Assembly

The term assembly refers to the assembly of various components.

This term is mainly used in nuclear technology , molecular biology , electronics , nanotechnology ( nanoassembly ) or for computers .

In virology , the term means the assembly of the individual components ( proteins and nucleic acids ) into a finished virus particle ( virion ) in the host cell .

Nuclear technology

In nuclear technology, the last sub-step in the manufacture of fuel elements for nuclear reactors. In simple terms, assembly means the assembly of individual nuclear fuel rods to form a fuel assembly.

In the manufacture of fuel assemblies for the most frequently used light water reactors, the process steps precede assembly

• Powder production (chemical conversion of enriched uranium hexafluoride to uranium oxide powder )
• Pellet production (pressing of the uranium oxide powder into tablet-shaped " pellets " approx. 2-3 cm long and 1 cm in diameter, sintering the pellets at around 1700 ° C in a sintering furnace , grinding the pellets to specified dimensions)
• Fuel rod production (filling the pellets into a 4–5 m long cladding tube made of a zirconium alloy , gas-tight welding of the cladding tube, testing of the weld seams )

Finally, in the “assembly” process step, up to 250 fuel rods (in the case of pressurized water reactors) are joined together to form finished fuel assemblies using spacers, headers and footers.