Tetra Tech provided engineering services for an update to two critical, independent standby emergency power generators (EPGs) at Ontario Power Generation (OPG) Pickering Nuclear Generating Station. The EPGs form part of the seismically qualified emergency power system, which is designed to provide power to safety-critical systems in the event of a design basis earthquake. Tetra Tech provided conceptual, preliminary, and detailed design for a significant overhaul of the aging system, which OPG initiated in late 2015. The upgrades ensure continued availability of the EPGs through 2025 to meet regulatory licensing requirements.

“This was a team that made a difference. Can do attitude. Thanks to all.”

Dave Calkin, Section Manager, OPG Design Projects

To ensure continuous plant operation, Tetra Tech worked to establish a strategy for securing the same or similar vintage engines that could be used for zero time overhaul and replacement for the current EPG engines. Tetra Tech developed feasible alternatives; interfaced with vendors; and developed cost, schedule, and risk mitigation plans. Our team’s preliminary engineering tasks included preparing technical scoping documents and design requirements, soliciting stakeholder inputs, and completing a constructability, operability, and safety review for the new system.

Tetra Tech also completed the detailed design, which included sourcing a new engine and preparing all technical documents and assessments to reflect the final configuration. The rigorous design requirements for this safety-related system included seismic qualification and nuclear safety assessments. In support of the procurement effort, Tetra Tech reviewed vendor factory-acceptance test plans, test results, and technical submissions to ensure compliance with technical and design requirements. In addition, Tetra Tech prepared the installation and commissioning work plans to support field execution.

From initiation to turnover, the replacement of the first EPG was completed in 6 months. Tetra Tech is currently in the process of preparing the design for replacement of the second EPG, completion of which will ensure safe, reliable commercial operation and future decommissioning of the facility. The client considered the project a tremendous success due to the quick turnaround for replacing the old systems and the Tetra Tech team’s flexibility and high-level of stakeholder engagement. OPG has hailed the project as a model of vendor-client collaboration.