The world’s first AP1000 nuclear power plant (earlier post) moved a step closer to commissioning with the completion of the cold hydrostatic test (CHT) at Sanmen Unit 1 in Zhejiang Province, China. The successful completion of CHT confirms that the reactor systems meet design pressures under operating and accident conditions and signifies the completion of the plant’s design and construction programs.
The AP1000 nuclear power plant is a two-loop pressurized water reactor (PWR) that uses a simplified, innovative and effective approach to safety. With a gross power rating of 3,415 megawatt thermal (MWt) and a nominal net electrical output of 1,110 megawatt electric (MWe), the AP1000 reactor, with a 157-fuel-assembly core, is suited for new baseload generation.
The AP1000 is an extension of the older AP600 design. (It is considered a Generation III Advanced Light Water Reactor.) It is modular in design, thereby promoting ready standardization and high construction quality; economical to construct and maintain (less concrete and steel and fewer components and systems mean there is less to install, inspect and maintain); and designed to promote ease of operation.
This test confirms that critical components within the reactor coolant system work as designed. The commissioning and testing team performed the cold hydrostatic test in a safe and event free manner which was an important factor in the test. The successful completion of cold hydrostatic test is a key step in the commissioning for the AP1000 plant and puts us in a great position to load fuel—a significant milestone we expect to complete at Sanmen 1 by year end.—Jeff Benjamin, Westinghouse senior vice president, New Plants and Major Projects
Initiated on 25 May, the test was completed within four hours with the unit’s reactor systems successfully maintaining a test pressure of 3,107 psig (pounds per square inch gauge) for 10 minutes without leakage. Inspection of the more than 1,800 required welds in the reactor coolant system test boundary found no leaks at that pressure. The CHT leads the way to the next two critical commissioning milestones, hot functional test and initial fuel load. The hot functional test, which tests all plant systems prior to loading fuel in the reactor, will begin in the next several weeks. Once complete, it will be followed by initial fuel load.
The company next will be gearing up for CHT at Haiyang Unit 1 in Shandong Province in the coming weeks. The lessons learned and best practices from each CHT will be applied to the successive tests conducted at other AP1000 plant construction projects including Sanmen Unit 2 and Haiyang Unit 2, as well as the four units under construction in the United States, two at the Vogtle plant in Waynesboro, Ga., and two at the V.C. Summer plant in Jenkinsville, S.C.