Assessment of Occupational Exposure and Radiation Protection in Some Selected Well-Logging and Industrial Radiography Facilities in Nigeria

Filed in Articles by on July 25, 2022

Assessment of Occupational Exposure and Radiation Protection in Some Selected Well-Logging and Industrial Radiography Facilities in Nigeria 

ABSTRACT  

Nigeria has for a very long time engaged in the peaceful application of nuclear technology. The use of ionizing radiation due to its unique properties has considerably increased over the years in oil and gas industry.

In this study, the radiation safety procedures have been evaluated and whole-body occupational exposure for workers in some selected industrial radiography and well-logging facilities were assessed using thermoluminescent dosimeters (TLDs) for a 10y period.

The TLDs were read using Harshaw dual-4500 TLD reader on quarterly basis. During the 10y study period, the average annual effective doses were found to be 1.3 mSv and 0.96 mSv for the industrial radiography and well-logging practices respectively.

The annual collective dose received by the exposed workers in industrial radiography and well-logging practices were found to be between the ranges 27.8-99.6-man mSv and 12.1-32.2-man mSv respectively, while the two practices contribute 768-man mSv to the total world collective dose value.

On the TLD return rates, well-logging practice records the highest with 95.7% while industrial radiography practice scored 90.1%.

The overall result showed that 89% of the workers received doses lower than 1 mSv and there was no instance where a worker received dose greater than the dose limits prescribed by Nigerian Nuclear Regulatory Authority (NNRA).

TABLE OF CONTENTS

Cover Page………….i
Title Page ………..ii
Declaration …………iii
Certification…………..iv
Acknowledgement………….vi
Table of Contents…………..viii
List of Figures…………….xii
List of Tables…………..xiii
List of Plates……………xiv
List of Appendices…………xv
Acronyms………xvi
Abstract………..xviii

CHAPTER ONE …………………………………………………………………………………………………….1
INTRODUCTION ………………………………………………………………………………………………….1
1.1 Background to the Study……………………………………………………………………………………..1
1.2 Statement of the Problem…………………………………………………………………………………….2
1.3 Aims and Objectives……………………………………………………………………………………………4
1.4 Justification of the Study …………………………………………………………………………………….4
1.5 Significance of the Study……………………………………………………………………………………..6
1.6. Scope of the Study ……………………………………………………………………………………………..7

CHAPTER TWO……………………………………………………………………………………………………8
LITERATURE REVIEW ……………………………………………………………………………………….8
2.1 Radiation…………………………………………………………………………………………………………..8
2.1.1 Alpha Radiation ……………………………………………………………………………………………….8
2.1.2 Beta Radiation………………………………………………………………………………………………….9
2.1.3 Gamma Radiation …………………………………………………………………………………………….9
2.1.4. Neutron radiation …………………………………………………………………………………………..10
2.2 Interactions of Radiation with Matter…………………………………………………………………..10
2.2.1 Interaction of Heavy Charged Particles with Matter ……………………………………………11
2.2.2 Interaction of Fast Electrons (β-particles) ………………………………………………………….12
2.2.3. Interactions of Photons with Matter………………………………………………………………….12
2.2.3.1 Photoelectric Effect………………………………………………………………………………………12
2.2.3.2 Compton Scattering ……………………………………………………………………………………..13
2.2.3.3 Pair Production ……………………………………………………………………………………………14
2.3 Radiation Protection Principles …………………………………………………………………………..15
2.3.1. Some Quantities and Units ……………………………………………………………………………..16
2.3.1.1. Absorbed dose…………………………………………………………………………………………….16
2.3.1.2. Radiation weighting factors and equivalent dose ……………………………………………16
2.3.1.3. Tissue Weighting Factors and Effective Dose……………………………………………….17
2.3.1.4 Committed equivalent dose and committed effective dose ………………………………..18
2.3.1.5 Collective equivalent dose and collective effective dose ………………………………….19
2.4. Biological Effects…………………………………………………………………………………………….19
2.4.1 Short term biological effects…………………………………………………………………………….19
2.4.2. Long term biological effects…………………………………………………………………………..21
2.4.2.1 Cancer……………………………………………………………………………………………………….21
2.4.2.2. Genetic Effects……………………………………………………………………………………………22
2.4.3. The Linear Non-Threshold Dose-Response Relationship ………………………………….22
2.5. Radiation Protection Procedures…………………………………………………………………………23
2.5.1. Exposure Situations …………………………………………………………………………………….24
2.5.1.1 Planned exposure situations………………………………………………………………………….24
2.5.1.2. Emergency exposure situations …………………………………………………………………..24
2.5.1.3. Existing exposure situations ………………………………………………………………………..25
2.5.2. Exposure categories………………………………………………………………………………………26
2.5.2.1. Occupational exposure………………………………………………………………………………..26
2.5.2.2. Public exposure………………………………………………………………………………………….26
2.5.2.3. Medical exposure of patients……………………………………………………………………..27
2.6. Principles ……………………………………………………………………………………………………..27
2.6.1. Justification of practice………………………………………………………………………………..27
2.6.2. Optimization of practice ………………………………………………………………………………28
2.6.3. Dose limits…………………………………………………………………………………………………28
2.7. Basic Concepts of Occupational Radiation Protection………………………………………..29
2.7.1. Control of Exposure to External Radiation………………………………………………………..29
2.7.2. Radiation Protection Programmes……………………………………………………………………30
2.7.3. Application of Annual Limits…………………………………………………………………………31
2.8 The Oil and Gas Industry…………………………………………………………………………………..32
2.8.1. Industry Structure ………………………………………………………………………………………..32
2.8.2. Application of Radiation Technologies in Oil and Gas Industry…………………………33
2.8.2.1 Industrial Radiography ………………………………………………………………………………..33
2.8.2.2. Well logging ……………………………………………………………………………………………..35
2.8.2.2.1. Logging tools and techniques…………………………………………………………………….35
2.9 Theory of Thermoluminescent Dosimeter (TLD) ………………………………………………….40
2.10. Review of Previous Work………………………………………………………………………………..42

CHAPTER THREE………………………………………………………………………………………………50
MATERIALS AND METHOD ……………………………………………………………………………..50
3.1 Materials ………………………………………………………………………………………………………….50
3.2 Research Methodology ……………………………………………………………………………………50
3.2.1 Measurement Principles and Instrumentations……………………………………………………50
3.2.1. 1 Principles …………………………………………………………………………………………………..50
3.2.1.2 Instrumentations………………………………………………………………………………………….51
3.2.1.2.1 Harshaw 4500 Manual TLD Reader…………………………………………………………….51
3.2.2 Read out Process and Dose Evaluation Procedures……………………………………………..52
3.2.3 Result Analysis………………………………………………………………………………………………54
3.2.3.1 Data Analysis………………………………………………………………………………………………54
3.2.3.2 Statistical Analysis……………………………………………………………………………………….55

CHAPTER FOUR…………………………………………………………………………………………………56
RESULTS AND DISCUSSION……………………………………………………………………………..56
4.1 Results……………………………………………………………………………………………………………..56
4.2 Discussion………………………………………………………………………………………………………..59

CHAPTER FIVE ………………………………………………………………………………………………….67
SUMMARY, CONCLUSION AND RECOMMENDATIONS ………………………………..67
5.1 Summary and Conclusion…………………………………………………………………………………..67
5.2 Recommendations……………………………………………………………………………………………..68

REFERENCES……………………………………………………………………………………………………..70
APPENDICES………………………………………………………………………………………………………76

INTRODUCTION  

Nigeria has, for a very longtime, engaged in the peaceful application of nuclear technology. The use of ionizing radiation, because of its unique properties, has considerably increased over the years in oil and gas industry.

Due to the adverse health effect when people are over-exposed to ionizing radiation, radiation is feared by many, worldwide, and Nigerians are no exception.

This concern is even much higher with inhabitants living at close proximity to nuclear establishments and other facilities using ionizing radiation sources.

What most people do not realize is that radiation is present everywhere, in everything in the environment and even in the bodies (Oyeyinka et al, 2012).

There is cosmic radiation made up of protons, alpha particles and heavy nuclei bombarding the earth from space which, upon interaction with the atmosphere results into large assortment of secondary particles,

including pie (π) and mu (µ) mesons, electromagnetic photons, neutrons, protons and electrons contributing high radiation dose burden to man even at sea level (Maduemezia et al, 2008).

REFERENCES

Abu-Jarad F., Fageeha O., Al-Sairi., Nassar R., (2007). Radiation-based technologies in the
oil and gas industry. EnviroArabia, 2007, the 5th Specialty Conference on
Environmental Progress in Oil and Petrochemical Industries, 22-25, April, Bahrain
Abu-Jarad F (2008). Application of Radiation Sources in the Oil and Gas Industry and
Shortages in their Services. International Symposium on the Peaceful Applications
of Nuclear Technology in th GCC Countries, Jeddah 2008. Radioisotope
Applications, session 10/No.3
Agbalabga E. O., Avwiri G.O and Chad-Umoren Y. (2013). Radiological impact of oil and
gas activities in selected oil fields in production land area of Delta State, Nigeria. J.
Appl. Sci. Environ. Manage. Vol. 17 (2) 279-288, available online@
www.bioline.org.br/ja
Agu, B.N. (1965). Observation of Radioactive Fallout in Nigeria up to 1961. Nature 205,
649-651
Avwiri, G.O., Agbalagba E.O and Enyinna, P.I. (2007a). Terrestrial radiation around oil
and gas facilities in Ughelli Nigeria. Asian Network for Science Information. J.
Applied Sci. 7(11):1543-1546
Avwiri, G.O., Chad-Umoren, Y.E., Enyinna, P.I. and Agbalagba E.O. (2007b).
Occupational Radiation Profile of Oil and Gas Facilities during Production and
Off-Production Periods in Ughelli, Nigeria. Journal Facta Universitatis:
Working and Living Environmental Protection,6(1):11-19

 

Comments are closed.

Hey Hi

Don't miss this opportunity

Enter Your Details