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1

Radiological characterization of the phosphate deposit in Al-Jalamid phosphate mining area, Saudi Arabia

Alhawsawi Abdulsalam M., Shababa E. I., Qutub Maher M. T., Banoqitah Essam M., Kinsara A. A.

Nukleonika

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2021

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Vol. 66, No. 1

35--44

EN

It is a known fact that phosphate rocks have high levels of natural radioactivity due to the presence of large concentrations of radionuclides. This work aims to estimate radiation exposure and dose levels at Al-Jalamid site in northern Saudi Arabia. Al-Jalamid area is one of the largest reserves of phosphate worldwide. Ma’aden, a Saudi Government public company, owns the mine and is responsible for all mining activities. Phosphate and soil samples collected from Al-Jalamid phosphate mining area have been analysed for their uranium and thorium content by an α-spectrometer using radiochemical techniques. The quantity of radon gas was measured both in groundwater and in the atmosphere (indoor and outdoor) at the site using a portable radiation survey instrument. Groundwater samples collected from wells surrounding the mining area were analysed using a liquid scintillation counter in addition to an α-spectrometer. Finally, it is found that phosphate rock concentrate products cannot be utilized economically based on the standards set by the International Atomic Energy Agency (IAEA), since the average activity concentration does not reach the limit set by IAEA and hence are not commercially feasible.

2

Determination of radiation doses to the skin due to 238U and 232Th series for the therapeutic application in the Merzouga sand baths

Touti Rodouan, Harrass Hicham

Polish Journal of Medical Physics and Engineering

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2020

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Vol. 26, Iss. 2

87--96

EN

In this work, we used CR-39 and LR-115 type II solid-state nuclear track detectors to measure 238U, 232Th,222Rn and 220Rn concentrations in Merzouga sand. The measured concentrations of 238U and 232Th in the studied sand samples vary from (332.59±16.62) mBq·cm-3 to (335.54±20.13) mBq·cm-3 and (80.43±4.02) mBq·cm-3 to (84.75±5.08) mBq·cm-3, respectively. We evaluated the radiation doses to the skin from the application of different sand baths by the patients by using a model based on specific alpha-dose and alpha-particle residual energy concepts. The maximum total equivalent dose to the skin due to the 238U and 232Th series from the cutaneous application of different sand baths by patients was found equal to (148.12±11.85) µSv y-1cm-2.

3

Precise determination of HPGe detector efficiency for gamma spectrometry measurements of environmental samples with variable geometry and density

Barrera M., Casas-Ruiz M., Alonso J. J., Vidal J.

Nukleonika

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2017

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Vol. 62, No. 1

47--59

EN

A methodology to determine the full energy peak efficiency (FEPE) for precise gamma spectrometry measurements of environmental samples with high-purity germanium (HPGe) detector, valid when this efficiency depends on the energy of the radiation E, the height of the cylindrical sample H, and its density ρ is introduced. The methodology consists of an initial calibration as a function of E and H and the application of a self-attenuation factor, depending on the density of the sample ρ, in order to correct for the different attenuation of the generic sample in relation to the measured standard. The obtained efficiency can be used in the whole range of interest studied, E = 120–2000 keV, H = 1–5 cm, and ρ = 0.8–1.7 g/cm3, being its uncertainty below 5%. The efficiency has been checked by the measurement of standards, resulting in a good agreement between experimental and expected activities. The described methodology can be extended to similar situations when samples show geometric and compaction differences.

4

High pure, carrier free 85Sr and 83Rb tracers obtained with AIC-144 cyclotron

Misiak R., Gaca P., Bartyzel M., Mietelski J.

Nukleonika

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2003

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Vol. 48, nr 3

151--153

EN

The method of obtaining carrier free tracers, 85Sr and 83Rb from proton-irradiated natRbCl target is described. The separation of the radionuclides was done using Sr-Resin, the resin based on a crown ether. Current and some other possible applications of the tracers are discussed.

5

Technical preparations for atmospheric radioactivity monitoring

Miyamoto Y., Oda T., Adachi T., Noguchi H., Nishimura H., Usuda S.

Nukleonika

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2001

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Vol. 46, nr 4

123-126

EN

To evaluate the suitability of a location for a radionuclide monitoring station of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) at Takasaki, Japan, the assessment was done in terms of the concentration of natural background radioactive nuclides in airborne dust and soil samples. The samples were taken four times at the proposed site and several points around the site, then their radioactivities were measured by gamma-ray spectrometry. For the airborne dust samples, only natural background radionuclides: 212Pb, 7Be and 214Pb were detected. The radioactivity concentrations of these radionuclides varied in four sampling periods but were almost the same as the previous measurements. For the soil samples, the concentration of an anthropogenic radionuclide, 137Cs, fluctuated among the different sampling points and periods, but the concentration of 40K was constant. These concentrations were 2 to 3 times lower than those of the soil taken at JAERI Tokai. Based on these results, the proposed site was evaluated and has been accepted by the CTBT Organization as a CTBT radionuclide monitoring station.

6

Response of Permanent Monitoring Station (PMS) to increased radioactivity level in comparison with thermoluminescent in comparison with thermoluminescent

Kozak K., Budzanowski M., Gaca P.

Nukleonika

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2001

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Vol. 46, nr 3

101-105

EN

In this work, the response of the Permanent Monitoring Station (PMS) was compared with the readings of environmental thermoluminescent dosimeters (TLD) based on high sensitive MCP-N (LiF:Mg, Cu, P) thermoluminecent detectors and Gamma Tracer, an active device. Thermoluminescent dosimeters were installed close to an automatic warning system of PMS and to a portable Gamma Tracer monitor which is used for long term, continuous measurements in the environment at the INP. For several weeks 137Cs, 60Co, 226Ra and 241Am gamma-ray sources have been placed at distances of a few meters from the dosimeters, in order to modify the radiation environment.

7

Decreasing of the natural background counting - passive and active method

Kozak K., Mietelski J., Jasińska M., Gaca P.

Nukleonika

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2001

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Vol. 46, nr 4

165-169

EN

The methods of passive and active shielding and the results of background gamma measurements, during the years 1996-2000 are presented. The spectrometer background was recorded in various shielding configurations. The ultra-low level gamma-spectrometer (called in the paper the spectrometer E), equipped with a veto-detector for cosmic muons (active shield) was under tests during 1999-2000.