Monitoring of Radionuclides in the Environment

Environmental control in respect of determining concentrations and isotope ratios, e.g. of U, Pu and other actinides, is also required in routine measurements near to nuclear power plants, uranium enrichment facilities or nuclear waste recycling companies. Groundwater samples are analyzed after dilution directly by ICP-MS for soils a digestion step before mass spectrometric measurement is necessary. If isobaric interferences are observed a trace matrix separation and/or a careful analyte separation (e.g. of U and Pu) is recommended. 

Plutonium at a concentration level of 0.3 pgg 1 in contaminated soil samples was determined directly by LA-ICP-SFMS using the isotope dilution technique and 240Pu/239Pu isotope ratios were measured by Boulyga et al.126 

Radiocarbon (14C) dating is the most common application of AMS, and is also relevant for compound specific measurements. PAHs in sediments from an urban reservoir were 14C-free, but most of the PAHs in these sediments were derived from fossil fuel combustion rather than biomass burning.136 

A detailed description of the analytical methods and further applications for the monitoring of radionuclides in environmental samples are described in Section 9.9. 

Vonderheide, A. P., Becker, J. S. and Caruso, J. A., SEC-ICP-MS An Important Analytical Tool for Elemental Speciation in Environmental and Biological Samples in ACS Symposium Series 893, A. M. Striegler (ed.), American Chemical Society, Washington, D. C., 168 (2004). 

Environmental monitoring of nuclear contamination, including the determination of the concentration and isotope ratios of long-lived radionuchdes, such as uranium, plutonium isotopes, thorium, Np, Se, Sr, I and others, at trace and ultratrace levels, is a fast growing and fascinating application field for inorganic mass spectrometry. Among the environmentally important radionuclides, I, Sr, uranium and transuranium elements are of special importance. For example, the natural I inventory in the atmosphere, hydrosphere and biosphere has been estimated to be about 263 kg.  

The determination of °Sr and Pu and °Pu isotopes at the ultratrace level was studied on groundwater samples from Kazakhstan. In order to avoid isobaric interferences at m/z =90 for °Sr determination (from °Zr+, °Ar °Cr Ni 02 and others) the measurements were 

As a highly selective and very sensitive isotopic analytical technique, accelerator mass spectrometry (AMS) is able to determine radionuchdes ( °Be, C1, A1, Tc, Np, Pu 

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As a result, a new branch of science was formed to deal with monitoring of radionuclides in the environment. In a broader sense, this field involves the elaboration of relevant analytical procedures and the study of the ways radionuclides come into the environment and the health hazards they present. 

Data from the monitoring of radionuclides in the environment ean also be used for the following subsidiary purposes ... 

It is very important to consider the pathways of radionuclides in the environment for design of the environmental monitoring program. Radionuclides enter the receiving environment via direct emissions to atmosphere, direct discharges to water bodies or releases from land burials of radioactive wastes. 

The development of applications of radioactive materials in research, industry, medicine, and agriculture, as well as the growth of nuclear power engineering programs, led to increasing amounts and varieties of radionuclides in the environment. This, together with the development of the nuclear sciences, has created the demand for proper analytical methods of monitoring radionuclides in the environment. 

Monitor the discharge of radionuclides from the storage facility and estimate dose rates and the concentrations of radionuclides in the environment due to the discharges, if so required by the Regulatory Body. 

Numerous separation methods of the types cited in Chapter 3 were developed and applied in radioanalytical chemistry during the past century. The hrst 30 years were devoted mostly to nuclear chemistry applications for identifying and characterizing the naturally occurring radionuclides. In the following years, attention shifted to the man-made ones these activities continue, as exemplified by the work described in Chapter 16. Currently, many methods are devoted to monitoring radionuclides in the environment, facility effluent, process streams, and workers. 

One important purpose of monitoring is to provide data that permit the analysis and evaluation of human radiation exposure. For this purpose, programmes for monitoring radionuclides in the environment should focus on pathways of human exposure. An exposure pathway defines routes from a source of radionuclides and/or radiation to a target individual or a population through media in the environment. There are two main categories of exposure pathway external exposure pathways (the source of exposure remains outside the body) and internal exposure pathways (the source of exposure is incorporated into the body). 

The nuclear power plant accident at Chernobyl in April 1986 (IAEA Technical Report 1991) proved to be a much more potent source of environmental contamination in many surrounding countries, over distances up to several thousands of kilometers, and was a cause of worldwide problems in international trade in food products contaminated (or possibly contaminated) with radionuclides. The resulting requirement by many countries to establish systems for monitoring radionuclides in foodstuffs and in the environment led to a large worldwide increase in the demand for suitable reference materials. 

Much information of relevance for the environment of the two atolls on the distributions and amounts of residual radionuclides is available in the results of the French monitoring programmes. For the reasons given above, the lAC decided to conduct an independent environmental sampling and surveillance campaign at the two atolls. The survey campaign was conducted at the atolls in July 1996. The campaign comprised a terrestrial part co-ordinated by the IAEA Seibersdorf Laboratory and an aquatic part co-ordinated by the lEA Marine environment Laboratory in Monaco. 

Production, Use, Release, and Disposal. The production of radon occurs directly from a radium source either in the environment or in a laboratory environment. The disposal of gaseous radioactive effluents has been documented. Increased radon concentrations have been detected in waste generated by uranium and phosphate mining therefore, these sites should be monitored on a continual basis. Although there are regulations for disposal of radionuclides in general, there are none that specifically address disposal of radon contaminated materials. Further research on the disposal of radon attached to charcoal, which is used in radon monitoring indoors, would be beneficial. 

Prevention of the escape of radioactive substances and chemicals in aqueous solutions into the environment is accomplished by setting up processing of aqueous process and drain solutions in the plant s process flows. The plant uses monitored discharge of the water used to cool apparatus, by employing automatic interlocks in the event of a hardware leak. The content of radionuclides in harmful chemicals and waste water is determined by collecting and later analyzing samples. 

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