Decontamination Work Research Articles

PROPERTIES OF URBAN SOILS AFTER DECONTAMINATION MEASURES ON THE RADIOACTIVELY CONTAMINATED TERRITORY OF THE CITY OF ELEKTROSTAL

We studied morphological properties, pH, organic carbon content, and specific activity of 137Cs and natural radionuclides (40K, 226Ra, 232Th) in the upper horizons of soils in deactivated and slightly damaged areas of the city. The studies were carried out in the urban ecosystems of the city of Elektrostal (Moscow region) in 2019, i.e. 6 years after local precipitation of 137Cs due to a radiation incident. Morphological features of the upper horizons of urban soils were: brownish-gray color, light-loamy composition, small-lumpy and lumpy structure, inclusions of construction and household waste. In the upper horizons of urbiquasizems and urban soils, a low carbon content (less than 1%) with high coefficients of variation - were detected. In the studied urban soils, a wide range of water pH values was noted: from acidic (4,6-5,5) to highly alkaline (> 8,0) reaction. Correlation analysis showed that in the upper horizons of UR, the content of organic carbon was reduced and alkalinization of the soil environment was observed. The accumulative type of distribution of 137Cs was recorded for soil profiles of polluted urban ecosystems in which decontamination measures were not carried out. The profiles of urban soils that were subjected to decontamination revealed low values of the specific activity of 137Cs in surface bulk layers and maxima in buried contaminated horizons. In the bulk horizons of UR, which include a large amount of crushed stone, there is an increase in the specific activity of 226Ra. Some technogenic horizons UR and TCH, consisting mainly of quartz sand, are characterized by very low values of specific activities 226Ra and 40K. Correlations of chemical and radiation indicators in the profiles of urban soils reflect the different composition and properties of upper horizons formed as a result of excavation and decontamination work.

Further development and application of a method for assessing radionuclide surface activity distribution and source location based on measurements of ambient dose equivalent rate. Examples for Andreeva Bay, Chernobyl NPP and Istiklol

A method for reconstructing surface activity density (SAD) maps based on the solution of the Fredholm equation has been developed and applied. The construction of SAD maps was carried out for the site of the temporary storage (STS) of spent fuel and radioactive waste (RW) in Andreeva Bay using the results of measuring campaign in 2001–2002 and for the sheltering construction of the solid RW using the results of measurements in 2021. The Fredholm equation was solved in two versions: under conditions of a barrier-free environment and taking into account buildings and structures located on the industrial site of the STS Andreeva Bay. Lorenz curves were generated to assess the compactness of the distributions of SAD and ambient dose equivalent rate (ADER) for the industrial site and the sheltering construction at STS Andreeva Bay, the area of the IV stage uranium tailing site near the city of Istiklol in the Republic of Tajikistan, and for roofs of the Chernobyl nuclear power plant. The nature of impact of the resolution (fragmentation) of the raster, the value of the radius of mutual influence of points (contamination sites), the height of the radiation detector above the scanned surface and the angular aperture of the radiation detector on the accuracy of the SAD reconstruction is shown. The method developed allows more accurate planning of decontamination work when only ADER measurements data is available. The proposed method can be applied to support the process of decontamination of radioactively contaminated territories, in particular during the remediation of the STS Andreeva Bay.

Radiation Measurements at Fukushima Medical University over a Period of 12 Years Following the Nuclear Power Plant Accident

Background: Fukushima Medical University (FMU) is located 57 km northwest of the Fukushima Daiichi Nuclear Power Plant. Our laboratory has been conducting environmental radiation measurements continuously before and after the nuclear accident. We aimed to report the observed behavior of radiation originating from the released radioactive materials due to the accident, predict future trends, and disseminate the results to the local residents.Materials and Methods: Measurements of the counting rate by a diameter of 76 mm and a length of 76 mm thallium-doped sodium iodide (NaI[Tl]) scintillation detector (S-1211-T; Teledyne Brown Engineering Environmental Services) in the central part of the laboratory, and the dose rate outward at the window by NaI(Tl) scintillation detector and digital processor (EMF211; EMF Japan Co. Ltd.) were conducted.Results and Discussion: Measurements by Teledyne S-1211-T showed that in the early stages, radiation from radioactive isotopes with short half-lives was dominant, while radiation from radioactive isotopes with longer half-lives became dominant as the measurement period became longer. Through nonlinear least squares regression, both short and long half-lives were successfully determined. It was also possible to predict how the radiation dose would decrease. The environmental radiation trends around FMU were measured by the EMF211. Both measurements were affected by rainfall and snow accumulation. Decontamination work on the FMU campus impacted measurements by the EMF211 especially.Conclusion: The results of two types of measurements, one at the center and the other at the window side of the laboratory, were presented. By applying a simplified model, radiation from radioactive isotopes with short and long half-lives was identified. Based on these results, future trends were predicted, and the information was used for public communication with the local residents.

Concurrent datasets on land cover and river monitoring in Fukushima decontaminated catchment during 2013–2018

After the Fukushima nuclear accident, the Japanese government implemented extensive decontamination work in 137Cs contaminated catchments for residents’ health and local revitalization. Whether dramatic land use changes in the upstream decontaminated regions affected river suspended sediment (SS) and particulate 137Cs discharge downstream remain unknown because of the poor quantification on land cover changes and long-term river SS dynamics. We here introduce a 6-year concurrent database of the Niida River Basin, a decontaminated catchment, including the first available vector decontamination maps, satellite images in decontaminated regions with a spatial resolution of 10 m, and long-term river monitoring datasets spanning decontamination (2013–2016) and subsequent natural restoration stages (2017–2018). These datasets allow us, for the first time, to directly link the transport dynamics of river SS (particulate 137Cs) to land use changes caused by humans in real-time, which provide fundamental data for better understanding the river response of sediment to land use change. Moreover, the data obtained by interdisciplinary methods offer a template for land use change impact assessment in other river basins.

Factors influencing acceptability of final disposal of incinerated ash and decontaminated soil from TEPCO's Fukushima Daiichi nuclear power plant accident

TEPCO's Fukushima Daiichi nuclear power plant accident prompted extensive decontamination work. The decontaminated soil and incinerated ash generated by the process are scheduled for final disposal by March 2045 outside Fukushima Prefecture. The final disposal is unprecedented worldwide. Clarifying their acceptability will contribute to the final disposal of decontaminated soil and incinerated ash, as well as add knowledge about the perceived risk of low-concentration radioactive waste. A questionnaire survey was conducted to assess the psychological factors influencing final disposal acceptability. The results of the structural equation modeling demonstrated stable results, with risk perception decreasing acceptability, social benefits increasing acceptability, and personal benefits having limited impact. The initiative for the final disposal of decontaminated soil and incinerated ash can facilitate the reconstruction of Fukushima Prefecture after the disaster. Trust and intergenerational expectations are critical factors influencing the acceptability of this disposal. The responses were classified based on the relevance of moral norms using cluster analysis and moral foundations. The influence of each element on acceptability varied depending on the cluster. Trust was identified as the most influential factor in acceptability, regardless of the level of importance placed on moral norms.

Thirty-Year Prediction of 137Cs Supply from Rivers to Coastal Waters off Fukushima Considering Human Activities

The Fukushima Daiichi Nuclear Power Plant accident caused an accumulation of 137Cs in coastal sediment. The 137Cs supply from rivers to the ocean can affect the long-term fate of 137Cs in coastal sediment. Since the Fukushima coastal river basins include large decontaminated and evacuation order areas, considering the decontamination work and resumption of agriculture is important for predicting the 137Cs supply. We conducted a 30-year prediction of the 137Cs supply from the Fukushima coastal rivers to the ocean using a distributed radiocesium prediction model, considering the effects of human activities. In river basins with decontaminated and evacuation order areas, human activities reduced the total 137Cs outflow from agricultural lands, urban lands, and forest areas to the rivers and the 137Cs supply to the ocean by 5.0% and 6.0%, respectively. These results indicated that human activities slightly impacted the 137Cs outflow and supply. The 137Cs supply from rivers impacted by the accident to the coastal sediment was estimated to correspond to 11–36% of the total 137Cs in the coastal sediment in the early phase of the accident. Therefore, the 137Cs supply from rivers to the ocean is important for the long-term behavior of 137Cs in coastal sediment.

A survey on the practice of bronchoscopy in county-level hospitals of China

Objective: To investigate the bronchoscopy resource allocation and technology application in county-level hospitals in China. Methods: A cross-sectional survey was conducted. In 2021, 12 provinces were sampled from all provinces in China according to the regional Gross Domestic Product (GDP) and the number of counties, in which a total of 291 county-level hospitals were randomly enrolled. Two county-level hospitals which carried out bronchoscopy technology in each province were randomly sampled to investigate the status of bronchoscopy resources, technical application, decontamination and anesthesia by using questionnaires. Independent sample t test or two related sample nonparametric test were used for comparison between groups. Spearman correlation analysis was used to explore the correlation. Bilateral P<0.05 was considered statistically significant. Results: According to the sampling results, it was estimated that in the county-level hospitals, the proportion of those performing bronchoscopy was 11.4% (9.9%, 13.8%), which was significantly correlated with the population in the province (r=0.64, P=0.025) and the regional GDP (r=0.65, P=0.025).The 24 county-level hospitals interviewed were equipped with (1.6±1.0) bronchoscopes on average, and the number of hospitals with electronic bronchoscopes and fiberoptic bronchoscopes was 22 (91.7%) and 6 (25.0%), respectively. Six (25.0%) hospitals performed bronchoscopy every working day. Twelve (50.0%) hospitals had relatively permanent physicians and nurses. All operating doctors had received special training. There was a significant increase in the number of bronchoscopy cases per hospital in 2020 compared to 2019 [140(70, 335) vs. 100(29, 254), P=0.001]. All hospitals used standard cleaning and sterilization workbenches, cleaning agents and disinfectants. Surface anesthesia was available in 24 hospitals, and bronchoscopy techniques under sedation and analgesia were performed in 10 (41.7%) hospitals. Atropine was still used to prevent airway secretions in 2 (8.3%) hospitals,although not recommended by guidelines. Conclusions: There was a large gap between the current status of bronchoscopy technology in county-level hospitals and the standards of the National Health Commission, together with regional disparities. Bronchoscopist training in the standardization and the decontamination work met the requirements. In some hospitals, the use of complementary medicines was not standardized or the sedatives were not given routinely according to the guidelines. We should promote the popularization and standardization of bronchoscopy technology, and strengthen the allocation of related resources in China's county hospitals.

Evaluation of external dose exposure of workers during house demolition and dose reduction work in a difficult-to-return zone

Since the accident at the Fukushima Daiichi Nuclear Power Plant, many decontamination works have been carried out. Although the exposure status of decontamination workers has been appropriately managed by the government, there are few examples of detailed analysis of external dose exposure conditions. In this study, on the basis of the GPS location information obtained from GPS devices carried by the workers together with their personal dosimeters, the air dose rate in the work area and the characteristics of each type of work were analyzed. The results showed that more than 50% of the measured actual exposure doses were more than twice the median planned exposure dose calculated from the air dose rate and the number of actual working hours. Furthermore, the analysis by work type showed that demolition workers tended to have higher exposure doses. Such information on workers' external exposure doses linked to location information is useful for a detailed analysis of external exposure factors. Such an analysis also contributes to the optimization of future radiation protection programs for workers.

Influence of operation of thermal and fast reactors of the Beloyarsk NPP on the radioecological situation in the cooling pond: Part II, Macrophytes and fish

The influence of waste technological waters of thermal and fast reactors of Beloyarsk NPP (Russia) on the accumulation of 60Co, 90Sr and 137Cs in macrophytes and ichthyofauna of the cooling pond has been studied. Critical radionuclides, routes of their entry into the ecosystem and periods of maximum discharge of radioisotopes into the cooling pond have been determined. It is shown that the technology of electricity generation at the Beloyarsk NPP, based on fast reactors, has a much smaller effect on the release of artificial radionuclides into the environment. Therefore, during the entire period of monitoring studies (1976–2019), the decrease in the specific activity of radionuclides of NPP origin in macrophytes was 13–25800 times, in ichthyofauna 1.5-44.5 times. The maximum discharge of artificial radionuclides into the Beloyarsk reservoir was noted during the period of restoration and decontamination work aimed at eliminating the emergencies at the AMB reactors of NPP. The factors influencing the accumulation of artificial radionuclides in the components of the freshwater ecosystem of the Beloyarsk cooling pond have been determined, including: the physicochemical nature of radioisotopes, their concentration in surface water, the temperature of the aquatic environment, the trophicity of the reservoir, the species of hydrobionts.

Important factors for public acceptance of the final disposal of contaminated soil and wastes resulting from the Fukushima Daiichi nuclear power station accident.

Large-scale decontamination work has been carried out in the aftermath of the Fukushima Daiichi nuclear power station accident in Japan in 2011. The soil that was removed and the wastes that were generated during the decontamination will be finally disposed of outside Fukushima Prefecture by 2045. To ensure successful and socially acceptable implementation of this final disposal process, it is essential to have a good understanding of what is considered important by the public. We used a choice-based conjoint analysis in the form of a web-based questionnaire to examine the relative importance of several factors in the choice of the final disposal sites of the removed soil and incinerated ash of the wastes. The questionnaires covered four attributes and 12 levels, namely the distance between the disposal site and a person’s residential area, procedural fairness (decision process), distributive fairness (direct mitigation of inequity through multiple siting locations), and the volume and radioactivity of the substances to be disposed. Responses were received from 4000 people nationwide, excluding Fukushima residents. The results showed that the respondents gave high importance to choosing sites that were far from residential areas and to the two types of fairness, especially distributive fairness. The respondents showed no preference for the volume and radioactivity. This indicates that the public cares about the fairness of the siting for the final disposal sites and feels uncomfortable with plans for a final disposal site located close to them. Distributive fairness is necessary to pursue consensus in addition to procedural fairness.

Assessment of localized and resuspended 137 Cs due to decontamination and demolition in the difficult-to-return zone of Tomioka town, Fukushima Prefecture.

As the next step that occurred more than one decade after the accident at the Fukushima Dai-ichi Nuclear Power Station (FDNPS), decontamination and demolition have been carried out in the Specified Reconstruction and Revitalization Base (SRRB) of the difficult-to-return zone around the FDNPS. However, the risk of internal exposure among workers due to airborne dust inhalation after building demolition operations has not been sufficiently evaluated. To evaluate the working environment and internal exposure risk due to inhalation in the SRRB of Tomioka town, Fukushima Prefecture, the cesium-137 (137 Cs) radioactivity levels in the airborne dust at building demolition sites were analyzed using gamma spectrometry. The 137 Cs radioactivity levels and resuspension factors of the airborne dust at the subject building sites in the difficult-to-return zone remained at high levels compared with those of the control, which was located in the evacuation order-lifted area in Tomioka town. However, the 137 Cs radioactivity levels did not increase significantly, despite demolition operations that used heavy machinery. In this case, no substantial increases in accident-derived 137 Cs levels due to decontamination and demolition in the SRRB of Tomioka town, Fukushima Prefecture, were observed in the airborne dust samples, which suggests that the 137 Cs radioactivity in the airborne dust is primarily associated with particles that are resuspended by localized winds accompanied by the transfer of construction vehicles as opposed to the decontamination and demolition operations. However, the internal exposure doses due to aspirating airborne dust containing 137 Cs were extremely low compared with the estimated annual effective doses of decontamination workers or the limits recommended by the Japanese government. Additionally, countermeasures such as wearing protective masks could help reduce the on-site inhalation of soil-derived radionuclides. Integr Environ Assess Manag 2022;18:1555-1563. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Design of 4π High-Efficiency Directional Radiation Detector Based on Compton Scattering

Obtaining directional information is required in many applications such as nuclear homeland security, contamination mapping after a nuclear incident and radiological events, or during the decontamination work. However, many directional radiation detectors are based on directional shielding, made of lead or tungsten collimators, introducing two main drawbacks. The first is the size and weight, making those detectors too heavy and irrelevant for utilization in handheld devices, drone mapping, or space applications. The second drawback is the limited field of view (FOV), which requires multiple detectors to cover the whole required FOV or machinery to rotate the detector&#x2019;s narrow FOV detector. We propose a novel <inline-formula> <tex-math notation="LaTeX">$4\pi $ </tex-math></inline-formula> directional detector based on a segmented hollow cubic detector, which uses the Compton effect interactions with no heavy collimators. The symmetrical cubical design provides both higher efficiency and <inline-formula> <tex-math notation="LaTeX">$4\pi $ </tex-math></inline-formula> detection ability. Instead of the traditional two types of detectors (scatterer and absorber) structure, we use the same type of detector, based on Gd₃Al₂Ga₃O₁₂ (GAGG) (Ce) scintillator coupled to silicon photomultiplier. An additional advantage of the proposed detector is obtained by locating the photon sensors inside the detector, behind the scintillators, which improves the radiation hardness required for space applications. Furthermore, such an arrangement flattens the temperature variation across the detector, providing better gain stability. The main advantage of the proposed detector is an efficient <inline-formula> <tex-math notation="LaTeX">$4\pi $ </tex-math></inline-formula> radiation detection for high-energy gamma rays without the use of heavy collimators.

Influence of operation of thermal and fast reactors of the Beloyarsk NPP on the radioecological situation in the cooling pond. Part 1: Surface water and bottom sediments

The results of radioecological monitoring of the cooling pond Beloyarsk NPP (Russia) have been presented. The influence of waste technological waters of thermal and fast NPP reactors on the content of artificial radionuclides in surface waters and bottom sediments of the Beloyarsk reservoir has been studied. The long-term dynamics of the specific activity of 60Co, 90Sr, 137Cs and 3H in the main components of the freshwater ecosystem at different distances from the source of radionuclide discharge has been estimated. Critical radionuclides (60Co and 137Cs), routes of their entry and periods of maximum discharge of radioisotopes into the cooling pond have been determined. It is shown that the technology of electricity generation at Beloyarsk NPP, based on fast reactors, has a much smaller effect on the flow of artificial radionuclides into the freshwater ecosystem of the reservoir. During the entire period of monitoring studies, the decrease in the specific activity of radionuclides from NPP origin in surface waters was 4.3–74.5 times, in bottom sediments 10–505 times. The maximum discharge of artificial radionuclides into the reservoir was noted during the period of restoration and decontamination work aimed at eliminating emergencies at the AMB thermal reactors of the first stage of the Beloyarsk NPP.

Limiting Wind-Induced Resuspension of Radioactively Contaminated Particles to Enhance First Responder, Early Phase Worker and Public Safety-Part 1.

An accidental radiological release or the operation of a radiological dispersal device (RDD) may lead to the contamination of a large area. Such scenarios may lead to health and safety risks associated with the resuspension of contaminated particles due to aeolian (wind-induced) soil erosion and tracking activities. Stabilization technologies limiting resuspension are therefore needed to avoid spreading contamination and to reduce exposures to first responders and decontamination workers. Resuspension testing was performed on soils from two sites of the Negev Desert following treatment with three different stabilization materials: calcium chloride, magnesium chloride, and saltwater from the Dead Sea in Israel. Two and six weeks post-treatment, resuspension was examined by inducing wind-driven resuspension and quantitatively measuring particle emission from the soils using a boundary-layer wind tunnel system. Experiments were conducted under typical wind velocities of this region. Treating the soils reduced resuspension fluxes of particulate matter < 10 μm () and saltating (sand-sized) particles to around background levels. Resuspension suppression efficiencies from the treated soils were a minimum of 94% for all three stabilizers, and the Dead Sea salt solution yielded 100% efficiency over all wind velocities tested. The impact of the salt solutions (brine) was directly related to the salt treatment rather than the wetting of the soils. Stabilization was still observed six weeks post-treatment, supporting that this technique can effectively limit resuspension for a prolonged duration, allowing sufficient time for decision making and management of further actions.

A brief overview of the registration system of radiation exposure doses for decontamination workers and their occupational health management.

Following the Fukushima nuclear accident in March 2011, decontamination and related works have been carried out over a wide area, mainly in Fukushima Prefecture. In November 2013, the Radiation Dose Registration and Management System for Decontamination Workers was established to manage the occupational exposure doses of workers engaged in such work. The Radiation Effects Association mainly operates the registration system. This paper summarizes existing reports on this system and occupational health issues among decontamination workers. We collected previous reports and related regulatory laws on occupational health management for decontamination workers working in Fukushima Prefecture, summarized the outline of the radiation dose registration and management system for these decontamination workers, and discussed future issues related to their health management. Approximately 100 000 decontamination workers were registered in the system as of 2020, but none showed radiation doses that exceeded the dose limit. To our knowledge, there have been no reports of decontamination workers presenting physical symptoms suspected to be related to radiation exposure. On the other hand, heatstroke countermeasures and anxiety about radiation exposure have been reported as possible issues in the occupational health management of decontamination workers. Although decontamination workers are unlikely to experience biological effects from radiation exposure, epidemiological studies are needed to examine this evidence. Further analysis is also needed on non‐radiation effects, which pose occupational health concerns for decontamination workers. The registration system would allow for tracking decontamination workers, providing data for analyzing radiological and non‐radiological effects.

The economic organization of decommissioning nuclear power plants – an institutional economic analysis with case studies in the US, UK, and Germany

Abstract. The process of decommissioning nuclear power plants (NPP) is a multidisciplinary task that involves technical, regulatory, financial, and organizational activities. In order to fully decommission and subsequently release a reactor from regulatory control, a multitude of tasks need to be realized, i.e., defueling the reactor core, storing spent nuclear fuel, decontamination work, deconstructing conventional buildings, etc. Decommissioning is thus an intricate good that includes the supply of a variety of services, which must be produced upstream or offered in parallel. This paper provides an economic analysis of different options of organizing (or: governing) the decommissioning process, so as to minimize the total costs for society, while of course respecting security standards set by the regulator. The costs of providing decommissioning result from the production and transaction costs. The former are largely determined by technical aspects and development of the decommissioning process, and the possibility of exploiting economies of scale and scope. Transaction costs, on the other hand, mainly result from coordination between the different tasks as well as the involved actors, often private and public actors with different target systems and equipped with different resources. Transaction cost economics (TCE) is used to identify coordination areas and applied to formulate propositions on how nuclear utilities, decommissioning service suppliers, and waste management companies can establish vertical coordination. Transactions in the decommissioning process take place in a regulated environment and are governed, at least partially, by some public actors. In general, market governance is often assumed to be the most efficient governance structure, but in this context, our hypothesis is that institutional constraints, uncertainty, and factor specificity may call for other governance forms (Williamson, 1985). First analyses of the actors and the potential of the decommissioning market suggest an only slowly evolving market with only a few specialized companies and their subsidiaries able to provide technologically demanding services (Seidel and Wealer, 2015; Volk et al., 2019), while small and medium companies are confronted with high barriers to entry into the market (EC, 2018). Nuclear countries have implemented quite different organizational models, varying from specific national decommissioning strategies implemented by a public agency to a relatively free choice of the strategy for plant operators (Wealer et al., 2019). In some countries, procurement laws have been put into place to create a competitive market. However, as the decommissioning market has evolved, challenges to the competitive ideal have arisen, i.e., market concentration and asymmetries of information. This oligopolistic structure combined with the increase in demand for decommissioning services gives rise to concerns regarding the functionality of the market. There are also key logistical issues that must be addressed, including supply chain bottlenecks and procurement strategies. A unified finding is that decommissioning is highly interlinked with nuclear waste management and is also the main source of uncertainty in terms of cost as well as the length of the decommissioning process, as the missing disposal solutions for high-level radioactive waste render it impossible to release the nuclear power plants from regulatory control.

Development of a novel tool for automation of the contamination measurement

Abstract. Considering that about 100 000 m2 of wall area per nuclear facility must be decontaminated (Hübner et al., 2017), the automation of mechanical decontamination work offers high potential to support people in performing their work and reduce errors in the decommissioning process. Furthermore, the exposure potential for people in contaminated environments is reduced and they are protected from health hazards (Petereit et al., 2019). In the ROBDEKON project, a competence center is being established in Germany to develop practical robotic systems for decontamination work in hazardous environments. To this end, four research institutions are working with industrial partners on the development of (partially) autonomous robotic systems for the decommissioning and decontamination of nuclear facilities, the handling of waste, and the remediation of landfills and contaminated sites (Petereit et al., 2019). At the Institute for Technology and Management in Construction (KIT-TMB), the focus is on development of an automated solution for the (clearance) measurement of near-surface contaminations. A mobile elevating working platform is used as the robotic platform with a contamination array as the tool. The array measures the surface activity on the wall areas and verifies compliance with the thresholds. The contamination array is based on two sensor concepts: measurement and localization. Up to four hand-held contamination-measuring devices are attached to the array to parallelize the measurement. In order to avoid damaging the sensitive detector window foil of the contamination probes, the wall surface to be measured is first examined for imperfections with the help of a laser scanner. For localization of the array, up to four laser sensors are used for distance measurements. Measurement results are automatically saved after each measurement in a table specific to the measurement method and are available to users for documentation purposes at any time. In the further course of the project, the measurement results depending on the radiation level will be overlaid with a geometric 3D environment mapping.

Development of an automated milling system for the decontamination of the wall surface in a nuclear power plant

Abstract. Nowadays, concrete decontamination is done by, e.g., grinding, milling, etc., always combined with labor resources. In order to relieve employees from the monotonous and physically stressful decontamination work, a novel milling system for automated surface decontamination has been developed and assembled. The current work presents this new concept for a milling tool that could automatically position itself to the wall surface and subsequently remove surface contamination. A process chain (Fig. 1) defined in the German Federal Ministry of Education and Research (BMBF)-funded project ROBDEKON was introduced first. The chain consists of a total of five steps for a compact process, from environmental exploration to the transportation of waste. This automated decontamination is the third step in the process chain for decontamination of building structures in nuclear facilities. The structure (Fig. 2) of the milling system and the function of each component are then explained in detail. With the assembled sensors, such as a laser distance sensor, a force sensor etc., the various physical quantities can be measured in real time, thus enabling automation of the milling process during decontamination.

Prevalence of non-communicable diseases among healthy male decontamination workers after the Fukushima nuclear disaster in Japan: an observational study

The health status of healthy decontamination workers employed after the Fukushima nuclear disaster remains unclear. This study aimed to evaluate the prevalence of non-communicable diseases among such workers. In this observational study, questionnaires on lifestyle and social factors were administered as part of a health promotion program for decontamination workers in 2016 in Minamisoma City, Fukushima. The questionnaires and health check-up results were compared with those of the 2016 National Health and Nutrition Examination Survey (NHANES) in Japan. Overall, 123 male decontamination workers were enrolled; 93 (75.6%) were drinkers, and 84 (68.3%) were current smokers. The age-adjusted prevalence (95% confidence interval) of hypertension, dyslipidemia, diabetes mellitus, and obesity were 27.2% (20.1–34.4%), 30.4% (22.6–38.2%), 11.3% (5.5–17.1%), and 49.0% (39.0–58.9%), respectively. The age-adjusted prevalence in the NHANES were 32.8% (31.1–34.5%), 16.1% (14.5–17.6%), 7.0% (6.2–7.7%), and 31.2% (29.9–32.5%), respectively. The prevalence of obesity, dyslipidemia, binge drinking, and smoking were higher in healthy male decontamination workers than in the general population. Decontamination workers in disaster-struck areas may have higher risks of developing non-communicable diseases, possibly due to their original health status. Continuous monitoring of their health status and proper interventions are warranted.

Editorial:Narrative‐BasedApproaches in Psychological Research and Practice

Editorial:<scp>Narrative‐Based</scp>Approaches in Psychological Research and Practice