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The undeclared release and subsequent detection of ruthenium-106 (106Ru) across Europe from late September to early October of 2017 prompted an international effort to ascertain the circumstances of the event. While dispersion modeling, corroborated by ground deposition measurements, has narrowed possible locations of origin, there has been a lack of direct empirical evidence to address the nature of the release. This is due to the absence of radiological and chemical signatures in the sample matrices, considering that such signatures encode the history and circumstances of the radioactive contaminant. In limiting cases such as this, we herein introduce the use of selected chemical transformations to elucidate the chemical nature of a radioactive contaminant as part of a nuclear forensic investigation. Using established ruthenium polypyridyl chemistry, we have shown that a small percentage (1.2 ± 0.4%) of the radioactive 106Ru contaminant exists in a polychlorinated Ru(III) form, partly or entirely as β-106RuCl₃, while 20% is both insoluble and chemically inert, consistent with the occurrence of RuO₂, the thermodynamic endpoint of the volatile RuO₄. Together, these findings present a clear signature for nuclear fuel reprocessing activity, specifically the reductive trapping of the volatile and highly reactive RuO₄, as the origin of the release. Considering that the previously established 103Ru:106Ru ratio indicates that the spent fuel was unusually young with respect to typical reprocessing protocol, it is likely that this exothermic trapping process proved to be a tipping point for an already turbulent mixture, leading to an abrupt and uncontrolled release.

The concept of defense in depth is the mainstay of nuclear energy technology to overcome potential environmental disasters from its power plants. The engineering approach dominates this concept, thus placing the environment as a receiving factor for the success or failure of the approach. The question of the reasons for this situation arises together with the question of how environmental approaches can play a role in the concept. An ethnographic study on the development and application of this concept was carried out through a content analysis of the literature. The results of the study indicate that there is an assumption that the prevention of environmental radioactive disasters will be achieved by reducing the frequency of severe accidents, the environment will be protected if humans are safe and there is not enough environmental and pollution approach to be applied to the concept. This study recommends the need for further studies on the capacity of the environment to accept radioactive contaminants and measures the suitability of nuclear power plants with their environment.

This study investigates the distribution, transfer, and potential ecological risks of naturally occurring radioactive materials, including radon-222 ( 222 Rn), radium-226 ( 226 Ra), thorium-232 ( 232 Th), and potassium-40 ( 40 K), in the aquatic ecosystem of Nasser Lake, Egypt. As Egypt’s largest freshwater reservoir and a critical source of drinking water and fish, Nasser Lake plays a key role in environmental stability and public health. A total of 40 environmental samples—sediment, water, aquatic plants, and fish—were collected from 10 strategically selected sites around the lake. Gamma spectroscopy using sodium iodide activated with thallium [NaI(Tl)] detectors and AlphaGUARD radon monitoring systems was employed to measure radionuclide activity concentrations. Spatial distribution patterns were analyzed using Geographic Information System (GIS) techniques to identify zones of elevated radioactivity. The highest concentrations of 226 Ra, 232 Th and 40 K were recorded in sediment samples near the High Dam, reaching 10.99 ± 0.42 Bq kg −1 , 23.94 ± 1.91 Bq kg −1 , and 277.38 ± 23.86 Bq kg −1 , respectively. A strong positive correlation (Pearson’s r = 0.913) was observed between 226 Ra and 222 Rn exhalation rates, confirming that sediment accumulation significantly contributes to local radiological emissions. Bioaccumulation studies showed progressive uptake of radionuclides along the aquatic food chain, with fish exhibiting a bioaccumulation factor (BAF) of 0.74 for 226 Ra. Estimated annual radiation doses from fish consumption reached up to 6.435 microsieverts per year (µSv y −1 ), remaining below international reference levels established by the World Health Organization (WHO). However, the combination of localized contamination near the High Dam and high fish consumption in nearby communities may present long-term radiological exposure risks. These findings highlight the importance of continuous monitoring of radioactive contaminants in sediment, water, and aquatic organisms in Nasser Lake. The study also provides a transferable framework for assessing the behavior of technologically enhanced naturally occurring radioactive materials (TENORM) in freshwater environments and supports the goals of the United Nations Sustainable Development Goals (SDGs) for clean water and good health.

The release of radioactive contaminants in nuclear facilities or facilities associated with radioactive materials could be harmful to the workers. The mechanical and natural ventilation system in the nuclear facilities can eliminate or reduce this potential risk. The purpose of this study is to analyse the correlation of natural ventilation with radon concentration in Interim Storage for Radioactive Waste in BATAN. In this study, the radon sources are not only from soil and building materials but mainly from Ra-226 radioactive waste, which was used in Brachytherapy to kill cancer cells. The simulation analysis was conducted using multi-zone airflow and contaminant transport code, CONTAM. The numerical simulation results were validated with analytical calculation and experimental measurement. The experimental measurement was performed using an electronic radon detector with real time monitoring, DURRIDGE RAD7. The results show that the change of radon concentration can be affected not only by temperature difference between indoor and outdoor but also by temperature difference between one room and the other room connected to it. The simulation- and calculation in this study are relatively consistent to the measurement results.

The Fukushima Daiichi Nuclear Power Plant accident led to contamination with radioactive cesium in an extensive environment in Japan in 2011. We evaluated the concentration of radioactive cesium in the skeletal muscles of 22 wild boars and the expression of IFN-γ , TLR3 , and CyclinG1 in the small intestine and compared them with those of wild boar samples collected from Hyogo prefecture. The average 137 Cs radioactivity concentration in wild boars in the ex-evacuation zone was 470 Bq/kg. Most of samples still showed radioactivity concentration that exceeded the regulatory limit for foods, but the dose remarkably decreased compared with samples just after the accident. IFN-γ expression was significantly higher in wild boars in the ex-evacuation zone than in samples from Hyogo prefecture. TLR3 expression was also upregulated. CyclinG1 expression also tended to be high. Hence, wild boars might have received some effects of low-dose radiation, and immune cells were activated to some extent. However, pathological examination revealed no inflammatory cell infiltration or pathological damage in the small intestine of wild boars in the ex-evacuation area. Long-term monitoring would be necessary, but we consider that the living body responds appropriately to a stimulus from a contaminated environment.

Japan’s decision to discharge the Fukushima-Daiichi radioactive treated water into the Pacific Ocean has drawn widespread international concern regarding radioactive contamination of seafood and its impact on the marine ecosystem and human health. China’s seafood import trade is confronted with a potentially significant threat. In the favorable circumstances created by China’s suspension of seafood imports from Japan, This article analyzes the impact of Japan’s radioactive treated water discharge on seafood safety and human health, as well as the importance of the Chinese market in the international trade of seafood, and analyzes the seafood export data from Southeast Asian countries to China from 2018 to 2024. A significant increase in seafood exports from countries such as Indonesia, Myanmar, and the Philippines to China was observed. Conversely, there has been a notable decline in the export volumes from Vietnam and Thailand. This paper proposes some proactive strategies for Southeast Asian seafood exports to China, including actively familiarizing with China’s import regulations and standards, optimizing export strategies, cultivating a positive and favorable product image, aligning with the needs of Chinese enterprises, and ensuring food safety.

Rice is a staple food in many developing countries, and its role in public health has been a focus of research for decades. In Ghana, a developing country in sub-Saharan Africa, per capita rice consumption is estimated at 50 kg per person per year (2023/2024 marketing year). Meanwhile, in the same period, Ghana’s milled rice production was estimated at 1.009 million metric tons, covering about 59% of the national consumption needs. And this is while, many developing countries often lack well-defined regulatory frameworks for pre-import evaluation of critical safety parameters in food products. To bridge the consumption gap, Ghana imports a significant portion of its rice, with imports forecasted at 950,000 metric tons. Despite the significance of imported rice in the national food supply, there is a notable lack of comprehensive radiological assessments focused on these products. Therefore, this study attempts to address this gap by analyzing radioactive contaminants—radium-226, radium-228, and potassium-40 —in imported rice consumed in Ghana. A total of 50 rice samples, with an average of 10 samples per brand from 5 distinct brands were collected from major markets in Accra, Kumasi, Tamale and analyzed using gamma-ray spectrometry with a High Purity Germanium (HPGe) detector. The mean activity concentrations were 2.13 ± 0.85 Bq/kg for 226 Ra, 3.69 ± 1.47 Bq/kg for 228 Ra, and 51.82 ± 7.93 Bq/kg for 40 K, all within international safety limits. The estimated total annual effective dose for an average adult was 408.44 µSv/y well below recommended international thresholds. The excess lifetime cancer risk (ELCR) was also calculated, with results indicating a negligible impact on public health. These findings highlight the importance of continuous monitoring of radioactive contaminants in imported food products to ensure consumer safety. Additionally, the study provides critical insights for policymakers, emphasizing the need for regulatory measures to control radioactivity levels in imported foods. This research supports Ghana’s public health initiatives and alignment with global food safety standards.

An earthquake and tsunami of historic proportions caused massive damage across the northeastern coast of Japan on the afternoon of 11 March 2011, and the release of radionuclides from the stricken reactors of the Fukushima nuclear power plant 1 was detected early on the next morning. High levels of radioiodines and radiocesiums were detected in the topsoil and plants on 15 March 2011, so sampling of food and water for monitoring surveys began on 16 March 2011. On 17 March 2011, provisional regulation values for radioiodine, radiocesiums, uranium, plutonium and other transuranic α emitters were set to regulate the safety of radioactively contaminated food and water. On 21 March 2011, the first restrictions on distribution and consumption of contaminated items were ordered. So far, tap water, raw milk, vegetables, mushrooms, fruit, nut, seaweeds, marine invertebrates, coastal fish, freshwater fish, beef, wild animal meat, brown rice, wheat, tea leaves and other foodstuffs had been contaminated above the provisional regulation values. The provisional regulation values for radioiodine were exceeded in samples taken from 16 March 2011 to 21 May 2011, and those for radiocesiums from 18 March 2011 to date. All restrictions were imposed within 318 days after the provisional regulation values were first exceeded for each item. This paper summarizes the policy for the execution of monitoring surveys and restrictions, and the outlines of the monitoring results of 220 411 samples and the enforced restrictions predicated on the information available as of 31 March 2012.

Soil samples from vegetable farmland in densely populated wards of Nepal were analyzed for natural radionuclide levels, employing a NaI(Tl) 3” × 3” gamma detector. The study aimed to evaluate the causes of radiation risk, attributing it to soil contamination resulting from the rapid urbanization and concretization that followed the earthquake in 2015. The activity concentration of radium-226, thorium-232, and potassium-40 and the ranges observed are 2.080±0.084–33.675±1.356 Bq kg - 1 , 17.222±0.198–119.949±1.379 Bq kg - 1 , and 11.203 ± 0.325–748.828±21.716 Bq kg - 1 , respectively. The average values obtained for hazard indices are as follows: radium equivalent activity (82.779 Bq kg - 1 ), absorbed dose rate (36.394 nGy h - 1 ), annual effective dose equivalent (0.045 mSv yearr - 1 ), gamma index (0.291), external hazard index (0.224), internal hazard index (0.253), excess lifetime cancer risk (0.159), annual gonadal dose equivalent (243.278 mSv year - 1 ), alpha index (0.054), and activity utilization index (0.716). However, in most places, thorium-232 concentration is greater than those of the world average and recommended values. In specific locations such as Ward 4 in Baluwatar, the soil was found to have concentrations of Ra 226 and K 40 exceeding recommended limits. Despite this localized concern, the overall analysis of hazard indices across the studied areas revealed that most values were within permissible limits. This suggests that, on a broader scale, radiation exposure may not be a significant concern in the investigated regions. Nonetheless, the study recommends regular monitoring in additional locations to ensure a comprehensive and ongoing assessment of radiation levels.

Herein, we report a new strategy for the rapid removal of uranium-containing contaminants from metal surfaces, and it relies on decontaminants made of NaOH-based molten salts. The addition of Na 2 CO 3 and NaCl to NaOH exhibited superior decontamination performance, with a decontamination rate of 93.8% within 12 min, outdoing the performance of the single NaOH molten salt. The experimental results demonstrated that the synergistic effects between CO 3 2− and Cl − promoted the corrosion efficiency of the molten salt on the substrate, which accelerated the decontamination rate. Additionally, benefiting from the optimization of the experimental conditions by the response surface method (RSM), the decontamination efficiency was improved to 94.9%. Notably, it also showed remarkable results in the decontamination of specimens containing different uranium oxides at low and high levels of radioactivity. This technology is promising for broadening the path in rapid decontamination of radioactive contaminants on metal surfaces.