Summary

This document presents current best practice guidance for the characterisation of contaminated or potentially contaminated land on nuclear-licensed sites and defence sites. Defence sites are here defined as sites currently owned by the Ministry of Defence where there is a potential for radioactive contamination to be present. These two categories of site are grouped together in this best practice guidance principally because of the issue of contamination of land by radioactivity. However, there are also other issues common to both categories of site, which may distinguish them from "conventional" contaminated land. Examples include increased client involvement, heightened public awareness and increased security requirements.

The report has been produced as the first technical task of the SAFEGROUNDS Learning Network, a project managed by CIRIA, in association with WS Atkins and the Environment Council, on behalf of stakeholders concerned with the health, safety and environmental management of contaminated land on nuclear-licensed sites and defence sites.

Most of the site characterisation technologies described in this guidance are conventional and well established. Many have been used extensively for the characterisation of chemically contaminated land and will be familiar to most readers. The technologies and instruments that may be less familiar are those concerned with the measurement of radioactivity. However, these are all conventional health physics equipment, with a long record of successful use.

In particular, this guidance focuses on those areas where site investigations on nuclear-licensed sites and defence sites differ from those on "conventional" contaminated land sites:

• nuclear-licensed and defence sites have a more complex regulatory regime. There is a need for site characterisation on such sites to satisfy a number of regulators, who regulate under different legislation and who may have different perspectives on the management of contaminated land
  

• because of the different regulatory regimes, the required endpoints of site characterisation on nuclear-licensed and defence site and on "conventional" contaminated sites may be different
  

• there will be greater client involvement on nuclear-licensed sites, primarily driven by nuclear site licence requirements
  

• site characterisation on nuclear-licensed sites and defence sites will have a higher public profile, because of the potential presence of radioactive contamination. Effective communication with stakeholders (typically a wider group than would be the case for characterisation of "conventionally" contaminated sites) is essential
  

• radioactive contamination is potentially present at all nuclear-licensed sites and defence sites. Best practice for characterisation of such sites is that Radiation Protection Advisers and Radiation Protection Supervisors are appointed to provide advice to the employer on compliance with the Ionising Radiations Regulations 1999 and with the Radioactive Substances Act 1993. Note that there is a requirement under IRR 1999 to appoint RPAs and RPSs if working with ionising radiations (i.e. if radioactive contamination is encountered)
  

• waste minimisation is a key issue on nuclear-licensed sites. There may be requirements for waste segregation, to ensure arisings of radioactive wastes are minimised
  

• on nuclear licensed sites, there is a requirement for long-term storage of records. This may influence the extent to which electronic collection and storage of data is used.

Structure of the Guidance

Section 1 describes the types of site addressed by this guidance and summarises the activities that may cause contamination and the types of chemical and radioactive contamination that may result.

Section 2 provides a summary for readers who do not have a technical background in issues concerned with radioactivity. It also discusses the concept of background levels of radioactivity, which are unrelated to activities at the site being characterised.

Section 3 summarises health, safety and environmental protection issues, with emphasis on issues concerned with radioactivity and with issues that are of particular importance on nuclear-licensed sites and defence sites.

Sections 4 and 5 present issues concerned with defining objectives for, and with the planning of, site characterisation programmes. Particular emphasis is given in Section 4 to describing the reasons why site characterisation may be required on nuclear-licensed sites and defence sites. It is recognised that the end-point for a site characterisation programme is dependent on the objective (i.e. the 'context' in which the characterisation is undertaken).

Section 4 also contrasts and compares the management regimes for chemically contaminated land and for radioactively contaminated land, presents the overall sequence of activities required to manage contaminated land and sets site characterisation in the context of these activities.

Section 5 emphasises the importance of early communication with stakeholders. Early interaction with regulators is essential, to clarify matters such as statutory ambiguities and methods of approach to characterisation. Early dialogue with the public and with bodies representing the public is also important. This chapter also presents some of the key technical considerations when planning a site characterisation programme, such as contingency planning, the role of the site conceptual model and the design of sampling strategies. The approach to establishing background environmental quality at a site, in particular background levels of radioactivity, is discussed.

Section 6 describes the principal techniques for characterising contaminated land on nuclear-licensed sites and defence sites. As previously, it is not the intention to reproduce this existing guidance in detail; only a summary and 'signposting' is presented. Instead, the focus is on describing those characterisation techniques that are specific to the investigation of radioactively contaminated land, and to highlight specific issues in the application of widely-used characterisation techniques to nuclear-licensed and defence sites. Non-intrusive radiation surveys, geophysical surveys, intrusive investigations and chemical/radiochemical analysis of samples are all discussed. Examples of site characterisations are presented in Case Studies given in Section 9.

Section 7 describes waste management and transport of radioactive materials. It presents the legislation relevant to categorisation of radioactive wastes, and stresses the importance of waste minimisation and waste segregation as part of the site characterisation process. Issues concerned with the management of chemically contaminated wastes are also presented.

Section 8 describes the management of data from site characterisation programmes, and focuses on the need for long-term storage of such records on nuclear-licensed sites. The benefits of electronic storage of data, for example by using geographic information systems (GIS) are given. Examples of uncertainties arising during site investigation, and possible actions that can be taken to reduce such uncertainties, are presented.

Current capabilities and lessons for practice are given in Section 9. The key differences between the characterisation of nuclear-licensed and defence sites and the characterisation of 'conventional' contaminated sites are summarised. These include the more complex legislative regime on nuclear-licensed and defence sites and the potential or actual presence of radioactive contamination. Areas where there is potential for improving the characterisation of nuclear-licensed sites and defence sites have been identified. The final section of the document describes areas where there is potential to improve best practice in the future.

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