摘要：Naturally Occurring Radioactive Materials (NORM) are present in earth’s crust with different concentrations.Human activities such as oil and gas production and mineral extraction and processing could enhance thenatural level of NORM in by-products and waste streams. To protect public and workers from these enhancedNORM sources, clearance levels should be established. Clearance levels are regulatory limits which aredefined in order to protect the environment and human from radiation sources. This study proposes a newapproach to derive both generic and specific clearance levels. This approach consists of two scenariosystems; Generic Scenario System (GSS) and Specific Scenario System (SSS). GSS is a comprehensiveassessment tool which can be applied for any country. GSS is assembled by extensive research and actualNORM management methods. GSS investigates the radiological impacts of NORM from generation throughfinal disposal. SSS is acquired through combination of GSS with field data and observation. This approachsimultaneously considers both human health and economic aspects. To examine the implication of thismethod, Lavan Island in Persian Gulf is chosen for case study. The comparison between the generic andspecific approaches for Lavan Island indicates that most exposure scenarios in generic approach whichcould result in extremely conservative values do not exist in specific scenarios regarding Lavan Island.Exposure groups, waste management options and enclosed circumstances of Islands, make them a preferablelocation to distinguish between SSS and GSS and understand the approach of this paper.
