Kilowatt Isotope Power System, Phase II Plan. Volume IV. Teledyne FSCD vs GDS Page: 117 of 264

                                
3. 0 - GROUND DEMONSTRATION SYSTEM

3.5.1          Heat Generation System
3.5.1.2        Summary
The Electrical Heat Source Assembly (EHSA) is a circular, stopped cylinder which
measures 12. 70 inches diameter at the mounting end (13.60 inches diameter at the
three mounting lugs), 10. 22 inches diameter at the midpoint, 12. 02 inches diameter
at the upper end, 28. 84 inches overall length from boiler tube inlet to outlet fitting and
weighs 80 pounds. See Figures 3.5. 1. 2-1A and B. There are three EHSA's in the Ground
Demonstration System (GDS) each supplying 2400 W(t) input to the GDS system for con-
version to output power.
Each EHSA is attached to the GDS baseplate by means of a triangular share ed, three
legged support structure. Electrical power input and in-trumentation receptacles,
as well as the inlet connections to the boiler assembly, are located in the mounting
(lower) end of the unit. The outlet connections to the boiler assembly are located in
the upper end of the unit. The EHSA is designed to permit end loading/unloading of
the electrical heat source without having to disturb either of the boiler assembly tube
connections. The unit also has the capability of being suspended from its upper end
by using a special fitting which threads into the center of the upper cover.
Each of the EHSA's in the GDS is identical except for the boiler centerbodies and the
location of instrumentation on each boiler assembly. The major components of an
EHSA are the housing, upper and lower end covers, penetration fitting assemblies,
fibrous insulation, multifoil insulation system, radiation barrier, electrical heat source
and the boiler assembly. See Table 3.5. 1. 2-I for a listing of individual components,
materials and weights.
Housing
The housing is machined from a hollow tube, 6061-T6 aluminum alloy forging which
initially measures 14. 00 inches outside diameter by 2. 50 inches wall thickn ess by
2.50 inches wall thickness by 23. 00 inches long. See Figure 3. 5. 1. 2-2 for final machined
configuration and dimensions. Based upon structural analysis aluminum was chosen
for the housing material because of its strength to weight characteristics. Price per
forging and availability were other selection factors. Because the physical properties
of such a large billet of material are not covered in existing commercial specifications,
room temperature tests were performed in accordance with ASTM E8-69 on test rings,
in each of three directions, to document ultimate and yield strengths as well as elonga-
tion characteristics of the basic forged material. These properties were then sub-
stituted for the properties used in the structural analysis to determine wall thicknesses
at various points in the housing.
In each end of the housing there is anAcme thread which allows each end cover to be
attached by using a specially machined lock ring. After machining and cleaning oper-
tions, a glass bead finish is applied to all exterior surfaces to remove machine tool
arks and to improve surface apprearance. The housing weight is 10. 13 pounds.

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