The Difficulties of Undertaking Site Characterisation on Operational Nuclear Licensed Sites

Undertaking site investigation on nuclear licensed sites is very different to site investigation on other sites, even those which are heavily contaminated. This paper sets out to highlight some of the issues which need to be considered when formulating a fit for purpose, yet defensible site characterisation programme on such a site. The first and most important aspect of the work is to set out clearly your objectives. There may be a number of reasons why a site investigation is being undertaken. These could include purely fulfilling your site licence conditions as an operator or they could be more specific like supporting a defined de-licensing or decommissioning project, installing a monitoring network, or determining the extent of ground contamination. Ensuring that a conceptual model exists is the next step, even if only at a preliminary stage, as this coupled with the desk study will help formulate the site characterisation programme. Logistical issues as well as technical requirements need to be factored in, but in order to maintain transparency it is important to declare the latter first. Like other sites with ground contamination, issues like sampling and analysis need to be considered. Clearance procedures on nuclear licensed sites are extremely stringent and can lead to delays. These need to be considered, especially if sending samples offsite for organics analysis. The laboratories themselves need to be licensed to handle radioactive samples and the transport regulations also need to be adhered to. Other logistical issues requiring consideration include safety cases, plant modification proposals and waste disposal. The technical side itself sets its own challenges in that decisions need to be closely linked into the logistics. Will the samples and data be collected primarily through intrusive techniques or is there a requirement to utilise non-intrusive methodology? How do you defend the proposed site sampling strategy when you have access restrictions? Do you need to have permanent monitoring facilities? These are just some of the questions which need to be answered if a site operator is to have a transparent and defensive site investigation programme on a nuclear licensed site.