May 31, 2017

AREVA NP is investing € 22 million to replace the hot rolling mill at the Rugles factory

AREVA NP is investing € 22 million to replace the 75-year-old hot rolling mill, the centerpiece of the Rugles site. This investment will be supported by a program to modify certain facilities on the site, which will start at the end of the year and be completed at the end of 2019.

The Rugles plant receives large pieces of zirconium (billets) of 12 to 16 centimeters thick from the Areva NP site at Ugine in Savoie, France. These pieces of zirconium are reduced to a thickness of 6 mm (in several cycles) upon coming out of the rolling mill after having been subjected to a temperature of 1,000 degrees and a pressure of 1,000 tons. The pieces of sheet metal then undergo further processing in the cold rolling mill, which transforms them into small zirconium billets after several hot and cold rolling phases. This makes it possible to roll 100 mm zirconium strips, by reducing their thickness so as to obtain sheets of up to less than a millimeter if necessary, depending on the products and the customers. The Rugles site is the only one in France to manufacture this type of sheet metal.

For Eric Prudhon, the site manager, replacing the hot rolling mill is essential to the manufacturing process. “It gives us visibility for the future and will make it possible to absorb variations in workload and to consolidate the site's leading position in France. It will also enable it to position itself on new international markets, especially in the United States and Japan. The old hot rolling mill will operate until the new one has been commissioned and qualified by our customers to ensure continuity of production and the sustainability of the site”.

Activities at the Rugles factory

Rugles performs operations involved in the nuclear fuel fabrication cycle. It is the world leader in the flat zirconium market destined to become elements of the grids and casings of fuel assemblies. The facility supplies AREVA NP and its main competitors (Westinghouse, GE / Hitachi, etc.). It exports most of its production to the United States, Germany and Japan.

The site is located in Normandy. With nearly 130 employees, the company transforms flat products into zirconium alloys through rolling, heat treatment, surface treatment and machining processes.

The plant has five workshops:

• The hot rolling shop rolls 100-mm-thick zirconium billets into zirconium sheets approximately 5 mm thick. The billets are heated in a salt bath before rolling;

• The cold rolling shop rolls the sheets produced by the hot rolling mill and carries out any necessary heat treatment operations. Some of these sheets are cold-rolled into coils to obtain strips (sheets with a thickness of about 2 to 3 mm);

• The strip finishing line continues to work the product to its final thickness by cold rolling (sometimes to 0.4 mm). Next, it finishes the product (side slitting, abrasion, pickling) and inspects the coils;

• The sheets and casings shop finishes the sheets produced in the cold rolling shop and inspects the finished product;

• The sheets casing and contours shop uses machine tools to finish the surface of certain categories of sheets.

The main steps in the manufacturing process

The various activities carried out in workshops at the Rugles plant make it possible to transform billets forged at Ugine into products ready to be transformed into components for nuclear fuel assemblies (grids and casings). Surface treatments require the use of chemicals such as hydrofluoric and nitric acids.