A research project on the development of radiation tolerant compact image sensor with a field emitter array started in 2013. The purpose of the project is to develop key components of the image sensor that has sufficiently high radiation tolerance, as a step to investigate the interior of the nuclear reactor of Nuclear Power Plant Fukushima the 1st. A volcano-structured double-gated Spindt-type field emitter array is now under development. As a photoconductor, a layer of cadmium telluride and cadmium sulfide is adopted. Fundamental characteristics of the image sensor with these components together with the radiation tolerance are examined.