Quantitative evaluation of radiation protection in industrial gamma radiography through regulatory inspection

Industrial gamma radiography is one of the industrial activities deemed as high radiological risk. It is classified by IAEA as Category 2, among five classes, due to the high probability of occurrence of radiological accidents and the use of high radioactive activity sources. Industrial radiography is responsible of relatively significant number of accidents in the world. These conditions have been receiving special attention from the Regulatory Authorities to maintain a high radiation protection level in radiography installations. This work presents a methodology to evaluate quantitatively the radiation protection in industrial gamma radiography installations during regulatory inspection. It was based on five steps: (1) analysis of 40 radiological accidents cases published by IAEA; (2) link among these accident cases, the main causes and the requirements items for regulatory inspection; (3) selection of 25 requirements items from step 2 to link with IAEA coercion classification; (4) stipulation of weight value for each coercion group depending on the risk of non-compliance; (5) verification, at the end of regulatory inspection, the negative points received by installation due to its non-compliance, for a total of 390 points. The methodology used showed that the higher score received by the installation means that the radiation protection level is in risk. The quantitative evaluation done after a regulatory inspection is a resource to verify the performance and specially to quantify of radiation protection level based on non-conformities. It can also become a tool of great assistance in the licensing process runs by the Regulatory Authority. (author)