To support the development of the scientific and technical bases that could lead to the commercialization of the Pebble Bed High Temperature Gas Cooled Reactor, Oregon State University (OSU) is in the process of developing a conceptual Pebble Bed experimental test program. OSU designed and constructed the integral effects test (IET) facility to study Very High Temperature Gas Cooled Reactors (VHTR). The facility, called the High Temperature Test Facility (HTTF), reproduces the integral transient thermal hydraulic response under various accidents conditions of the prototype reactor design. The test data will serve as a basis for thermal hydraulic code validation. The OSU HTTF, currently configured to model a prismatic core block design, may be capable of meeting the needs for a pebble bed reactor system integral test program. In order to do that, a redesign of the facility is required. Redesign criteria should not only conform to the existing facility layout but also follow the similarity criteria and be coherent with dimensional analyses with reference to the selected prototype, pebble bed reactor model. The objective of this paper is to expand the utilization of a currently operating integral gas cooled reactor thermal fluid test facility to the validation of the design and safety thermal-hydraulic methods of the pebble bed reactor. The experiments that will be used to generate data for the NGNP thermal-fluids validation matrix will most be related to the Chinese HTR-PM reference reactor via scaling relationships. This paper summarizes test facility redesign aspects including scaling parameters, materials selection, components replacement, heating concept and instrumentation needs.