Overhead view of engineers inspecting a turbine in a nuclear power station.

Projects | Nuclear

Major Component Replacement Project

Primary Heat Transfer and Moderator Drying and Ventilation Project 

Cheme was engaged to design and commission equipment to support a Major Component Replacement (MCR) project. This project involved refurbishing multiple reactor units at one of the largest electricity suppliers in Ontario. The two equipment modules needed were: a vacuum dry system for the Primary Heat Transport; and a redundant venting and drying system for the Moderator. The systems were designed to remove heavy water and tritium and meet specific safety and functional requirements.

Cheme optimized the process to drain and dry the premium heat transfer (PHT) and moderator systems of the nuclear power plant as part of the MCR Program. The previous process took over nine months to complete and was filled with stoppages due to operator and equipment issues. If the PHT and Moderator are dried sufficiently, the amount of PPE required by contractors to work on these systems is greatly reduced. This reduces overall timelines and cost of the MCR operations.

Cheme worked extensively with the client to optimize the process for site conditions developing PFD’s, P&ID’s and functional specifications for the project. We then worked in the field to provide technical and troubleshooting support to ensure the system was rigorously tested and verified to function as per specifications and design.

Our team developed manuals to support the project, including an operating manual for engineers, an operating manual for plant operations staff, a troubleshooting guide for alarms, and a preventative maintenance schedule. Cheme worked on-site to verify the installation and provide on-site support during the initial start-up and drying cycles.

The operation of the equipment exceeded expectations and reduced the timeline to drain and dry the PHT system.

Project Snapshot


Ontario, Canada

Project Type

Nuclear Power Generation

Expert Spotlight

Nik Krpan

Head of North American Strategy

Nik is the Head of North American Strategy of Cheme and a Consulting Engineer with 20 years of progressive experience in process engineering and management (business and project).
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If we are working on your project, we will find a way to get it done. Leadership and values matter a great deal at Cheme. I serve our team by being the best example I can be, and by creating a place to work that we can all be proud of.
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