Daiichi Nuclear Power Plant Accident Research Articles

Cohesive/Adhesive strengths of CsOH-chemisorbed SS304 surfaces

ABSTRACT During the Fukushima Daiichi Nuclear Power Plant (1F) accident, volatile radioactive fission products (FPs) such as Cs-137 were released, which significantly influenced mid- to long-term decommissioning strategies. A substantial amount of the remaining cesium in the pressure vessel may have deposited onto the 304 stainless steel (SS304) steam separators and dryers. This deposited cesium presents a safety hazard during 1F’s decommissioning, as it can generate radioactive dust and complicate waste storage. However, the cohesive and adhesive strengths of CsOH-chemisorbed oxide scales, crucial for understanding the release of cesium-bearing particles from SS304 surfaces, remain undefined. In this study, we explore how CsOH chemisorption affects the cohesive and adhesive strengths between oxide scales and SS304 substrates using a scratch tester. Our tests revealed that cracks formed at approximately the same load, but the overall cohesive strength of the oxide scales decreased following CsOH chemisorption. Furthermore, the transition from cracks to bulk separation occurred more rapidly in CsOH-chemisorbed SS304 substrates, especially those with lower silicon content. Finally, we found that adhesive failure could not be achieved even at 70 N, suggesting that the deposited cesium cannot be completely removed from SS304 during the decommissioning of 1F.

Changes in air dose rates due to soil moisture content in the Fukushima prefecture forests

Radionuclides released and deposited because of the 2011 Fukushima Dai-ichi Nuclear Power Plant accident caused an increase in air dose rates in Fukushima Prefecture forests. Although an increase in air dose rates during rainfall was previously reported, the air dose rates in the Fukushima forests decreased during rainfall. This study aimed to develop a method to estimate rainfall-related changes in air dose rates, even in the absence of soil moisture data, in Namie-Town and Kawauchi-Village, Futaba-gun, Fukushima Prefecture. Moreover, we examined the relationship between preceding rainfall (Rw) and soil moisture content. The air dose rate was estimated by calculating the Rw in Namie-Town from May to July 2020. We found that the air dose rates decreased with increasing soil moisture content. The soil moisture content was estimated from Rw by combining short-term and long-term effective rainfall using half-live values of 2 h and 7 d and considering the hysteresis of water absorption and drainage processes. Furthermore, the soil moisture content and air dose rate estimations showed a good agreement with coefficient of determination (R2) scores >0.70 and >0.65, respectively. The same method was tested to estimate the air dose rates in Kawauchi-Village from May to July 2019. At the Kawauchi site, variation in estimated value is relatively large due to the presence of water repellency in dry conditions, and the amount of 137Cs inventory was low, so estimating air dose from rainfall remained a challenge. In conclusion, rainfall data were successfully used to estimate soil moisture and air dose rates in areas with high 137Cs inventories. This leads to the possibility of removing the influence of rainfall on measured air dose rate data and could contribute to the improvement of methods currently used to estimate the external air dose rates for humans, animals, and terrestrial forest plants.

Effect of soil organic matter on the fate of 137Cs vertical distribution in forest soils

Understanding the fate of the vertical distribution of radiocesium (137Cs) in Japanese forest soils is key to assessing the radioecological consequences of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. The 137Cs behavior in mineral soil is known to be primarily governed by interaction with clay minerals; however, some observations suggest the role of soil organic matter (SOM) in enhancing the mobility of 137Cs. Here we hypothesized that soil organic carbon (SOC) concentration profile determines the ultimate vertical pattern of 137Cs distribution in Japanese forest soils. In testing this hypothesis, we obtained soil samples that were collected before the FDNPP accident at four forest sites with varying SOC concentration profiles and quantified the detailed vertical profile of 137Cs inventory in the soils roughly half a century after global fallout in the early 1960 s. Results showed that the higher the SOC concentration in the soil profile, the deeper the 137Cs downward penetration. On the basis of the data for surface soils (0–10 cm), the 137Cs retention ratio for each of the 2-cm thick layers was evaluated as the ratio of 137Cs inventory in the target soil layer to the total 137Cs inventory in and below the soil layer. A negative correlation was found between the ratio and SOC concentration of the layer across all soils and depths. This indicates that the ultimate fate of 137Cs vertical distribution can be predicted as a function of SOC concentration for Japanese forest soils, and provides further evidence for SOM effects on the mobility and bioavailability of 137Cs in soils.

Radiocesium-bearing microparticles discovered on masks worn during indoor cleaning

A decade has passed since the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident on March 11, 2011. However, radioactive particles have recently been detected in the indoor air of some residences near the FDNPP. Following the recommendations of previous research, we determined the presence of radiocesium-bearing microparticles (CsMPs) and measured the radioactivity of radiocesium that adhered on non-woven face masks worn by six persons during the indoor cleaning of 59 residences in Namie, Futaba, Okuma, and Tomioka towns in Fukushima Prefecture. Of the 284 masks worn in this study, significant 137Cs radioactivity was detected in 268, and 44 new CsMPs were discovered in 28. The results of this study also suggest the presence of highly concentrated soluble radiocesium particles or soluble radioactive cesium aerosols adhered to house dust. This implies that the CsMPs constituted a large proportion of radioactivity in the indoor air contamination for particles in the 1.0–2.5 µm size range due to the radioactive radiocesium particles. It is desirable to wear masks during cleaning to prevent inhalation of CsMPs.

Local atmospheric transport behaviors of representative radionuclides during the Fukushima accident: A 200-m-resolution cross-scale study from site to 20 km

Modeling of local atmospheric radionuclide transport is essential for nuclear emergency response. However, very few studies of the Fukushima Dai-ichi nuclear power plant (FDNPP) accident have focused on this topic because of the complex meteorology and the cross-scale transport behaviors from the site to 20 km of the FDNPP. In this study, both the local meteorology and transport behaviors were investigated at high resolution (200 m) using ensembles of different meteorology and models. Four wind fields calculated from onsite observations and three regional-scale meteorological fields (i.e., the 1-km ECMWF, 3-km and 1-km NHM-LETKF), and two transport models: the RIMPUFF Lagrangian puff model and the SPRAY particle model were considered and combined with each other. These eight simulations and their ensemble mean were analyzed based on onsite observations of wind and gamma dose rates, and local-scale observations of 137Cs concentration. Results revealed that at the site, the Onsite wind field which captured the frequently changing wind, best reproduced the onsite gamma dose rates with the grid resolution of 200 m. At the local scale (up to 20 km), the observations present a smoother temporal change. The wind fields assimilated with Japanese domestic observations presented advantageous performance, and the 1-km NHM-LETKF achieved the best score of the factor of 5 metric of 0.49 for the simulated 137Cs concentration. The SPRAY coupled with the three-dimensional (3D) convolution method and RIMPUFF showed better performance in simulating the onsite gamma dose rate and the local-scale concentration, respectively. The ensemble mean achieved robust metrics, better simulated the baseline of onsite gamma dose rates, and reproduced more peaks of local-scale concentration at the expense of peak value deviation.

Sensitivity Analysis of Effectiveness of FLEX Strategies Using a CDF-Based Importance Measure Under Accident Conditions

One of the lessons learned from the Fukushima Daiichi nuclear power plant (NPP) accident is strengthening the station blackout (SBO) mitigation capabilities by enhancing defense in depth for all existing and new NPPs. One of the possible remedies is diverse and flexible coping strategies (FLEX). The objective of this study is to address the benefits of FLEX in various accident scenarios in terms of both risk and cost. FLEX was originally devised against SBO accidents. In this research, we investigate the fundamental plant responses against accidents considering two fundamentally different cases: accidents that lead to high pressure on the primary side and accidents that lead to low pressure on the primary side. Several uncertainties are associated with the characteristics of the FLEX portable equipment. Specifically, the time for FLEX deployment may depend on several factors such as type of accident, point of injection, availability of safety systems, battery backup timings, and human actions. This study utilizes a dynamic risk assessment framework to analyze accident scenarios and suggests a novel importance measure, which is a cumulative distribution function–based importance metric that characterizes the influence of input distribution on complete output distribution. The importance of the existing and newly developed FLEX strategy based on risk significance is illustrated with examples. The suggested measure provides clear insight into how FLEX affects risk of the whole system and additional risk margins thanks to new safety systems.

Radiocesium mobility in different parts of the two major tree species in Fukushima

Radiocesium (137Cs) released in the Fukushima Dai-ichi Nuclear Power Plant accident is still cycling in the forest ecosystem. We examined the mobility of 137Cs in the external parts—leaves/needles, branches, and bark—of the two major tree species in Fukushima, Japanese cedar (Cryptomeria japonica) and konara oak (Quercus serrata). This variable mobility will likely lead to spatial heterogeneity of 137Cs and difficulty in predicting its dynamics for decades. We conducted leaching experiments on these samples by using ultrapure water and ammonium acetate. In Japanese cedar, the 137Cs percentage leached from current-year needles was 26–45% (ultrapure water) and 27–60% (ammonium acetate)—similar to those from old needles and branches. In konara oak, the 137Cs percentage leached from leaves was 47–72% (ultrapure water) and 70–100% (ammonium acetate)—comparable to those from current-year and old branches. Relatively poor 137Cs mobility was observed in the outer bark of Japanese cedar and in organic layer samples from both species. Comparison of the results from corresponding parts revealed greater 137Cs mobility in konara oak than in Japanese cedar. We suggest that more active cycling of 137Cs occurs in konara oak.

The rule of law: A fragile tool for the development of emerging nuclear technologies

Before the Fukushima Daiichi Nuclear Power Plant accident in Japan in 2011, the nuclear industry had strongly promoted the idea that the time of nuclear renaissance had come after a long, fallow period in the wake of the nuclear accidents at Three Mile Island (1979) and Chernobyl (1986). During the post-Fukushima period, there were few new projects, but growing demand for energy and anxieties raised by climate change have brought us to a turning point. Despite the Fukushima accident, which led to some nuclear projects being delayed or cancelled, there is still a great deal of interest in the use of nuclear power for civil purposes. This is primarily because, as the International Energy Agency’s (IEA) Executive Director Fatih Birol has rightly pointed out: “Without an important contribution from nuclear power, the global energy transition will be that much harder.”1 In this regard, in 2010, 67 reactors were under construction, 120 planned and 441 in operation.2 In 2022, 11 years after the Fukushima Daiichi accident, there were 60 under construction, 104 planned and 338 proposed.3 The International Atomic Energy Agency (IAEA) estimates that nuclear electric power capacity will have increased by as much as 23% by 2030 and more than doubled by 2050.4 In addition to this renewed interest, many projects are now in development, opening up new prospects for the use of the atom for civil purposes. Nuclear fusion, small modular reactors (SMRs), the use of artificial intelligence, floating, underwater and space reactors, and nuclear batteries, to name but a few of the projects on the table, lead us to think that the “nuclear renaissance” is slowly shifting to a “nuclear spring”. In this view, where the concept of a renaissance involves new impetus for nuclear energy, with the construction of new facilities, the concept of “spring” refers to a determination to break with nuclear traditions, in terms of concepts, means and players. Consequently, this phenomenon calls for new legal rules which, in some cases, have already started to be debated.

Dynamics of suspended and dissolved radiocaesium in a small irrigation pond based on vertical water quality profiles

Following the Fukushima Daiichi Nuclear Power Plant accident, extensive research has been conducted on the dynamic distribution of radiocaesium in large reservoirs. However, studies on small ponds, particularly those used for rice cultivation, are limited. This study analyzed the vertical water quality profiles, including the bioavailable Caesium-137 (137Cs) in an irrigation small pond classified as discontinuous cold polymictic based on water mixing type, and subjected to a high (2.0 MBq m−2) deposition of 137Cs and evaluated their potential risk associated with agricultural use. During 2014–2015, the suspended and dissolved concentrations of 137Cs in the pond water ranged from 0.10 to 7.7 Bq L−1 and 0.03–0.88 Bq L−1, respectively. The elution of dissolved 137Cs from the bottom sediment occurred only during the summer when the water temperature exceeded 15 °C, NH4+ increased, and dissolved oxygen decreased. Except during flood inflow mixing events, the activity concentration of dissolved 137Cs in the bottom layer did not increase in the surface layer at depths ≤ 1.0 m. In a 3 m shallow pond without a well-defined thermocline, a gradual density stratification primarily occurred in the lower layer during summer, limiting the transport of dissolved 137Cs from the bottom to the surface layer. About 5 % of 137Cs in the suspended solids and bottom sediment are exchangeable, indicating the mica-rich soils and geological conditions with a high fixation capacity of 137Cs reduce the risk of 137Cs elution. Even after three to four years of considerable depositions, the risk of radiocaesium absorption by paddy rice and subsequent increase in radiocaesium concentration in brown rice was negligible as long as the surface water of the pond was used for agriculture.

Soil dust and bioaerosols as potential sources for resuspended 137Cs occurring near the Fukushima Dai-ichi nuclear power plant

One of the current pathways to radiation exposure, caused by the radionuclides discharged during the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, is the inhalation of resuspended 137Cs present in the air. Although wind-induced soil particle resuspension is recognized as a primary resuspension mechanism, studies regarding the aftermath of the FDNPP accident have suggested that bioaerosols can also be a potential source of atmospheric 137Cs in rural areas, although the quantitative impact on the atmospheric 137Cs concentration is still largely unknown. We propose a model for simulating the 137Cs resuspension as soil particles and bioaerosols in the form of fungal spores, which are regarded as a potential candidate for the source of 137Cs-bearing bioaerosol emission into the air. We apply the model to the difficult-to-return zone (DRZ) near the FDNPP to characterize the relative importance of the two resuspension mechanisms. Our model calculations show that soil particle resuspension is responsible for the surface-air 137Cs observed during winter–spring but could not account for the higher 137Cs concentrations observed in summer–autumn. Higher 137Cs concentrations are reproduced by the emission of 137Cs-bearing bioaerosols (fungal spores) that replenishes the low-level soil particle resuspension in summer–autumn. Our model results show that the accumulation of 137Cs in fungal spores and large emissions of spores characteristic of the rural environment are likely responsible for the presence of biogenic 137Cs in the air, although the former must be experimentally validated. These findings provide vital information for the assessment of the atmospheric 137Cs concentration in the DRZ, as applying the resuspension factor (m−1) from urban areas, where soil particle resuspension would dominate, can lead to a biased estimate of the surface-air 137Cs concentration. Moreover, the influence of bioaerosol 137Cs on the atmospheric 137Cs concentration would last longer, because undecontaminated forests commonly exist within the DRZ.

Subarctic-scale transport of 134Cs to ocean surface off northeastern Japan in 2020

We studied the spatiotemporal variations in 134Cs, 137Cs, and 228Ra concentrations at the sea surface off southeastern Hokkaido, Japan (off-Doto region) from 2018 to 2022 using low-background γ-spectrometry. The 134Cs concentrations in the off-Doto region, decay-corrected to the date of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, exhibited wide lateral variation each year (e.g., 0.7–1.1 mBq/L in 2020). By studying the 228Ra concentrations and salinity, this variation was explained based on the current mixing patterns. Furthermore, the 134Cs concentrations in the waters highly affected by the Oyashio Current (OYC) gradually increased from 2018 to 2020, and subsequently decreased in 2022. This implies that the water mass maximally contaminated with 134Cs was transported back to the side of the Japanese islands 10 years after the FDNPP accident along with counter-clockwise currents (e.g., the OYC) in the northern North Pacific Ocean. The 134Cs concentrations in the OYC-affected waters in the off-Doto region in 2020 were ~ 1/6 times those in the 134Cs-enriched core of waters off the western American Coast in 2015, which can be ascribed to dilution via spatial dispersion during subarctic current circulation. Overall, we elucidated the ocean-scale subarctic current systems in the northwestern North Pacific Ocean, including water circulation timespans.

Alteration of the Cesium-137 soil profile by wild boar rooting after the Fukushima Daiichi Nuclear Power Plant accident

Large amounts of Cesium-137 (137Cs, physical half-life ca. 30 years) were released into the environment from the 2011 Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in Japan. Initially contaminants from the accident were deposited on the surface soil layers in terrestrial ecosystems, but over time vertical migration of 137Cs has occurred, with most 137Cs now distributed a few centimeters below the soil surface. Wild boar (Sus scrofa) rooting likely alters the distribution of contaminants in soil profiles. Such impacts may be particularly pronounced in areas contaminated from the FDNPP accident, given the increase in abundance of wild boar in these areas. Our objective was to determine whether rooting by wild boar alters the distribution of 137Cs contamination within soil profiles through collection of soil cores from control sites and two different types of rooting samples, “new depressions” and “old depressions” within the difficult-to-return zone surrounding the FDNPP. The 137Cs ratio [activity concentration of 137Cs at each depth / the maximum activity concentration of 137Cs in each core sample] rapidly decreased after reaching a peak at the control sites. However, the 137Cs ratio at all rooted sites decreased more slowly, and 137Cs was distributed deeper into the soil layers than control sites, across both new and old rooting sites. Moreover, the 137Cs soil profiles varied greatly among core samples and sampling sites. These results demonstrate that soil disturbance from wild boar rooting can directly influence the distribution of contaminants within soil profiles. However, the extent to which deeper layers are affected by contamination depends on the unique characteristics (i.e., depth of rooting) of each wild boar rooting disturbance. Further studies are needed to examine the effects of long-term rooting on the alteration of 137Cs in soil profiles.

Bioaccumulation and risk assessment of radiocesium in the Northwest Pacific Ocean from Fukushima Dai-ichi Nuclear Power Plant accident

To understand which biota are more exposed to radionuclides, the bioaccumulation and risk assessment of radiocesium (137Cs and 134Cs) release from FDNPP in the Northwest Pacific Ocean were analyzed using ERICA tools. The activity level was determined by the Japanese Nuclear Regulatory Authority (RNA) in 2013. The data were used as input to the ERICA Tool modeling software to evaluate the accumulation and dose of marine organisms. The highest and lowest accumulate concentration rate were observed in birds (4.78E+02 Bq kg−1/Bq L−1) and the Vascular plant (1.04E+01 Bq kg−1/Bq L−1), respectively. The total dose rate range for the 137Cs and 134Cs ranged between 7.39E−04 and 2.65E+00 μGy h−1 and 4.24E−05 and 2.91E−01 μGy h−1, respectively. There is no considerable risk to the marine biota in the research region since the cumulative dose rates of radiocesium to the chosen species were all less than 10 μGy h−1.

DOSE ESTIMATION TO WILD MEDAKA AROUND FUKUSHIMA DAI-ICHI NUCLEAR POWER PLANT.

More than 10y have passed since the Fukushima Dai-ichi Nuclear Power Plant (F1-NPP) accident, but there are still many areas with high levels of radioactive contamination, especially reservoirs and lakes, where the levels decrease slowly. The exposed dose to non-human biota is of great concern. In this work, the exposure dose to wild medaka (small aquarium fish) around F1-NPP was measured/estimated by two approaches: in situ measurement and with the ERICA assessment tool. S2 is a reservoir located 7.5km from F1-NPP, and the ambient dose rate was 25.0μSv per h in 2012, but decreased to 4.82μSv per h in 2021. The external exposure dose rate to wild medaka living there was 0.8-11.8 μGy per h (2017-21) by in situ measurement, and the estimated dose rate with the ERICA assessment tool was 0.6-54.5 μGy per h (2012-21). The estimated and measured doses to wild medaka are not expected to cause any significant radiation effects.

Frequency of visits to Tomioka town and related factors among evacuees more than a decade after the Fukushima Daiichi Nuclear Power Plant accident.

This study aimed to clarify the frequency of visits (FOV) to Tomioka town, Japan, and related factors among evacuees more than a decade after the Fukushima Daiichi Nuclear Power Plant accident. A questionnaire survey was conducted on residents (age ≥ 18years) who had residence cards in August 2021. Of the 2260 respondents, the FOV to Tomioka was as follows: 926 (41.0%) more than twice a year (Group 1 [G1]), 841 (37.2%) once a year (G2) and 493 (21.8%) no visits (G3). About 70% of the respondents who had decided not to return to Tomioka visited once a year or more. No significant differences in the FOV or radiation risk perception were found between groups. Multinomial logistic regression analysis using G3 as a reference revealed independent associations between living inside Fukushima in G1 (odds ratio [OR] = 5.4, 95% confidence interval [CI]: 4.1-7.3; P < 0.01) and G2 (OR = 2.3, 95% CI: 1.8-3.0, P < 0.01), undecided about returning in G1 (OR = 2.5, 95% CI: 1.9-3.3, P < 0.01), females in G1 (OR = 2.0, 95% CI: 1.6-2.6, P < 0.01) and motivation to learn more about tritiated water in G2 (OR = 1.8, 95% CI: 1.3-2.4, P < 0.01). Overall, 80% of the residents had visited Tomioka within a decade after the accident. These findings suggest the need to continue the effective dissemination of information about the effects of a nuclear accident and the subsequent decommissioning process to evacuees after evacuation orders have been lifted.

Rapid Environmental Mapping with Instrumented Unmanned Aerial Vehicle: Experience and Lessons Learned from the Commissioning and Trial Measurements in the Areas Affected by TEPCO Fukushima Daiichi Nuclear Power Plant Accident

Rapid Environmental Mapping with Instrumented Unmanned Aerial Vehicle: Experience and Lessons Learned from the Commissioning and Trial Measurements in the Areas Affected by TEPCO Fukushima Daiichi Nuclear Power Plant Accident

Impact of lifting the mandatory evacuation order after the Fukushima Daiichi Nuclear Power Plant accident on the emergency medical system: a retrospective observational study at Minamisoma City with machine learning analysis

ObjectivesThis study aimed to identify factors that delayed emergency medical services (EMS) in evacuation order zones after the 2011 Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant accident...

Thermophysical and mechanical properties of LaB6 and CeB6 synthesized through spark plasma sintering

ABSTRACT Following the Fukushima Daiichi nuclear power plant accident in 2011, the development of accident tolerant fuels (ATFs) has become an integral part of the promotion of nuclear safety. Of the many design criteria, a high thermal conductivity reduces a fuel pellet’s peak temperature and radial temperature gradient. Although various uranium borides such as UB2 and UB4 are promising ATFs that have high-temperature stability, high uranium density, and good thermal conductivity, little is known about UB6, as it has yet to be fabricated under normal conditions. As a metal hexaboride, UB6 may have excellent electrical conductivity, likely giving it a much higher thermal conductivity than that of UO2. In this work, we investigate the thermophysical and mechanical properties of non-radioactive LaB6 and CeB6 to estimate the potential properties of UB6, as it has yet to be successfully fabricated. The thermophysical properties of UB6 are compared with those of UO2, UB2, and UB4 to help clarify whether future attempts at fabricating UB6 under high pressure or with other dopants are worthwhile for the development of ATFs.

Long-Term Analysis of Internal Exposure Dose-Reduction Effects by Food Regulation and Food Item Contribution to Dose after the Fukushima Daiichi Nuclear Power Plant Accident.

Over 10 years have passed since the Fukushima Daiichi Nuclear Power Plant accident. This study verifies the efficacy of longitudinal regulation on internal exposure doses and analyzes food group contributions to radiation doses using accumulated monitoring test results. The committed effective doses in 10,000 virtual persons from fiscal year (FY) 2012 to 2021, with and without regulation, were estimated as products of radioactivity concentrations randomly sampled from the test results, food intake, and dose coefficient. The distributed values of food intake rather than a mean value in dose estimation were assumed to reflect food intake variations and avoid underestimation of internal exposure doses for high-intake consumers. Furthermore, the ingestion of radioactive cesium from the calculation was analyzed per food group. The 95th percentile of the internal exposure dose (the dose of a "representative person") was less than 1 mSv/year in both FYs. The regulation effect was substantial in FY 2012, and no noticeable difference in radiation doses was found between the regulation and no regulation conditions after FY 2016. Internal exposure doses decreased until approximately FY 2016 and then remained constant. It was also shown that not only radioactivity concentration but also food intake is a major factor affecting cesium intake. In summary, it was confirmed that Japan had ensured food safety regarding radioactive materials.

DOIENVRAD: A database of environmental radioactivity at TEPCO’s Fukushima Dai-ichi Nuclear Power Plant Accident and associated bibliography

A database of artificial radioactivity derived from the Tokyo Electric Power Company’s Fukushima Dai-ichi Nuclear Power Plant accident in March 2011 and of related research articles was established. The database was named as DOIENVRAD. We have already published 58 datasets, in which total number of records is 2.5 million. The database site also allows researchers to search the published datasets and retrieve raw data by specifying time, latitude, longitude, altitude/depth, radionuclide name and sample type. Newly 1.8 million records are subjected to retrieval at this moment and all published data together with already published data will be included for retrieval.