Rugles

The Rugles plant specializes in the rolling of zirconium alloy sheets and strips. The site exports a substantial portion of its production and is renowned worldwide for its excellence in the manufacture of flat products.

The Rugles plant uses zirconium billets (rectangular bars) supplied by the Ugine plant.

Pilgering of sheets and strips

Zirconium slabs supplied by the Ugine site constitute the main raw material processed at the Rugles plant. The slabs are transformed, through hot and cold pilgering, into thin strips used in the fabrication of structural fuel assembly.  

The Rugles plant's main activities take place in five shops:

  • The Hot Pilgering shop pilgers 100-millimeter-thick zirconium slabs into approximately 5-millimeter-thick zirconium sheets after they have been heated in a salt bath.
  • The Cold Pilgering shop pilgers the sheets produced in the hot pilgering shop and performs the necessary thermal treatments. A portion of these sheets is further cold-rolled to obtain strips 2 to 3 millimeters in thickness.
  • The Strip Finishing Line shop continues to work the product to its final thickness (sometimes down to 0.4 millimeters). The metal coils are subsequently finished with side-slitting, abrasion and pickling before inspection.
  • The Sheets-Casings workshop finishes and inspects the sheets produced in the cold pilgering shop.
  • The Contour Channel Strip workshop uses machining equipment to finish the surface of certain strips.

The various activities performed at the Rugles site convert zirconium slabs from Ugine into products that are ready to be transformed into components for nuclear fuel assemblies (grids, casings, channel boxes). Surface treatments require the use of chemical products like hydrofluoric and nitric acid.

Products manufactured at the Rugles site

Channel boxes : once folded and welded, the channel boxes form an intermediary envelope for boiling water reactor fuel.

Strips : thin metal ribbons that are delivered in coils to be cut and stamped in order to produce spacer grids. These grids are then bundled together to form the fuel assembly skeletons that hold the fuel rods in place.

Contour Channel Boxes : machined contour channel boxes