to the sea through hull penetrations. However, the technology has not yet 

 been developed that would allow the hull penetrations required for adequate 

 heat removal at the high power levels for depths of 6,000 feet and more. 



In addition to the feasibility of fabricating pressure hulls of adequate 

 size to enclose the power plant equipment, a suitable technique for heat 

 removal must be developed for large submersible power plants. Because of 

 the major developmental effort that would thus be required, the larger 

 power plants of 1 ,000 and 3,000 kw at depths of 6,000 feet and over were 

 eliminated from further consideration in this study program. 



A potential means of meeting large power loads is to use several small 

 power sources. However, some of the technical problems involved in 

 paralleling multiple units are related to electrical characteristics, deployment, 

 and retrieval. In addition, the cost would be very great for multiple units. 



conversion 

 machinery 



i 



■LJ^^; 



sen 



Figure 3. In-situ power plant arrangement for 1,000 and 3,000 kw. 



The physical parameters of pressure hulls for various reactor power 

 plants at operating depths of interest are shown in Table 4. Minimum 

 diameters have been estimated for the reactor based on obtaining access to 

 the pressure hull for hull inspection and maintenance (painting). For carbon 

 steel hulls, these diameters vary from 9 feet for the 30-kw plant to 21 feet 

 for the 3,000-kw plant. Two factors which will significantly modify these 

 dimensions are the type of material in the pressure hull and the extensive use 

 of iron shielding to suppress neutron flux levels and reduce activation of the 

 pressure hull. The high-strength steels, HY 80 and HY 130, which contain 

 nickel with cobalt impurities, are not the most effective for shielding. HY 18( 

 steel contains almost 5% cobalt and requires diameters approximately 2 feet 

 larger than the lower strength steels. Material activation is of importance in 

 the design of the pressure hull. 



17 



