Radiological Assessments, Environmental 

 Monitoring, and Study Design 



WAYNE R. HANSEN and DONALD R. ELLE 



Studies of the behavior of transuranic elements in the environment form the basic data 

 for applied programs in radiological assessment, environmental monitoring, derivation of 

 radiation-protection standards, and environmental impact statements. This chapter 

 introduces some of the major information requirements of these applications of 

 transuranic research data. Giaracteristics of the source terms from nuclear activities 

 usually are needed for an analysis of environmental pathways or deployment of 

 monitoring systems. Major inhalation and ingestion pathways are considered in 

 assessments of hazards from transuranics and are discussed from the viewpoint of research 

 needed. 



In conducting radiological assessments, writing environmental impact statements, 

 attempting to derive standards, or designing monitoring programs for transuranic 

 elements, one must rely on data from existing studies of transuranic elements in the 

 environment. In each of these types of assessments, man is usually the major receptor 

 considered for a variety of pathways. The data used to estimate the radiological impact of 

 transuranics on man derive from the results of research carried out with a variety of 

 objectives. The objectives may have been hmited to the assessment of a specific pathway 

 at a specific site. Data obtained for a particular pathway or portion of a pathway and 

 geographical area often are applied, with modifying assumptions, to other geographical 

 areas for lack of data specific to the area of interest. 



The design of environmental monitoring programs for estimating radiological effects 

 on man must include consideration of a large number of factors. The following discussion 

 reiterates some of these factors in study design and analysis for use in radiological 

 assessments. A brief discussion of the nontechnical influences on radiological assessments 

 and thus study design is also included. Statistical considerations and modeling are 

 considered elsewhere but will be referred to as necessary. Hopefully, a statistician will 

 always be included in the design phase of any study or monitoring system. 



Prior to the projected growth of the nuclear-power industry, efforts to study the 

 environmental behavior of transuranic elements were centered around dispersal by 

 nuclear weapons testing programs. Early radiological assessments of the behavior of 

 transuranium elements in the environment relied on conservative assumptions owing to 

 the lack of empirical data and concentrated on plutonium, which was the major 

 transuranic element in weapons manufacture and testing. Weapons plutonium is still the 

 major transuranic element available for study. Data are less available or nonexistent for 

 curium, americium, and neptunium, but assessments should still include these elements. 



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