STP is located around 20 kilometers southwest of Bay City, Texas. In 2006 MHI received an order for two RRVCHs for STP Units 1 and 2, 1,364 MWe (megawatts of electricity) each, which commenced operation in 1988 and 1989, respectively. The second unit is slated for delivery in February 2010.
The RRVCHs ordered are made of low-alloy steel, have a diameter of approximately 5 meters. MHI manufactures RRVCHs at its Kobe Shipyard and Machinery Works. With each RRVCH for STP, 57 stainless-steel control rod drive mechanisms (CRDM) are mounted, and the overall structure measures around 10 meters in height and weighs about 100 tons. CRDMs are devices that play a key role in the safe and stable operation of nuclear power plants. In the unlikely event of a system malfunction, CRDMs promptly insert the control rods into the reactor core to achieve emergency shutdown.
Since 2002 MHI has received orders for 15 RRVCHs, six replacement steam generators (RSG) and one replacement pressurizer in US.
