Tritium uptake in crops in the area with a high level of atmospheric tritium oxide in the territory of the former Semipalatinsk test site.

During the period from 2019 to 2021, a series of experiments were carried out to study the uptake of tritium by crops in an area heavily contaminated with atmospheric tritium oxide (HTO), at the former Semipalatinsk test site in Kazakhstan. A quantitative assessment is given of the tritium uptake by typical crops (lettuce, tomatoes, peppers and beans) cultivated all over Kazakhstan in the case of a short-term tritium oxide vapor exposure. The plant samples were collected during and after exposure and analyzed for the tritium concentration in two chemical forms: tissue-free water tritium (TFWT) and organically bound tritium (OBT). During the entire series of experiments, the tritium concentration in free water from leaves and ambient air was of the same order of magnitude. The tissue water tritium concentrations of stems and edible parts was 1 to 2 orders of magnitude lower than in the surrounding air. The average value of the TFWT/HTOatm ratio in the leaves and the edible part was (0.73±0.2) and (0.04±0.002), respectively. The organically-bound tritium concentration is 1-2 orders of magnitude lower than the tissue water tritium and ambient air concentrations. Under aerial tritium oxide uptake, the distribution of tritium in non-leafy crops was as follows: leaf-stem-fruit (in decreasing order). After exposure, a non-significant amount of tritium is firmly retained in plants for a long time. The tissue water tritium concentrations correlate closely with atmospheric tritium oxid (r = 0.76), correlate weakly with temperature (r = 0.43) and relative humidity (r = -0.43), and correlate moderately with solar radiation intensity (r = 0.56). There was no reliable correlation between the concentration of tritium in organic matter and in ambient air. The concentration of tritium in the free water of leaves is closely correlated with the concentration in the free water of the stems (r = 0.95) and fruits (r = 0.78). The organically-bound tritium concentration in leaves is closely correlated with the organically-bound tritium concentration in stems (r = 0.99) and fruits (r = 98). The results of the study should be considered when evaluating the impact of tritium oxide emissions on the population living near nuclear power.

Validating the application of the revised ICRP's biokinetic models for organic14C and organically bound tritium to members of the public.

In 2016, the International Commission on Radiological Protection (ICRP) has revised the biokinetic models for carbon and tritium in Publication 134 to calculate the dose coefficients of these radionuclides for workers. The following publication for members of the public is now in the process of revising by the ICRP. According to the draft manuscript published for consultation in 2023, the same models will be adopted for members of the public, although the parameters in these models are not corroborated by the metabolic data of radionuclides in foods. Dose coefficients for adult were estimated using modified models developed in this study to validate the application of the revised ICRP models to members of the public. In the modified models, several parameters were replaced based on the metabolic data of these nuclides in foods and compartments of radio-insensitive tissues were introduced. For these estimations, we utilised an inhouse program for internal-dose calculation developed by the Japan Atomic Energy Agency. The estimated dose coefficient values for ingestion of organic14C and organically bound tritium (OBT) ranged from 3.2 × 10-11-7.6 × 10-11Sv Bq-1and from 3.5 × 10-11-5.4 × 10-11Sv Bq-1, respectively. We concluded that the dose coefficient value of 1.6 × 10-10Sv Bq-1obtained by the revised ICRP's carbon model was conservative for members of the public, while the value of 5.1 × 10-11Sv Bq-1for OBT was appropriate.

Radioecological characteristics of Siberian roe deer (Capreolus pygargus Pal., 1771) inhabiting locations of nuclear weapon tests.

This paper reports the activity concentrations of 137Cs, 90Sr, 239+240Pu, 241Am, and 3Н in the form of tritiated water (НТО) and organically bound tritium (ОBТ) in the tissues and organs of roe deer (Capreolus pygargus Pal., 1771) that inhabit the 'Degelen' test location of the Semipalatinsk Test Site. Tissues and organs were sampled from six deer by killing. The activity concentrations of specific radionuclides in the samples were measured using γ-, α-, and ß-spectrometry. The radionuclide activity concentrations in the tissues and organs showed considerable variation, for example, 0.6-170 Bq kg-1 for 137Cs and 0.3-2.8×103 Bq kg-1 for 90Sr. The activity concentrations of radionuclides in animal muscular tissue did not exceed permissible values for the meat of wild animals. The tissues and organs in the roe deer were arranged as follows in descending order of their ability to accumulate 137Cs and 90Sr: for 137Cs, muscular tissue-kidneys-lungs-spleen-heart-liver-bone tissue; for 90Sr, bone tissue-liver-lungs-muscular tissue-spleen-heart-kidneys. The activity concentrations of 241Am and 239+240Pu did not exceed the minimum detectable activity. Therefore, no quantitative values could be determined for 241Am, and the 239+240Pu activity concentration could be derived for only one sample: 0.5±0.1 Bq kg-1 (liver). The distribution pattern of these radionuclides in the tissues and organs of the roe deer could not be determined because of insufficient data. The HTO volumetric activity in the tissues and organs of the examined animals ranged from 2.6×10-2 to 77 kBq l-1; activity concentration of OBT, 3.0×10-2 to 16 kBq kg-1; and OBT-to-HTO ratios, 2.0×10-3 to 5.3×102. This ratio can serve as an indicator of how long the examined animals stay in radioactively contaminated ecosystems. Within the 'Degelen' site, the activity concentrations of 90Sr and tritium, in the form of HTO and OBT, are expected to be high in the bone tissues, soft tissues, and organs, respectively.

Assessment of environmental impacts from authorized discharges of tritiated water from the Fukushima site to coastal and offshore regions.

In August 2023, the long-planned discharging of radioactive wastewater from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) started after the confirmation of its feasibility and safety. As this water contains elevated amounts of tritium even after being diluted, a lot of resources have been invested in the monitoring of the Fukushima coastal region where the discharge outlet is located. We compare the first 3H surface activity concentrations from these measurements (up to the end of November 2023) with the available background values to evaluate a possible impact of the long-term discharging on humans and environmental levels of the radionuclide of interest in the same or nearby area. From our results, we can conclude that the joint effect of horizontal and vertical mixing has been significant enough to reduce tritium concentrations at the monitored locations in the region close to the FDNPP port two days after the end of the respective phase of the discharging beyond the detection limit of the applied analytical methods (∼0.3 Bq L-1) which is by five orders of magnitude lower than safety limit for drinking water set by the World Health Organization (WHO). Moreover, the distant correlation analysis showed that tritium concentrations at stations located further than 1.4 km were very close to pre-discharge levels (∼0.4 Bq L-1). We also estimated that the 3H activity concentration in the offshore Fukushima region would be elevated by 0.01 Bq L-1 at maximum over a year of continuous discharging, which is in concordance with the already published modeling papers and much less than the impact of the FDNPP accident in 2011.

Tissue-free water tritium and non-exchangeable organically bound tritium concentrations in fish near coastline during and after operation of Japan's first nuclear fuel reprocessing facility.

The risks from radioactive wastewater release from nuclear facilities into the ocean are a global concern. Radioactive contaminants, such as tritium (3H), in both forms of tissue free water tritium (TFWT) and non-exchangeable organically bound tritium (NE-OBT), can be incorporated into marine biota and cause radiation doses to biota and future consumers. However, no studies have been conducted to measure both forms of 3H in marine fish as well as evaluate the residence time in the vicinity of a nuclear fuel reprocessing facility. Here, fish from a brackish lake and from the Pacific Ocean coastline of Japan, which are near such a facility, were collected between 2006 and 2021. The reprocessing facility was operational between 2006 and 2009, during which time about 300 times more tritiated water was discharged per year into the ocean compared to the period when the facility was not operational. During operation the annual release was 30 times higher than the treated water released annually from Fukushima Daiichi. As expected, TFWT and NE-OBT concentrations increased in marine fish during operations and had peak values of 3.59 ± 0.03 and 0.56 ± 0.03 Bq/L, respectively. Total dose rates to the fish were 36,000 times lower than the 10 µGy h-1 benchmark. Concentrations gradually decreased to pre-operational levels as the facility was turned off with NE-OBT taking twice as long. Fish sampled from the brackish lake tended to have more incorporated TFWT and NE-OBT concentrations than ocean fish. This indicates that ocean tides might have contributed to the accumulation of discharged tritiated water in the lake via a narrow water channel, which highlights the importance of examining all marine ecosystems in future operations. In both marine environments, the estimated committed effective dose using the highest observed data through ingestion was well below public limits (91,000 times lower).

Optimization of a new liquid scintillation spectrometer for the measurement of environmental levels of 3H in water samples.

The activity concentration of 3H in water samples collected from places unaffected by nuclear activities or for human consumption can be very low. In these cases, determination procedures must achieve a Minimum Detectable Activity (MDA) low enough to ensure that 3H is accurately determined. In this paper, we present a method that uses a new Liquid Scintillation Spectrometer (LSC in what follows): the Quantulus GCT 6220. Furthermore, a new liquid scintillation cocktail, the ProSafe LT+, has been tested for 3H measurement, showing to be a good option for the determination of low levels of this radionuclide. The MDAs achieved are low enough to enable the measurement of very low levels of 3H in recent environmental water. The results obtained using a Quantulus GCT 6220 and Prosafe LT + are compared to those obtained with a Quantulus 1220 and Prosafe HC + as liquid scintillation cocktail.

Identification of tritium-contaminated areas using a tritium survey on the snow cover, the case of Semipalatinsk test site.

The article presents research findings on the content of tritium in the snow cover of test locations 'Balapan' and 'Sary-Uzen' in the territory of the Semipalatinsk Test Site. Based upon results, a number of tritium-contaminated areas were revealed. At the 'Balapan' site, elevated tritium concentrations in the snow were revealed in the vicinity of the 'Atomic lake' close to the 'Karazhyra' deposit and at the location of Lake 'Kishkensor'. At the 'Sary-Uzen' site, elevated tritium concentrations in the snow were discovered near borehole 101, at object 'Lazurite' and at an unnamed creek outflowing from the mountain range. Maximal of tritium activity concentration in the snow were 45 Bq/kg and 36 Bq/kg at the 'Balapan' and 'Sary-Uzen' sites, respectively. Background tritium concentrations in the snow cover of the STS territory were found to be 4.6-12 Bq/kg.

Interlaboratory comparison exercises for organically-bound tritium in the development of reference materials of environmental samples.

The complex behavior of tritium and the probability of increasing tritium concentrations released in the environment were the promotors for the research and development of laboratory methods that enable to accurately determine the various forms of tritium including organically-bound tritium (OBT) for public and regulatory assurance. The measurement of tritium is a key step for dose and risk assessment. The Cernavoda Nuclear Power Plant (NPP) in Romania improved preparation methods and tested environmental matrices for OBT analysis through intercomparison exercises. This paper describes the international Organically-Bound Tritium (OBT) intercomparison exercise, organized by the Cernavoda Nuclear Power Plant (NPP) in 2019-2020, using fruit sample (quince) from Cernavoda town. Evaluation of the results from the participating laboratories was performed using both robust analysis (Algorithm A) method described in the ISO 13528:2015 standard and ANOVA method. The results obtained are encouraging as an increased number of participating laboratories did not change the observed dispersion of the results for activity concentration level around 50 Bq/L of combustion water. The stability of the remaining sample will be checked in time to investigate its use as a reference material for OBT analysis at the environmental levels.

Estimation of accumulation potential for tritium in olive flounder on exposure of treated water derived from Fukushima Daiichi Nuclear Power Station: Tritium transfer from seawater and food chain into organically bound tritium in the targeted fish.

This study estimated the accumulation potential of tritium, a major radionuclide released from the Fukushima Daiichi Nuclear Power Station (FDNPS), into the olive flounder as organically bound tritium (OBT) using a computer simulation model. In this estimation, two transfer pathways into the OBT were assumed: formation from tritiated water (HTO) in the tricarboxylic acid (TCA) cycle, and ingestion of OBT through the food chain (from phytoplankton, small fish, to the flounder). The food chain structure was reconstructed based on fish growth model. The OBT concentration in the flounder was estimated on three scenarios: Tritium was supplied to the flounder as only HTO in seawater (Scenario 1), as HTO in seawater and OBT formed from HTO in the small fish (Scenario 2), and as HTO in seawater and OBT accumulated in the small fish through the formation and ingestion of OBT in phytoplankton (Scenario 3). The estimated OBT concentrations in the flounder were in the following order: Scenario 3 > 2 > 1. The ratio of the estimated concentration in Scenario 1 to that in Scenario 3 reached a certain value (66 % after a year from the start of HTO exposure), indicating that the tritium transfer from the seawater into the flounder more significantly contributed to this concentration than ingestions of the small fish and the phytoplankton. Additionally, the difference between the estimations of Scenarios 1 and 2 is significantly larger than that between Scenarios 2 and 3. This suggests that phytoplankton contributed weakly to the OBT concentration in the flounder compared to the small fish.

Development of methodology for identification and assessment of ecosystems with an underground source of tritium.

The article considers the issues of working out the suitable approaches for identifying zones with the presence of underground near-surface waters with increased concentrations of tritium discharged into a surface reservoir. The following methods were used as possible methods: determination of tritium content in snow cover, determination of tritium content in vegetation in the form of tritium of free water and organically bound tritium, determination of tritium content in river water and coastal vegetation. The studies were carried out at a previously identified site where groundwater with a tritium concentration of up to 6000 Bq/l is present, located in the vicinity of the city of Obninsk (Kaluga region, Russia). As a result of the conducted research, it was concluded that the analysis of the distribution of tritium in vegetation is an excellent methodological technique for identifying areas of location of near-surface underground waters contaminated with tritium. As a control parameter, both the concentration of tritium in the free water of plants and the content of organically bound tritium can be used. To detect underground tritium contamination the most promising use is the following indicator - the content of OBT in the shoots of woody plants. This parameter is very informative, and the sampling procedure for its determination has no seasonal restrictions, unlike such parameters as the content of tritium in grass and leaves, the content of tritium in snow cover, surface waters, which are preferably collected only in summer or winter. It should be noted that the control of surface waters of the groundwater discharge zone may not be a sufficiently informative indicator for identifying areas of polluted water inflow, since it depends on the ratio of the volumes of leaking polluted groundwater and the annual flow of the watercourse.

Evaluation of Deuterium Oxide Deposition Velocity over a Forest Environment.

ABSTRACT: Field experiments were performed to evaluate the deposition velocity of tritium oxide within a forest environment at the Savannah River Site near Aiken, SC. Field releases were designed to guide selection of deposition velocity values for use in safety-basis modeling. Six releases of deuterium oxide were conducted in 2020 and 2021 with corresponding air samples during and following each release. Samples were analyzed to determine the deuterium-to-hydrogen ratio in water and converted to concentrations of deuterium in the air during the experiment. Measurements were compared to prior model simulations to evaluate model performance and deposition velocity estimates. Field releases demonstrated vertical and horizontal mixing of a plume in a forest. Predicted deposition velocities ranged from 2.4 to 5.4 cm s -1 on average. In all cases, model simulations underpredicted deuterium concentration by 1 to 2 orders of magnitude, indicating the model does not sufficiently mix the plume into the forest. While the model underestimated the transfer of material downward through the forest, it does suggest that the model's estimates are conservative for making downwind dose estimates because of lower plume depletion, leading to higher concentration and dose estimates. While the field releases do not cover all possible meteorological conditions, we conclude it is appropriate to use a non-zero deposition velocity when performing safety-basis modeling of tritium oxide based on conservatism within the model. A recommendation of 1.0 cm s -1 as a deposition velocity is made, which is beyond the 95 th percentile value estimated from the prior modeling study.

Use of tritium in characterizing the leachate migration from a landfill - Central de tratamento de resíduos sólidos (CTRS) BR040 (Belo Horizonte, Minas Gerais, Brazil).

Landfills often become a source of environmental impact due to the percolation of the leachate (liquid resulting from the decomposition of buried waste), which can eventually disperse and contaminate the soil and water bodies. This study aimed to evaluate quantitatively and spatially the leachate plume from the former Belo Horizonte landfill in the Coqueiros and Taiobas watersheds by using tritium (3H) concentration in nineteen (19) sampling points: 14 groundwater, 4 surface water and 1 leachate. Among the methodologies applied to determine the 3H content in the leachate, pre-filtration proved to be the most effective due to the ease treating of the sample, as well as the identical results obtained compared to the traditional method. The 3H contents resulted in concentrations up to thirty times higher in the leachate (=96,19 to 111,87 TU) and ten times in groundwater (PM23/3 = 45,06 TU), compared to the calculated threshold (TS) of rainfall tritium (TS_3Hrain = 3,41 TU). Temporal series results indicate no trend and no influence of seasonality regarding the entry of pluvial tritium, leachate liquid level and wells water level. The 3H contour maps shows a transport of the mixture (water and leachate) towards the Coqueiros stream, with a higher concentration of leachate in wells closer to the landfill slope (PM13, PM14, PM15, and PM23) and in the southwest margin of the Coqueiros stream (PM17). In the furthest portion of the landfill, 3H levels are higher than the base threshold only at the deepest level of PM20 (=3,90 TU), possibly due to factors such as: i) denser character of the leachate compared to groundwater; ii) greater influence of recharge for regions further away from the landfill slope; and iii) the presence of the rock about 50 m from the surface. Based on the hydrogeological conceptual model, the transport of the leachate water mixture in the groundwater water compartment of the Coqueiros watershed basin seems to follow a piston or dispersion flow, with a small Peclet number (Pd = 0,05, as an example), as indicated by the high correlation coefficient values (R2 ≈ 0,85 to 0,99) from graphic interpolation. The mixture of water and leachate results in a transient time (tt) ≈ 30 years and linear velocity (Vl) ≈ 3-14 m/year in the interpolated sections. These indicate a coherent correlation with the mean hydraulic conductivity (K ≈ 29,34 m/year), as they result in effective porosity values between (Ne) ≈ 0.16 to 0.36, which corresponds to Ne range for unconsolidated sediments, similar to the wells lithotype profiles. Time series evaluation combined with lumped parameter approach suggest to be an interesting way to better understanding the HCM, and, therefore, to determine hydrodynamic parameters using tritium as a tracer.

Influence of irrigation approaches and spatial geolocation on tritium speciation, uptake and depuration.

Pine needles and tree cores from a tritium (T) contaminated phytoremediation forest at the Savannah River Site (SRS in Aiken, SC) Mixed Waste Management Facility (MWMF) were measured for total T and T speciation and compared to other locations at the SRS and the surrounding area. Tree core ages ranged from 9 to 14 years old, covering over half of the ∼20-year on-going remediation efforts, while pine needles represent more recent time periods of 1-to-2-year increments. Remedial irrigation efforts at the MWMF are found to directly influence the pine needle T concentrations. The T content in the MWMF samples is higher than non-irrigated needle samples from other locations around the SRS. Further, the different forms of organic bound T are preferentially stored in tree core tissue, compared to pine needles where tritiated water dominates.

Analysis of environmental biological effects and OBT accumulation potential of microalgae in freshwater systems exposed to tritium pollution.

The ecological risk of tritiated wastewater into the environment has attracted much attention. Assessing the ecological risk of tritium-containing pollution is crucial by studying low-activity tritium exposure's environmental and biological effects on freshwater micro-environment and the enrichment potential of organically bound tritium (OBT) in microalgae and aquatic plants. The impact of tritium-contaminated wastewater on the microenvironment of freshwater systems was analyzed using microcosm experiments to simulate tritium pollution in freshwater systems. Low activity tritium pollution (105 Bq/L) induced differences in microbial abundance, with Proteobacteria, Bacteroidota, and Desulfobacterota occupying important ecological niches in the water system. Low activity tritium (105-107 Bq/L) did not affect the growth of microalgae and aquatic plants, but OBT was significantly enriched in microalgae and two aquatic plants (Pistia stratiotes, Spirodela polyrrhiza), with the enrichment coefficients of 2.08-3.39 and 1.71-2.13, respectively. At the transcriptional level, low-activity tritium (105 Bq/L) has the risk of interfering with gene expression in aquatic plants. Four dominant cyanobacterial strains (Leptolyngbya sp., Synechococcus elongatus, Nostoc sp., and Anabaena sp.) were isolated and demonstrated good environmental adaptability to tritium pollution. Environmental factors can modify the tritium accumulation potential in cyanobacteria and microalgae, theoretically enhancing food chain transfer.

Development of a Novel Passive Monitoring Technique to Showcase the 3D Distribution of Tritiated Water (HTO) Vapor in Indoor Air of a Nuclear Facility.

Tritiated water (HTO), a ubiquitous byproduct of the nuclear industry, is a radioactive contaminant of major concern for environmental authorities. Although understanding spatiotemporal heterogeneity of airborne HTO vapor holds great importance for radiological safety as well as diagnosing a reactor's status, comprehensive HTO distribution dynamics inside nuclear facilities has not been studied routinely yet due to a lack of appropriate monitoring techniques. For current systems, it is difficult to simultaneously achieve high representativeness, sensitivity, and spatial resolution. Here, we developed a passive monitoring scheme, including a newly designed passive sampler and a tailored analytical protocol for the first comprehensive 3D distribution characterization of HTO inside a nuclear reactor facility. The technique enables linear sampling in any environment at a one-day resolution and simultaneous preparation of hundreds of samples within 1 day. Validation experiments confirmed the method's good metrological properties and sensitivity to the HTO's spatial dynamics. The air in TU Wien's reactor hall exhibits a range of 3H concentrations from 75-946 mBq m-3 in the entire 3D matrix. The HTO release rate estimated by the mass-balance model (3199 ± 306 Bq h-1) matches the theoretical calculation (2947 ± 254 Bq h-1), suggesting evaporation as the dominant HTO source in the hall. The proposed method provides reliable and quality-controlled 3D monitoring at low cost, which can be adopted not only for HTO and may also inspire monitoring schemes of other indoor pollutants.

Environmental airborne tritium monitoring system based on absorption of tritiated water on calcium chloride.

Environmental monitoring of tritium around nuclear facilities is conducted in order to demonstrate compliance with regulatory requirements on the protection of members of the public. Multiple techniques are used to monitor its concentration in air, soil and flora. A new monitoring system was developed, which is based on the absorption of tritiated water on Calcium Chloride grains. Calcium Chloride has an improved capability to absorb water vapor, compared with other absorbents/adsorbents: it can absorb water vapor as much as three times its own weight. The Calcium Chloride is inserted inside a plastic bag where it interacts with environmental vapor through a membrane filter "window". The tritium absorption rate is then controlled by adjusting the free area of the membrane filter. After the determination of the tritium activity absorbed in the calcium chloride using a liquid scintillation system, a model is used to estimate its airborne concentration, considering the environmental conditions.

Transit time estimation of drying springs in Uttarakhand region using environmental tritium concentration.

Many parts of the Uttarakhand state, situated in the hilly terrain of the Himalayan region of India are facing acute water crisis due to the drying up of the perennial springs which are the only source of potable water in those regions. Tritium (3H), the radioactive isotope of hydrogen (half-life of 12.32 years) and also a part of water molecule (in the form of HTO) acts as a very useful tracer in estimating the transit time of the hydrological systems. Tritium concentrations of three springs (S-1, S-2 and S-3) were monitored consecutively for three years (2017-2019) to better constrain the transit time estimation. The tritium concentrations of the springs are found to vary between 3.66 and 4.15 TU. All the springs show gradual decrease in tritium concentration with the passage of time indicating the diminishing percentage of freshly recharged modern water component. Among various lumped parameter models, the piston-flow model (PFM), exponential mixing model (EMM), exponential piston-flow model (EPM) and partial exponential mixing model (PEM) have been employed in this study. The historical record of weighted mean concentration of tritium in precipitation available for the Uttarakhand region is taken as input function in the modelling procedure. The application of various LPMs (PFM, EMM, EPM and PEM) indicates that the transit time of the S-1 spring ranges from 1.26 to 1.46 years whereas for S-2 spring, the transit time is found to vary from 5 months to 1.1 years. The MTT of S-3 spring ranges from 5 months to 11 months. The relatively short residence time of these springs indicates the actively recharged system. The estimation of accurate transit time is thus very crucial for understanding the renewability of the spring water systems.

Toward an efficient determination of tissue-free water tritium in food.

Introduction: Tritium in the environment constitutes a radiological concern because it can become part of the hydrogen pool in environmental and biological reservoirs and thereby expose people to radiation. Methods: Tissue-free water tritium (TFWT) analysis in food is an important subject of environmental radiation monitoring which plays an important role in the estimation of health risks from environmental tritium exposure. At present, tritium content in food is generally determined by liquid scintillation counter (LSC). To improve the analytical efficiency in tritium determination, we developed a novel method to treat TFWT in food using microporous membranes. Results: The microporous membrane treatment method developed in this study has the following characteristics: It has a wide range of application and can process TFWT samples with conductivity below 5 µS/cm. Sample loss for the microporous membrane treatment is approximately 5%. The average treatment time is only 5 min, significantly shortened compared with the currently used atmospheric distillation treatment method (1.5 h). The results of the comparison and spike experiment show that the samples prepared by microporous membrane treatment provides equally satisfactory tritium measurement results as classic distillation method. Discussion: The developed microporous membrane method is simple to operate, efficient, and environmentally friendly, and effectively improves the analysis efficiency of TFWT in food.

Distribution of hydrogen isotope in the soil around the Qinshan Nuclear Power Plant.

When a different types of reactor are operating at the same area and the same period of time, released radionuclides are hard to follow in the environment. In general, isotopic techniques can be used for source localization. To obtain the distribution of hydrogen isotope in soil, eight sampling points were selected along the local dominant wind direction with different distances away from Qinshan Nuclear Power Plant, and soil samples at different depths (0-2, 2-5, 5-10, 10-20, 20-30 cm) were collected in December 2019 and December 2020, respectively. The concentrations of hydrogen isotopes were measured in the soil samples at different depth. The spatial distribution of tritium and deuterium in the surface soil was related to soil properties and the distance from the nuclear power plant. It was found that tritium and deuterium are generally enriched in the upper layer. Determination of the deuterium concentration in the environment may be a new way to trace the released tritium from the reactors.

Impact of the Fukushima Accident on 3H and 14C Environmental Levels: A Review of Ten Years of Investigation.

The investigation of the impact of the Fukushima accident is still going on although more than ten years have passed since the disaster. The main goal of this paper was to summarize the results of tritium and radiocarbon determinations in different environmental samples, possibly connected with the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. A document containing compiled data may serve as a solid basis for further research in the selected fields. To accomplish such effort, we went through dozens of relevant published papers, reporting 3H and 14C activity concentrations in precipitations, groundwater, seawater, river systems, tree rings, and, in some more extraordinary samples, such as herbaceous plants or debris from the damaged reactor buildings. As the referenced results would not be obtainable without adequate analytical techniques, the most common methods for routine measurement of tritium and radiocarbon concentrations are discussed as well. We believe that the correct identification of the affected environmental compartments could help quantify the released 3H and 14C activities and track their following fate, which could be especially important for plans to discharge contaminated water from the FDNPP in the upcoming years.