CAST: back in action9 October 2014
The long-established French nuclear fuel manufacturer AREVA has branched out into China through a 50:50 joint venture with CNNC to make zirconium tubes for fuel assemblies, CAST. Four years on, the company has received its first order from Chinese manufacturers and is ramping up production at its factory.
The CNNC AREVA Shanghai Tubing Company Ltd was established in 2010, after four years of negotiation. The move marked a further step in front-end collaboration between AREVA and Chinese companies, which have been working in partnership in the nuclear fuel supply chain for more than 20 years.
CNNC AREVA Shanghai Tubing Company Ltd, or CAST, is a 50:50 JV between AREVA subsidiary CEZUS, the world's leading manufacturer of zirconium components, and Shanghai Gaotai Tubing Company Ltd (SGTC), a CNNC affiliate specializing in the manufacture of zirconium tubes.
The CAST facility near Shanghai is based on SGTC's previous tube plant that originally supplied material for aeronautics, medical, military and nuclear markets. It benefitted from technology transfer from AREVA and ZIRCATEC Co of Canada for nuclear zirconium claddings in the 1990s, but these projects were cancelled before completion; later nuclear industry qualification under CNNC control also failed. The AREVA re-designed CAST plant is now 100% devoted to zirconium cladding for nuclear power. Today, it employs 70 employees but the workforce will peak at 125.
Factory operations began in April 2011. The first goal was to qualify tubing and cladding with conventional Zircaloy 4 cladding. This was achieved with the first deliveries to Qinshan NPP in 2011, followed by more in 2012.
The next stage involved technology transfer and licensing of the facility to produce tubes using AREVA's M5TM technology. These tubes are used in the fabrication of AREVA AFA 3G pressurized water reactor nuclear fuel for Chinese reactors. These fuel designs are manufactured in China under technology transfer agreements, using components supplied by AREVA.
AREVA began transfer of its M5TM technology to the JV and completed licensing of the factory to produce M5TM alloy in September 2013. In October 2013, the CNNC fuel-manufacturing unit China Jianzhong Nuclear Fuel Co Ltd qualified CAST, indicating that it was ready to fabricate fuel assemblies with CAST products for Chinese nuclear power plants.
Unusually, the licensing and qualification processes were carried out in parallel.
“CJNF is not only a customer; it is also a part-owner," CAST general manager Yves Combres told Will Dalrymple in April. "These licensing and qualification processes are normally sequential, but in this case they were overlapping thanks to the collaborative relationships of both groups," explains Combres.
“Also in November 2013 CAST became a qualified supplier to CNNC. So, one of CNNC's main targets, to localize zirconium claddings for nuclear fuel production, has been reached," he adds. Chinese fuel manufacturers import zirconium tubes from foreign suppliers such as AREVA CEZUS, and then fill them with enriched UO2 pellets at factories such as CJNF's Yibin plant in Sichuan Province.
Gearing up for expansion
Following a three-year production and development programme CAST is now planning to ramp up production. Yves Combres explained: "Starting at the end of 2013, we made a pause in our plan to upscale the plant capacity, which was limited to 200-300 km/yr cladding capacity.
“Right now we are kicking it up to 1500 km/yr. The plant has been significantly redesigned, although the main core exists. Changes have been applied based on AREVA Plant Design, and technology has been imported from AREVA.
“Now all of this is behind us; plant changes are almost 100% complete. Machines are being commissioned. It is a very busy period. There are many suppliers and subcontractors.
“August is the rehearsal of production. I am the conductor of a very lively orchestra from which I expect beautiful music!" The rehearsal aims to check if production quality meets internal expectations before starting official and mass production, in September.
“In June, we signed a purchase order for mass production with CJNF. This good news switches CAST's existence from project-type to normal life of the plant.
“The plant has been designed in such a way that, through its utilities, if the board decides to double the capacity, we are ready to accept that (although the market is not ready right now)."
Combres explained that tube manufacture is a complicated process involving many machines – if relatively conventional – combined with specialized technologies and know-how.
“The CAST Board wanted to minimize the industrial risk; therefore AREVA technology was chosen. But it was also the intent to localize, especially using mature Chinese technologies. A long process enabled the selection of appropriate suppliers; in most of cases the results have been very good, but there also have been some failures. The localization in China amounts to 50% of purchases, but not in value terms."
Looking beyond tube manufacture, AREVA has recently expanded its CAST focus, vertically. "CAST deals with the very last stages of cladding metallurgy," said Combres. "Consequently, AREVA and CNNC officially signed a letter of intent in December 2013 related
to the upstream activities of the CAST tube venture, that goes from sponge to intermediate product. It would fabricate and convert zirconium alloy, up to 600 tons by 2017, for the Chinese market."