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Neutronic Study of Two Reactor Cores Cooled with Light and Heavy Water Using Computation Method

Authors: Z. Gholamzadeh, A. Zali, S. A. H. Feghhi, C. Tenreiro, Y. Kadi, M. Rezazadeh, M. Aref


Most HWRs currently use natural uranium fuel. Using enriched uranium fuel results in a significant improvement in fuel cycle costs and uranium utilization. On the other hand, reactivity changes of HWRs over the full range of operating conditions from cold shutdown to full power are small. This reduces the required reactivity worth of control devices and minimizes local flux distribution perturbations, minimizing potential problems due to transient local overheating of fuel. Analyzing heavy water effectiveness on neutronic parameters such as enrichment requirements, peaking factor and reactivity is important and should pay attention as primary concepts of a HWR core designing. Two nuclear nuclear reactors of CANDU-type and hexagonal-type reactor cores of 33 fuel assemblies and 19 assemblies in 1.04 P/D have been respectively simulated using MCNP-4C code. Using heavy water and light water as moderator have been compared for achieving less reactivity insertion and enrichment requirements. Two fuel matrixes of (232Th/235U)O2 and (238/235U)O2 have been compared to achieve more economical and safe design. Heavy water not only decreased enrichment needs, but it concluded in negative reactivity insertions during moderator density variations. Thorium oxide fuel assemblies of 2.3% enrichment loaded into the core of heavy water moderator resulted in 0.751 fission to absorption ratio and peaking factor of 1.7 using. Heavy water not only provides negative reactivity insertion during temperature raises which changes moderator density but concluded in 2 to 10 kg reduction of enrichment requirements, depend on geometry type.

Keywords: Reactivity, Reactor Core, multiplication factor, MCNP-4C, Peaking factor

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[1] Heavy Water Reactors. Status and Projected, IAEA, Vienna:160, 2002.
[2] J. J. Lipsett, J. T. Dunn "Advanced technology and design for heavywater reactors" IAEA BULLETIN, 1989, pp.22-24.
[3] P. Oberle, Application of a new resonance formalism to Pressurized Water Reactors, PhD thesis, Stuttgart University, 2010.
[4] Thorium fuel cycle ÔÇö Potential benefits and challenges, IAEA, VIENNA: ISSN 1011-4289, 2005.
[5] J. F. Briesmeister MCNP- A General Monte Carlo N-Particle Transport code, Version 4C, Los Alamos National Laboratory Report: LA-13709-M, 2000.
[6] R Jacimovic, M. Maucec, A. Trkov "Verification of Monte Carlo Calculations of the Neutron Flux in the Carousel Channels of the TRIGA Mark II Reactor" Radioanal Nucl Chem 257,2003, pp. 513- 517.
[7] T. Goorley, Criticality Calculations with MCNP5: A Primer (Los Alamos National Laboratory, X-5, LA-UR-04-0294)
[8] N. Ashoub, H. G. Saleh "Evaluation of Two Proposed Fuel Lattice Pitches for ET-RR-1 Reactor" Ann Nucl Energ 27, 2000, pp.553-561.
[9] P. R. Kaste "Review of the Radkowsky Thorium Reactor Concept" Sci Glob Secur 7:10, 1998, pp. 237-269.