222Rn and 220Rn levels in drinking water, emanation, and exhalation assessment, and the related health implications in the U-bearing area of Poli-Cameroon.

The inherent radioactivity of radon gas presents potential exposure risks to human beings through ingestion and inhalation of its radioisotopes 222Rn (radon) and 220Rn (thoron) from water sources. Recent studies have been conducted to assess radon concentrations in different environmental matrices such as water, air, and soil, due to their detrimental impact on human health. As the main cause of lung cancer in non-smokers and an acknowledged contributor to stomach cancer when ingested, the present study aimed to preliminarily assess radon and thoron levels in the Uranium bearing area of Poli in the Faro division of Cameroon, known for its significant U-deposits. The assessment included measuring 220, 222Rn concentrations in drinking water, emanation, and exhalation, with a specific focus on evaluating the exposure of different age groups within the local population. The radon/thoron levels in water and their related exposure and cancer risk data indicated no immediate health hazards. However, continuous monitoring and prospective measures are deemed essential due to the area's abundant U-minerals. The emanation measurements showed sparsely distributed data with a singularity at Salaki, where the equipment recorded values of 8.14 × 1012 Bqm-3 and 3.27 × 1012 Bqm-3 for radon and thoron, respectively. Moreover, radon/thoron transfer coefficients from the soil to the air indicated levels below unity. While the calculated doses suggest minimum potential risk in line with WHO and UNSCEAR guidelines, the obtained results are expected to significantly contribute to the establishment of national standards for radon levels in drinking water, emanation, and exhalation. Furthermore, these findings can play a crucial role in monitoring radon/thoron levels to ensure public health safety.

Monte Carlo optimum management of 241Am/Be disused sealed radioactive sources.

The optimum encapsulation of 241Am/Be disused sealed radioactive sources (DSRS) based on PHITS Monte Carlo simulations for their long-term storage in Cameroon was performed. The country capacity for the management of disused neutron sources was also evaluated and showed that a Am1 P60 capsule is sufficient for the total available inventoried 241Am/Be DSRSs. The effective dose rate was computed in the enclosures of the DSRS container, which will be temporarily stored in the centralized radioactive waste facility. The obtained results were in agreement with the ALARA principle for the exposure rate optimization and the obtained exposure dose rates were found to be 1.830 µSv/h (horizontal calculation) and 0.137 µSv/h (vertical computation) which values are lower than the 2.5 µSv/h acceptable limit for the public area. The dose profile for 241Am/Be source obtained, the neutron flux, and gamma generated from neutron absorption showed agreement with the research hypothesis. The Monte Carlo assessment achieved in the present research will be useful for dismantling and preparing the waste package for long-term storage.

Recovering and restitution of unknown, unidentified, and unlabeled samples in laboratories using EDXRF analysis.

This Study presents a method to recover and label unknown samples in a nuclear laboratory using Energy Dispersive X-Ray Fluorescence (EDXRF) spectrometry based on spectra differentiation and analysis. This method was found to be a new powerful tool that can be used in different laboratories where a certain number of samples cannot be identified because they have never been identified, their labeling and identification cannot be assessed because of degradation, and/or any other causes. The method was found to be simple, timely appropriate, not expensive, and powerful in identifying and recover the information needed for a sample. The EDXRF spectrometry method for recovering unknown samples in laboratories was based on the following three main points:•EDXRF method allows the elemental characterization of any sample without clear identification in a laboratory;•The displaying of several samples' spectra on the same graph allows direct comparison and identification when the sample's data overlap one of the stored data; and•The identification of the unknown sample based on the EDXRF results: The faster method being the overlapping comparison while the elemental characterization-based identification needs high skilled expertise in X-ray fluorescence analysis.

Precision measurement of radioactivity in gamma-rays spectrometry using two HPGe detectors (BEGe-6530 and GC0818-7600SL models) comparison techniques: Application to the soil measurement.

To obtain high quality of results in gamma spectrometry, it is necessary to select the best HPGe detector for particular measurements, to calibrate energy and efficiency of gamma detector as accurate as possible. To achieve this aim, the convenient detector model and gamma source can be very useful. The purpose of this study was to evaluate the soil specific activity using two HPGe model (BEGe-6530 and GC0818-7600SL) by comparing the results of the two detectors and the technics used according to the detector type. The relative uncertainty activity concentration was calculated for 226Ra, 232Th and 40K. For broad energy germanium detector, BEGe-6530, the relative uncertainty concentration ranged from 2.85 to 3.09% with a mean of 2.99% for 226Ra, from 2.29 to 2.49% with a means of 2.36% for 232Th and from 3.47 to 22.37% with a mean of 12.52% for 40K. For GC0818-7600SL detector, it was ranged from 10.45 to 25.55% with a mean of 17.10% for 226Ra, from 2.54 to 3.56% with a means of 3.10% for 232Th and from 3.42 to 7.65% with a mean of 5.58% for 40K. The average report between GC0818-7600SL model and BEGe-6530 model was calculated and showed the mean value of 3.36. The main study was based on the following points: •Determination of The relative uncertainty activity concentration of 226Ra, 232Th and 40K•Determination of the relative uncertainty related to the radium equivalent activity to compare the performance of the two detection systems•Proved that the activity concentration determination in gamma spectrometry depended on the energy range emitted by a radionuclide. This study showed that the standard deviation measurement was less important to the result realized with BEGe-6530 HPGe model. Our findings were demonstrated that the results of the Broad Energy Germanium detector were more reliable.