48 TRANS URANIC ELEMENTS IN THE ENVIRONMENT 



this book, starting with the source term. Characteristics of the source term are important 

 for the selection of monitoring methods and instrumentation. Some of the general 

 characteristics of the transuranics to be considered are 



1. Quantity. 



2. Rate of release. 



3. Chemical form. 



4. Physical characteristics, such as particle size distribution or ionic state. 



5. The presence of radionuclides. 



6. The presence of nonradioactive chemicals. 



For routine operation of such facilities as plutonium fabrication, reactor-fuel fabrication, 

 and reactor-fuel reprocessing, the emission and effluent monitoring systems will provide 

 the infomiation about quantities and rates of release. The chemical fomi may be inferred 

 from the operations being carried out by the facility. The physical characteristics of the 

 emissions or effluents can be identified by a specific study or inferred from the operating 

 parameters for the waste-treatment system. The transuranic isotopic composition is 

 usually well defined by criticality and safeguards calculations or by analysis of actual 

 effluent samples. The presence of other radionuclides, such as fission products, may 

 interfere in monitoring transuranics or may be helpful by serving as tracers from which 

 ratios with respect to transuranics can be determined. The presence of nonradioactive 

 chemicals combined with the transuranics in emission or effluents may alter the original 

 chemical forms introduced into the waste-treatment systems. For normal operation of 

 nuclear facilities handHng transuranics, the quantities released usually are small. 

 Monitoring for the transuranics in the environment from nonnal operations of facilities 

 fabricating plutonium metal, heat sources, or reactor fuel or reprocessing reactor fuel 

 become oriented to long-term buildups. The source-tenn parameters for unexpected or 



Fig. 1 Simplified pathways between radioactive materials released to atmosphere and 

 man. [From International Commission on Radiological Protection (1965).] 



