[en] The transportation of Kozloduy NPP’s WWER-1000 spent nuclear fuel requires design and validation of a special transport equipment. The exploitation of such equipment requires the fulfillment of IAEA Safety Standards Series Safety Guide No. NS-G-1.4 recommendations and compliance with the Bulgarian legislation, which states that the maximal dose rate at the external cask surface shall not exceed 2 mSv/h at any point. The cask TK-13/3 together with the internal basket 37/3 are used for the transportation of spent nuclear fuel from the spent fuel pool in the reactor building to the spent fuel storage facility. The dose rate distribution around the TK-13/3 cask is calculated with the widely used and validated for similar analyses software system SCALE. The analysis is done using the latest version of SCALE – 6.2.3 with the application of modules ORIGAMI→ORIGEN→MAVRIC. The results show that all normative requirements and recommendations are met.