Managing uncontrolled releases and contaminated site clean-up are con­sidered in detail in Chapter 8 and Part III so only a summary derived from them is provided here. Agreed international safety requirements cover such situations (IAEA, 2003c). To ensure that protective measures can be quickly and efficiently implemented to mitigate the adverse effects of an accident or other forms of long-term contamination at a nuclear site requires good planning, clear strategies and a good managerial team. Preparations for environmental remediation should ideally be done in two phases: prelimi­nary planning, which should be available as part of normal operation, or emergency preparedness for each nuclear facility; and detailed remediation planning, which takes into account site (and accident where applicable) specific information.

According to the IAEA Safety Glossary (IAEA, 2007) remediation is defined as any measure that may be carried out to reduce the radiation exposure from existing contamination of land areas through actions applied to the contamination itself (the source) or to the exposure pathways to humans. An important element in the overall remediation concept is that complete removal of the contamination is not implied. Remediation aims to achieve optimised protection of the public, workers and the environment. The goal of remediation activities is the timely and progressive reduction of hazard and eventually, if possible, unrestricted release of the site. However, there are situations where this goal may not be achievable and then it must be demonstrated that as a minimum any unacceptable risks to human health and the environment have been removed. When choosing a remedia­tion option, a range of factors must be considered, such as the impacts on health, safety and the environment; and technical, social and financial factors. National remediation strategies are needed to specify, prioritise and to ensure remediation situations are managed in a manner commensurate with the risks associated with the contaminated areas and taking into account possible effects on neighbouring countries.

In general, remediation of a contaminated area involves preparation and approval of a remediation plan; remediation operations; and management of RAW resulting from the remediation activities. It needs to be based on collection and assessment of all available information of current and past activities at the site. Therefore an appropriate assessment of both the radio­logical and non-radiological impacts of the situation must be performed and the benefits and detriments associated with possible remedial measures, including the associated restrictions and institutional arrangements follow­ing remediation must be identified based on established reference levels as part of the decision-making process.

The remediation plan has to be subject to the approval of the regulatory body prior to its implementation and must state, as a minimum: the goal for the remediation; reference levels for remediation; the nature, scale and duration of the remedial measures to be implemented; the waste disposal or storage site, as appropriate; any post-remediation restrictions; and the monitoring and surveillance programmes and arrangements for institu­tional control for the remediation area. During the implementation of remedial measures, consideration must be given to (i) radiation safety, transport safety and waste safety, general health and safety issues and envi­ronmental issues so as to minimise hazardous impacts, and (ii) the potential for prolonged exposure after the termination of remediation activities.

The area has to be monitored and surveyed regularly during remediation so as to verify the levels of contamination; to ensure compliance with the requirements for site release and for waste management, and to detect any unexpected levels of radiation. Before an area can be released for unre­stricted use, a survey must be performed to demonstrate that the end-point criteria and conditions, as established by the regulatory body, have been met. The organisation responsible for the surveillance and verification of activities must be clearly identified. An appropriate programme, including any necessary provisions for monitoring and surveillance, has to be estab­lished to verify the long-term effectiveness of the completed remedial meas­ures. As part of the overall management system, arrangements for archiving, retrieval and amendment of all important records concerning the initial characterisation of the area, the choice of options for remediation and the implementation of remedial measures, including all restrictions and the results of all monitoring and surveillance programmes, must be established and maintained in all cases.