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Dr. Eleodor Nichita

Eleodor Nichita

Associate Professor

Faculty of Engineering and Applied Science

Dr. Nichita’s research focuses on mathematical modelling and computer simulations of physical processes. He uses such techniques for diverse applications like special-purpose power systems (e.g., arctic, space, hydrogen production), nuclear reactor design and safety, medical and industrial radionuclide production, industrial and medical imaging methods, radiation detection and dosimetry, and epidemiological modeling.

  • PhD - Nuclear Engineering Georgia Institute of Technology, USA
  • MS - Health Physics Georgia Institute of Technology, USA
  • MS - Medical Physics McMaster University, Hamilton, Ontario
  • BS - Engineering Physics University of Bucharest, Romania

Simple Point-Kinetics Simulator for Molten-Salt-Fuelled Reactors

June 5, 2022

41st Annual Conference of the Canadian Nuclear Society

Modeling COVID-19 Transmission using IDSIM, an Epidemiological-Modelling Desktop App with Multi-Level Immunization Capabilities

December 3, 2021

Association of Public Health Epidemiologists of Ontario

Virtual Classes, Real Results: Teaching from Home to Stay-at-Home Students During a Pandemic

Washington, DC November 30, 2021

2021 American Nuclear Society Winter Meeting and Technology Expo

The Physics of Radionuclide Production

May 17, 2021

CNS Workshop on Science and Technologies of Radio-Isotopes

Heavy-Water Reactors

Published in Encyclopedia of Nuclear Energy Vol. 1 June 24, 2021
Eleodor Nichita

This chapter is an overview of heavy-water power reactors. The main characteristic of such reactors is that, because of the excellent moderating properties of heavy water, they can be fueled with natural uranium, or with only slightly enriched (usually below 2%) uranium. The natural-uranium option, in particular, has the advantage of not requiring enrichment facilities for fuel fabrication. A relatively large number of heavy-water power reactor designs have been developed over the years in different countries, using both pressure-tube and pressure-vessel concepts. This chapter surveys those designs, with emphasis on the CANDU system, which has the largest worldwide prevalence among heavy-water power reactors. Only designs of reactors built for power production are included. Designs that have not been built and research reactors are not included.

View more - Heavy-Water Reactors

Problems in Elementary Reactor Physics, with Solutions

January 1, 2017
Eleodor M. Nichita, Benjamin Rouben

This collection of problems is intended primarily for undergraduate students studying reactor physics. Graduate students and nuclear-industry professionals interested in reviewing fundamental reactor-physics concepts will also find it useful. Readers will get a better understanding of essential reactor-physics concepts through simple problems with solutions that require, for the most part, only modest mathematical tools that won’t obscure the underlying physical phenomena. The originality of included problems makes them a valuable complement to those found in undergraduate reactor-physics textbooks. Detailed solutions are provided for all the problems in the book. A comprehensive summary of definitions and formulas useful for solving elementary reactor-physics problems is also included.

View more - Problems in Elementary Reactor Physics, with Solutions

Reactor Statics

Published in W. Garland, Editor. The Essential CANDU September 1, 2014
Eleodor M. Nichita, Benjamin Rouben

This chapter is devoted to the calculation of the neutron flux in a nuclear reactor under special steady-state conditions in which all parameters, including neutron flux, are constant in time. The main calculation method explored in this chapter is the neutron-diffusion equation. Analytical solutions are derived for simple neutron-diffusion problems in one neutron energy group in systems of simple geometry. Two-group diffusion theory and the approximate representation of the diffusion equation using finite differences applied to a discrete spatial mesh are introduced. The rudimentary reactor-physics design of CANDU reactors is presented. The two-step approach to neutronics calculations is presented: multi-group lattice transport calculations, followed by full-core, few-group diffusion calculations. Finally, the chapter covers fuel-property evolution with fuel burnup and specific features of CANDU neutronics resulting from on-line refuelling.

View more - Reactor Statics

Reactor Dynamics

Published in W. Garland, Editor. The Essential CANDU September 1, 2014
Eleodor M. Nichita, Benjamin Rouben

This chapter addresses the time-dependent behaviour of nuclear reactors. This chapter is concerned with short- and medium-time phenomena. Long-time phenomena are studied in the context of fuel and fuel cycles and are presented in Chapters 6 and 7. The chapter starts with an introduction to delayed neutrons because they play an important role in reactor dynamics. Subsequent sections present the time-dependent neutron-balance equation, starting with “point” kinetics and progressing to detailed space-energy-time methods. Effects of Xe and Sm “poisoning” are studied in Section 7, and feedback effects are presented in Section 8. Section 9 is identifies and presents the specific features of CANDU reactors as they relate to kinetics and dynamics.

View more - Reactor Dynamics

Fellow of the Canadian Nuclear Society

President of the Canadian Nuclear Society


Best Reactor-Physics Paper Award

American Nuclear Society

Awarded at the American Nuclear Society Winter Conference in Washington DC, 2007.

Member Alpha Nu Sigma

Nuclear Science and Engineering Honour Society affiliated with the American Nuclear Society

Modelling of COVID-19 Transmission in the Regional Municipality of Durham, Ontario

NSERC Alliance COVID 19 Grant

Computational Methods and Tools for Neutronics Calculations for Molten-Salt Nuclear Reactors

NSERC Discovery

Professional Engineers Ontario

Canadian Nuclear Society

American Nuclear Society

Canadian Organization of Medical Physicists

American Association of Physicists in Medicine

Alpha Nu Sigma, ANS Nuclear Science and Engineering Honour Society

  •     Introduction to Nuclear Physics (undergraduate)
  •     Medical Imaging (undergraduate)
  •     Therapeutic Applications of Radiation (undergraduate)
  •     Nuclear Reactor Design (undergraduate)
  •     Nuclear Reactor Kinetics (undergraduate + graduate)
  •     Nuclear Concepts (graduate)
  •     Neutron Detectors for Reactor Instrumentation (graduate)
  •     Reactor Production of Radionuclides (graduate)
  •     Mathematical Methods for Nuclear Applications (graduate)
  •     Numerical Methods for Reactor Analysis (graduate)
  •     Modelling and Simulation Tools for Reactor Physics (graduate)
  •     Monte Carlo Methods (graduate)
  •     Neutron and Radiation Transport Theory (graduate)
  •     Reactor Physics (graduate, UNENE)