The above computations are considered conservative for nominal 

 pressure hull collapse loads. However, a detailed analysis of the final structure 

 design for a submersible hull is required before definitive collapse pressures 

 can be defined. 



Material Selection. The selection of materials for in-situ plant pressure 

 hulls depends on submergence depth, size, cost, and weight-to-displacement 

 ratio. HTS and HY 80 steels were selected for hulls at depths of 600 to 

 2,000 feet, HY 130 steel for hulls at depths of 6,000 to 15,000 feet, and 

 HY 180 steel for hulls at depths of 15,000 to 20,000 feet. As stronger 

 material becomes available, a reevaluation of the material selection should be 

 made for these depths. 



Corrosion and Fouling Protection Systems. A 5-year or more 

 no-maintenance mission was established for the in-situ plant pressure hull. 

 To meet this requirement, very high quality corrosion protection systems 

 are required. Paint coating systems, metallized coatings, antifouling paints, 

 and cathodic protection systems were considered. The preferred systems 

 selected for a 5-year no-maintenance life include the following. 



1. Paint coating systems consisting of zinc-based primers followed by 

 several coats of vinyl or straight epoxy paints, with one or two 

 coats of copper-base antifouling paint on the outer surface. 



2. Metallized coating systems consisting of 3 to 5 mils of flame-sprayed 

 aluminum sealed with a combination of vinyl sealing and top coating 

 paints and finished with a full wet coat of organotin antifouling 

 paint. 



3. Cupronickle plating systems for steel hulls applied by explosive or 

 roll bonding or flame spraying to provide a corrosion-resistant sur- 

 face with inherent antifouling characteristics. 



For long life, supplementary cathodic protection should be provided 

 in areas where noble metal is concentrated or where stray electrical currents 

 can occur. Both sacrificial zinc anode and impressed current systems can 

 serve this purpose. The preferred protective coatings would have to be 

 analyzed further to determine their relative heat transfer characteristics on 

 pressure hulls used as heat exchangers. 



Analysis of In-Situ Plant Configuration 



Several constraints, assumptions, and requirements dictate the 

 configuration or arrangement of the in-situ power plant and its deployment. 

 Since it was established that the load module would be deployed with the 



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