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of machining or close tolerances. These design
improvements were made possible by relaxing the
restriction that the wall be thin enough to permit
reduction of the permeability to the 10 -7-cn1 2/se~
range by impregnation. This requirement was
eliminated because, as discussed in Part 5, there
appears io be more hope for obtaining very low
Permeability through a surface sealing technique,
which would not be limited by wall thickness, than
through impregnation, which requires thin sections.
The fuel enters and leaves the reactor through
separate pipes rather than by the concentric pipe
arrangement employed in the previous concepts.
The new design eliminates the need for the inner
slip joint and also relieves the thermal stress
problems that existed in certain temperature ranges.
The thermal. expansion loops now shown in the
salt piping add to the fuel salt volume in the sys-
tem, but this is of less significance thao it would
have been in the 40-w/cm3 reactor, which had only
one-half the core volume.
T. W. Pickel W. Terry
The heat exchanger for transfering heat from the
fuel salt to the coolant salt remains essentially
unchanged since the last report. The exchanger
is shown in Fig. 5.11, and the design data are
given in Table 5.3. As mentioned previously,
there has been some change in the salt headers.
Design of the gas sparging system has not been
completed.
5.5 BLANKET HEAT ~ X ~ ~ A ~ G ~ ~
T. W. Pickel W. Terry
No major changes have been made iil the heat
exchanger which transfers heat from the fertile,
or blanket, salt to the coolant salt. The exchanger
is shown in Fig. 5.12, and the pertinent data are
listed in Table 5.4. The blanket heat exchanger
has been lowered in the cell so that the pump
drive shaft will be the same length as the fuel
pump drive shaft and thus allow interchangeability
of parts. The coolant salt piping has also been
modified to replace the concentric piping formerly
used.
76
Table 5.3. Fuel Heat Exchanger Specifications
Number requiied per reactor module I
Rate of heat transfer, Mw
52 9
Rate of heat tiansfer, Btu/hr 1.80 x io9
Shell side
Hot fluid or cold fluid
Entrance temperature, OF
Exit temperature, OF
Entrance pressure, psi
Exit pressure, psi
AI' across exchanger, psi
Mass flow rate, lb/hr
Tube side
Hot fluid or cold fluid
Entrance temperature, O F
Exit temperature, OF
Entrance pressure, psi
Exit pressure, psi
AP across exchanger, psi
Mass flow rate, lb/hr
Tube material
Tube OD, in.
Tube thickness, in.
Tube length, tube sheet to
tube sheet, ft
Inner annulus
Outer annulus
Shell material
Shell thickness, in.
Shell ID, in.
Tube sheet material
Tube sheet thickness, in.
Top outer annulus
Top inner annulus
Floating head
Number of tubes
Inner annulus
Outer annulus
Pitch of inner annulus tubes, in.
Radial
Circumferential
Pitch of outer annulus tubes, in.
Type of baffle
Number of baffles
Inner annulus
Outer annulus
Cold
(coolant salt)
85 0
1110
198
164
31
1.68 lo7
Hot
(fuel salt)
1300
1000
146
50
96
1.09 lo7
Hastelloy N
0.3 75
0.03 5
15.3
16.7
Hastelloy N
1
67
Hastelloy N
1.5
2.5
3.5
4317
3791
0.600
0.673
0.625,
triangular
Doughnut
4
10