Usage and conditions of radiation protection of nuclear meters in Brazil

The industries of mining, pulp, oil, etc. which require a quality control in the processes, use the nuclear meters with sealed radioactive sources coupled to a radiation detector that generate accurate and fast answers regarding the level, thickness, density and humidity of different types of materials. Nuclear meters are classified as fixed or portable and use transmission, backscatter or reactive systems. As they use radioactive sources with various ranges of activities, they are classified by the International Atomic Energy Agency - AIEA as Category 3 and 4, of medium and low radiological risk, and must therefore have a suitable level of radiation protection for safe use in the installation. The Brazilian National Energy Commission - CNEN controls approximately 500 authorized facilities with nuclear meters. The paper technically describes the nuclear meters and the radiological protection procedures that must be followed for the safety of the IOEs (occupationally exposed individuals) and individuals from the public, based on the specific nuclear meter test program for CNEN radiation protection supervisor. The professionals who handle these nuclear meters should be aware of the radiological risk to their own protection and to individuals in the public. For safe operation with nuclear meters, a number of requirements must be observed according to the type and need of the installation