Controller for nuclear power plants

Triple modular redundant Tricon system simplifies licensing process, enables easier nuclear modernisation projects

Version 10 of Invensys's Triconex® Tricon® controller has been approved for use in safety-related nuclear power plant instrument and control applications by the United States Nuclear Regulatory Commission. In a Safety Evaluation Report (SER) dated April 12, 2012, the NRC indicates that the latest version of the Tricon controller can now be used in safety-related (1E) applications, like reactor protection systems, in U.S. nuclear power plants and U.S. Department of Energy facilities that require licensing or oversight by the NRC. It is the first controller from a dedicated automation vendor to achieve such certification from the NRC and it remains the only triple-modular-redundant system to be qualified.

“The Triconex Tricon system is extremely important to us as we continue to migrate to digital technology, while providing safe, clean, reliable power to our customers in California,” said Scott Patterson, program manager for I&C obsolescence for Pacific Gas & Electric, which operates the Diablo Canyon Power Plant in San Luis Obispo, Calif. “Partnering with Invensys, an automation vendor whose core competency is safety systems, gives us an additional layer of protection as we upgrade older safety-related equipment. NRC certification means we can move forward with modernising and optimising our plants to ensure their continuous safe operation. We are confident this technology will enhance future upgrades and new designs, as well as ease the licensing process.”

The Tricon controller’s state-of-the-art fault tolerant, triple-modular-redundant—TMR—architecture removes single points of failure by integrating three isolated, parallel control systems and extensive diagnostics into one system. The system uses two-out-of-three voting to provide high-integrity, error-free, uninterrupted process operation. True TMR is the only such technology certified by the NRC. The Commission’s SER encompasses the Tricon controller’s software and hardware, including termination panels, chassis, power supplies, main processor modules, communication modules, input/output modules and interconnecting cabling.


"In 2002, the NRC certified an earlier version of our Tricon controller, and since that time we have made a number enhancements,” said Clayton Scott, chief nuclear officer, Invensys Operations Management. “We sought this unprecedented second certification so that we can continue to deliver the industry’s most reliable safety controller, helping our customers produce the safest, most reliable energy possible. Enabled by our Triconex technology, our nuclear customers can now apply Tricon controllers in both their existing fleet and new builds. This certification will be of tremendous value to the fleet of U.S. nuclear plants that require modernisation. It also sets a new standard for control and safety excellence for the global nuclear industry.”

“Partnering with Pacific Gas & Electric and the Diablo Canyon team to renew nuclear safety certification for the Tricon controller gives other nuclear plants wanting to modernise their safety systems and meet the latest regulatory guidelines a strong point of reference,” said Harry Forbes, senior analyst with ARC Advisory Group. “The NRC’s approval enables other nuclear power plants to expedite their system modernisation plans with shorter schedules and more predictable project costs. ARC believes the Tricon controller will help nuclear power plants globally migrate to digital control with a simplified licensing process.”

Invensys leads the market when it comes to overall safety shutdown systems. As one of the world’s most rigorously evaluated control systems, more than 10,000 Tricon controllers are in use today in safety and critical control applications worldwide, and they have collectively amassed more than 650 millions of hours of operation without failure upon demand.