The stainless steel boiling potassium loop was discontinued after 2265 hours of operation due to a failure in the boiler. Testing of the Haynes25 alloy boiling heat transfer loop was continued to 3600 hours at which time a loop failure terminated the test program. A preliminary dynamic analysis of the SNAP-50/SPUR power plant was completed on the CANEL electric analog computer. Design was continued on the power plant pumps and drive motors. Modifications to the fuel testing program were made to provide an evaluation of fuels at conditions corresponding to those used for Reference Reactor Design No.
Data on potential SNAP-50/ SPUR fuels indicate that serious limitations may exist at design conditions associated with Reference Design No. A pressure vessel test program was initiated for SNAP-50/SPUR designs using ten- inch vessels. The full-scale LCRE prototype vessel completed 4800 hours of a 10,000 hour test. The four-inch more » pressure vessels completed 91 hours of their scheduled 10,000 hour tests. Test temperatures were increased to those of interest for SNAP-50/ SPUR. Environmental tests of control drive components were continued utilizing residual LCRE material. 3 (2 Mwt) which is based on a maximum fuel temperature of 2300F and a maximum fuel burnup of 1.5 percent. Emphasis has been shifted to Reference Reactor Design No. 2 (8 Mwt) was integrated into the SNAP-50/SPUR power plant design. A design study of the integration of the SNAP- 50/SPUR power plant with a space craft for use with the Titan 111C launch vehicle was completed. A preliminary reactor design of both rectangnlar and spherized core shapes was done using a common set of operating conditions so that reactor weights could be compared. A spherized core with fuel pins appeared to offer a potential weight advantage over the cylindrical core. Investigation of the problems and advantages of various core configurations resulted in the conclusion that regardiess of core shape, pin shaped fuel elements and axial coolant fiow present the simplest compact core design. Many design concepts studied are compatible with the LCRE type reactor. In addition, reactor control schemes, compatible with the basic requirement of simplicity, such as movable radiation cooled reflectors and radiation cooled poison drums, were investigated. The reactor pressure vessel and core support structure for these cores were also investigated. Spherical and spherized cylinder cores, (cores in the form of cylinders with hemispherical ends) were investigated because of their inherent minimum core size. The results are presented of a study conducted for the purpose of generating concepts and ideas applicable to the SNAP- 50 system.