Patent ID: 8461540

Claim:
An inside-tube-wall radioactive contamination monitor to monitor for radioactive contamination of an inner surface of a tube, comprising: a rod-like light guide bar whose section is polygonal; a plurality of scintillators mounted on an outer circumference of the rod-like light guide bar; a net-like protective tube attached to cover an outer circumference of the plurality of scintillators with a space to a surface of the scintillators; a guide portion in a shape in which a diameter decreases with a decreasing distance to a tip of the guide portion, the guide portion being attached to a tip portion of the net-like protective tube and supporting a tip portion of the rod-like light guide bar; a photoelectric conversion unit coupled to a base end of the net-like protective tube and containing a photoelectric conversion element; and a signal processing unit connected to the photoelectric conversion unit.