Accomplished senior nuclear industry executive brings over 35 years of leadership experience to operation of Canada’s national nuclear laboratory

 Chalk River, ON – April 01, 2020 – Canadian Nuclear Laboratories (CNL), Canada’s premier nuclear science and technology organization, is pleased to announce that it has appointed Joe McBrearty as its new President and Chief Executive Officer (CEO). Mr. McBrearty served as CNL’s Chief Operating Officer (COO) for the past year and will replace Mark Lesinski, who has successfully completed his term as President and CEO, and will be continuing his career elsewhere in the nuclear industry.

As President and CEO at CNL, Joe will continue to enact improvements to the company’s research program, safety performance, security posture, capital program, and waste management activities. While Joe is currently focused on CNL’s response to the COVID-19 Pandemic, his mandate will include the delivery of major environmental remediation projects, the operation of Canada’s national nuclear research program, and the $1.2 billion revitalization program to modernize CNL’s Chalk River campus.

“I have had the privilege of working with Joe during his tenure as COO, and I believe he is exceptionally well-qualified to continue the momentum we have built at CNL over the past few years,” commented Lesinski. “Joe possesses a unique combination of leadership experience and an exceptional track record operating complex nuclear installations throughout North America, with a career that spans all areas of the nuclear industry. CNL is in good hands with Joe.”

“Mark’s leadership has been instrumental in navigating CNL through a period of transformational change, and he has put the company in a strong position to seize new commercial opportunities, safely address the Government of Canada’s nuclear liabilities, and complete the revitalization of the Chalk River Laboratories campus,” commented McBrearty. “On behalf of everyone at CNL, I would like to thank Mark for his commitment and service over the past five years, and wish him the very best in the future.”

Prior to joining CNL, Joe served as COO and Deputy Director for Field Operations with the Office of Science at the U.S. Department of Energy (DOE), where he oversaw the operations of 10 U.S. national laboratories and over 25,000 contract and federal staff. In this role, Joe realized major improvements in nuclear operations, led strategic planning and oversight of laboratory operations, and spearheaded infrastructure and management policy changes in support of the U.S. DOE’s research and development program. Joe also served in the U.S. Navy with extended tours of duty on board four nuclear submarines, including command of USS DALLAS.  Joe’s other experience in high-profile positions includes the Nuclear Propulsion Examining Board, command of the TRIDENT Refit Facility, and command of the U.S. Navy’s Officer Training Command.

Joe also has extensive experience in community and stakeholder relations, leading the revitalization of the American Museum of Science and Energy in Oak Ridge, Tennessee; in trades and education, guiding the reestablishment of an Apprenticeship Training Program; and in site revitalization, working to lay the foundation for the U.S. DOE to develop strategic plans to assess, fund, and upgrade their general purpose infrastructure.

For more information on CNL, including its leadership team, please visit

About CNL

Canadian Nuclear Laboratories is a world leader in nuclear science and technology offering unique capabilities and solutions across a wide range of industries. Actively involved with industry-driven research and development in nuclear, transportation, clean technology, energy, defence, security and life sciences, we provide solutions to keep these sectors competitive internationally.

With ongoing investments in new facilities and a focused mandate, Canadian Nuclear Laboratories is well positioned for the future. A new performance standard reinforced with a strong safety culture underscores every activity.

For more information on the complete range of Canadian Nuclear Laboratories services, please visit or contact [email protected].



Patrick Quinn
Director, Corporate Communications
CNL, 1-866-886-2325