Environmental Geochemistry and Health, Dec 1, 2022
Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radi... more Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radionuclides in the soils, building materials and rocks, but the level may vary depending on the anthropogenic activities prevalent in each location. Presently, in Nigeria, there are concerns due to environmental health implications of all sorts of mineral mining and processing spreading across the southwestern states of the country. As a result, a total of 200 composite soil samples were taken in ve states in the southwest of Nigeria, close to active mining sites at the rooting (0.2 m) and at deep planting zones (0.5 m) for analysis by gamma-ray spectrometry using NaI(Tl) detector. The activity concentrations of natural radionuclides in the composite soil samples were determined to vary in the order of 40 K > 232 Th > 226 Ra/ 238 U for all locations. In contrast to the other locations, Olode and Igbokoda had average radium equivalent activities (Ra eq) to be 1.6 and 1.8 times higher than the reference limit of 370 Bqkg − 1. The estimated excess life cancer risk values were lower than the 0.29 x 10 − 3 global average value for soil by UNSCEAR and ICRP. A negative and low skewness value of 0.16 and 1.20 for 40 K and 232 Th were obtained in Olode and Sagamu. The kurtosis analysis of the activity concentrations was low and negative for soil at Itagunmodi for 40 K and 226 Ra/ 238 U; Olode for 40 K and 232 Th; and Igbokoda for 226 Ra/ 238 U and 232 Th where mining activities are common. The variation in the obtained results has been attributed to different agriculture practices and artisanal mining operations in each location.
Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radi... more Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radionuclides in the soils, building materials and rocks, but the level may vary depending on the anthropogenic activities prevalent in each location. Presently, in Nigeria, there are concerns due to environmental health implications of all sorts of mineral mining and processing spreading across the southwestern states of the country. As a result, a total of 200 composite soil samples were taken in five states in the southwest of Nigeria, close to active mining sites at the rooting (0.2 m) and at deep planting zones (0.5 m) for analysis by gamma-ray spectrometry using NaI(Tl) detector. The activity concentrations of natural radionuclides in the composite soil samples were determined to vary in the order of 40K > 232Th > 226Ra/238U for all locations. In contrast to the other locations, Olode and Igbokoda had average radium equivalent activities (Raeq) to be 1.6 and 1.8 times higher than...
Exposure to radiation from different types of television sets was measured to ascertain the level... more Exposure to radiation from different types of television sets was measured to ascertain the levels of hazards posed to the human biological system. Measurement of the annual radiation dose hazards was performed using a halogen-quenched GM tube with thin mica end window having a density of 1.5 mg/cm2, effective window diameter of 0.360 inch and side wall of 0.012 inch thick. The GM tube was placed for 180 minutes and the sensor faced the screens of the various TV sets, one meter apart. The annual radiation dose ranged from 0.012 ± 0.006 mSv/yr for plasma-SONY to 0.13 ± 0.012 mSv/yr for SHARP and SAMSUNG 24 inch TV sets, containing cathode ray tubes. The annual doses from the 15 and 24 inch-LG TVs (manufactured with cathode ray tubes) were relatively low, with values of 0.031 ± 0.017 and 0.035 ± 0.005 mSv/yr, respectively. The 21 inch THERMOCOOL and PROTECH (with cathode ray tubes), produced annual doses of 0.110 ± 0.052 Sv/yr and 0.063 ± 0.002 mSv/yr, respectively. This provides an i...
The need to ascertain the neutron flux stability after the recent installation of permanent 1.0 m... more The need to ascertain the neutron flux stability after the recent installation of permanent 1.0 mm cadmium lined in the larger outer irradiation channel A-3 was performed in this work. The specific activity ratios, inner-to-outer channel of Nigeria Research Reactor-1 (i.e. A-1/B-4, B- 2/B-4, and B-3/B4) were determined averagely to be 2.06 with a percentage deviation error of 4.63 %. The inner-to-outer with cadmium lined (i.e. A-1/A-3, B-2/A-3, B-3/A-3) was found on the average to be 22.66 with percentage deviation error of 1.58%. Also, the outer-to-outer with cadmium (i.e. A-2/A-3) was obtained to be 11.55 with percentage deviation error of -0.87%. The values of resonance-to-thermal cross section of the inner channels oscillate in a stable trend and for the outer channel B-4, it was observed to be good. These stable trends in the obtained nuclear data I0(α) and Q0(α) values and the specific activity ratios indicates that the neutron flux distributions after installation of a cadmiu...
The activity concentration of gross alpha and gross beta particles in four samples of borehole dr... more The activity concentration of gross alpha and gross beta particles in four samples of borehole drinking water consumed in Ibrahim Badamasi Babangida University (IBBU), Lapai, Niger State-Nigeria was measured, using a portable single channel gas free proportional counter (MPC2000B-DP) detector. This study focused on cancer related problems and the bio-data of the environment was discussed as well as the radiological effect of the water on consumers. Higher concentration of alpha and beta were observed in Hostel block A (DD) with values of 0.085 0.024 and 11.229 0.901 BqL-1, respectively. However, lower concentration of alpha and beta particles were observed in the Faculty of Management Science (AA) with values of 0.006 0.005 and 0.001 0.276 BqL-1, respectively. Out of the four sampling sites studied, only the Faculty of Management Science fall below the guideline levels of gross alpha (0.5 BqL-1) and gross beta (1.0 BqL-1) in drinking water, established by the World Health Organi...
The evaluation of I0 (α) and Q0 (α) for Gold, Cupper, Thorium, Uranium and Potassium in Modified ... more The evaluation of I0 (α) and Q0 (α) for Gold, Cupper, Thorium, Uranium and Potassium in Modified Irradiation Site of Nigeria Nuclear Reactor-1 (NIRR-1) was done using Instrumental Neutron Activation Analysis (INAA) and off-line gamma ray spectrometric technique. It was found that before the Cd-lined installation i.e. modification of the large irradiation site (A-3) of NIRR-1, the deviation parameter (α) was positive with a value of 0.024±0.002 indicating high neutron thermalization. However, after the Cd-line installation, the α-parameter was found to be negative with a value of -0.9274 ± 0.016 indicating poor thermalization and as a consequence achieved the purposed of the modification. Further correction for Q0 to Q0 (α) and I0 to I0 (α) for the nuclides; Au, Cu, Th, U, and K in the modified large outer irradiation channel A-3 were done. Before Cdlined installation the Q0 (α) values for Au was 15.05, for Cu was 0.88, for Th was 10.05, for U was 0.86 and for K was 90.37. However, a...
Prompt neutron lifetime calculations have been performed for the NIRR-1 reactor HEU and LEU cores... more Prompt neutron lifetime calculations have been performed for the NIRR-1 reactor HEU and LEU cores using the 1/v insertion and the Adjoint flux weighing methods. Results of calculations obtained for the HEU and LEU cores are respectively 57.3±0.8 and 47.5±0.7 for the 1/v insertion and 56.9±0.3 and 46.3±0.5 for the Adjoint flux. There is a good agreement seen between the two methods for both cores. The prompt neutron lifetime was observed to be shorter in the LEU than for the HEU as expected. However, the Adjoint flux weighing method seemed to be the easiest method in calculating the prompt neutron lifetime for NIRR-1.
Gamma-ray spectrometry is a very powerful tool for radioactivity measurements. The gamma-ray spec... more Gamma-ray spectrometry is a very powerful tool for radioactivity measurements. The gamma-ray spectrometer laboratory in Centre for Energy Research and Training (CERT), Ahmadu Bello University, Zaria, Nigeria is accredited to perform measurements of radioactive content of samples collected from the environment, food chain or industrial products with the aid of a high resolution HPGe detector. For accurate gamma-ray spectrometry, certain measurements were considered; the efficiency of the detector was performed experimentally against energies within the range of 59.50 keV (241 Am) to 2204.50 keV (226 Ra) for the respective geometries of 1-6 cm. The sustained solid angle relations with respect to the inverse square of sample geometries from 1-6 cm were evaluated. Another main point of this work was focused on the efficiency at geometry of 5 cm with respect to the three selected energies: 661.60 keV (137 Cs), 1173.2 keV (60 Co) and 1332 keV (60 Co) for the main axis, ten degree off main axis, forty five degree off main axis and ninety degree off the detector main axis. In order to verify optimum geometries in our laboratory for both short lived and long lived radionuclides analyses, the evaluation of efficiencies for the respective energies: 1173.2 keV (60 Co), 1332.5 keV (60 Co), 1764 keV (226 Ra) and 2294 keV (226 Ra) were plotted against geometries of 1 to 6 cm from the detector end cap along the main axis.
A Titanium dioxide (TiO 2) based Die Sensitised Solar Cell (DSSC) using Flame of the Forest (Bute... more A Titanium dioxide (TiO 2) based Die Sensitised Solar Cell (DSSC) using Flame of the Forest (Butea monosperma) was fabricated on a glass substrate and characterized with scanning electron microscopy (SEM). The cell had TiO 2 as a photo electrode, flame of forest as a dye sensitizer, iodide/iodide solution as an electrolyte and Platinum/Transparent Conducting Oxide as a counter electrode. The photo electrochemical characteristics of TiO DSSCs were tested under simulated sunlight AM 1.5 from a solar simulator with the radiant power of 100mW/cm 2. It was found that the DSSC based on TiO 2 generated photocurrent with short-circuit current, I sc = 0.14mA; open-circuit voltage, V oc = 0.5; fill factor, ff = 0.652 and a photo conversion efficiency of 0.08%. This is comparatively good when evaluated with similar low-cost DSSCs. The Isc was found to increase with increasing thickness of the TiO 2 photo electrode, while the V oc of TiO 2 DSSC was found to be independent of the morphology and dye adsorption surface area of TiO 2 .
World Journal of Nuclear Science and Technology, 2014
Prior to the installation of the Cd-liner in one of the large outer irradiation channels of NIRR-... more Prior to the installation of the Cd-liner in one of the large outer irradiation channels of NIRR-1, a Monte Carlo simulation was performed using MCNP5 version 1.4 code. This was done to investigate the effect of installation of Cd-liner in either an inner or outer irradiation channel on reactor physics parameters. Data obtained indicate that the core excess reactivity in both inner and outer irradiations channels is reduced by 3.60 ± 0.07 mk and 0.64 ± 0.06 mk, respectively. Considering the fact that NIRR-1 has a cold core excess reactivity of 3.77 mk, results obtained show that installation of the 1 mm thick Cd-sheet in one of the large outer irradiation channels would have no significant impact on the core physics data. After installation of a 1 mm Cd sheath in a large outer irradiation channel, the neutron flux distribution and the stability in the irradiation channels were monitored by foil activation method. Results indicate that the uniformity of neutron flux distribution in the irradiation channel is preserved and the neutron flux data were found to be comparable with the data obtained before the installation.
... aDepartment of Physics, Ibrahim Badamasi Babangida University, Lapai, Niger State, Nigeria E-... more ... aDepartment of Physics, Ibrahim Badamasi Babangida University, Lapai, Niger State, Nigeria E-mail: njingaraymond@yahoo.co.uk bCenter for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria E-mail: yakub@yahoo.com cAfrican Leadership Academy ...
A Monte Carlo simulation of additional safety rods for NIRR-1 HEU and LEU cores was carried out u... more A Monte Carlo simulation of additional safety rods for NIRR-1 HEU and LEU cores was carried out using the MCNP5 version 1.6 code. Two additional safety control rods having the same material composition as the main central control rod except for the surface area were studied. The following reactor core physics parameters were determined; neutron flux distribution within the core with safety rods withdrawn, control rod (CR) worth for each rod, core excess reactivity, shutdown margin and some kinetic parameters. Results obtained indicate that it would be feasible to include two additional safety control rods to improve safety level of the MNSR with little or no modification to the existing core configuration.
People of all ages and genders utilize herbal medicine to treat varieties of problems all around ... more People of all ages and genders utilize herbal medicine to treat varieties of problems all around the world. The accumulation of Cd and Cr in therapeutic herbs (Adansonia digitata, Psidium guajava, and Carica papaya) can lead to a variety of health complications. These leaf extracts are used to treat varieties of ailments, including cancer, in the northern Nigerian states of Borno, Jigawa, and Kano. The researchers employed high-resolution continuous source atomic absorption spectrometry. The statistical parameters such as mean, range, minimum and maximum were computed along with one-way analysis of variance (ANOVA) to assess activity concentrations of Major Chemical Carcinogens (MCCs) in the herb extracts from the three states. The result demonstrated substantial statistical variation in the concentration of Chromium between groups with C. papaya (F = 190.683, p = 0.000), P. guajava (F = 5.698, p = 0.006), A. digitata (F = 243.154, p = 0.000). The post hoc test revealed that the C. ...
The present study aimed at the determination of the specific activity of naturally occurring radi... more The present study aimed at the determination of the specific activity of naturally occurring radioactive materials and the evaluation of the radiological health hazards radioactivity in twenty four cement samples presenting six cement types commonly used in Cameroon for building construction have been analyzed. A high purity germanium detector (HPGe) spectrometer was used for quantification of gamma emitting radionuclide in the cements to demonstrate the radiological health hazards. Terrestrial absorbed dose rate (D), annual effective dose equivalent (AEDE), radium equivalent activity (Ra eq), external (H ex)/internal (H in) hazard index, activity gamma (I γ) and alpha index (I α) caused by gamma emitting natural radionuclide are determined from the obtained values of 226 Ra, 232 Th and 40 K. The calculated values of the absorbed dose rate and the indoor annual effective dose are slightly higher comparably to the recommended worldwide values. The details of the samples preparation procedure and the gamma-ray spectrometry technique are presented, together with the preliminary investigated results of specific activity of naturally occurring radionuclide chains for six representative cement type analyzed in this current work.
The k 0-NAA standardization method has been applied to investigate the metal contents of industri... more The k 0-NAA standardization method has been applied to investigate the metal contents of industrial effluents collected at several sites in NorthWestern part of Nigeria. Ten elements (Cr, Co, Ca, Na, Eu, Hf, Th, Dy, Sb and Cs) were determined from 10 samples from the leather, textile and petrochemical industries. The enrichment factors were determined by comparison of the elemental concentration with that of a typical soil from non-industrial area within the same locality of the survey. Some of the industrial effluents had high elevated concentration for chromium, calcium, cobalt, sodium, antimony and dysprosium.
Journal of Environmental Science and Management, 2019
This study measures the 226Ra, 232Th and 40K activity concentrations using gamma spectrometry to ... more This study measures the 226Ra, 232Th and 40K activity concentrations using gamma spectrometry to asses first order exposure risks for the persons residing in Walvis Bay and Swakopmund towns in Erongo Region, Namibia. The concentrations of 226Ra, 232Th and 40K in the soil samples vary from 14.94 Bq kg-1 to 48.24 Bq kg-1, 17.68 Bq kg-1 to 52.51 Bq kg-1 and 162.58 Bq kg-1 to 259.35 Bq kg-1, respectively, with average values of 30.38 ± 11.28 Bq kg-1, 32.58 ± 10.09 Bq kg-1 and 203.62 ± 27.00 Bq kg-1 in Walvis Bay town. For Swakopmund town, the concentrations vary from 71.38 Bq kg-1 to 155.80 Bq kg-1, 41.63 Bq kg-1 to 131.58 Bq kg-1 and 360.82 Bq kg-1 to 761.76 Bq kg-1, respectively, with average values of 99.59 ± 24.39 Bq kg-1 90.90 ± 31.99 Bq kg-1 and 553.07 ± 107.17 Bq kg-1. The radium equivalent activity (Raeq ) calculated for the same composite soil samples varies from 62.14 Bq kg-1 to 126.69 Bq kg-1 with an average value of 92.64 Bq kg-1 in Walvis Bay town. In Swakopmund town, it va...
Abstract: Medicinal plant consumption can be a source of human exposure to radioactive elements s... more Abstract: Medicinal plant consumption can be a source of human exposure to radioactive elements such as 238U and 232Th, which can lead to internal radiation doses. The uptake of 238U and 232Th from soils to the leaf samples of three different medicinal plant species (Eucalyptus globulus, Acacia mearnsii and Hyparrhenia filipendula) from the purlieu of the Princess gold mine dump, an abandoned contaminated tailings storage site (TSS), located at longitude 27˝551002E and latitude 26˝091302S in Davidsonville (Roodepoort, west of Johannesburg, South Africa) was measured. This was done using ICP-MS spectrometry and substantial differences were observed in the soil-plant transfer factor (TF) values between these radionuclides. The plant species E. globulus exhibited the highest uptake of 238U, with an average TF of 3.97, while that of H. filipendula was 0.01 and the lowest TF of 0.15 ˆ 10´2 was measured for A. mearnsii. However, in the case of 232Th, the highest average TF was observed fo...
Not all gamma rays emitted by the source that pass through the detector will produce a count in t... more Not all gamma rays emitted by the source that pass through the detector will produce a count in the system. The probability that an emitted gamma ray will interact with the detector and produce a count is the efficiency of the detector and is measured by comparing a spectrum from a source of known activity, count rates in each peak, count rates expected from the known intensities of each gamma ray. The energy of the gamma rays being detected is an important factor in the efficiency of the detector. An efficiency curve can be obtained by plotting the efficiency at various energies. This curve can then be used to determine the efficiency of the detector at energies different from those used to obtain the curve. A comparison of two gamma-ray efficiency determination methods; Canberra’s LabSOCS and the source-based efficiency calibrations using marinelli beaker geometry were measured and the results revealed +96% confidence levels for each gamma peak lines. This means that the Canberra’...
Raymond L. Njinga, Victor M. Tshivhase, and Fatima B. Yusuf Centre for Applied Radiation Science ... more Raymond L. Njinga, Victor M. Tshivhase, and Fatima B. Yusuf Centre for Applied Radiation Science and Technology, North-West University, Mafikeng, Private Bag X2046 Mmabatho, 2735, South Africa, Department of Physics, Federal University Dutse, P.M.B 7156, Jigawa State, Nigeria Department of Physics, Ibrahim Badamasi Babangida University, Lapai, P.M.B 11, Niger State, Nigeria *Corresponding author’s email: njingaraymond@yahoo.co.uk
Background: In this study, the health risk associated with three types of drinking waters (fissur... more Background: In this study, the health risk associated with three types of drinking waters (fissure, underground treated and surrounding waters) from two mines in South Africa were assessed. Materials and Methods: The measurement of the radionuclides concentra on was carried out by liquid scin lla on counter and alpha spectrometer. The es mated radiological risk pose to the people consuming the water types were evaluated based on the calculated radionuclide concentra ons. Results: The value of the gross alpha was 1.08 ± 0.02 Bq/L and gross beta ac vity was 0.65 ± 0.04 Bq/L in the treated underground water. These values were several fold above the limit value of 1.0 Bq/L for gross alpha and 0.1 Bq/L for gross beta. For the fissure water, the gross alpha ac vity value was 0.59 ± 0.07 Bq/L which is less than the limit of 1.0 Bq/L and the gross beta ac vity was high with a value of 0.54 ± 0.05 Bq/L compared to the limit value of 0.1 Bq/L. The results around the Princess gold mine showed ...
Environmental Geochemistry and Health, Dec 1, 2022
Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radi... more Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radionuclides in the soils, building materials and rocks, but the level may vary depending on the anthropogenic activities prevalent in each location. Presently, in Nigeria, there are concerns due to environmental health implications of all sorts of mineral mining and processing spreading across the southwestern states of the country. As a result, a total of 200 composite soil samples were taken in ve states in the southwest of Nigeria, close to active mining sites at the rooting (0.2 m) and at deep planting zones (0.5 m) for analysis by gamma-ray spectrometry using NaI(Tl) detector. The activity concentrations of natural radionuclides in the composite soil samples were determined to vary in the order of 40 K > 232 Th > 226 Ra/ 238 U for all locations. In contrast to the other locations, Olode and Igbokoda had average radium equivalent activities (Ra eq) to be 1.6 and 1.8 times higher than the reference limit of 370 Bqkg − 1. The estimated excess life cancer risk values were lower than the 0.29 x 10 − 3 global average value for soil by UNSCEAR and ICRP. A negative and low skewness value of 0.16 and 1.20 for 40 K and 232 Th were obtained in Olode and Sagamu. The kurtosis analysis of the activity concentrations was low and negative for soil at Itagunmodi for 40 K and 226 Ra/ 238 U; Olode for 40 K and 232 Th; and Igbokoda for 226 Ra/ 238 U and 232 Th where mining activities are common. The variation in the obtained results has been attributed to different agriculture practices and artisanal mining operations in each location.
Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radi... more Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radionuclides in the soils, building materials and rocks, but the level may vary depending on the anthropogenic activities prevalent in each location. Presently, in Nigeria, there are concerns due to environmental health implications of all sorts of mineral mining and processing spreading across the southwestern states of the country. As a result, a total of 200 composite soil samples were taken in five states in the southwest of Nigeria, close to active mining sites at the rooting (0.2 m) and at deep planting zones (0.5 m) for analysis by gamma-ray spectrometry using NaI(Tl) detector. The activity concentrations of natural radionuclides in the composite soil samples were determined to vary in the order of 40K > 232Th > 226Ra/238U for all locations. In contrast to the other locations, Olode and Igbokoda had average radium equivalent activities (Raeq) to be 1.6 and 1.8 times higher than...
Exposure to radiation from different types of television sets was measured to ascertain the level... more Exposure to radiation from different types of television sets was measured to ascertain the levels of hazards posed to the human biological system. Measurement of the annual radiation dose hazards was performed using a halogen-quenched GM tube with thin mica end window having a density of 1.5 mg/cm2, effective window diameter of 0.360 inch and side wall of 0.012 inch thick. The GM tube was placed for 180 minutes and the sensor faced the screens of the various TV sets, one meter apart. The annual radiation dose ranged from 0.012 ± 0.006 mSv/yr for plasma-SONY to 0.13 ± 0.012 mSv/yr for SHARP and SAMSUNG 24 inch TV sets, containing cathode ray tubes. The annual doses from the 15 and 24 inch-LG TVs (manufactured with cathode ray tubes) were relatively low, with values of 0.031 ± 0.017 and 0.035 ± 0.005 mSv/yr, respectively. The 21 inch THERMOCOOL and PROTECH (with cathode ray tubes), produced annual doses of 0.110 ± 0.052 Sv/yr and 0.063 ± 0.002 mSv/yr, respectively. This provides an i...
The need to ascertain the neutron flux stability after the recent installation of permanent 1.0 m... more The need to ascertain the neutron flux stability after the recent installation of permanent 1.0 mm cadmium lined in the larger outer irradiation channel A-3 was performed in this work. The specific activity ratios, inner-to-outer channel of Nigeria Research Reactor-1 (i.e. A-1/B-4, B- 2/B-4, and B-3/B4) were determined averagely to be 2.06 with a percentage deviation error of 4.63 %. The inner-to-outer with cadmium lined (i.e. A-1/A-3, B-2/A-3, B-3/A-3) was found on the average to be 22.66 with percentage deviation error of 1.58%. Also, the outer-to-outer with cadmium (i.e. A-2/A-3) was obtained to be 11.55 with percentage deviation error of -0.87%. The values of resonance-to-thermal cross section of the inner channels oscillate in a stable trend and for the outer channel B-4, it was observed to be good. These stable trends in the obtained nuclear data I0(α) and Q0(α) values and the specific activity ratios indicates that the neutron flux distributions after installation of a cadmiu...
The activity concentration of gross alpha and gross beta particles in four samples of borehole dr... more The activity concentration of gross alpha and gross beta particles in four samples of borehole drinking water consumed in Ibrahim Badamasi Babangida University (IBBU), Lapai, Niger State-Nigeria was measured, using a portable single channel gas free proportional counter (MPC2000B-DP) detector. This study focused on cancer related problems and the bio-data of the environment was discussed as well as the radiological effect of the water on consumers. Higher concentration of alpha and beta were observed in Hostel block A (DD) with values of 0.085 0.024 and 11.229 0.901 BqL-1, respectively. However, lower concentration of alpha and beta particles were observed in the Faculty of Management Science (AA) with values of 0.006 0.005 and 0.001 0.276 BqL-1, respectively. Out of the four sampling sites studied, only the Faculty of Management Science fall below the guideline levels of gross alpha (0.5 BqL-1) and gross beta (1.0 BqL-1) in drinking water, established by the World Health Organi...
The evaluation of I0 (α) and Q0 (α) for Gold, Cupper, Thorium, Uranium and Potassium in Modified ... more The evaluation of I0 (α) and Q0 (α) for Gold, Cupper, Thorium, Uranium and Potassium in Modified Irradiation Site of Nigeria Nuclear Reactor-1 (NIRR-1) was done using Instrumental Neutron Activation Analysis (INAA) and off-line gamma ray spectrometric technique. It was found that before the Cd-lined installation i.e. modification of the large irradiation site (A-3) of NIRR-1, the deviation parameter (α) was positive with a value of 0.024±0.002 indicating high neutron thermalization. However, after the Cd-line installation, the α-parameter was found to be negative with a value of -0.9274 ± 0.016 indicating poor thermalization and as a consequence achieved the purposed of the modification. Further correction for Q0 to Q0 (α) and I0 to I0 (α) for the nuclides; Au, Cu, Th, U, and K in the modified large outer irradiation channel A-3 were done. Before Cdlined installation the Q0 (α) values for Au was 15.05, for Cu was 0.88, for Th was 10.05, for U was 0.86 and for K was 90.37. However, a...
Prompt neutron lifetime calculations have been performed for the NIRR-1 reactor HEU and LEU cores... more Prompt neutron lifetime calculations have been performed for the NIRR-1 reactor HEU and LEU cores using the 1/v insertion and the Adjoint flux weighing methods. Results of calculations obtained for the HEU and LEU cores are respectively 57.3±0.8 and 47.5±0.7 for the 1/v insertion and 56.9±0.3 and 46.3±0.5 for the Adjoint flux. There is a good agreement seen between the two methods for both cores. The prompt neutron lifetime was observed to be shorter in the LEU than for the HEU as expected. However, the Adjoint flux weighing method seemed to be the easiest method in calculating the prompt neutron lifetime for NIRR-1.
Gamma-ray spectrometry is a very powerful tool for radioactivity measurements. The gamma-ray spec... more Gamma-ray spectrometry is a very powerful tool for radioactivity measurements. The gamma-ray spectrometer laboratory in Centre for Energy Research and Training (CERT), Ahmadu Bello University, Zaria, Nigeria is accredited to perform measurements of radioactive content of samples collected from the environment, food chain or industrial products with the aid of a high resolution HPGe detector. For accurate gamma-ray spectrometry, certain measurements were considered; the efficiency of the detector was performed experimentally against energies within the range of 59.50 keV (241 Am) to 2204.50 keV (226 Ra) for the respective geometries of 1-6 cm. The sustained solid angle relations with respect to the inverse square of sample geometries from 1-6 cm were evaluated. Another main point of this work was focused on the efficiency at geometry of 5 cm with respect to the three selected energies: 661.60 keV (137 Cs), 1173.2 keV (60 Co) and 1332 keV (60 Co) for the main axis, ten degree off main axis, forty five degree off main axis and ninety degree off the detector main axis. In order to verify optimum geometries in our laboratory for both short lived and long lived radionuclides analyses, the evaluation of efficiencies for the respective energies: 1173.2 keV (60 Co), 1332.5 keV (60 Co), 1764 keV (226 Ra) and 2294 keV (226 Ra) were plotted against geometries of 1 to 6 cm from the detector end cap along the main axis.
A Titanium dioxide (TiO 2) based Die Sensitised Solar Cell (DSSC) using Flame of the Forest (Bute... more A Titanium dioxide (TiO 2) based Die Sensitised Solar Cell (DSSC) using Flame of the Forest (Butea monosperma) was fabricated on a glass substrate and characterized with scanning electron microscopy (SEM). The cell had TiO 2 as a photo electrode, flame of forest as a dye sensitizer, iodide/iodide solution as an electrolyte and Platinum/Transparent Conducting Oxide as a counter electrode. The photo electrochemical characteristics of TiO DSSCs were tested under simulated sunlight AM 1.5 from a solar simulator with the radiant power of 100mW/cm 2. It was found that the DSSC based on TiO 2 generated photocurrent with short-circuit current, I sc = 0.14mA; open-circuit voltage, V oc = 0.5; fill factor, ff = 0.652 and a photo conversion efficiency of 0.08%. This is comparatively good when evaluated with similar low-cost DSSCs. The Isc was found to increase with increasing thickness of the TiO 2 photo electrode, while the V oc of TiO 2 DSSC was found to be independent of the morphology and dye adsorption surface area of TiO 2 .
World Journal of Nuclear Science and Technology, 2014
Prior to the installation of the Cd-liner in one of the large outer irradiation channels of NIRR-... more Prior to the installation of the Cd-liner in one of the large outer irradiation channels of NIRR-1, a Monte Carlo simulation was performed using MCNP5 version 1.4 code. This was done to investigate the effect of installation of Cd-liner in either an inner or outer irradiation channel on reactor physics parameters. Data obtained indicate that the core excess reactivity in both inner and outer irradiations channels is reduced by 3.60 ± 0.07 mk and 0.64 ± 0.06 mk, respectively. Considering the fact that NIRR-1 has a cold core excess reactivity of 3.77 mk, results obtained show that installation of the 1 mm thick Cd-sheet in one of the large outer irradiation channels would have no significant impact on the core physics data. After installation of a 1 mm Cd sheath in a large outer irradiation channel, the neutron flux distribution and the stability in the irradiation channels were monitored by foil activation method. Results indicate that the uniformity of neutron flux distribution in the irradiation channel is preserved and the neutron flux data were found to be comparable with the data obtained before the installation.
... aDepartment of Physics, Ibrahim Badamasi Babangida University, Lapai, Niger State, Nigeria E-... more ... aDepartment of Physics, Ibrahim Badamasi Babangida University, Lapai, Niger State, Nigeria E-mail: njingaraymond@yahoo.co.uk bCenter for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria E-mail: yakub@yahoo.com cAfrican Leadership Academy ...
A Monte Carlo simulation of additional safety rods for NIRR-1 HEU and LEU cores was carried out u... more A Monte Carlo simulation of additional safety rods for NIRR-1 HEU and LEU cores was carried out using the MCNP5 version 1.6 code. Two additional safety control rods having the same material composition as the main central control rod except for the surface area were studied. The following reactor core physics parameters were determined; neutron flux distribution within the core with safety rods withdrawn, control rod (CR) worth for each rod, core excess reactivity, shutdown margin and some kinetic parameters. Results obtained indicate that it would be feasible to include two additional safety control rods to improve safety level of the MNSR with little or no modification to the existing core configuration.
People of all ages and genders utilize herbal medicine to treat varieties of problems all around ... more People of all ages and genders utilize herbal medicine to treat varieties of problems all around the world. The accumulation of Cd and Cr in therapeutic herbs (Adansonia digitata, Psidium guajava, and Carica papaya) can lead to a variety of health complications. These leaf extracts are used to treat varieties of ailments, including cancer, in the northern Nigerian states of Borno, Jigawa, and Kano. The researchers employed high-resolution continuous source atomic absorption spectrometry. The statistical parameters such as mean, range, minimum and maximum were computed along with one-way analysis of variance (ANOVA) to assess activity concentrations of Major Chemical Carcinogens (MCCs) in the herb extracts from the three states. The result demonstrated substantial statistical variation in the concentration of Chromium between groups with C. papaya (F = 190.683, p = 0.000), P. guajava (F = 5.698, p = 0.006), A. digitata (F = 243.154, p = 0.000). The post hoc test revealed that the C. ...
The present study aimed at the determination of the specific activity of naturally occurring radi... more The present study aimed at the determination of the specific activity of naturally occurring radioactive materials and the evaluation of the radiological health hazards radioactivity in twenty four cement samples presenting six cement types commonly used in Cameroon for building construction have been analyzed. A high purity germanium detector (HPGe) spectrometer was used for quantification of gamma emitting radionuclide in the cements to demonstrate the radiological health hazards. Terrestrial absorbed dose rate (D), annual effective dose equivalent (AEDE), radium equivalent activity (Ra eq), external (H ex)/internal (H in) hazard index, activity gamma (I γ) and alpha index (I α) caused by gamma emitting natural radionuclide are determined from the obtained values of 226 Ra, 232 Th and 40 K. The calculated values of the absorbed dose rate and the indoor annual effective dose are slightly higher comparably to the recommended worldwide values. The details of the samples preparation procedure and the gamma-ray spectrometry technique are presented, together with the preliminary investigated results of specific activity of naturally occurring radionuclide chains for six representative cement type analyzed in this current work.
The k 0-NAA standardization method has been applied to investigate the metal contents of industri... more The k 0-NAA standardization method has been applied to investigate the metal contents of industrial effluents collected at several sites in NorthWestern part of Nigeria. Ten elements (Cr, Co, Ca, Na, Eu, Hf, Th, Dy, Sb and Cs) were determined from 10 samples from the leather, textile and petrochemical industries. The enrichment factors were determined by comparison of the elemental concentration with that of a typical soil from non-industrial area within the same locality of the survey. Some of the industrial effluents had high elevated concentration for chromium, calcium, cobalt, sodium, antimony and dysprosium.
Journal of Environmental Science and Management, 2019
This study measures the 226Ra, 232Th and 40K activity concentrations using gamma spectrometry to ... more This study measures the 226Ra, 232Th and 40K activity concentrations using gamma spectrometry to asses first order exposure risks for the persons residing in Walvis Bay and Swakopmund towns in Erongo Region, Namibia. The concentrations of 226Ra, 232Th and 40K in the soil samples vary from 14.94 Bq kg-1 to 48.24 Bq kg-1, 17.68 Bq kg-1 to 52.51 Bq kg-1 and 162.58 Bq kg-1 to 259.35 Bq kg-1, respectively, with average values of 30.38 ± 11.28 Bq kg-1, 32.58 ± 10.09 Bq kg-1 and 203.62 ± 27.00 Bq kg-1 in Walvis Bay town. For Swakopmund town, the concentrations vary from 71.38 Bq kg-1 to 155.80 Bq kg-1, 41.63 Bq kg-1 to 131.58 Bq kg-1 and 360.82 Bq kg-1 to 761.76 Bq kg-1, respectively, with average values of 99.59 ± 24.39 Bq kg-1 90.90 ± 31.99 Bq kg-1 and 553.07 ± 107.17 Bq kg-1. The radium equivalent activity (Raeq ) calculated for the same composite soil samples varies from 62.14 Bq kg-1 to 126.69 Bq kg-1 with an average value of 92.64 Bq kg-1 in Walvis Bay town. In Swakopmund town, it va...
Abstract: Medicinal plant consumption can be a source of human exposure to radioactive elements s... more Abstract: Medicinal plant consumption can be a source of human exposure to radioactive elements such as 238U and 232Th, which can lead to internal radiation doses. The uptake of 238U and 232Th from soils to the leaf samples of three different medicinal plant species (Eucalyptus globulus, Acacia mearnsii and Hyparrhenia filipendula) from the purlieu of the Princess gold mine dump, an abandoned contaminated tailings storage site (TSS), located at longitude 27˝551002E and latitude 26˝091302S in Davidsonville (Roodepoort, west of Johannesburg, South Africa) was measured. This was done using ICP-MS spectrometry and substantial differences were observed in the soil-plant transfer factor (TF) values between these radionuclides. The plant species E. globulus exhibited the highest uptake of 238U, with an average TF of 3.97, while that of H. filipendula was 0.01 and the lowest TF of 0.15 ˆ 10´2 was measured for A. mearnsii. However, in the case of 232Th, the highest average TF was observed fo...
Not all gamma rays emitted by the source that pass through the detector will produce a count in t... more Not all gamma rays emitted by the source that pass through the detector will produce a count in the system. The probability that an emitted gamma ray will interact with the detector and produce a count is the efficiency of the detector and is measured by comparing a spectrum from a source of known activity, count rates in each peak, count rates expected from the known intensities of each gamma ray. The energy of the gamma rays being detected is an important factor in the efficiency of the detector. An efficiency curve can be obtained by plotting the efficiency at various energies. This curve can then be used to determine the efficiency of the detector at energies different from those used to obtain the curve. A comparison of two gamma-ray efficiency determination methods; Canberra’s LabSOCS and the source-based efficiency calibrations using marinelli beaker geometry were measured and the results revealed +96% confidence levels for each gamma peak lines. This means that the Canberra’...
Raymond L. Njinga, Victor M. Tshivhase, and Fatima B. Yusuf Centre for Applied Radiation Science ... more Raymond L. Njinga, Victor M. Tshivhase, and Fatima B. Yusuf Centre for Applied Radiation Science and Technology, North-West University, Mafikeng, Private Bag X2046 Mmabatho, 2735, South Africa, Department of Physics, Federal University Dutse, P.M.B 7156, Jigawa State, Nigeria Department of Physics, Ibrahim Badamasi Babangida University, Lapai, P.M.B 11, Niger State, Nigeria *Corresponding author’s email: njingaraymond@yahoo.co.uk
Background: In this study, the health risk associated with three types of drinking waters (fissur... more Background: In this study, the health risk associated with three types of drinking waters (fissure, underground treated and surrounding waters) from two mines in South Africa were assessed. Materials and Methods: The measurement of the radionuclides concentra on was carried out by liquid scin lla on counter and alpha spectrometer. The es mated radiological risk pose to the people consuming the water types were evaluated based on the calculated radionuclide concentra ons. Results: The value of the gross alpha was 1.08 ± 0.02 Bq/L and gross beta ac vity was 0.65 ± 0.04 Bq/L in the treated underground water. These values were several fold above the limit value of 1.0 Bq/L for gross alpha and 0.1 Bq/L for gross beta. For the fissure water, the gross alpha ac vity value was 0.59 ± 0.07 Bq/L which is less than the limit of 1.0 Bq/L and the gross beta ac vity was high with a value of 0.54 ± 0.05 Bq/L compared to the limit value of 0.1 Bq/L. The results around the Princess gold mine showed ...
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