ments, GSC would need to change only a portion of the tool to revert to the two-piece design. Te contingency plan was never needed. Typically, new part designs at
Westinghouse go through a pre- prototype, prototype, preproduction and production run. After the first prototype parts were tested, Westing- house refined the design and sent it back to GSC for final optimization for castability. GSC produced a wax tool to cast a small run of preproduction castings machined to the final dimen- sions. Westinghouse assembled the cast nozzles to a fuel assembly for full- size flow testing that simulated flow conditions in the nuclear core. Tis initial test proved a 30% reduction in pressure drop across the nozzle. Based on the results of the pre-
production testing, the Westinghouse design team made a few more design tweaks, as well as manufacturability improvements, such as modifying radii and chamfer sizes and adjusting toler- ances for many features. Frequently consulting with the casting supplier led to a final design with excellent process capability and minimal rework or scrap. “What is different about this
process was that most engineering companies engineer and send out the drawings, and that’s it,” Lewis said. “We met with our supplier twice and they came to our facility once, before we even issued our first drawing. Tat way, we were able to leverage the knowledge base of the supplier.”
From Cast Part to Nuclear Power Production parts of the new design
were approved and ready for the world’s first AP1000 reactor at China’s Sanmen Unit 1, located in the coun- try’s Zhejiang province. Westinghouse has contracts to build four AP1000 reactors in China and four in the U.S. from 2012 through 2016, with the first reactors powering up in 2014. Te final nozzle design weighed
18 lbs. and resulted in at least a 30% pressure reduction in the nozzle, which meant Westinghouse could use a lower capacity reactor pump. Te new nozzles also were developed so they could be used with the exist- ing reactors. Te supply chain team
January 2013 MODERN CASTING | 45
reported that decreased forces in the fuel assembly reduced the propensity for the assembly to bow and eased the on- and off-loading of the reactor core. Te new design significantly stream- lined the value stream for the nozzle to just one supplier, which reduced the component’s total cost of ownership and administrative management bur-
den. Each reactor requires 150 nozzles. “We are looking to find the most
effective use of our resources,” Peterson said. “We wanted a turn-key supplier that provided us with a nozzle we could directly put into the assembly. It helped us with lead time and inven- tory, and eventually it will help with overall cost.”
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