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 Mult...
ABSTRACT The 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 out characterize the neutron spectrum at the irradiation sites of GHARR-1 to ascertain the impact of the conversion on the neutron spectrum. This was done theoretically using the MCNP5 code. The neutron spectrum parameters (a and f ), neu...
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 1Ci Am-Be...
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 initially performed. ...
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 operated a...
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 degradat...
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 (helium ga...
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 radionucli...
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 oper...
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 supplies i...