[en] The SAREF program requires a panoply of diagnostic techniques in order to obtain needed experimental information. After surveying various fuel motion monitoring techniques, the hodoscope has been chosen as the reference device because of its proven record and because data extrapolations and calculations indicate adequate response for small and large test sections. A hodoscope system for STF would be designed to perform both fuel and clad monitoring during transients. It would also provide distinctive fuel and clad radiographic information before and after transients. Large-test resolution of less than 100 gm and time resolution down to 0.1 msec are projected. Two orthogonal collimators for three-dimensional viewing would each cover 180 x 31 cm viewing area with a combined total of 6000 detectors