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Eleodor Nichita, PhD - University of Ontario Institute of Technology. Oshawa, ON, CA

Eleodor Nichita, PhD Eleodor Nichita, PhD

Associate Professor, Faculty of Energy Systems and Nuclear Science | University of Ontario Institute of Technology

Oshawa, ON, CANADA

Developing advanced computational models for nuclear reactor safety analysis and radiation dosimetry

Biography

Nuclear fission is the world’s main source of electricity with near-zero greenhouse-effect-inducing carbon dioxide emissions. The more than 440 commercial nuclear power plants operating in 31 countries provide over 11 per cent of the world’s electricity as continuous and reliable base-load power. Another 60 reactors are under construction. Durham Region is home to two nuclear power plants, both within a 30 km radius of the University of Ontario Institute of Technology (UOIT).

To remain an important contributor to Ontario’s energy supply, CANDU reactors must satisfy ever-increasing economic and safety demands. In particular, increasingly detailed and accurate simulation models are required for the safety analysis of existing and future CANDU reactors. To that end, Eleodor Nichita, PhD, Associate Professor in the Faculty of Energy Systems and Nuclear Science, is primarily focused on computational reactor and radiation physics to ensure the long-term safety of these and other nuclear power plants. In collaboration with the University Network of Excellence in Nuclear Engineering and Ontario Power Generation, Dr. Nichita’s latest research focuses on modelling the static and dynamic behaviour of CANDU reactors and on developing CANDU computational benchmarks to be used to evaluate existing and emerging reactor-physics computational tools.

His other research investigates the dynamic characteristics of Pressure-Tube Supercritical-Water-Cooled Reactors (which contribute to the design of the control and safety systems of the Canadian Generation IV advanced reactor concept); computational radiation dosimetry studies for the protection of radiation workers; and medical radionuclide production methods.

Dr. Nichita’s motivation to confront two of the world’s most critical issues – energy and health, spurred his educational path. He earned a Bachelor of Science in Engineering Physics from the University of Bucharest in Romania, a Master of Science in Medical Physics from McMaster University in Hamilton, Ontario, and both a Master of Health Physics and a Doctorate in Nuclear Engineering from the Georgia Institute of Technology in Atlanta, Georgia. He then moved back to Canada and spent his first six years in industry as a reactor core physicist for Atomic Energy of Canada Limited, before joining UOIT in 2004 as an assistant professor. A former President of the Canadian Nuclear Society, Dr. Nichita has earned several awards for his work.

Industry Expertise (11)

Advanced Medical Equipment Education/Learning Energy Information Technology and Services Nuclear Program Development Professional Training and Coaching Renewables and Environmental Research Safety Utilities

Areas of Expertise (10)

Software Development Modelling and Simulation Nuclear Medicine and Radionuclides Reactor Safety Analysis Reactor Design Standards Development Educational Curriculum Development Reactor and Radiation Physics Neutron and Radiation Transport Nuclear Reactor Kinetics and Control

Accomplishments (3)

Fellow, Canadian Nuclear Society (professional)

2016-01-01

Appointed to this role, the Canadian Nuclear Society promotes the exchange of information on all aspects of nuclear science and technology and its applications.

Best Paper Award, American Nuclear Society (professional)

2007-01-01

Awarded at the American Nuclear Society Winter Conference in Washington DC.

Member Alpha Nu Sigma National Honor Society, (professional)

1996-01-01

Affiliated with the American Nuclear Society, Alpha Nu Sigma National Honor Society recognizes high scholarship, integrity, and potential achievement among outstanding degree-seeking nuclear engineering students at institutions of higher learning.

Education (4)

Georgia Institute of Technology: PhD, Nuclear Engineering

Georgia Institute of Technology: MS, Health Physics

McMaster University: MS, Medical Physics

University of Bucharest: BS, Engineering Physics

Affiliations (6)

  • Professional Engineers Ontario
  • Canadian Nuclear Society
  • American Nuclear Society
  • Canadian Organization of Medical Physicists
  • American Association of Physicists in Medicine
  • Alpha Nu Sigma, Nuclear Science and Engineering Honour Society

Event Appearances (10)

Designing a Computer Code to Calculate the Committed Dose Equivalent to Internal Organs Following the Injection of a Radiopharmaceutical

35th Annual Conference of the Canadian Nuclear Society  Saint John, New Brunswick

2015-05-31

Temperature Distribution Inside Fresh-Fuel Pins of Pressure-Tube SCWR

7th International Symposium on Supercritical Water-Cooled Reactors  Helsinki, Finland

2015-03-15

Axial Power and Coolant-Temperature Profiles for a Non-Re-entrant PT-SCWR Fuel Channel

7th International Symposium on Supercritical Water-Cooled Reactors  Helsinki, Finland

2015-05-15

Progress Towards an Accurate Lattice-Homogenization Technique for Pressure Tube Supercritical Water-Cooled Reactor Neutronic Calculations

PHYSOR 2014 International Conference the Role of Reactor Physics Toward a Sustainable Future  Kyoto, Japan

2014-09-28

Preliminary Evaluation of Coolant Void Reactivity of a Re-entrant Channel Pressure Tube Supercritical Water-Cooled Reactor

PHYSOR 2014 International Conference on the Role of Reactor Physics Toward a Sustainable Future  Kyoto, Japan

2014-09-28

Preliminary Space-Time Kinetics Simulation of a Coolant Voiding-Induced Transient for a Supercritical Water-Cooled Reactor with Re-entrant Fuel Channels

19th Pacific Basin Nuclear Conference  Vancouver, British Columbia

2014-08-24

Preliminary Comparison of Transport Codes Applied to a Second-Generation PT-SCWR Lattice

Canada-China Conference on Advanced Reactor Development 2014  Niagara Falls, Ontario

2014-04-27

Preliminary Serpent Calculations for a PT-SCWR Lattice

SERPENT User Group Meeting  Berkeley, California

2013-11-06

Preliminary Study of Dynamic Properties of a Th-Pu Pressure-Tube Supercritical Water-Cooled Reactor

The 6th International Symposium on Supercritical Water-Cooled Reactors  Shenzhen, Guangdong, China

2013-03-03

Uncertainties in Kinetics Parameters of Natural-Uranium-Fuelled CANDU Cores Introduced by Lattice Homogenization and Group Condensation

24th Nuclear Simulation Symposium  Ottawa, Ontario

2012-10-14

Research Grants (2)

Improved CANDU-Core Homogenization and Benchmark Models

NSERC Collaborative Research and Development Grant 

2014-04-01

For CANDU reactors to continue to be an important contributor to the Ontario energy supply they have to satisfy ever-increasing economic and safety demands. The broad objective of this work is twofold: to develop a new, more accurate, method for calculating the neutron power distribution in a nuclear reactor by using advanced homogenization methods, and to develop detailed CANDU-specific benchmark problems to test the newly developed method, as well as other methods and codes in current use in the Canadian nuclear industry.

Study of Kinetics Characteristics of a Pressure-Tube Supercritical Water Reactor

NSERC Collaborative Research and Development Grant 

2011-01-01

In order to analyze the safety attributes of the Pressure-Tube, Supercritical Water-Cooled Reactor, and design its control and safety systems, its kinetic characteristics must be assessed. This project is studying the four aspects related to the kinetics of PT-SWCR and aims to contribute to the design and analysis of the PT-SCWR Generation IV advanced reactor concept in Canada.

Courses (5)

Introduction to Nuclear Physics

NUCL 2500U, 2nd Year Undergraduate Course

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Reactor Kinetics

NUCL 3820U, 3rd Year Undergraduate Course

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Medical Imaging

RADI 3200U, 3rd Year Undergraduate Course

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Introduction to Nuclear Concepts for Engineers and Scientists

NUCL 5060U, Graduate Course

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Modelling and Simulation Tools for Reactor Physics

NUCL 5005U, Special Topics, Graduate Course

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Articles (3)

Burnup-Dependent Effect of Lattice-Level Homogenization and Group Condensation on Calculated Kinetics Parameters for CANDU-Type Lattices Nuclear Engineering and Design

2015-05-01

Modern analysis of nuclear reactor transients uses space-time reactor kinetics methods. In the Canadian nuclear industry, safety analysis calculations use almost exclusively the Improved Quasistatic (IQS) flux factorization method. The IQS method, like all methods based on flux factorization, relies on calculating effective point kinetics parameters, which dominate the time behavior of the flux, using adjoint-weighted integrals. The accuracy of the adjoint representation influences the accuracy of the effective kinetics parameters. Routine full core calculations are not performed using detailed models and transport theory, but rather using a cell-homogenized model and two-group diffusion theory. This work evaluates the effect of homogenization and group condensation at different burnups, for three fuel types: natural-uranium (NU) fuel, low-void reactivity (LVR) fuel and Advanced CANDU Reactor (ACR) fuel.

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Moderator Displacers for Reducing Coolant Void Reactivity in CANDU Reactors: A Scoping Study Nuclear Technology

2016-10-13

When the coolant is voided in the lattice of a Canada deuterium uranium (CANDU) reactor, the net reactivity change is positive, due primarily to the fact that the coolant and moderator are separated and the coolant volume is much smaller than the moderator volume. The modest loss in moderation occurring when coolant is lost is not sufficient to offset the positive reactivity contributions of increased fast fission rate and reduced epithermal absorption. A way to achieve a negative net reactivity effect on coolant voiding is to increase the importance of moderation in the coolant by decreasing the moderator-to-coolant volume ratio. This work proposes reducing the moderator-to-coolant volume ratio in existing CANDU reactors by packing the moderator with displacers in the shape of hollow spheres in a close-packed pattern.

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Effect of Lattice-Level Homogenization and Group Condensation on Calculated Kinetics Parameters of a Natural-Uranium-Fueled Equilibrium CANDU Core Nuclear Science and Engineering

2013-10-01

Modern analysis of nuclear reactor transients uses space-time reactor kinetics methods. In the Canadian nuclear industry, safety analysis calculations use almost exclusively the improved quasi-static (IQS) flux factorization method. The IQS method, like all methods based on flux factorization, relies on calculating effective point-kinetics parameters, which dominate the time behavior of the flux, using adjoint-weighted integrals. The accuracy of the adjoint representation influences the accuracy of the effective kinetics parameters. Routine full-core calculations are not performed using detailed models and transport theory, but rather using a cell-homogenized model and two-group diffusion theory. This work evaluates the effect of homogenization and group condensation on the calculated effective kinetics parameters of an equilibrium CANDU core.

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