ABSTRACT
Reports of high radiation-related accidents have been associated with industrial radiography than in any other radiography sub-specialty, mainly due to breach of radiation protection practices. This study examines the availability and utilization of radiation monitoring devices, the means of environmental protection during field operations and the commonly used radiation sources in Saipem Contracting Nigeria limited (SCNL). A descriptive survey design was adopted and convenience sampling technique was used in selecting both the study company and study sample. The respondents responded to a 32 item structured instrument in form of interview guide containing questions on the availability, utilization, means of environmental protection from radiation as well as commonly used radiation sources. Critical ratio test was performed and used in testing the hypotheses. The findings show that radiation monitoring devices are available and are utilized during field operations. Findings also show that x-ray machines and radionuclide are the commonly used sources of radiation and that there is adequate source-operator distance during operation as well as a means of protecting the environment during field operation. The study recommends that basically trained Radiographers be incorporated into SCNL and that constant update courses on radiation protection be organized for all the NDT staff irrespective of their rank. The study also recommends that the use of various radiation monitoring devices be strongly adhered to.
TABLE OF CONTENTS
Title page-----
Approval page-----
Certification-----
Dedication -----
Acknowledgment-----
Table of Contents -----
List of Tables -----
List Figures -----
Abstract-----
CHAPTER ONE
INTRODUCTION
1.1Background of Study-----
1.2Statement of Problems-----
1.3Purpose of Study-----
1.3.1General Purpose-----
1.3.2Specific Objectives-----
1.4Significance of Study -----
1.5Scope of Study-----
CHAPTER TWO
THEORETICAL BACKGROUND
2.1 Industrial Radiography-----
2.2 Industrial Radioactive Sources-----
2.3Industrial radiography X-Ray Equipment---
2.3.1 Gamma Radiography Sources and Containers--
2.3.2X Ray Radiography Equipment----
2.3.3 Accelerators-----
2.3.4 Pipe Crawler Equipment-----
2.4 Radiation Protection-----
2.5 Principles of Radiation Protection----
2.6Types Of Radiation And Their Shielding Techniques-
2.7 Shielding Design-----
2.8 Monitoring -----
2.9 Radiation Monitoring-----
2.9.1 Environmental Monitoring-----
2.9.2 Source Monitoring-----
2.9.3 Instruments for Radiation Measurement.---
CHAPTER THREE
RESEARCH METHODOLOGY
3.1Research Design-----
3.2 Location of Study-----
3.3 Target Population-----
3.4 Sample Technique-----
3.5Sample Size-----
3.6Subject Description-----
3.7Selection Criteria-----
3.7.1 Inclusion Criteria-----
3.7.2 Exclusion Criteria-----
3.8 Sources of Data Collection-----
3.10 Methods of Data Analysis-----
CHAPTER FOUR
DATA ANALYSIS, PRESENTATION AND DISCUSSION
4.1 Data Analysis-----
4.2Data Presentation-----
4.3 Chi-Square Analysis – (The X2 Test of Independence)-
CHAPTER FIVE
DISCUSSION, CONCLUSION, RECOMMENDATION AND LIMITATIONS
5.1 Discussion and Implication of Result----
5.1.1 Demographic Findings----
5.2 Summary and Conclusion----
5.3 Recommendations----
5.4Limitations of Study----
5.5Area of Further Studies----
References
Appendix
Questionnaire
LIST OF TABLES
Table 1. Respondents’ gender and level of educational
Table 2. Respondents’ professional inclination and duration of practice.----
Table 3: Respondents’ professional classification and frequency of utilization of personnel monitoring devices.
Table 4: Availability of radiation monitoring devices during field operation.----
Table 5: Rate of utilization of radiation monitoring devices during field operations.----
Table 6: Means of alerting and protecting people within the radiation environment during exposure in SCNL
Table 7: The commonly used radiation sources used in SCNL
Table 8: Rate of utilization of radiation monitoring devices during field operations with respect to gender of
the participants.----
Table 9. Rate of utilization of radiation monitoring devices during field operations with respect to level of education of attained by radiation workers in SCNL.
Table 10. Rate of utilization of radiation monitoring devices during field operations with respect to basic profession of participants.---
Table 11: Rate of utilization of radiation monitoring devices during field operations with respect to duration of practice.-----
LIST OF FIGURES
FIG 1: Class P portable exposure device--
FIG 2: Class M portable exposure device--
FIG 3: Panoramic radiating tube assembly with
conical anode.---
FIG. 4: Direct radiating portable X ray tube assembly.
FIG: 5Portable X ray betatron.---
INTRODUCTION
Industrial radiography uses x-rays and Gamma rays to produce a radiograph of specimen or material, showing any changes in thickness, defect (internal or external), and assembly details, to ensure optimum quality. This application is called Non-destructive testing.1
Three types of radiation sources are typically available for such purposes.
•Radioactive materials that are gamma ray emitters such as Iridium -192 (192Ir), Cesium-137 (137cs) and Cobalt-60 (60Co)
•Neutrons that are produced in reactors or by other means (particle accelerators, Radionuclide) and this application of neutrons is specifically referred to as neutron radiography.
•X-ray tubes that are characteristic of conventional x-ray machines.
Industrial radiography machines which are x-ray tube based can produce dose rates in air of about 2Gy per minutes at one metre. These machines are usually portable or mobile and convenient for use in a wide range of conditions such as at air craft hangers, pipeline construction and deployment, fabrication facilities, offshore platforms operations, bridges or construction sites. At work sites, the working conditions coupled with frequent manipulation of such high-intensity radiation sources present much potential for radiation exposure to occur. Both the workers and other persons proximal to the work area can be exposed to high radiation fields which, potentially could lead to injuries or death.2
In another industrial application, there are systems specifically designed to focus intense beam of high energy electrons that melt and bond metal under vacuum conditions and these electron-metal interactions can produce x-rays as a by-product of the bonding process. Such systems are called Electron beam welders. Beam current and high voltages are typically in the range of 20-200milliAmpers and 120-450kilovoltage respectively. Consequently, the operations of electrons beam welders present a potential for exposure to x-rays and electrons, which are types of ionizing radiation.
In general, the interaction of ionizing radiation with matter is probabilistic, that is, there may or may not be an interaction. The interaction with individual cells of living organisms may be direct or indirect. At the cellular level, direct interaction with Deoxyribonucleic acid (DNA), or other constituents can cause damages. Various possibilities exist for the fate of cells exposed to ionising radiation.
1.Damaged cells are completely repaired by the body’s inherent repair mechanisms.
2.Damaged cells die during their attempt to reproduce. Thus tissues and organs in which there is substantial cell loss may become functionally impaired
3.Damaged cells survive the radiation insult, but are misrepaired and are able to undergo subsequent divisions. These cells, with the progression of time may be transformed by external agents (e.g. chemicals, diet, radiation exposure, life style, etc.), and may develop into leukaemia or cancer after some years. Such latent effects being referred to as stochastic. Should germ cells in the ovaries or testes be modified by radiation, hereditary effects may occur in the progeny of the individual exposed to radiation. Exposure of embryo or foetus to ionising radiation could increase the risk of leukaemia in infants and, during certain periods in early pregnancy, may lead to mental retardation and congenital malformation if the amount of radiation is sufficiently high.4
Thus, exposure to ionising radiation has the potential to cause early or late adverse health effect. This is why the radiation risks associated with industrial radiography operations need to be managed. This study is designed to ascertain the radiation protection procedures adopted by Saipem Contracting Nigeria Limited (SCNL)