The components of a nuclear power plant are usually called nuclear power equipment. There are about 48,000 sets of equipment in each system, including about 6,000 sets of mechanical equipment, more than 5,000 sets of electrical equipment and more than 25,000 sets of instruments, with a total weight of about 67,000 tons. A 2*600MW PWR nuclear power plant has about 290 systems, which belong to nuclear island (NI), conventional island (CI) and auxiliary facilities (BOP).