Nowadays thousands of radioactive sources are used in hospitals, scientific research, agriculture and industry. The activity of these sources varies according to the needs of the domains. The use, the storage of these sources require laws, rules to follow, according to the category and this from the reception until the end of use according to their categories. The IAEA has published quite a few documents and guides that present the code of conduct (CoC) that the user must follow from the ordering of the source until storage after exhaustion or return to the manufacturer. Negligence of nuclear security protocols and non-compliance with the COC can lead to disastrous consequences even if the activity is not considerable. A presentation of the principle of nuclear security will be presented in this document as well as the CoC of the AiEA The nuclear security culture is necessary to ensure the protection of the population against the misuse of these sources, whether by mistake or malicious acts.