Author(s)

K. Lehto & J. Lahdenperä

Abstract

Posiva is a Finnish nuclear waste management company with the duty to take care of the high-level nuclear waste produced in Finland. Pursuant to the Decision-in-Principle of 2001 Posiva has moved to the phase of underground characterisation of the repository site. The main objective of this phase is to confirm the suitability of the Olkiluoto site by investigations conducted underground. A programme of monitoring has been launched as part of the investigations and to follow the changes occurring within the site due to the construction. The programme of monitoring started in the year 2004, one year before the construction work. Baseline monitoring was carried out prior to the construction phase and the results gained from monitoring during construction phase are compared to the baseline data. Rock mechanics, hydrology, geochemistry, environment, and the use of foreign materials are included the monitoring programme. Keywords: monitoring, high-level nuclear waste, hydrology, rock mechanics, geochemistry, environment, foreign materials, underground rock characterization facility. 1 Introduction Posiva Oy is a Finnish high-level nuclear waste management company owned by the two Finnish nuclear companies Teollisuuden Voima Oy and Fortum Power & Heat Oyj. Posiva’s duty is to take care of final disposal of spend nuclear fuel. Posiva is established in the year 1996. In the year 2001, the Finnish Parliament ratified the Decision-in-Principle on the disposal of spent fuel from the Finnish nuclear power reactors. According to the decision, Posiva may concentrate the investigation on one site, Olkiluoto, in

Keywords

monitoring, high-level nuclear waste, hydrology, rock mechanics, geochemistry, environment, foreign materials, underground rock characterization facility.