After around three years of research, development and testing, NEC Corporation is to deliver a system for monitoring signs of malfunction in large-scale plants to Chugoku Electric Power Company’s Shimane nuclear power plant in Japan.

The system, which NEC says will be installed at Shimane unit 2 from late June, utilises enormous amounts of plant data (big data) for detecting signs of facility malfunctions.

NEC has been working with Chugoku Electric Power to develop the system since 2011.

Initially, the system analysed sensor information from August 2011 through November 2012, learning how to detect abnormalities based on past examples of defects. In October 2012, Chugoku deployed the system in its technical training facilities at the Shimane nuclear power station on a test basis, and conducted simulations of various malfunctions in order to detect their signs.

Following the successful conclusion of these tests, the companies have now decided to introduce the system Shimane unit 2, a 789 MW boiling water reactor (BWR-5).

"In late June, the companies are scheduled to begin adjusting the detection sensitivity and other factors for the system to be deployed at the Shimane plant as part of ensuring the system’s effectiveness," says NEC Corporation.

NEC says the system, which uses its proprietary invariant analysis technology, can perform the following functions:

  • Automatically detect relationships between different sensors based on the information of many sensors already installed. Correlate various items of measurement information, including vibration, pressure, temperature and acceleration to detect signs of malfunction with a high rate of accuracy.
  • Comprehensively handle large amounts of sensor information, analyse and define normal conditions and signal an alarm when any unusual sign is detected.
  • Automatically identify the range of impact and the causes of any unusual sign that is detected. This saves time and labour when compared to conventional analysis.

Photo: Shimane nuclear power plant