| Popis: |
Contamination of the ground and groundwater on nuclear sites might result from historical as well as current practices and incidents. Such incidents might be a consequence of cross-contamination from poorly designed boreholes and might include leaks from buildings and tanks, spills during the transportation of materials, and leaks from historical waste disposal trenches. Due to the potential risk to human health or the environment from such contamination it may be necessary to remediate specific areas of the site in order to control or eliminate this risk. Contamination may be radiological or nonradiological in nature and in many instances will be a combination of the two. As a nuclear licensed site moves towards the end of its lifecycle, decommissioning activities are likely to accelerate, although it should be recognized that decommissioning is not undertaken exclusively upon a site’s closure. There are examples where decommissioning activities will occur in parallel to ongoing site operations, especially at sites with a long historical legacy. Remediation is invariably an expensive exercise so it is necessary to understand the drivers for carrying out such work as well as the potential options available to meet any required remediation or dose targets. The drivers to undertake remediation might include site delicensing, offsite migration of contaminants, or stakeholder pressures; it also may form part of the site’s overall decommissioning strategy. Adopting a sustainable remediation approach, especially in countries with limited available funding, might be necessary. In such instances it is important to set and agree upon required cleanup targets prior to the commencement of any work so that regulatory and, in many instances, public approval can be acquired. A remediation program should be well planned and designed around a sound understanding of the site and its immediate environment, usually though the prior production of a conceptual site model. Understanding a site’s lifecycle and how the two technical activities of decommissioning and remediation might interact is therefore important. As mentioned previously, a remediation program might form part of the decommissioning or site release strategy, but it may also be required as a standalone activity without any decommissioning taking place at the site. The timing of any remediation program needs to correlate with both the drivers and the other potential activities being carried out at the site. While the primarily focus of this chapter will be to highlight examples of where remediation has been carried out on nuclear licensed sites that are also undergoing decommissioning it will also discuss why in some instances remediation is or has been recently undertaken without the presence of decommissioning activities. |
