Research Papers/Topics in Nuclear Engineering

Investigating The Thermal Hydraulic Performance Of Combined Split And Swirl Vanes Using Star-Ccm+

ABSTRACT For effective evacuation of heat from nuclear fuels and increasing the Critical Heat Flux (CHF) of nuclear fuel bundles, mixing vanes are attached to spacer grids in fuel assemblies. However, the presence of spacer grids increases the pressure drop across the fuel bundle which has economic implications on the operations of Nuclear Power Plants (NPPs) in general. Nuclear fuel vendors are therefore continually improving upon the designs of mixing vanes in order to improve the the...

Simulation Of Groundwater Flow In The Voltaian (Around Tamale) Using Carbon-14

ABSTRACT Studying the process of groundwater flow in subsurface systems using numerical simulation has been widely practiced. The purpose of this study was to establish a 2D groundwater flow model for evaluating groundwater resources of the Voltaian Basin (around Tamale) in the Northern Region of Ghana. To understand the rate of abstraction of groundwater in the study area, a finite-element, steady-state groundwater flow model was used to simulate groundwater flow in the aquifer. COMSOL...

Investigation of Heat Transfer and Distribution in the Core of Ghana Research Reactor-1 (GHARR-1) using STAR-CCM+ CFD Code

ABSTRACT In the present work, STAR-CCM+ CFD code was used to investigate steady state thermal hydraulic parameters in the core of Ghana Research Reactor-1 (GHARR-1). The core was segmented into 21 axial segments. 3D-CAD parametric solid modeler embedded in STARCCM+ was used to model the geometry. The geometry was discretized by the use of appropriate meshing models. GHARR-1 operating conditions were set as boundary conditions for the STAR-CCM+ simulation conducted. Heat flux specific to ...

Stability and Control of Supercritical Water Reactor System: A Study into Concepts and Applications

ABSTRACTThe study addresses the stability and control of nuclear systems with emphasis on the Supercritical Water Reactor (SCWR) as proposed in the Generation IV International Forum. The literature on the stability and control of the SCWR is presented. A Computational Fluid Dynamics code, STAR-CCM+, is used to study the flow stability problems in circular channels, fuel bundle slices with and without heating structures. Some of the effects of numerical discretisation, turbulence model effects...

Characterization Of Ghana Research Reactor-1 Low Enriched Uranium Core Irradiation Sites Using A Theoretical Method

ABSTRACTThe GHARR-1 is in the final stages of converting its HEU (90.2 %) fuel to LEU (13 %)fuel. Due to the differences if the LEU core design as compared to that of the HEU;fuel density, dummy arrnagement, number of fuel elements, this study was carried outcharacterize the neutron spectrum at the irradiation sites of GHARR-1 to ascertain theimpact of the conversion on the neutron spectrum. This was done theoretically using theMCNP5 code. The neutron spectrum parameters (a and f ), neutron f...

Determination of Hydrogen Content of Petroleum Products from Tema Oil Refinery Using Neutron Backscatter Technique

ABSTRACT The hydrogen content of hydrocarbon materials is very important in several areas of industrial process such as mining, vegetable oil extraction and crude oil exploration and refining. A fast and more universal technique based on thermal neutron reflection was employed to determine the total hydrogen contents of petroleum samples from Tema Oil Refinery (TOR) and Crude oil samples from Jubilee field and Nigeria. The experimental set-up consisted of a source-holder housing a 1...

Radiological Safety Assessment Of The Ghana Research Reactor-1 At Shutdown Using Atmospheric Dispersion Model

A radiological safety assessment of the GHARR-1 was evaluated by calculating approximately the TEDE of radionuclides release from the reactor at shutdown using atmospheric dispersion model before the commencement of the core conversion from HEU to LEU fuel. A condition essentially needed for safety and environmental impact assessment to obtain the core conversion (removal) program license. In doing so, a source term estimation and radiological safety assessment were i...

Assessment Of The Reliability Of Thermal-Hyraulic And Neutronics Parameters Of Ghana Research Reactor-1 Control Systems

ABSTRACT The thermal–hydraulics and neutronics parameters of GHARR-1 control systems were assessed for its reliability after 18 years of operation using the Micro-Computer Closed Loop System (MCCLS) and original Control Console (CC). The MCCLS and some components that control the sensitivity and the reading mechanism of the meters on the control systems have been replaced with new ones over the years, due to ageing, repairs and obsolescence. The results show that when reactor is ...

Binary Collision And Molecular Dynamics Simulation Of Feni-Cr Alloys At Supercritical Water Condition

ABSTARCT Fe-Ni-Cr alloys are commonly used as pressure vessel (in-core) materials for nuclear reactors and have been classified as candidate materials for Supercritical Water-Cooled Reactors (SCWR). In service, the in-core materials are exposed to harsh environments: intense neutron irradiation, mechanical and thermal stresses, and aggressive corrosion prone environment which all contribute to the components’ deterioration. For better understanding of the mechanisms responsible for de...

Reactor Core Conversion Studies Of Ghana Research Reactor – 1 And Proposal For Addition Of Safety Rod

ABSTRACT The inclusion of an additional safety rod in conjunction with a core conversion study of Ghana Research Reactor-1 (GHARR-1) was carried out using neutronics, thermal hydraulics and burnup codes. The study is based on a recommendation by Integrated Safety Assessment for Research Reactors (INSARR) mission to incorporate a safety rod to the reactor safety system as well as the need to replace the reactor fuel with LEU. Conversion from one fuel type to another requires a complete ...

Thermal Analysis of a Pebble Bed High Temperature Gas Cooled Reactor

ABSTRACT The pebble bed type of high temperature gas cooled nuclear reactor is a promising option for next generation reactor technology and has the potential to provide high efficiency and cost effective electricity generation. The reactor unit heat transfer poses a challenge due to the complexity associated with it. In the pebble bed, heat is generated in kernels inside the fuel sphere. The generated heat is conducted to the sphere surface where it is transferred to the coolant (h...

Neutronics And Dose Calculation For Prospective Spent Nuclear Fuel Cask For Ghana Research Reactor-1 Facility.

ABSTRACT Ghana Research Reactor-1 core is to be converted from Highly Enrich Uranium (HEU) fuel to Low Enriched Uranium (LEU) fuel in the near future; a storage cask will be needed to store the HEU fuel. Notwithstanding the core conversion process, it is also important for the facility to have a storage cask ready when the fuel is finally spent to temporarily store the fuel until permanent storage is provided. Winfrith Improved Multigroup Scheme-Argonne National Laboratory (WIMS-ANL), R...

Modelling and Simulation of Groundwater Flow and Radionuclide Transport in Aquifers of Dahomeyan System of the Accra Plains in Ghana

ABSTRACT Locating a suitable radioactive waste disposal site in the Dahomeyan System of the Accra Plains has become necessary in isolating radionuclide waste from the biosphere to reduce risk to human and environment. Radionuclide as leaked from canister into the groundwater is carried by groundwater through fractured domain in space and time lead to groundwater contamination that poses threat to humans and the environment. Previous researches carried out in the study area modelled radi...

Effects of Injection Pipe Orientation on Mixing Behavior in Contributing to Thermal Fatigue in a T-junction of a Pipe

ABSTRACT  The thesis dealt with the temperature fluctuation in a T-junction with two fluid streams of different temperature. This phenomenon is of crucial importance in many engineering applications such as Nuclear Power Plants, because temperature fluctuation leads to thermal fatigue and subsequently might result in failure of structural material. In mixing areas of a Nuclear Power Plant where piping structure is exposed to unavoidable temperature differences in a bid to maintain plant ...

Effects of Wall Roughness on Flow Stability Analysis of Supercritical Heated Channel

CHAPTER ONE: INTRODUCTION 1.1 Background of the Study The world‟s population growth is increasing rapidly and requires a corresponding growth in electric energy production. The current worldwide electricity sources, consists of approximately coal 41%, gas 20%, oil 6%, nuclear 15%, and hydro and renewable together 18% [1]. For the world to support its population there must be an increase in the use of energy supplies that are clean, safe and cost-effective. Prominent among these suppli...