Steve Gregoris

Chief Nuclear Officer at Ontario Power Generation

Steve Gregoris is the Chief Nuclear Officer for Ontario Power Generation. He is responsible for OPG’s nuclear fleet consisting of two stations and 10 nuclear units.

Steve has worked in the Nuclear Power industry for over 30 years, all with Ontario Power Generation/Ontario Hydro at both the Darlington and Pickering Nuclear Generating Stations. He brings expertise in areas such as operational excellence, leader development, performance improvement, and organizational effectiveness.

He started his career in Engineering and then moved to Operations, where he has held several positions including Certified Shift Manager and Operations Manager at Pickering, and Director of Operations and Maintenance at Darlington. In 2017, Steve completed a secondment with the World Association of Nuclear Operators in Atlanta as an Organizational Effectiveness Evaluator. Steve was Deputy Vice President for Pickering and prior to his current position, he was Senior Vice President for the Darlington Nuclear Generating Station.

Steve is a graduate of McMaster University with a B.A.Sc in Mechanical Engineering and is a member of Professional Engineers Ontario.



  • Chief Nuclear Officer

    January, 2022 - present

  • Senior Vice President, Darlington Generating Station

  • Senior Vice President, Darlington Generating Station

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