The Onkalo nuclear waste disposal facility under construction in Olkiluoto, Finland, will be the world's first permanent geological repository for spent nuclear fuel and high-level radioactive waste. Posiva is using a Scanclimber® by Tractel® hybrid hoist-work platform SC2000 in assembly work inside the personnel shaft in Onkalo. The product was custom-built according to Posiva's requirements. The SC2000 hoist-work platform is a hybrid of a hoist and a mast climber (MCWP).
Jarno Säippä is the project manager at Posiva's (www.posiva.fi) Final disposal - project. He has worked in the mining industry in various positions and is now responsible for the project’s shaft construction.
The first time I came to the Posiva Onkalo construction site in 2006, I was employed by a mining contractor. I have also previously worked at the gold mine and as the inspector for STUK (Radiation and Nuclear Safety Authority of Finland) to supervise this construction site.
Onkalo is a unique project, the first of its kind in the world. The International Atomic Energy Agency's (IAEA) general director called Onkalo
The Onkalo spent nuclear fuel repository is planned for the final disposal of spent nuclear fuel. It is located near the Olkiluoto Nuclear Power Plant in the municipality of Eurajoki, on the west coast of Finland. Posiva is constructing it, and the concept is based on the KBS-3 method of nuclear waste burial developed in Sweden by Svensk Kärnbränslehantering AB (SKB). The facility should be operational in 2023.
The actual construction of the Onkalo shafts and main tunnels started in 2004 and ended in 2012. During these years, Posiva also built an Onkalo research facility. At the time of our visit to the facility, Posiva started building and excavating the final nuclear waste placement tunnels. The officials gave the permit to build nuclear waste disposal facilities in 2015, and the construction works began in 2016. Posiva will be building the world’s first safe and efficient nuclear waste disposal plant ever.
In 1994, parliament amended the Finnish Nuclear Energy Act to specify that all nuclear waste produced in Finland must also be disposed of in Finland. The Finnish government selected Olkiluoto in 2000 as the terminal placement site for a long-term underground storage facility for nuclear fuel spent in Finland. The facility, named "Onkalo" (meaning ‘small cave’ or ‘cavity’), is being built in the granite bedrock at the Olkiluoto site, about five kilometers from the nuclear power plants. The municipality of Eurajoki issued a building permit for the facility in August 2003. Excavation began in 2004.
About the challenges of building the facility, Jarno comments:
At the general level, the main challenges in this project have been that we are making the world's first facility of this kind. So, we are setting an example and standard to the rest of the world that nuclear waste can be safely and efficiently disposed of into the stable bedrock.
Construction of Onkalo
The entire construction and disposal will take about 100 years. Then the premises will be closed. When the facilities are ready, the tunnels' total length will be about 50km and have a total volume of approximately 1.5 million cubic meters. According to the plans, 6,500 tonnes of spent nuclear fuel will be finalized, which means over 3,000 copper capsules.
Building the facility is a vast project and demands specific kinds of tools and equipment. The four shafts in the facility are almost 0.5km deep. Several works needed to be carried out inside the shafts and on the shaft walls.
Hybrid hoist + mast climber
In assembly work inside the personnel shaft, Posiva is using a Scanclimber® by Tractel® hybrid hoist-work platform SC2000. The product was custom-built according to Posiva's requirements. The SC2000 hoist-work platform is a hybrid of a hoist and a mast climber (MCWP). Posiva wanted a ‘platform’ in the personnel shaft from which to assemble the steel frames and do the HVAC work.