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Azah CK, Deatanyah P, Appiah PM, Osei S, Amoako JK, Sam F. Evaluation of calibration factors of digital survey meters in a secondary standard dosimetry laboratory. Radiat Prot Dosimetry 2024; 200:113-119. [PMID: 37819630 DOI: 10.1093/rpd/ncad268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 09/07/2023] [Accepted: 09/16/2023] [Indexed: 10/13/2023]
Abstract
The calibration of radiological survey meters is an important consideration in achieving standardisation of doses. This provides traceability for field instruments to an International System of Units. Seventy-one digital survey meters were calibrated by the substitution method in a 137Cs beam in a secondary standard dosimetry laboratory using a PTW spherical ionisation chamber coupled to a Physikalisch-Technische-Werkstaetten (PTW) UNIDOS Electrometer. The calibration factors determined ranged from 0.59 to 1.98. Thirty-six pieces of equipment have their calibration factors within 0.9-1.1. A total of 36% of the survey meters recorded calibration factors corresponding to a percentage deviation above 20% whilst 64% fell within 20% deviations from the true value. The best value of a calibration factor obtained in this work was 1.00 from two survey meters. The errors due to survey meters being out of calibration can usually be corrected by frequent recalibration.
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Affiliation(s)
- Collins K Azah
- Radiation Protection Institute, Ghana Atomic Energy Commission, PO Box LG80, Legon, Accra, Ghana
- Department of Nuclear Safety and Security, Graduate School of Nuclear and Allied Sciences, University of Ghana, PO Box AE1, Kwabenya, Accra, Ghana
| | - Philip Deatanyah
- Radiation Protection Institute, Ghana Atomic Energy Commission, PO Box LG80, Legon, Accra, Ghana
- Department of Nuclear Safety and Security, Graduate School of Nuclear and Allied Sciences, University of Ghana, PO Box AE1, Kwabenya, Accra, Ghana
| | - Prince M Appiah
- Radiation Protection Institute, Ghana Atomic Energy Commission, PO Box LG80, Legon, Accra, Ghana
| | - Samuel Osei
- Radiation Protection Institute, Ghana Atomic Energy Commission, PO Box LG80, Legon, Accra, Ghana
| | - Joseph K Amoako
- Department of Nuclear Safety and Security, Graduate School of Nuclear and Allied Sciences, University of Ghana, PO Box AE1, Kwabenya, Accra, Ghana
| | - Frederick Sam
- Department of Physics, University of Cape Coast, Private Mail Bag, Cape Coast, Ghana
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Faanu A, Adukpo OK, Tettey-Larbi L, Lawluvi H, Kpeglo DO, Darko EO, Emi-Reynolds G, Awudu RA, Kansaana C, Amoah PA, Efa AO, Ibrahim AD, Agyeman B, Kpodzro R, Agyeman L. Natural radioactivity levels in soils, rocks and water at a mining concession of Perseus gold mine and surrounding towns in Central Region of Ghana. Springerplus 2016; 5:98. [PMID: 26877896 PMCID: PMC4735091 DOI: 10.1186/s40064-016-1716-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 01/13/2016] [Indexed: 11/10/2022]
Abstract
Levels of naturally occurring radioactive materials prior to processing of gold ore within and around the new eastern concession area of Perseus Mining (Ghana) Limited were carried out to ascertain the baseline radioactivity levels. The study was based on situ measurements of external gamma dose rate at 1 m above ground level as well as laboratory analysis by direct gamma spectrometry to quantify the radionuclides of interest namely; (238)U, (232)Th and (40)K in soil, rock, ore samples and gross alpha/beta analysis in water samples. The average absorbed dose rate in air at 1 m above sampling point using a radiation survey metre was determined to be 0.08 ± 0.02 μGyh(-1) with a corresponding average annual effective dose calculated to be 0.093 ± 0.028 mSv. The average activity concentrations of (238)U, (232)Th, and (40)K in the soil, rock, and ore samples were 65.1 ± 2.2, 71.8 ± 2.2 and 1168.3 Bqkg(-1) respectively resulting in an average annual effective dose of 0.91 ± 0.32 mSv. The average Radium equivalent activity value was 257.8 ± 62.4 Bqkg(-1) in the range of 136.6-340.2 Bqkg(-1). The average values of external and internal indices were 0.7 ± 0.2 and 0.9 ± 0.2 respectively. The average gross alpha and gross beta activity concentrations in the water samples were determined to be 0.0032 ± 0.0024 and 0.0338 ± 0.0083 Bql(-1) respectively. The total annual effective dose from the pathways considered for this study (gamma ray from the soil, rock and ore samples as well as doses determined from the gross alpha/beta activity concentration in water samples) was calculated to be 0.918 mSv. The results obtained in this study shows that the radiation levels are within the natural background radiation levels found in literature and compare well with similar studies for other countries and the total annual effective dose is below the ICRP recommended level of 1 mSv for public exposure control.
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Affiliation(s)
- A. Faanu
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - O. K. Adukpo
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - L. Tettey-Larbi
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - H. Lawluvi
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - D. O. Kpeglo
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - E. O. Darko
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - G. Emi-Reynolds
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - R. A. Awudu
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - C. Kansaana
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - P. A. Amoah
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - A. O. Efa
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - A. D. Ibrahim
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - B. Agyeman
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - R. Kpodzro
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
| | - L. Agyeman
- Environmental Protection and Waste Management Centre, Radiation Protection Institute, Ghana Atomic Energy Commission, Legon, P. O. Box LG 80, Accra, Ghana
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