Measuring method of contamination distribution inside radioactively contaminated piping

摘要

In a method of measuring the contamination profile of the inner surfaces of a radioactively contaminated pipe embedded within a concrete structure in a nuclear reactor facility, the detecting surface of a detector to be inserted into the contaminated pipe is fitted with a movable shield plate or cover, which is moved by a specified distance and the radioactive contamination profile within a limited area of the inner surfaces of the pipe is measured in terms of the difference in radiation intensity measured in two states, one where the shield plate or cover is in contact with the detecting surface and the other where it is spaced from the latter.