Journal of Environmental Radioactivity

The irradiated Saccharomyces cerevisiae (Y-7) has good biosorption ability for strontium ions. To investigate the mechanism of strontium ion bioaccumulation in Y-7, we employed CRISPR/Cas9 gene editing technology to engineer Saccharomyces cerevisiae Y-7 and knock out the RSN1 gene, successfully constructing a RSN1 gene knockout strain (Y-7-rsn1Δ). When tested for strontium ion adsorption, the Y-7-rsn1Δ strain exhibited decreased capacity for adsorbing strontium ions and increased resistance to strontium ions...

We evaluate the impact of the radiological contamination of the Grote Nete catchment in Belgium to people and non-human biota. This region has received effluents from the phosphate and nuclear industries via tributaries of the Grote Nete river in past decades, resulting in the presence of radionuclides such as 241 Am, 60 Co, 137 Cs, 40 K, 210 Pb, 238 Pu, 239,240 Pu, 226 Ra, 228 Ra, 228 Th, 232 Th, 234 U, 235 U and 238 U. During the period 2016-2021, we measured these radionuclides in the water column, the bed sediment and riverbanks...

The consequences of mass radiological events, particularly those involving the activation of a radiological dispersion device (RDD), have been extensively studied by scientific groups. However, the critical initial period of such an event, usually spanning the first 100 h, can be characterized by a scarcity of information, potentially leading to delays in mitigating strategies. In response, a research group utilized computer simulations to generate solid, conservative analytical details that can aid decision-making and guide the prioritization of initial care based on variables such as age, sex, location, and local atmospheric stability conditions...

Current nuclear facility emergency planning zones (EPZs) are based on outdated distance-based criteria, predating comprehensive dose and risk-informed frameworks. Recent advancements in simulation tools have permitted the development of site-specific, dose, and risk-based consequence-driven assessment frameworks. This study investigated the computation of advanced reactor (AR) EPZs using two atmospheric dispersion models: a straight-line Gaussian plume model (GPM) and a semi-Lagrangian Particle in Cell (PIC)...

The Laptev Sea is remote from the impact of technogenic radionuclides, which makes it a convenient natural testing ground for determining the natural flux of radionuclides to the marine environment and further to sediments. Analysis of the use of different models for dating recent sediments using 210 Pb showed that in conditions of erosion-accumulative (unstable) sedimentation of the shelf, the constant initial concentration (CIC) model is most preferable. This study uses a new age-depth model "RUS2023" to recalculate the excess 210 Pb (210 Pbex ) activity into calendar years, which is a variation of the CIC model...

Removal of litter-associated 137 Cs from the forest floor (litter removal) can reduce the 137 Cs uptake by plants; however, the proposed effective period for litter removal was 1-2 years after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. This is because the 137 Cs in forest soil migrates rapidly from the litter to surface mineral soil layers in Japanese forests, and thus the effectiveness of litter removal will quickly become limited. However, it is unknown whether this approach can be applied to forests whose vertical migration of 137 Cs in the forest soil is relatively slow...

Following the accident at the Fukushima Dai-ichi Nuclear Power Station, radiocaesium concentrations were specifically elevated in rockfish species compared to other fish species. To clarify the likely reasons, a caesium metabolic rate in the Japanese rockfish Sebastes cheni was derived by an aquarium experiment of live fish collected from the area off Fukushima. Stable caesium and 137 Cs concentration in prey organisms, stomach contents and muscle of rockfish were measured and the bioavailable fraction in prey organisms was evaluated...

This study explores the impact of a simulated radiological dispersal device (RDD) event in an urban area on young adults around 20 years old. The RDD releases radioactive Cs-137 (7.0E+3 Ci), a common industrial sterilization source. The study aims to demonstrate that combining computational codes and epidemiological models can produce valuable data to guide initial actions when confronting a hostile radioactive environment. The HotSpot Health Physics and RESRAD-RDD codes were used in the simulation to evaluate the event's initial phase...

In Harghita and Covasna County (Romania) are many mofettes. The mofette is mainly CO2 composed low temperature volcanic gas emanation. The mofettes can contain important quantities of radon. In these regions of Romania, the mofettes have long been used on curative purposes. We proposed monitoring the seasonal variation of radon activity concentration (RAC) in 10 frequented mofettes. Measurements in mofettes have shown radon concentrations ranging from a few hundred to several thousand becquerels per cubic meter (Bq/m³)...

The radon exhalation rate of surrounding rocks in underground roadways is an important parameter in determining radon exhalation capacity and ventilation flowrate for radon removal. By approximating the roadways as thick-walled, porous cylinders, this study investigates radon exhalation from their surrounding rocks via simulations using computational fluid dynamics (CFD). Radon exhalation rates of single and double underground roadways were computed and analysed under different pressure differences, radon diffusion coefficients, permeabilities of rocks, single roadway locations and additional parallel roadway orientation...

Advances in the development of gamma-ray spectrometers have resulted in devices that are ideal for use in conjunction with the increasingly reliable systems of autonomously flying uncrewed aerial vehicles (UAVs) that have recently become available on the market. Airborne gamma-ray spectrometry (GRS) measurements have many different applications. Here, the technique is applied to a former uranium mining and processing site, which is characterized by relatively low specific activities and, hence, low count rates, requiring relatively large detectors and correspondingly big size UAVs...

A global network of monitoring stations is set up that can measure tiny concentrations of airborne radioactivity as part of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty. If Treaty-relevant detections are made, inverse atmospheric transport modelling is one of the methods that can be used to determine the source of the radioactivity. In order to facilitate the testing of novel developments in inverse modelling, two sets of test cases are constructed using real-world 133 Xe detections associated with routine releases from a medical isotope production facility...

The radiocesium (137 Cs) activity concentration in stemflow, which is an element of the 137 Cs cycle in the forest, is determined by the supply of 137 Cs from the outer bark and leaves. Long-term monitoring data of deciduous broad-leaved trees since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident have shown the 137 Cs activity concentration in the outer bark decreasing exponentially, while that in the leaves has remained nearly constant. Therefore, it is expected that the contribution of the outer bark to 137 Cs in stemflow eventually becomes smaller than that of leaves over time...

Radon, an environmental pollutant gas, occurs naturally in soil. Although loess, an essential building material in northwest China, is commonly used, research on radon emissions from loess remains limited. This study aims to address this gap by conducting both field and laboratory experiments to examine the impact of water content on radon emission from loess. The findings reveal that the radon emission rate from loess follows a non-linear pattern with respect to water content, initially increasing and then decreasing...

Numerous algorithms have been developed to determine the source characteristics for an atmospheric radionuclide release, e.g., (Bieringer et al., 2017). This study compares three models that have been applied to the data collected by the International Monitoring System operated by the Comprehensive Nuclear-Test-Ban Treaty Organization Preparatory Commission to estimate source event parameters. Each model uses a different approach to estimate the parameters. A deterministic model uses a possible source region (PSR) approach (Ringbom et al...

Many countries are considering nuclear power as a means of reducing greenhouse gas emissions, and the IAEA (IAEA, 2022) has forecasted nuclear power growth rates up to 224% of the 2021 level by 2050. Nuclear power plants release trace quantities of radioxenon, an inert gas that is also monitored because it is released during nuclear explosive tests. To better understand how nuclear energy growth (and resulting Xe emissions) could affect a global nonproliferation architecture, we modeled daily releases of radioxenon isotopes used for nuclear explosion detection in the International Monitoring System (IMS) that is part of the Comprehensive Nuclear Test-Ban Treaty: 131m Xe, 133 Xe, 133m Xe, and 135 Xe to examine the change in the number of potential radioxenon detections as compared to the 2021 detection levels...

The trenches of the waste burial site in the Chornobyl Red Forest represent a big reservoir of radionuclides for the artificial plantation of Scots pine established in that area, but the long term dynamics of tree biomass contamination, especially with 90 Sr, remains unclear. The present study was conducted between 2005 and 2018 on two groups of trees of the same age. The IN group is represented by trees growing on the trench containing highly radioactive contaminated fertile soil and organic matter, while the OUT group is located outside the trench...

We present a novel methodology to dynamically calculate dose rates to people and wildlife from hospital-released radionuclides reaching the environment through water treatment plants (WTPs), using the biokinetic model D-DAT for aquatic wildlife, applied to 18 F, 123 I, 131 I, 153 Sm, 99m Tc and 201 Tl. We have also developed a method to calculate doses to WTP workers and to farmers from agricultural practices. This proof-of-concept study simulates a generic source term of radionuclide levels in the Belgian Molse Nete River during the year 2018, chosen because the river flow was very low during that year, which constitutes a very conservative, bounding case...

This paper provides an in-depth discussion of the CFD implications to the design/study of interior environments and an overview of the most widely used CFD model for indoor radon and thoron dispersion study. For the design and analysis of indoor environments, CFD is a powerful tool that enables simulation and measurement-based validation. Simulating an indoor environment involves deliberate thought and skilful management of complicated boundary conditions. User and CFD programs can develop results through gradual effort that can be relied upon and applied to the design and study of indoor environments...

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