Power Reactor and Nuclear Fuel Development Corporation (PNC), using computer codes developed and/or modified at PNC, has analyzed the Phase IIB passive safety test (PST) proposed for the Fast Flux Test Facility (FFTF). Major interests of PST are understanding core bowing and mitigating extremely low probability accidents. It is confirmed that the PNC code system is applicable to all aspects of the FFTF Phase IIB PST program. Results of the pretest analysis indicate that the proposed Phase IIB PST in FFTF can be devised to provide very useful data for validation of the analytical models that treat reactivity feedback effects due to core bowing. Recommendations to the test program are also made. With those analytical tools, future fast breeder reactor concepts will incorporate to a greater degree than earlier designs passive safety features on neutronic aspects as well as on thermohydraulic aspects.