Case Study: Implementing the JWM Guard Tour System at Daya Bay Nuclear Power Station


Daya Bay Nuclear Power Station
The Daya Bay Nuclear Power Station, China’s first large-scale commercial nuclear power plant, is located in the eastern part of Shenzhen, 45 kilometers from Hong Kong. It is the largest Sino-foreign joint venture in China. Situated at 22°36’02.70″ N and 114°32’57.75″ E in the Daya Bay Nuclear Power Base, Longgang District, Shenzhen, Guangdong Province, it is the largest nuclear power base in China in terms of operational installed capacity. The base houses the Daya Bay Nuclear Power Station and the first phase of the Ling Ao Nuclear Power Station, with four million-kilowatt-class pressurized water reactor nuclear power units, generating nearly 30 billion kWh annually. 70% of the electricity produced by the Daya Bay station is supplied to Hong Kong, accounting for about a quarter of Hong Kong’s total electricity consumption, while the remaining 30% is fed into the Southern Power Grid. The Ling Ao Phase I station supplies all its generated power to the Southern Power Grid.

Main Challenge

The 220KV Ping Nuclear Line, a crucial power transmission line, faced significant challenges. Due to delayed patrols by third parties, issues such as scavengers stealing tower iron poles, bird nesting, and external construction damages were frequent. Theft or forced dismantling of tower iron poles required maintenance personnel to transport new poles from the base of the mountain for welding and reinforcement, a laborious and time-consuming process.


The primary focus was on the inspection of high-voltage towers. Inspections were scheduled for specific lines, with GPS satellite positioning perfectly integrated with Google Maps. This integration allowed the tracking of inspectors’ routes on digital maps.
guard patrol
Using GPS coordinates, the exact locations of the patrol personnel and their inspection activities were accurately monitored. The 220KV Ping Nuclear Line and its branch line, spanning 38 kilometers with 112 towers, were each designated as inspection points. The frequency of inspections was set according to the schedule. Four inspection teams were assigned, each equipped with a handheld inspection device.

Product: WM5000PH7


  • GPS positioning of the towers, combined with digital maps, provided clear information on the location of the towers and the direction of the high-voltage lines, including the surrounding environment and other high-voltage lines.
  • The system recorded the time inspectors reached each tower, their duration of stay, and their inspection trajectory.
  • Data from patrolling were collected for summary and statistical analysis, which was used for assessment of inspection activities.
  • Regular patrols led to a decrease in theft incidents. Problems were reported and addressed promptly, saving manpower and material costs while ensuring the safe transmission of electricity.