The site selection for a deep geological repository in Japan will be undertaken by means of a three-stage process according to the Final Disposal Act of 2000 and the Amendment to Basic Policy of May 2015. The three stage are: literature survey (LS), preliminary investigation (PI) and detailed investigation (DI). The objective of the LS stage is to select preliminary investigation areas (PIAs) on the basis of existing information on the proposed or volunteering areas and the surrounding regions, and to develop exploration programmes, including borehole investigations.

Key to the LS stage is the development of a qualified assessment basis for each area, which can support the evaluation process. The assessment basis includes a wide spectrum of empirical data from the literature - from field investigations in the areas, laboratory investigations and data from underground constructions and studies. The specific challenge at the LS stage is that the data have not been obtained under NUMO's Quality Management System (QMS).

NUMO initiated a project to develop: a) a strategy on how to evaluate, qualify and include data and information collected by third parties to NUMO’s database (Phase 1); b) practical discipline-specific quality-control procedures considering the variability of data quantity and quality (Phase 2) and application to the database (Phase 3). The results from Phase 1 are reported in this paper.