Atlas Copco Rental helps Chinese nuclear plant optimize maintenance time for turbine cooling

During maintenance of a nuclear plant the process of cooling down the steam turbines is one of the most time-consuming. The total maintenance time is crucial since the shorter it is, the less financial impact on the operations. Finding ways to safely cool down the turbine as fast as possible is an important success factor during a turnaround at any nuclear plant around the globe. The Yangjiang Nuclear Power Station is a nuclear power plant in Guangdong province, China. It’s one of the major energy projects of the Eleventh Five-year Plan. The station will have six 1,000 megawatt CPR-1000 pressurized water reactors (PWR). It began commercial operation in March 2014. The CPR-1000 is a design developed by China from the French Areva-designed PWRs at the Daya Bay Nuclear Power Plant. Yangjiang marks a step in the development of China's domestic nuclear industry. For the first turnaround in early 2016 experts from the China Guangdong nuclear group suggested that in order to get a faster cooling speed, and therefore a shorter cooling time of the steam turbines, it would be better to use compressed air. This was a big challenge because this method had never been used before. With this new method, compressed air is the key factor that affects the result of the cooling, and determines whether the project will succeed or fail. During the cooling process the compressed air flow needs to be stable, and at the same time the temperature and pressure dewpoint have to exactly match the customer’s specifications. If any of these parameters are not met, not only would the cooling rate would be very low, but also the turbine would be damaged. After several technical meetings and careful consideration, Yangjiang nuclear decided to cooperate with Atlas Copco Rental on this project. We then developed a tailor-made solution that could both fulfil the requirements and ensure the shortest possible cooling time.