ORNL-2106 - the Molten Salt Energy Technologies Web Site

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ANP PROJECT PROGRESS REPORT
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UNCLASSIFIED
ORNL-LR-DWG 44946
Fig. 1.1.4. Cross Section Used in Composite-
Deck Analysis.
purpose, calculations have been undertaken to
obtain preliminary estimates of the energy-
deposition rates throughout this region (see Chap.
1.2, “Art Physics”). The locations in the north
head at which these rates might lead to relatively
large temperature rises are indicated in Fig. 1.1.5.
The calculations of the associated temperature
distributions and the thermal stresses are presently
under way, If these calculations yield excessive
temperature gradients, it is planned to review the
initial energy-deposition estimates and, if neces-
sary, perform more precise analyses.
Sodium Expansion Tank Design
The design analysis of the sodium expansion
tank was completed, and the configuration which
was found to be acceptable from both the pressure
and thermal stress viewpoints is shown in Fig.
1.1.6. The proposed design consists of a vertical
wall of more or less elliptical shape ioined to
an end cap of slightly cylindrical curvature. This
cap (or roof) is welded to the control-rod thimble,
which passes through the center of the ellipse.
The stress analysis of this design was based on
an idealized model consisting of a short, elliptical
cylinder with a flat-plate cap subjected .to an
22
A
internal pressure of 30 psi. The stresses in the
cap were computed from the relations for an
elliptical plate with various edge conditions. The
stresses at the joint and in the vertical walls
were computed from the relations for an equivalent
circular cylinder with a flat head. These calcu-
lations indicate that the maximum stress (1000
psi) is due to the bending moment at the cylinder-
cap junction.
During full-power operation the tank will be
partially filled with sodium at 127O0F to an
assumed depth of 2 in., and the upper portion of
the side walls and the roof of the tank will be ex-
posed to direct gamma radiation from the sodium
(Fig. 1.1.7). The outer surfaces of the tank are
to be surrounded by insulating material, and, if
no cooling is provided for these surfaces, the
metal temperature in the roof will rise to 1420OF.
Since the side walls are to be welded to the
pressure shell, which will be at 125OoF, there
will be differential thermal growth between the
roof and the sheII,which willgive rise to a’thermal
stress of 80,000 psi (based on an elastic analysis)
at the roof-wall intersection. This stress is con-
sidered to be excessive; and therefore cooling is
to be provided for the roof, Sodium at a tempera-
ture of 1250°F will be taken from the pressure-
shell cooling circuit and fed into a system of
tubes welded to the bottom surface of the roof.
A total flow of 3 gpm will pass through this circuit
at a pressure drop of 15 psi. The coolant sodium
will leave the roof circuit at 1270°F and spill
into the expansion tank volume, With this supply
of coolant, the average roof temperature will be
reduced to 128OOF. The temperature profiles in
the roof in the vicinity of a-cooling tube are shown
in Fig. 1.1.8. The maximum thermal stress due to
this temperature structure is 10,000 psi.
ALUMINUM NORTH-HEAD MOCKUP FLOW
STUDIES
E. R. Dytko’
R. Curry’ R. E. MacPherson
D. Ward
A full-size aluminum mockup of the fuel system
components in the north head of the ART has been
set up with external piping to complete the
20n assignment from Pratt & Whitncy Aircraft.
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