Canadian Nuclear Society

Société Nucléaire Canadienne

480 University Ave., Suite 200, Toronto, Ontario, Canada M5G 1V2

Telephone: (416) 977-7620 Fax: (416) 977-8131


The Toronto Branch of the Canadian Nuclear Society Announces a Public Seminar

Speaker: Dr. John C. Luxat, Manager, Nuclear Safety Technology,

Ontario Power Generation (OPG)

Topic: Safety Analysis Technology:

Evolution, Revolution and the Drive to Re-Establish Margins

Date and Time: 11:45 AM - 1 PM, Tuesday, January 23, 2001

Location: Main Auditorium, OPG Head office, 700 University Ave., Toronto

Visitors please enter the OPG front doors outside Queens Park subway station and take the stairs or elevator to the Mezzanine Level and follow the signs.

Coffee and donuts will be provided.


Over the past two decades safety analysis at OPG, and similarly in the Canadian industry, has been based upon deterministic methods with significant conservatisms built-in. These conservatisms, considered appropriate at the time, were applied to offset limitations in the technology of the era - the models, the analysis computer codes and the underlying knowledge base to validate the models and codes.

With time, and as enhancement and development of improved analysis technology was made, the methodology evolved. However, the technology remained rooted in bounding deterministic methods. Events which were at the boundary of both the design basis and the associated risk spectrum and some that were beyond the design basis - eventually were perceived as representing a "more probable reality". This in turn led to the perception of a lack of margin in design and to safety analysis that was not robust to perturbations in either the knowledge base or the analysis assumptions.

Efforts are underway at OPG and AECL to demonstrate that significant margins do indeed exist. This effort is focused on a more revolutionary technology development which has an underlying probabilistic basis and is referred to as "Best Estimate plus Uncertainty Analysis". The presentation presents a historical perspective on the evolution of safety analysis technology at OPG and discusses the key elements of the new analysis methodology.

Speaker's Biography

Born in Zimbabwe in 1945, John Luxat was educated in South Africa and Canada. He received B.Sc(Eng) and M.Sc. degrees in Electrical Engineering from the University of Cape Town, South Africa, in 1967 and 1969, respectively. Subsequently he received his Ph.D. in Electrical Engineering from the University of Windsor, Ontario, Canada in 1972. Since graduating from university he has worked in the Canadian nuclear industry, initially as a consultant to AECL and Ontario Hydro, and subsequent to 1977, as an employee of Ontario Hydro and OPG. He has broad ranging experience and expertise in the areas of nuclear safety, reactor physics, safety thermalhydraulics and reactor and plant control.

In his present position, as Manager of the Nuclear Safety Technology Department OPG he has responsibility for providing leadership and technical direction for the development of safety analysis methodology. Additionally, he has project management responsibility for the OPG Verification and Validation of Safety Analysis Software program.

For more information, please see and follow Branches -> Toronto

Or freely contact either:

Adam McLean, University of Toronto, Teruo Takahashi, Marubeni Canada Ltd.

(416) 535-0616, (416) 368-1171 ext. 232,