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4.2.8 Available environmental remediation techniques and resources

The nature of the source, the size of the plume, and the transmissivity of an aquifer will directly affect the effectiveness of the remediation whether it will be an in-situ or an ex-situ treatment of the radioactive contamination. Most environmental remediation technologies currently available are expensive to implement and take long periods of time to complete. Continued research is ongoing worldwide to develop new techniques for in-situ and ex-situ remediation. A general list and description of these technologies can be found in Section 4.5 of this document. Care should be taken to evaluate the success or failure of the technologies which have been developed and to compare the site specific characteristics against the test site to determine the viability at a particular site. Critical parameters of the environmental remediation technology being evaluated should be identified for comparing the viability of success at each site. For example, a technology may work quite well at a site with alluvial sands, but not at all at a site with fractured rock [IAEA-1999a].

Based on the analysis performed on the site characterization data, a list of alternatives and technologies may be compiled. A screening process should determine if active remediation is required or if a passive alternative (institutional controls, no action, monitoring, etc.) is desired. If an active remediation option is chosen, a detailed analysis of technologies should be performed.

During the detailed analysis, remedial alternatives that have been retained from the alternative development phase should be analyzed against a number of evaluation criteria. The purpose of the detailed analysis should be to compare alternatives so that the remedy that offers the most favourable balance among a set of criteria can be selected.

As an example, the analysis of a remedial action for groundwater can be made on the basis of the following evaluation criteria [IAEA-1999a]:

  • Overall protection of human health and the environment;
  • Compliance with applicable regulations;
  • Long term effectiveness and permanence;
  • Reduction of toxicity, mobility, or volume;
  • Short term effectiveness;
  • Implement ability;
  • Cost;
  • Community or government acceptance;
  • Final disposal of residues.

Other criteria may also be established based on site specific conditions. A narrative discussion and summary table should be prepared for each part of the detailed analysis to provide a historical paper documenting the decision process.