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4.2 Design of an environmental remediation plan

After a decision has been taken to remediate a contaminated site, a remediation plan should be prepared and should show that the environmental remediation can be performed safely. Such a plan should be prepared for each contaminated site, unless otherwise required by the regulatory body, and should be subject to the approval of the regulatory body prior to its implementation and execution [IAEA-2007a].

The first steps in the development of this plan should be to determine and evaluate possible remediation options. These options can range from complete remediation and unrestricted release of the site to more limited remediation with some subsequent uses of the site being restricted [IAEA-2007a].

The degree of complexity of a given remediation process may vary depending on site specific situations. However, there are several components of the remediation process that should be considered essential for any site area being considered for remediation.

The goal of environmental remediation activities is the timely and progressive reduction of hazard and eventually, if possible, the removal without restrictions of regulatory control from the site. However, there are situations in which the removal of control from the site cannot practicably be achieved. In such cases, at least the unacceptable risks to human health and the environment should be removed. In these cases, any restrictions on access to or use of the site and any other restrictions should be established on the basis of an optimization process so as to maximize the net benefit to society. In the choice of the optimized remediation option, a wide variety of factors should be considered, and impacts on health, safety and the environment should be considered together with technical, social and financial factors. Non-radiological hazards should be considered in conjunction with the radiological hazards. Remediation should be aimed at reducing existing exposures and averting the potential for prolonged exposures to occur in the future. Remediation should [IAEA-2003]:

  • Reduce the doses to individuals or groups of individuals being exposed;
  • Avert doses to individuals or groups of individuals that are likely to arise in the future;
  • Prevent or reduce environmental impacts from the radionuclides present in the contaminated site.

Reductions in the doses to individuals and reduced environmental impacts should be achieved by means of interventions to remove the existing sources of contamination, to modify the pathways of exposure or to reduce the numbers of individuals or other receptors exposed to radiation from the source [IAEA-2003].

The level of effort associated with planning an environmental remediation is based on the complexity of the remediation(s) to be performed. Large, complicated sites generally receive a significant amount of effort during the planning phase, while smaller sites may not require as much planning. This graded approach defines remedial requirements according to the type of environmental remediation action(s) being designed, the risk of making a decision error based on the data collected, and the consequences of making such an error. This approach provides a more effective environmental remediation design combined with a basis for judging the usability of the data collected.