and reflector are bound to the proper temperature windows. As for the helium coolant, the results are also similar compared to the previous study. Table 2 summarizes the computational results.
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M.-Y. Ahn et al. / Fusion Engineering and Design 86 (2011) 2289–2292
Fig. 8. Temperature contour in breeding zone (a) on the top plane (b) on the middle plane and (c) on the bottom plane.
Table 2 Summary of the computational results. Zone Solid (max/min temperature) Be armor RAFM structural material Li4 SiO4 breeder Be multiplier Graphite reflector Coolant in BM1 Pressure drop Coolant in FW Inlet/outlet temperature Pressure drop Coolant in BM2 Pressure drop Coolant in SW and BZ Inlet/outlet temperature Pressure drop
Results 569 ◦ C/419 ◦ C 561 ◦ C/313 ◦ C 834 ◦ C/412 ◦ C 517 ◦ C/414 ◦ C 575 ◦ C/452 ◦ C 5 kPa 300 ◦ C/379 ◦ C 10 kPa
still slightly over the allowable temperature limit despite of overall improvement. As for the BZ and SW, all the layers are effectively cooled within the temperature window. While further thermohydraulic design optimization is necessary, thermo-mechanical analysis is being carried out using ANSYS-11 on the temperature data exported from the present study. Acknowledgments This research was supported by National R&D Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology and Ministry of Knowledge Economy (2010-0000556)
30 kPa 390 ◦ C/489 ◦ C 609 kPa
4. Conclusions The three-dimensional flow analysis and thermo-hydraulic analysis were performed on the BMs and the whole TBM, respectively. From the flow analysis, simulated flow distributions on the updated BMs were obtained and they were imposed as the inlet boundary conditions for the thermo-hydraulic simulation, rather than modeling the whole TBM with the BMs. The computational results show that temperature of the side edge region of the FW is
References [1] S. Cho, M.-Y. Ahn, D.H. Kim, E.-S. Lee, S. Yun, N.Z. Cho, et al., Current status of design and analysis of Korea helium-cooled solid breeder test blanket module, Fusion Engineering and Design 83 (2008). [2] M.-Y. Ahn, S. Cho, D.H. Kim, E.-S. Lee, H.-S. Kim, J.-S. Suh, et al., Preliminary safety analysis of Korea helium cooled solid breeder test blanket module, Fusion Engineering and Design 83 (2008). [3] S. Cho, M.-Y. Ahn, D.Y. Ku, D.H. Kim, I.-K. Yu, S. Han, et al., Current R&D activities on Korean helium cooled solid breeder test blanket module, Fusion Science and Technology 56 (2009). [4] M.-Y. Ahn, S. Cho, D.Y. Ku, H.-S. Kim, J.-S. Suh, LOCA analysis for Korean helium cooled solid breeder test blanket module, Fusion Engineering and Design 84 (2009). [5] M.-Y. Ahn, D.Y. Ku, S. Cho, I.-K. Yu, Thermo-hydraulic and thermo-mechanical analysis of Korean helium cooled solid breeder TBM, Fusion Engineering and Design 85 (2010), doi:10.1016/j.fusengdes.2010.05.009.