Portuguese 
English 
Spanish 
3 min of reading 
0 comments 
Copper Piece of 17 Tons Will Be Used in the Onkalo Nuclear Repository, with Structure Designed to Prevent Leaks and Corrosion
A decisive step has been reached in Finland with the production of the first raw cast copper piece intended for the deep geological repository of used nuclear fuel from Onkalo. The manufacturing was carried out by the Finnish company Posiva, specialized in radioactive waste management. The work took place at the Luvata plant, located in the city of Pori.
The Casting Was Considered Successful
The produced piece, referred to as a “blank,” is the first in a series of six that are part of the current production campaign.
The process was completed in just one work shift. According to Posiva, this initial step is crucial to ensure the quality of the containers that will be used for the final storage of irradiated fuel.
-
While modern pilots respect a minimum altitude of 300 meters, a P-51 flew under the Eiffel Tower chasing a Bf 109 in 1944.
-
Scientists warn that the AMOC ocean current could collapse, trigger extreme events in various parts of the planet, weaken monsoons that sustain food production, and even affect Brazil.
-
“Good” mosquito against dengue has already reduced cases by up to 89% in Brazil and could change the fight against the disease in the coming years
-
Science issues a concerning warning about a common bedtime habit: using your phone at night may affect your mind much more than you think.
Jouko Lammi, manufacturing coordinator of cans at Posiva, explained that the casting process had a good outcome.
“Good casting quality is important for the subsequent phases of can production,” he stated. Lammi also highlighted a significant technical advancement: “One of the most important achievements was the increase in the diameter of the casting with a larger gravity die.”
The process was supervised by the Finnish Nuclear and Radiation Safety Authority (STUK).
Strict Inspection Before Shipping
After the casting, the copper blank goes through a series of steps. The first is sawing, in which the front and rear ends are cut.
Samples are also taken for material analysis. After that, the cast piece is precisely machined, which includes preparing its surfaces for the next inspections.
Next, the piece undergoes non-destructive testing, which includes a visual inspection and the use of penetrating liquid to detect flaws.
After these steps, Posiva conducts a final technical inspection and reviews all related documentation. Only then is the item packaged and prepared for transport to the cylinder manufacturer.
The blank has an initial weight of over 17 tons. After the cutting and machining processes, the final weight of the piece delivered to the manufacturer is approximately 12 tons.
Container Structure Protects Against Corrosion and Leaks
The cast copper piece will form the main body of the disposal container. It will also consist of a lid and a bottom, all made from the same material, welded together. The resulting cylinder will have copper walls that are five centimeters thick.
Inside, there will be an internal structure made of cast iron with graphite. This part is responsible for supporting the weight and positioning the 12 fuel elements that will be inserted. The iron lid will seal the interior, and the assembly will be covered by a copper sheath.
Posiva explained that the main role of the copper cylinder is to prevent the corrosion of the cast iron. The container lid will be hermetically welded, preventing groundwater from entering its interior. This will also prevent radioactive substances from entering the geosphere and the biosphere.
With information from Interesting Engineering.
Be the first to react!