complicated turbulent flow, the standard k-ε model for high Re number type was
used for a turbulence model. Heat deposition distribution by the primary proton
beam, which was calculated by a hadronic cascade code PHITS [8], was used for
the analysis. The internal pressure to the inside of the beam window was set to
0.3 MPa in consideration of the flowing Pb-Bi and the cover gas. On the outer side
of the beam window and the border of the atmosphere, release of the radiant heat
was considered. Embrittlement of the structural materials by irradiation was not
considered.
The analyses were performed by changing flow rates from 1 to 4 l/s. In each case,
a dead region was commonly formed in the center of the inside of the beam
window. The maximum velocity of Pb-Bi was confirmed at the rectification lattice
part and was approximately 1.2 m/s in the case of the inlet flow rate of 1 l/s. When
the inlet flow rate increased to 4 l/s, the maximum velocity in the target reached
4.8 m/s, which is too high to apply to the Pb-Bi target. The maximum temperature is
544
C in the case of a 3-mm-thick window. The peak temperature can be decreased
to 477
C in the case of 2-mm-thick window. The temperature differences between
outside and inside at the center of the window were 65 and 37
C in the case of the
3-mm-thick window and the 2-mm-thick window, respectively. From these results,
it was determined that a condition of 2 mm was desirable.
Based on the results provided by STAR-CD, analysis to verify the feasibility of
the beam window was performed by ABAQUS code. The operating conditions for
the first stage of material irradiation in TEF were decided by a result of the analysis
on each condition. The temperature and thermal stress for the steady state were
estimated using ABAQUS code, the computational code for the finite-element
method. In the ABAQUS code, only a beam window was modeled as the
cylinder-slab geometry. From the analysis result for the 2-mm-thick window, the
stress strength reached the maximum value of 190 MPa on the outer surface of the
beam window. When the maximum temperature of the beam window is adopted to
470
C from the result of STAR-CD, maximum stress is lower than the tolerance
level of the materials for fast reactor, and hence, the feasibility of a designed beam
window was confirmed.
Fig. 8.2 Prototype LBE
spallation target for TEF-T
8 Design of J-PARC Transmutation Experimental Facility
77
used for a turbulence model. Heat deposition distribution by the primary proton
beam, which was calculated by a hadronic cascade code PHITS [8], was used for
the analysis. The internal pressure to the inside of the beam window was set to
0.3 MPa in consideration of the flowing Pb-Bi and the cover gas. On the outer side
of the beam window and the border of the atmosphere, release of the radiant heat
was considered. Embrittlement of the structural materials by irradiation was not
considered.
The analyses were performed by changing flow rates from 1 to 4 l/s. In each case,
a dead region was commonly formed in the center of the inside of the beam
window. The maximum velocity of Pb-Bi was confirmed at the rectification lattice
part and was approximately 1.2 m/s in the case of the inlet flow rate of 1 l/s. When
the inlet flow rate increased to 4 l/s, the maximum velocity in the target reached
4.8 m/s, which is too high to apply to the Pb-Bi target. The maximum temperature is
544
C in the case of a 3-mm-thick window. The peak temperature can be decreased
to 477
C in the case of 2-mm-thick window. The temperature differences between
outside and inside at the center of the window were 65 and 37
C in the case of the
3-mm-thick window and the 2-mm-thick window, respectively. From these results,
it was determined that a condition of 2 mm was desirable.
Based on the results provided by STAR-CD, analysis to verify the feasibility of
the beam window was performed by ABAQUS code. The operating conditions for
the first stage of material irradiation in TEF were decided by a result of the analysis
on each condition. The temperature and thermal stress for the steady state were
estimated using ABAQUS code, the computational code for the finite-element
method. In the ABAQUS code, only a beam window was modeled as the
cylinder-slab geometry. From the analysis result for the 2-mm-thick window, the
stress strength reached the maximum value of 190 MPa on the outer surface of the
beam window. When the maximum temperature of the beam window is adopted to
470
C from the result of STAR-CD, maximum stress is lower than the tolerance
level of the materials for fast reactor, and hence, the feasibility of a designed beam
window was confirmed.
Fig. 8.2 Prototype LBE
spallation target for TEF-T
8 Design of J-PARC Transmutation Experimental Facility
77