Fukushima Daiichi

This study established specialized radiation dose models to evaluate the internal radiation doses derived from 137 Cs and 134 Cs in fishes in the port of the Fukushima Daiichi Nuclear Power Plant from 2012 to 2023. By August 2018, the activities of 134 Cs and 137 Cs in fishes decreased at the T1/2 of 176 d and 191 d, respectively. The corresponding mass concentrations were far lower than 1 mg/kg and the chemical toxicity can be negligible. Regarding radiotoxicity, 18,000 Bq/kgfresh weight of 134 Cs and 137 Cs in grouper Sebastes schlegelii produced 276 μGy/h of radiation dose, which was below the no-effect-dose-rate benchmarks (400 μGy/h)...

Understanding radioactive Cs contamination has been a central issue at Fukushima Daiichi and other nuclear legacy sites; however, atomic-scale characterization of radioactive Cs in environmental samples has never been achieved. Here we report, for the first time, the direct imaging of radioactive Cs atoms using high-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). In Cs-rich microparticles collected from Japan, we document inclusions that contain 27 - 36 wt% of Cs (reported as Cs2 O) in a zeolite: pollucite...

Collection and cooking of wild vegetables have provided seasonal enjoyments for Japanese local people as provisioning and cultural ecosystem services. However, the Fukushima Daiichi Nuclear Power Plant accident in March 2011 caused extensive radiocesium contamination of wild vegetables. Restrictions on commercial shipments of wild vegetables have been in place for the last 10 years. Some species, including buds of Aralia elata, are currently showing radiocesium concentrations both above and below the Japanese reference level for food (100 Bq/kg), implying that there are factors decreasing and increasing the 137Cs concentration...

The Fukushima Daiichi accident resulted in the release of a novel form of radioactive Cs contamination into the environment, called Cs-bearing microparticles (CsMP). CsMPs constitute a substantial portion of the radioactive pollution near the nuclear power station and traveled beyond several hundred kilometers. Extensive characterization of the CsMPs revealed an amorphous silica matrix, along with Cs and other minor or trace elements such as Fe and Zn. This study explores the unclear generation mechanism of CsMPs by conducting experimental molten core concrete interactions (MCCI) as a source of Si and analyzing the resultant aerosols...

UNLABELLED: A major incident occurred at the Fukushima Daiichi Nuclear Power Station following the tsunami triggered by the Tohoku-Pacific Ocean Earthquake in March 2011, whereby seawater entered the torus room in the basement of the reactor building. Here, we identify and analyze the bacterial communities in the torus room water and several environmental samples. Samples of the torus room water (1 × 109 Bq137 Cs/L) were collected by the Tokyo Electric Power Company Holdings from two sampling points between 30 cm and 1 m from the bottom of the room (TW1) and the bottom layer (TW2)...

BACKGROUND: The Fukushima Daiichi Nuclear Power Plant accident (2011) released large amounts of radioactive substances into the environment and generated highly radioactive debris. Post-accident countermeasures are currently in the phase of fuel debris removal, which requires the analysis of radioactive contaminants in the environment and fuel. The spectra of solely β-emitting nuclides, such as 90 Sr, overlap; thus, an effective method for nuclide separation is desired. Since conventional methods for high-dose sample analysis pose substantial exposure risks and generate large amounts of secondary radioactive waste, faster procedures allowing for decreased radiation emission are highly desirable...

No abstract text is available yet for this article.

Radioactive particles often contain very high radioactivity concentrations and are widespread. They pose a potential risk to human health and the environment. Their detection, quantification, and characterization are crucial if we are to understand their impact. Here, we present the use of a real-time autoradiography gaseous detector (using parallel ionization multiplier) to expedite and improve the accuracy of radioactive particle screening in complex environmental samples. First, standard particles were used to assess the detector capabilities (spatial resolution, spectrometry, and artefact contributions), then, we applied the technique to more complex and environmentally relevant samples...

Removal of fuel debris is planned to start at Unit 2 of the Fukushima Daiichi Nuclear Power Plant. During the removal, it is desirable to distinguish fuel debris from radioactive wastes and to sort the fuel debris accordingly to the amounts of nuclear material contained. Muon scattering tomography invented at Los Alamos in the early 2000s is highly sensitivity to high-atomic-number materials such as uranium. A muon scanner to sort the debris is designed and currently in production. One of the challenges is to operate the muon scanner in the presence of high γ -ray radiations from the debris: muon-event-identification electronics and a muon-tracking algorithm in the presence of high γ -ray radiations were developed...

Radioactive materials were released into the ocean following the Fukushima Daiichi Nuclear Power Plant accident in 2011. Six years after the accident, the radioactive material concentration was markedly increased in the Okhotsk Intermediate Water (OIW) of the Sea of Okhotsk. This material may have been subjected to southward subsurface dispersal by the North Pacific Intermediate Water (NPIW), which originates from the OIW. The spatiotemporal limitations of available methods have made it challenging to track the dispersal paths of radioactive materials in the North Pacific Subpolar region...

OBJECTIVE: This study examined the effectiveness of an intervention program to enhance the self-confidence of kindergarten teachers who address radiation-related health concerns among parents following the Fukushima Daiichi Nuclear Power Plant accident in March 2011, wherein radiation anxiety among mothers with young children was high. Kindergarten teachers are expected to address the concerns of these parents. METHODS: Participants from 2 private kindergartens in Fukushima City were assigned to either the intervention group (n = 10), which received an intervention program comprising lectures, group discussions, and presentations, or the control group (n = 16), which received only written materials used in the intervention program...

In the aftermath of the Fukushima Daiichi Nuclear Power Plant accident, a pioneering large-scale decontamination project was initiated, aiming to enable the return of evacuees. This project, the first of its kind in human history, involved the transportation of soils collected during decontamination to interim storage facilities. Before recycling or disposal, these soils undergo processes like volume reduction. However, there's a need for innovative methods to reduce volume effectively and treat secondary wastes more efficiently...

What is the role of experts and their expertise in the context of trans-science, in which issues that are raised in scientific terms cannot be answered by science alone? This article examines the discourses and practices around safety of low-dose exposure to radiation in the ongoing aftermath of the Fukushima Daiichi Nuclear Power Plant accident in Japan in 2011. Following the nuclear fallout, scientific experts and STS scholars in Japan debated what forms of science communication were adequate to address the situation...

No abstract text is available yet for this article.

The medical situation during disasters often differs from that at usual times. Disasters can lead to significant mortality that can be difficult to monitor. The types of disaster-related deaths are largely unknown. In this study, we conducted a survey to categorize the disaster-related deaths caused by a radiation disaster. A total of 520 people living in Minamisoma City, Fukushima Prefecture, at the time of the Fukushima Daiichi Nuclear Power Plant accident, who were certified to have died due to disaster-related causes were surveyed...

Persistent concerns regarding environmental hazards arise from the difficulty in disposing of radioactive plant-based wastes originating from the nuclear accident at the Fukushima Daiichi Nuclear Power Plant (FNPP) in Japan in 2011. In this study, three anaerobic digestion (AD) strategies were proposed: Sole anaerobic wet fermentation, and wet fermentations with either alkaline-heat or ultrasonic pre-treatment, which were employed for long-term anaerobic treatment of a genuine radioactive grass stemming from the FNPP accident...

This study sought to explore factors related to community transition after the mandatory evacuation of psychiatric inpatients to other hospitals owing to the Fukushima Daiichi Nuclear Power Plant accident. A retrospective cohort design was adopted and 391 psychiatric patients were examined. Univariate and multivariate analyses were conducted to confirm the association between the achievement or non-achievement of discharge to community living and their backgrounds (age, gender, evacuation destination, psychiatric diagnoses, and physical complications)...

Radioactively contaminated soil from the Fukushima Daiichi nuclear power station accident in 2011 is required by law to be finally disposed of outside Fukushima Prefecture by 2045. To gain public acceptance of this policy, it is essential to promote understanding and nationwide discussion. We conducted a web-based survey of 2000 people in Japan to examine public attitudes toward final disposal of the contaminated soil outside Fukushima Prefecture. Results show that policy approval was negatively correlated with perceived risk of a final disposal site, sense of inequity associated with building a final disposal site near residential areas, and values that are absolutely non-negotiable or protected from trade-offs with other values (protected values)...

After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011, the wild boar (Sus scrofa) population within the Fukushima Evacuation Zone (FEZ) increased substantially in size and distribution. This growing population and their potential dispersal from the FEZ, where they are exposed to high levels of radionuclides, into the surrounding landscape underscores the need to better understand boar movement patterns in order to establish policies for managing shipping restrictions for boar meat and develop management strategies...

Wet scavenging was critical in the atmospheric transport of 137 Cs aerosols following the Fukushima accident. The aerosol size diversity and related microphysical processes produce complex behaviors during wet scavenging. Such behaviors are difficult to investigate using traditional simplified size distributions, resulting in inaccurate modeling. This study establishes an improved size-resolved wet scavenging model that considers the activation process. Using this model, five monodisperse simulations with five representative observed diameters with realistic solubility setting are performed to investigate the spatiotemporal wet scavenging behaviors of 137 Cs aerosols...