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Pressurized water reactor (PWR) cores operate under extreme environmental conditions due to coolant chemistry, operating temperature, and neutron exposure. Extending the life of PWRs requires detailed knowledge of the changes in mechanical and corrosion properties of the structural austenitic stainless steel components adjacent to the fuel (internals) that are inherent to such conditions. This program represents the first time that significant amounts of PWR internals have been available to allow the effects of reactor service on the materials' mechanical and corrosion properties to be determined. This report contains the results of room temperature and elevated temperature tensile testing and of elevated temperature slow strain rate tensile corrosion testing (SSRT) of samples machined from decommissioned reactor internals. Tensile testing revealed that the yield strength and ultimate tensile strength of annealed 304SS at room temperature both increase as a result of neutron irradiation. Unirradiated values for room temperature yield strength and ultimate tensile strength (from the retrieved material certification sheets) are oy = 35 ksi (240 MPa), T.S. % 80 ksi (550 MPa), respectively. Irradiation causes an increase of approximately 400% in the yield strength and 80% in the ultimate tensile strength at approximately 5 dpa, at which point the strength increase is nearly saturated. Unirradiated values for yield strength and ultimate tensile strength at 608°F (320°C) (by testing nearly unirradiated program material) are oy = 25 ksi (170 MPa), T.S. 65 ksi (450 MPa). Irradiation causes an increase of approximately 500% in the yield strength and 190% in the ultimate tensile strength at approximately 5 dpa, at which point the strength increase is nearly saturated. At room temperature, and for high levels of neutron irradiation, the yield strength and ultimate tensile strength become similar, but yielding and necking do not coincide as a result of the high ductility enabled by a martensitic phase transformation from the austenitic parent phase. Specimens having the highest levels of irradiation failed intergranularly. At elevated temperature (608"F, 320°C) there appeared to be very little or no martensitic phase transformation, and the yield point coincided with the onset of necking. Material strength at elevated temperature was lower than at room temperature. At elevated temperature there is a marked decrease in ductility compared with room temperature, however all specimens failed in a ductile manner. There is little change in properties as measured by tensile specimens of different sizes, in strength or in ductility. Tensile properties measured with the miniature gage diameter specimens may be regarded as typical of those that would be obtained with a larger specimen design.