[en] Measurements of γ-ray dose rate behind a concrete shield wall with a steel-walled straight cylindrical duct were analyzed using a multigroup γ-ray scattering code G-33. The measurements were performed in the Dry Shielding Facility of JRR-4 in various geometrical configurations of 1, 2 and 4 in. in duct diameter, 75 and 150 cm in wall thickness, and 0°, 15° and 30° in incident angle of the γ-ray beam to the duct mouth. The configurations were classified into 3 types, namely, the source area is viewed, perfectly (configuration 1), partially (configuration 2) and not at all (configuration 3), through the duct from the detector point on the duct axis behind the wall. In the configurations 1 ∼ 3 with the thickness 75 cm, the calculated values agreed with the measured ones within 20 % at the positions of the maximum dose rate and within a factor of 2 at the other positions. With the thickness 150 cm, the calculated-to-measured values were about 0.5 at the positions in the duct exit in the configuration 3 and lower than 0.5 at the positions apart from the duct exit in the configurations 1 and 2. (author)