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U.S. Department of Energy
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Posiva's Onkalo{sup R} FST (Full-Scale In Situ System Test) - 20051

Conference ·
OSTI ID:23030344
 [1];  [2]
  1. Posiva Oy (Finland)
  2. Posiva Solutions Oy (Finland)
The FST - Full-scale In Situ System Test - is a unique full-scale demonstration of disposal system in crystalline host rock. The FST was constructed in ONKALO{sup R} demonstration area at the disposal depth of 420 metres, in Posiva's actual final disposal facility at Olkiluoto, Finland. The demonstration has included design, manufacture, installation and comprehensive instrumentation for monitoring the evolution of the disposal system and its components. The demonstration tunnel and experimental deposition holes were excavated in 2010 in ONKALO to address that they can be excavated to meet the requirements set for them. Two experimental deposition holes, bored in the floor of the tunnel, host each a canister surrounded by bentonite clay buffer rings/segments in the holes. Inside the canisters are heating elements to simulate decay heat emitted by spent fuel. The tunnel part used for the test is about 50 m long and it was filled with bentonite clay backfill after the installation of the canisters and buffer components. The tunnel is closed with a steel-reinforced concrete plug. The test is equipped with 500 sensors to monitor early evolution of the system. To forecast the evolution of the system, a mathematical model has been created. (authors)
Research Organization:
WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
OSTI ID:
23030344
Report Number(s):
INIS-US--21-WM-20051
Country of Publication:
United States
Language:
English