The recently-launched DOPAS project ("Demonstration Of Plugs And Seals" will run for four years (September 2012-August 2016) and is financially supported by EURATOM's Seventh Framework Programme, providing around 55% of the project funding.
Finnish nuclear waste management company, Posiva Oy, is responsible for coordinating the project, which will include of a set of full-scale underground demonstrations, laboratory experiments, and performance assessments.
The project aims to compile the design basis of plugs and seals; to develop new technology for plug and seal materials and for the assembly and construction of plug and seal systems; to carry out full or partial design of the systems, and to perform five full-scale plug and seal tests.
Full-scale industrial tests will be carried out at research facilities in the Czech Republic, Finland, France and Sweden.
Jean-Michel Bosgiraud, from the French radioactive waste management authority, Andra outlined France's role in the DOPAS project. "As a participant to the DOPAS Project, Andra will carry out, in a surface workshop located in Saint-Dizier, a full scale test of a seal as designed for a horizontal drift, in the French repository concept (called Cigéo): a swelling clay (bentonite) core between two concrete containment plugs", Bosgiraud said.
"The design and construction of the drift model have started, material formulations are well advanced. The seal construction as such should take place by mid-2013," he added.
Meanwhile, Posiva will perform the deposition tunnel's full-scale plugging test in the underground rock characterization facility, ONKALO, in Finland. The plug design has already started, and the construction will be carried out in 2013-2014.
"Excavation of the plug area with wire sawing is also a new and innovative task for Posiva as part of the deposition tunnel plug construction test. A low-pH concrete, especially developed for geological disposal conditions, will be used for the plugging structure. The reason for using this type of special concrete is to maintain the chemical conditions of the underground geological environment as natural as possible," said Johanna Hansen, Posiva's coordinator of the DOPAS project.
In 2016, the DOPAS project team will organize an international seminar on plugging and sealing technology for geological disposal of radioactive waste.
Caption: Posiva's deposition tunnel plug experiment in ONKALO, Finland