D.C. Cook Reactor Controls System Digital Upgrade

Sargent & Lundy performs digital upgrade to reactor controls system to improve plant reliability and operability

Unit 1 and Unit 2 Donald C. Cook Reactor Controls System Digital Upgrade Project
Bridgman, Michigan
Client: American Electric Power (AEP)

Project Highlights:

  • Over $50 million engineering, construction, and equipment project.
  • 18,000 wiring terminations per unit.
  • Complicated requirements for system design, testing, and implementation.
  • Nominated in 2017 by AEP for the Nuclear Energy Institute’s Top Industry Performance award as a showcase digital upgrade project.

Project Description:

AEP selected Sargent & Lundy’s nuclear digital engineering team to perform a full upgrade of D.C. Cook Nuclear Station’s reactor controls and instrumentation (RCI) system. The new control system was a first-of-a-kind for the domestic nuclear fleet, and featured state-of-the-art technology combined with a redundant, fault-tolerant operating platform.

The original reactor control system employed vintage stand-alone hardware components that had become obsolete, required unavailable replacement parts, or were no longer supported by their respective OEMs.

Accordingly, the main objective of this project was to replace the existing reactor controls systems’ control processing modules, associated displays, and supporting components with a fault-tolerant distributed control platform that increased system availability and provided reliable and event-free operation.

Sargent & Lundy began work to upgrade the station’s reactor controls systems in early 2013 for Units 1 and 2. The reactor controls system comprises various loops that perform a variety of critical control and indication functions, including but not limited to:

  • Reactor coolant system pressure control.
  • Steam generator water level control.
  • Pressurizer level control.
  • Chemical and volume control system level control.
  • Steam dump system control.
  • Automatic rod speed control.

The replacement reactor control system included redundancy features for hardware, processing, and system power supplies. It also eliminated single-point vulnerabilities associated with the previous system. The new system captures over 700 inputs and outputs per unit and includes advanced features for man-machine interfaces, data trending, and real-time diagnostics.

Unit 2 was successfully implemented in the spring of 2018, and Unit 1’s implementation was completed in the spring of 2019.

As a result of the successful completion of the project, Sargent & Lundy has become AEP’s preferred digital engineering service provider and functions in an integrated role with AEP’s instrument and controls design engineering group to handle the station’s ongoing digital upgrade projects and initiatives.

Project Scope:

Sargent & Lundy provided the following services as part of the Unit 1 and Unit 2 D.C. Cook Reactor Controls Digital Upgrade project:

  • Production of system hardware and software specifications.
  • Development of detailed designs for each unit, including:
    • Replacement of control system equipment.
    • Replacement of main control room hardware and display equipment for use by plant reactor operators.
    • Replacement of feedwater valve control positioners and trip solenoids.
  • Development of separate design package for a custom building for digital equipment assembly, staging, and testing.
  • Interface with equipment controls vendor, including vendor-site system development activities and factory acceptance test witnessing.
  • On-site engineering support team of 12 digital engineers during pre-outage, in-outage, and post-outage implementation phases.

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