After consideration of the above criteria, the selected site has to be checked for its engineerability to meet the safety requirements, given its character­istics such as its seismicity, geology, hydrology, soil characteristics and vul­nerability to flooding. These assessments can be made by local experts with appropriate outside support where required. Another consideration in site selection should address the capability of the site to host future NPPs. The reason is that worldwide it is now recognized that it is advantageous to install several NPP units at one site, the ‘cluster concept’ as it is called. This concept facilitates better utilization of the infrastructure developed at the site including the trained manpower available readily. While doing this, due consideration has to be given to factors like the adequacy of the ultimate heat sink, sharing of systems between the units, and feasibility of construc­tion of new units with one or more units in operation at the site. Security implications of the presence of a large construction force including contrac­tor personnel at the site with operating units in existence also need to be addressed. One other benefit of the cluster concept is that a nuclear training centre including a training simulator for NPP units of the same design can be established at the site to cater to the manpower training requirements. Experienced personnel from the operating units who will be readily avail­able to impart training to newcomers will be another advantage for the functioning of the training centre at such a site.

The site should also be checked from the consideration of storage and disposal of radioactive waste that will be generated from the operation of the NPP. In case it is planned to have the waste repository at a different location, it should be ensured that temporary storage of the waste at the site is feasible before it is shipped out.

The radiation dose to the public, by both direct as well as indirect expo­sure pathways, should be ensured to be well within the prescribed limits. Appropriate apportionment of the committed radiation dose to the public for the first NPP unit should be done, keeping sufficient reserve for future units that are planned to be installed at the site. The site should also be amenable for implementation of countermeasures that may be required in the unlikely event of an accident with significant impact in the public domain.

A detailed radiological survey of the environment around the site should be carried out well before the start of the NPP operation towards establishing the background radiation levels. These surveys should then be carried out periodically after the NPP goes into operation to assess the radiological impact of plant operation on the site. It is useful to establish an environmental survey laboratory for this purpose. Such surveys involve measuring very low background radiation levels and extremely low levels of radioactivity in samples of soil, air, water, vegetation and food items. To carry out such measurements a good deal of expertise using sophisticated instruments is required and the instruments have also to be calibrated periodically using standards. Towards ensuring correctness of measure­ments a good practice is to engage in intercomparison exercises with other laboratories carrying out similar work. As the environmental survey work starts before the NPP is established and continues throughout the operating life of the NPP and beyond, it is important that national expertise in this field is developed early and maintained at the state-of-the-art level.

The work done for the siting of the first NPP should be utilized to further augment the expertise in this field in the operating organization and the regulatory body as well as the technical support organizations, taking into account new technological developments and worldwide experience in siting. This will be of immense use in siting future NPPs as also during periodic safety review of operating units towards ensuring that the site continues to meet the current siting criteria.