Decadal trends in 137Cs concentrations in the bark and wood of trees contaminated by the Fukushima nuclear accident.
Abstract
Understanding the actual situation of radiocesium (137Cs) contamination of trees caused by the Fukushima nuclear accident is essential for predicting the future contamination of wood. Particularly important is determining whether the 137Cs dynamics within forests and trees have reached apparent steady state. We conducted a monitoring survey of four major tree species (Japanese cedar, Japanese cypress, konara oak, and Japanese red pine) at multiple sites. Using a dynamic linear model, we analyzed the temporal trends in 137Cs activity concentrations in the bark (whole), outer bark, inner bark, wood (whole), sapwood, and heartwood during the 2011–2020 period. The activity concentrations were decay-corrected to September 1, 2020, to exclude the decrease due to the radioactive decay. The 137Cs concentrations in the whole and outer bark samples showed an exponential decrease in most plots but a flat trend in one plot, where 137Cs root uptake is considered to be high. The 137Cs concentration ratio (CR) of inner bark/sapwood showed a flat trend but the CR of heartwood/sapwood increased in many plots, indicating that the 137Cs dynamics reached apparent steady state within one year in the biologically active parts (inner bark and sapwood) and after several to more than 10 years in the inactive part (heartwood). The 137Cs concentration in the whole wood showed an increasing trend in six plots. In four of these plots, the increasing trend shifted to a flat or decreasing trend. Overall, the results show that the 137Cs dynamics within forests and trees have reached apparent steady state in many plots, although the amount of 137Cs root uptake in some plots is possibly still increasing 10 years after the accident. Clarifying the mechanisms and key factors determining the amount of 137Cs root uptake will be crucial for predicting wood contamination.
Introduction
After the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March of 2011, a wide area of forests in eastern Japan was contaminated with radionuclides. In particular, radiocesium (137Cs) has the potential to threaten the forestry and wood production in the contaminated area for many decades because it was released in large amounts (10 PBq)1 and has a relatively long half-life (30 years). Radiocesium levels for some wood uses are strictly regulated in Japan (e.g., 40 Bq kg−1 for firewood2 and 50 Bq kg−1 for mushroom bed logs3), meaning that multipurpose uses of wood from even moderately contaminated areas are restricted. Although a guidance level of radiocesium in construction wood has not been declared in Japan, the permissible levels in some European countries (370–740 Bq kg−1)4,5,6 suggest that logging should be precautionary within several tens of kilometers from the FDNPP, where the 137Cs activity concentration in wood potentially exceeds 1,000 Bq kg−1 [refs. 7,8]. To determine whether logging should proceed, the long-term variation in wood 137Cs concentration must be predicted as accurately as possible. Many simulation models successfully reproduce the temporal variations in the early phase after the FDNPP accident, but produce large uncertainties in long-term predictions9. To understand the 137Cs dynamics in forests and trees and hence refine the prediction models, it is essential to provide and analyze the observational data of 137Cs activity concentrations in tree stem parts.
Accident-derived 137Cs causes two types of tree contamination: direct contamination by 137Cs fallout shortly after the accident, and indirect contamination caused by surface uptake from directly contaminated foliage/bark10,11 and root uptake from contaminated soil12. The 137Cs concentration in bark that pre-exists the accident was affected by both 137Cs drop/wash off from bark surfaces and 137Cs uptake because the bark consists of a directly contaminated outer bark (rhytidome) and an indirectly contaminated inner bark (phloem). Given that the 137Cs content was 10 times higher in the outer bark than in the inner bark in 201213 and the 137Cs concentration in the whole bark decreased during the 2011–2016 period at many study sites8, the temporal variation in the whole bark 137Cs concentration during the early post-accident phase must be mainly contributed by drop/wash off of 137Cs on the outer bark surface.
In contrast, stem wood (xylem) covered by bark was contaminated only indirectly. Although 137Cs distribution in sapwood (outer part of stem wood; containing living cells) and heartwood (inner part of stem wood; containing no living cells) is non-uniform and species-specific8,13,14,15, the 137Cs concentration in whole wood depends on the amount of 137Cs uptake. Because the dissolvable 137Cs on the foliar/bark surface decreased significantly within 201116, the main route of 137Cs uptake since 2012 is likely root uptake rather than surface uptake. A monitoring survey during 2011–2016 showed that the temporal trend in the whole wood 137Cs concentration can be increasing, decreasing, or flat8, suggesting that 137Cs root uptake widely differs among sites and species.
Meanwhile, many simulation models have predicted an initial increase in the whole wood 137Cs concentration after the accident, followed by a gradual decline9. The initial increase is attributable to the increase in soil 137Cs inventory, and the following decline is mainly attributed to radioactive decay, dilution by wood biomass increment, and immobilization in the soil. Therefore, the trend shift from increasing to decreasing is a good indicator that shows the 137Cs dynamics within the forest have reached apparent steady state, which is characterized by slower changes in 137Cs concentration, bioavailability, and partitioning in the forest12,17,18. However, the timing of the trend shift predicted by the models have large uncertainty, varying from several years to a few decades from the accident9. Moreover, the trend shift has not been confirmed by observational data after the FDNPP accident. Although our monitoring survey cannot easily identify the key driving factors of the temporal trends, it can directly discern the trend shift from increasing to decreasing, and the timeframe of the increasing trend. The confirmation of the trend shift will accelerate the understanding of key factors of 137Cs root uptake, because important parameters such as transfer factor and CR are originally defined for a steady state condition18.
The present study aims to clarify the temporal trends of 137Cs concentrations in bark and wood of four major tree species (Japanese cedar, Japanese cypress, konara oak, and Japanese red pine) at multiple sites during the 10 years following the FDNPP accident. Detecting a trend shift from increasing to decreasing in the wood 137Cs concentration was especially important to infer whether the 137Cs dynamics within the forest have reached apparent steady state. We update Ohashi et al.8, who analyzed the monotonous increasing or decreasing trends during 2011–2016, with observational data of 2017–2020 and a more flexible time-series analysis using a dynamic linear model (DLM). The DLM is suitable for analyzing data including observational errors and autocorrelation, and has the advantage of being applicable to time-series data with missing years. For a more detailed understanding of bark contamination and the 137Cs dynamics in tree stems, we also newly provide data on the 137Cs concentrations in the outer and inner barks. The temporal trends in the 137Cs CRs of outer bark/inner bark, heartwood/sapwood, and inner bark/sapwood were analyzed to confirm whether the 137Cs dynamics within the trees have reached apparent steady state.
Materials and methods
Monitoring sites and species
The monitoring survey was conducted at five sites in Fukushima Prefecture (sites 1–4 and A1) and at one site in Ibaraki Prefecture (site 5), Japan (Fig. 1). Sites 1, 2, and A1 are located in Kawauchi Village, site 3 in Otama Village, site 4 in Tadami Town, and site 5 in Ishioka City. Monitoring at sites 1–5 was started in 2011 or 2012, and site A1 was additionally monitored since 2017. The tree species, age, mean diameter at breast height, initial deposition density of 137Cs, and sampling year of each sample at each site are listed in Table 1. The dominant tree species in the contaminated area, namely, Japanese cedar (Cryptomeria japonica [L.f.] D.Don), Japanese cypress (Chamaecyparis obtusa [Siebold et Zucc.] Endl.), konara oak (Quercus serrata Murray), and Japanese red pine (Pinus densiflora Siebold et Zucc.) were selected for monitoring. Japanese chestnut (Castanea crenata Siebold et Zucc.) was supplementally added in 2017. The cedar, cypress, and pine are evergreen coniferous species, and the oak and chestnut are deciduous broad-leaved species. Sites 1 and 3 each have three plots, and each plot contains a different monitoring species. Site A1 has one plot containing two different monitoring species, and the remaining sites each have one plot with one monitoring species, giving ten plots in total.
Sample collection and preparation
Bulk sampling of bark and wood disks was conducted by felling three trees per year at all sites during 2011–20168,25 and at sites 3–5 and A1 during 2017–2020. Partial sampling from six trees per year was conducted at sites 1 and 2 during 2017–2020 (from seven trees at site 2 in 2017) to sustain the monitoring trees. All the samples were obtained from the stems around breast height. During the partial sampling, bark pieces sized approximately 3 cm × 3 cm (axial length × tangential length) were collected from four directions of the tree stem using a chisel, and 12-mm-diameter wood cores were collected from two directions of the tree stem using an automatic increment borer (Smartborer, Seiwa Works, Tsukuba, Japan) equipped with a borer bit (10–101-1046, Haglöf Sweden, Långsele, Sweden). Such partial sampling increases the observational errors in the bark and wood 137Cs concentrations in individual trees26. To mitigate this error and maintain an accurate mean value of the 137Cs concentration, we increased the number of sampled trees from three to six. The sampling was conducted mainly in July–September of each year; the exceptions were site-5 samples in 2011 and 2012, which were collected irregularly during January–February of the following year. The collected bark pieces were separated into outer and inner barks, and the wood disks and cores were split into sapwood and heartwood. The outer and inner bark samples during 2012–2016 were obtained by partial sampling of barks sized approximately 10 cm × 10 cm from 2–3 directions on 2–3 trees per year.
The bulk samples of bark, sapwood, and heartwood were air-dried and then chipped into flakes using a cutting mill with a 6-mm mesh sieve (UPC-140, HORAI, Higashiosaka, Japan). The pieces of the outer and inner bark were chipped into approximately 5 mm × 5 mm pieces using pruning shears, and the cores of the sapwood and heartwood were chipped into semicircles of thickness 1–2 mm. Each sample was packed into a container for radioactivity measurements and its mass was measured after oven-drying at 75 °C for at least 48 h. Multiplying this mass by the conversion factor (0.98 for bark and 0.99 for wood)8 yielded the dry mass at 105 °C.
Radioactivity measurements
The radioactivity of 137Cs in the samples was determined by γ-ray spectrometry with a high-purity Ge semiconductor detector (GEM20, GEM40, or GWL-120, ORTEC, Oak Ridge, TN). For measurements, the bulk and partial samples were placed into Marinelli containers (2.0 L or 0.7 L) and cylindrical containers (100 mL or 5 mL), respectively. The peak efficiencies of the Marinelli containers, the 100-mL container, and the 5-mL container were calibrated using standard sources of MX033MR, MX033U8PP (Japan Radioisotope Association, Tokyo, Japan), and EG-ML (Eckert & Ziegler Isotope Products, Valencia, CA), respectively. For the measurement of the 5-mL container, a well-type Ge detector (GWL-120) was used under the empirical assumption that the difference in γ-ray self-absorption between the standard source and the samples is negligible27. The measurement was continued until the counting error became less than 5% (higher counting errors were allowed for small or weakly radioactive samples). The activity concentration of 137Cs in the bark (whole) collected by partial sampling was calculated as the mass-weighted mean of the concentrations in the outer and inner barks; meanwhile, the concentration in the wood (whole) was calculated as the cross-sectional-area-weighted mean of sapwood and heartwood concentrations. The activity concentrations were decay-corrected to September 1, 2020, to exclude the decrease due to the radioactive decay.
Discussion
Causes of temporal trends in bark 137Cs concentration
The 137Cs concentration in the whole bark decreased in many plots, clearly because the outer bark 137Cs concentration decreased. However, the whole bark 137Cs concentration showed a relatively small decrease or even a flat trend in some plots (site-2 cedar and site-1 cypress and oak). In the site-1 cypress plot, where the whole bark 137Cs concentration decreased relatively slowly, the inner bark 137Cs concentration notably increased. Similarly, although we lack early phase monitoring data in the site-2 cedar and site-1 oak plots, the inner bark 137Cs concentration in both plots is considered to have increased prior to monitoring because the sapwood 137Cs concentration increased in both plots and the CR of inner bark/sapwood was constant in all other plots. Therefore, the low-rate decrease or flat trend in the whole bark 137Cs concentration in some plots was probably caused by an increase in the inner bark 137Cs concentration, itself likely caused by high 137Cs root uptake (as discussed later).
The 137Cs concentration in the outer bark decreased in all four plots monitored since 2012 (site-1 and site-3 cedar, site-1 cypress, and site-3 pine), confirming the 137Cs drop/wash off from the bark surface. The constant (exponential) decrease in three of these plots indicates that the 137Cs drop/wash off was still continuing in 2020 but with smaller effect on the outer bark 137Cs concentration. In contrast, the decrease in the site-1 cypress plot seemed to slow down since around 2017. Furthermore, Kato et al.32 reported no decrease in 137Cs concentration in the outer bark of Japanese cedar during the 2012–2016 period. Such cases cannot be fitted by a simple decrease of the outer bark 137Cs concentration. As a longer-term perspective, in the outer bark of Norway spruces (Picea abies) affected by the Chernobyl nuclear accident, the biological half-life of 137Cs concentration was extended in areas with higher precipitation, suggesting that high root uptake of 137Cs hinders the decreasing trend33. The present study showed that 70–80% or more of the 137Cs deposited on the bark surface (outer bark) was removed by drop/wash off after 10 years from the accident and that the 137Cs CR of outer bark/inner bark became constant in some plots. These facts suggest that the longer-term variations in outer bark 137Cs concentration will be more influenced by 137Cs root uptake, although it is uncertain whether root uptake caused the slowing down of the decrease rate seen in the site-1 cypress plot. Further studies are needed to understand the 137Cs concentration in newly formed outer bark and to determine the 137Cs CR of outer bark/inner bark at steady state.
Causes of temporal trends in wood 137Cs concentration
The temporal trends of the 137Cs concentration in the whole wood basically corresponded to those in the sapwood. The exceptions were the site-3 and site-4 cedar plots, where the sapwood 137Cs concentration did not increase but the whole wood 137Cs concentration was raised by the notable increase in the heartwood 137Cs concentration. This behavior can be attributed to a species-specific characteristic of Japanese cedar, which facilitates Cs transfer from sapwood to heartwood8,15,34. The present study newly found that the increase in the 137Cs CR of heartwood/sapwood in the cedar plots became smaller or shifted to a flat trend around 2015–2016, indicating that 137Cs transfer between the sapwood and heartwood has reached apparent steady state at many sites 10 years after the accident. Therefore, after 2020, the whole wood 137Cs concentration in cedar is unlikely to increase without a concomitant increase in the sapwood 137Cs concentration.
The increasing trends in the 137Cs concentrations in whole wood and sapwood (site-2 cedar, site-1 cypress, and site-1 and site-3 oak plots) are seemingly caused by the yearly increase in 137Cs root uptake; however, the wood 137Cs concentration can also increase when the 137Cs root uptake is constant or even slightly decreases each year. This behavior can be shown in a simple simulation of the temporal variation in the wood 137Cs content (the amount of 137Cs in stem wood of a tree). If the 137Cs dynamics within a tree have reached steady state and the proportion of 137Cs allocated to stem wood become apparently constant, the wood 137Cs content in a given year can be considered to be determined by the amount of 137Cs root uptake and the amount of 137Cs emission via litterfall. The flat 137Cs CR trend of inner bark/sapwood during 2012–2020 (see Fig. 5) indicates that the 137Cs dynamics, at least those between the inner bark and sapwood, reached apparent steady state within 2011. Here we assume that (1) the annual amount of 137Cs root uptake is constant, (2) the proportion of 137Cs allocated to stem wood is apparently constant, and as assumed in many forest Cs dynamics models17,35,36,37, (3) a certain proportion of 137Cs in the stem wood is lost via litterfall each year. Under these conditions, the simulated amount of 137Cs emission balanced the amount of 137Cs root uptake after sufficient time, and the wood 137Cs content approached an asymptotic value calculated as [root uptake amount × allocation proportion × (1/emission proportion − 1)]. Note that the asymptotic value increases with increasing root uptake amount and decreasing emission proportion and does not depend on the amount of 137Cs foliar/bark surface uptake in the early post-accident phase. Nevertheless, the amount of 137Cs surface uptake in the early phase critically determines the trend of the wood 137Cs content. More specifically, the trend in the early phase will be increasing (decreasing) if the surface uptake is smaller (larger) than the asymptotic value. Finally, the temporal variation of the 137Cs concentration in wood is thought to be the sum of the dilution effect of the increasing wood biomass and the above-simulated variation in the wood 137Cs content. Therefore, in the early post-accident phase, the wood 137Cs concentration will increase when the wood 137Cs content increases at a higher rate than the wood biomass. As the wood 137Cs content approaches its asymptotic value (i.e., steady state), its increase rate slows and the dilution effect proportionally increases. Then, the wood 137Cs concentration shifts from an increasing trend to a decreasing trend. The trends of the 137Cs concentrations in whole wood and sapwood in the site-3 oak plot follow this basic temporal trend, which is similarly predicted by many simulation models9.
In other plots with the increasing trend (site-2 cedar and site-1 cypress and oak), the increase in the 137Cs concentrations in whole wood and sapwood became smaller or shifted to a flat trend around six years after the accident; however, it did not shift to a decreasing trend. This lack of any clear shift to a decreasing trend, which was similarly seen at sites with hydromorphic soils after the Chernobyl nuclear accident38,39, cannot be well explained by the above simulation. A core assumption of the simulation that the yearly amount of 137Cs root uptake is constant is probably violated in these plots, leading to underestimations of the root uptake amount. Although the inventory of exchangeable 137Cs in the organic soil layer has decreased yearly since the accident, that in the mineral soil layer at 0–5 cm depth has remained constant40. In addition, the downward migration of 137Cs has increased the 137Cs inventory in the mineral soil layer below 5-cm depth41,42. If the steady state 137Cs inventory of the root uptake source can be regarded as sufficient for trees, any increase in the 137Cs root uptake is likely explained by expansion of the root distribution and the increase in transpiration (water uptake) with tree growth. When the wood 137Cs content increases at a similar rate to the wood biomass, the increasing trend will not obviously shift to a decreasing trend. Therefore, assuming the 137Cs allocation and emission proportions in the mature trees do not change considerably with time, the amount of 137Cs root uptake is considered to be increasing yearly in these four plots.
In the remaining plots with the decreasing or flat trend (site-1 cedar, site-4 cedar without outliers, site-5 cypress, and site-3 pine), according to the above simulation, the amount of initial 137Cs surface uptake was larger than or similar to the asymptotic value, i.e. the amount of 137Cs root uptake is relatively small and/or the proportion of 137Cs emission via litterfall is relatively high. However, the amount of 137Cs root uptake in the plots with the flat trend is possibly increasing because the flat trend has not shifted to a decreasing trend. In these plots, although it is difficult to confirm apparent steady state of the soil–tree 137Cs cycling because of the lack of an initial increasing trend, the recent flat trends in the 137Cs CRs of heartwood/sapwood and inner bark/sapwood indicate that the 137Cs dynamics, at least within the trees, have reached apparent steady state.
Various factors were found to increase the 137Cs root uptake after the Chernobyl nuclear accident; for example, high soil water content, high soil organic and low clay content (i.e., low radiocesium interception potential [RIP]), low soil exchangeable K concentration, and high soil exchangeable NH4 concentration12,43. After the FDNPP accident, the 137Cs transfer from soil to Japanese cypress and konara oak was found to be negatively correlated with the soil exchangeable K concentration44,45 and the 137Cs mobility is reportedly high in soils with low RIP46. However, neither the soil exchangeable K and Cs concentrations nor the RIP have explained the different 137Cs aggregated transfer factors (defined as [137Cs activity concentration in a specified component/137Cs activity inventory in the soil]) of Japanese cedars at sites 1–446,47. Because the 137Cs dynamics within the forest and trees in many plots reached apparent steady state at 10 years after the FDNPP accident, the 137Cs aggregated transfer factor is now considered to be an informative indicator of the 137Cs root uptake. Therefore, a comprehensive analysis of the 137Cs aggregated transfer factor and the soil properties at more sites than in the present study will be important to understand key factors determining the amount of 137Cs root uptake by each tree species at each site.
Validity and limitation of the trend analyses
Although the application of the smooth local linear trend model failed in plots monitored for less than five years, it was deemed suitable for analyzing the decadal trend because it removes annual noises, which are probably caused by relatively large observational errors (including individual variability)26. Moreover, the algorithm that determines the trend and its shift between 2 and 4 delimiting years was apparently reasonable, because the detected trends well matched our intuition. However, when judging a trend, the algorithm simply assesses whether the true state values significantly differ between the delimiting years. Therefore, it cannot detect changes in the increase/decrease rate (i.e., whether an increasing/decreasing trend is approaching a flat trend). For example, the whole bark 137Cs concentration in the site-1 cypress plot was determined to decrease throughout the monitoring period. In fact, the decrease rate slowed around 2014 and the decreases were slight between 2014 and 2020 (see Fig. 2). Similarly, the sapwood 137Cs concentration in the site-1 cypress and oak plots was determined to increase throughout the monitoring period, but the increase rate has clearly slowed since around 2017. To more sensitively detect the shift from an increasing/decreasing trend to a flat trend, other algorithms are required. Nevertheless, this algorithm is acceptable for the chief aim of the present study; that is, to detect a trend shift from increasing to decreasing.
Conclusions
In many plots monitored at Fukushima and Ibaraki Prefectures, the 137Cs concentrations in the whole and outer bark decreased at almost the same yearly rate for 10 years after the FDNPP accident, indicating that the direct contamination of the outer bark was mostly but not completely removed during this period. Moreover, the 137Cs concentration in the whole bark decreased at relatively low rates or was stable in plots where the 137Cs root uptake was considered to be high. This fact suggests that indirect contamination through continuous root uptake can reach the same magnitude as direct contamination by the accident.
In all of our analyzed plots, the 137Cs CR of inner bark/sapwood has not changed since 2012, indicating that 137Cs transfer among the biologically active parts of the tree stem had already reached apparent steady state in 2011. In contrast, the 137Cs CR of heartwood/sapwood in six out of nine plots increased after the accident. In four of these plots, the 137Cs CR of heartwood/sapwood plateaued after 3–6 years; in the other two plots, the plateau was not reached even after 10 years. Therefore, saturation of 137Cs in heartwood (an inactive part of the tree stem) requires several years to more than one decade.
The 137Cs concentration in the whole wood showed an increasing trend in six out of nine plots. In four of these plots, the increasing trend shifted to a flat or decreasing trend, indicating that the 137Cs dynamics in many forests reached apparent steady state at 10 years after the accident. However, the lack of the clear shift to a decreasing trend indicates that the 137Cs root uptake is probably still increasing in some plots. Continuous monitoring surveys and further studies clarifying the complex mechanisms of 137Cs root uptake in forests are needed in order to refine the simulation models and improve their prediction accuracy.
Japan OKs plan to release Fukushima nuclear plant wastewater
Japan’s nuclear regulator has approved plans by the operator of the wrecked Fukushima nuclear plant to release its treated radioactive wastewater into the sea next year, saying the outlined methods are safe and risks to the environment minimal
By Mari Yamaguchi Associated Press, May 18, 2022,
………. There is still concern in the community and neighboring countries about the potential health hazards of the release of the wastewater that includes tritium — a byproduct of nuclear power production and a possible carcinogen at high levels.
The government and TEPCO say more than 60 isotopes selected for treatment can be lowered to meet safety standards, except for tritium, but that it is safe if diluted. Scientists say impact of long term low-dose exposure to the environment and humans are unknown, and that tritium can have a bigger impact on humans when consumed in fish than in water.
,,,,,,,,,, Under the plan, TEPCO will transport water that has been treated to below releasable levels through a pipeline from the tanks to a coastal facility, where the water is diluted with seawater.
From there, the water will enter an undersea tunnel to be discharged at a point about 1 kilometer (0.6 mile) from the plant to ensure safety and minimize the impact on local fishing and the environment, according to TEPCO.
The plan will become official after a 30-day public review, a formality that is not expected to overturn the approval.
………..The contaminated water is being stored in about 1,000 tanks at the damaged plant, which officials say must be removed so that facilities can be built for its decommissioning. The tanks are expected to reach their capacity of 1.37 million tons next year — slower than an earlier estimate of later this year……….. https://abcnews.go.com/Technology/wireStory/japan-oks-plan-release-fukushima-nuclear-plant-wastewater-84800836
Japan prepares to dump water ignoring nuclear safety fears
China Daily April, 2022 The Tokyo Electric Power Company has begun construction work to prepare for the discharge of contaminated water from the crippled Fukushima nuclear plant into the Pacific Ocean next spring, Japanese media reports say.
The Japanese government and TEPCO are advancing this plan made by the Japanese government on April 13 last year, in spite of strong opposition at home and abroad.
Given that the water was used to cool the fused reactors at the nuclear plant after the Fukushima region was devastated by a tsunami in March 2011, and contains radioactive material, its potential to cause harm to the marine ecological environment, food safety and human health cannot be underestimated……………………
Japan should earnestly respond to the legitimate concerns of the international community, and reverse its decision to discharge the contaminated water into the ocean, thus fulfilling its international obligations. http://global.chinadaily.com.cn/a/202204/29/WS626b2624a310fd2b29e5a056.html
Construction projects surge at Fukushima nuclear plant despite decommissioning progress
Construction projects surge at Fukushima nuclear plant despite decommissioning progress
April 4, 2022 Mainichi Japan OKUMA, Fukushima — The site of the Fukushima Daiichi Nuclear Power Station continues to host new construction projects some 11 years after the disaster triggered by the 2011 Great East Japan Earthquake and tsunamis.
This Mainichi Shimbun reporter had the opportunity to visit the plant for the first time in seven and a half years, and reflect on why new facilities continue to appear even as the plant moves toward decommissioning…………..
While decommissioning seems to be advancing, various facilities have been newly constructed, and the issue of water remains. A rising number of tanks store treated water contaminated after it was pumped to cool fuel debris that melted down in the accident, as well as groundwater and rainwater that flowed into the buildings. Inside the tanks, the contaminated water is made to reach a radioactive concentration below regulation levels.
On the seventh floor of a building located near the site’s entrance, a Tokyo Electric Power Co. Holdings Inc. (TEPCO) representative gave me an outline of the entire facility. I could see two large cranes on the ocean side around Units 1 to 4, and another large crane and framework structure on the mountain side. When I asked about it, the representative told me the frame was being assembled in a remote location to reduce worker radiation exposure. But it wasn’t a facility being dismantled; it’s a cover measuring 66 meters long, 56 meters wide, and 68 meters high that will wrap around Unit 1.
The hydrogen explosion in Unit 1 blew the building’s roof off, and 392 pieces of nuclear fuel remain in its spent fuel pool near the ceiling. Their removal is scheduled to start in fiscal 2027 to 2028. For this to happen, the surrounding debris must be removed, and the cover’s installation will help prevent the work dispersing radioactive dust.
Ground improvements works were progressing on the neighboring Unit 2’s south side. There, a working platform to remove 615 pieces of nuclear fuel from Unit 2 will be built, with its start slated for fiscal 2024 to 2026.
The buildings for Units 1 through 4 were damaged and contaminated, so different structures, such as platforms and covers, had to be built to remove nuclear fuel from the pools. Particularly conspicuous was the thick steel frame of the Unit 4 facility, from which fuel was completely removed in 2014. Although 53 meters high, it surprisingly uses about the same amount of steel as the 333-meter-high Tokyo Tower. Since the nuclear fuel is being removed in order, new construction work continues in reactor buildings’ vicinities………………
The company listed at least 10 facilities earmarked for future construction. Put another way, the tanks need to be removed to provide land for these facilities.
Related construction work had already started at the seashore, where workers dug vertical holes to contain treated water before its release. After the implementation plan’s approval, undersea tunnel construction and other necessary work to release the water 1 km offshore will also begin.
Meanwhile, some broken cranes and damaged buildings have been left on site without being dismantled. The representative told the Mainichi Shimbun this was partly due to them trying to keep the solid waste processing volume low.
Also underway is construction of facilities to handle ever-increasing solid waste amounts. The representative said a white building I spotted in the site’s northwest side was the volume reduction facility, and that building work is going ahead for a solid waste storage facility in front of it.
The volume reduction facility scheduled for completion in March 2023 will use crushing and other methods to reduce concrete and metal debris volumes. Although nine storage buildings already exist, a 10th will soon be constructed. Nearby was also a new incineration facility for burning logged trees. TEPCO estimates solid waste generated will reach a volume of 794,000 cubic meters by March 2033, and that there will continue to be more related facilities.
Fuel debris removal will begin at the end of 2022. In the future, facilities to hold fuel debris and to store and reduce volumes of solid waste with high doses of radiation generated by the work will also be needed.
Each year creates new tasks that generate more waste, and the facilities to accommodate it. These buildings are also destined to eventually become solid waste. While this cycle continues, a final disposal method for the waste is undetermined. The government’s and TEPCO’s timetable says 20 to 30 years of plant decommissioning remain. But on site, where new construction projects continue to appear, a clear picture of when decommissioning will finish has yet to emerge.
(Japanese original by Takuya Yoshida, Science & Environment News Department) https://mainichi.jp/english/articles/20220402/p2a/00m/0na/027000c
11 years on, Fukushima morass still poses danger
| 11 years on, Fukushima morass still poses danger By KARL WILSON in Sydney | CHINA DAILY 2022-03-14 ”…………………………. Little progress has been made on the most pivotal and hardest work of decommissioning the Fukushima Daiichi power plant－how to remove the nuclear residue from the meltdown. The plant owner, Tokyo Electric Power Co, has said it could take another 30 years to retrieve undamaged fuel, remove resolidified melted fuel debris, disassemble the reactors and dispose of contaminated cooling water.The International Research Institute for Nuclear Decommissioning of Japan estimated that the nuclear waste mix from melted fuel rods and other materials in pressure vessels that melted during the accident could weigh as much as 880 metric tons. Hiroaki Koide, a retired researcher at Kyoto University, said the Japanese government and Tokyo Electric Power Co’s 30-40 year plan for decommissioning the reactors could not be achieved because it would be “impossible even in 100 years” to remove the large amount of scattered nuclear debris, which would have to be sealed in a “sarcophagus”. Moreover, 11 years after the disaster, the reactors at Fukushima are still being cooled down, said associate professor Nigel Marks of the physics and astronomy department at Curtin University, Western Australia. “And this will continue for many years to come. A vast number of large storage tanks have been built on the site, but space is rapidly running out.” Despite resistance from locals and neighboring countries, the Japanese government is sticking with its decision in April last year to discharge the nuclear contaminated water into the sea starting in spring next year. About 1 million tons of radioactive wastewater, now stored in 1,000 tanks on the site, was used to cool the reactors and contains radioactive cesium, strontium, tritium and other radioactive substances……………. http://global.chinadaily.com.cn/a/202203/14/WS622e7e15a310cdd39bc8c4ef.html |
Eleven years on and impact of Fukushima still felt in Japan.Eleven years on and impact of Fukushima still felt in Japan.
Eleven years on and impact of Fukushima still felt in Japan.
The 11 March marks the eleventh anniversary of the terrible accident at the Fukushima nuclear power plant in Japan. With the world’s attention now focused on the dangers posed to nuclear plants by the conflict in Ukraine, Nuclear Free Local Authorities also want to highlight the dangers posed to coastal nuclear plants by the sea.
Operated by the Tokyo Electric Power Company (TEPCO), the Fukushima Daiichi Nuclear Power Plant was hit by two natural disasters, an earthquake closely followed by a tsunami, on 11 March 2011. When the earthquake was detected, the reactors automatically shut down, cutting off the electricity supply; this in turn caused diesel electric generators to kick in to provide power to the essential coolant system. However, the 46-feet high tsunami which followed overwhelmed the sea defences, shutting off the generators and flooding reactors 1 to 4. Without coolant, a disaster unfolded with three nuclear meltdowns, three hydrogen explosions and a release of radiation from reactors 1, 2, and 3.
Atmospheric radiation forced government authorities to evacuate 154,000 people from the surrounding area over a 20-mile radius; the accident was classed as a Level 7 incident on the International Nuclear Event Scale for its overall impact on neighbouring communities – the same designation given to the disaster at Chernobyl in 1986. Radiation was carried in the air and in the oceans for many miles, and fishing in contaminated water remains prohibited to this day.
In a 2018 report, written for the NFLA by renowned independent radiation expert Dr Ian Fairlie, it was revealed that Japanese authorities attributed the deaths of nearly 2,000 people to the effects of the evacuations necessary to avoid high radiation exposures from the Fukushima disaster, including at least 56 from related suicides, and evidenced the significantly increased rates of diseases, mental illness, despair and societal detachment amongst evacuees.
Many Japanese remain displaced from their original communities and are still fearful of the long-term health impact of radiation exposure, with a recent compensation case filed against TEPCO by six young adults who have suffered from thyroid cancer.
There is also the costly and problematic legacy of clean-up, including the millions of tons of seawater, used to cool the irreparable reactors and now contaminated and stored in barrels. The Japanese government now intends to build an underwater pipe out to sea and discharge the radioactive water there. The NFLA stands in solidarity with the many Japanese who are bitterly opposed to the plans, especially the local fishing community.
NFLA Steering Committee Chair, Councillor David Blackburn, said: “British anti-nuclear activists will I am sure mark this anniversary sombrely. Although we see in Ukraine, nuclear power plants threatened by the conflict, we ignore at our peril the dangers posed to such facilities by our natural environment.
“As at Fukushima, most British nuclear power plants have also been located on the coast. Building is now underway at Hinkley Point C, and there are plans to develop further new large and smaller plants at various other sites by the sea, most notably at Sizewell and Bradwell.
The NFLA remains implacably opposed to any new nuclear plants, on grounds of cost and safety, and because of the toxic legacy of decommissioning and waste they bring. However, we must also oppose them because, although they damage our environment, in coming decades these plants might in turn be threatened by the sea. Nuclear sites are being impacted by coastal erosion and rising sea levels caused by global heating, and military nuclear bases, including those where Trident missile submarines are based, are also under threat.”
“There has been recent excellent research on this subject and the NFLA is inviting all of those interested in the subject, particularly Councillors and anti-nuclear campaigners from coastal communities, to join us for a special webinar in April.”
Councillor Blackburn will be chairing the NFLA webinar ‘Might the sea have them? Climate change and coastal nuclear infrastructure’ on Wednesday 6 April, 6-7pm with Dr Sally Brown from Bournemouth University and NFLA Policy Advisor Pete Roche.
The link to book a place on the webinar can be found at:
Legal action on Fukushima nuclear disaster’s impact on health
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Fukushima Disaster’s Impact on Health Will Be Challenged in Court https://thediplomat.com/2022/02/fukushima-disasters-impact-on-health-will-be-challenged-in-court/
A link between radiation from the Fukushima nuclear disaster and cancer will be the focal point of the civil court case against operator TEPCO. By Thisanka Siripala, February 17, 2022
Almost 11 years have passed since the Fukushima Daiichi nuclear power plant catastrophe. But even as Fukushima prefecture gets ready to launch a new revitalization slogan – “Making Fukushima’s reconstruction a reality one step at a time” – it is still struggling to overcome the lingering aftereffects of the accident. Earlier this month, a group of six men and women diagnosed with thyroid cancer as children filed a class action case against Tokyo Electric Power Company (TEPCO), seeking $5.4 million in compensation.
Eastern Japan was hit by a massive magnitude 9.1 earthquake and 15-meter tsunami on March 11, 2011. The disaster shut off power and cooling to three reactors at the Fukushima Daiichi nuclear power plant, triggering the release of radiation for up to six days.
The plaintiffs, who are aged between 17 and 27, are seeking to hold TEPCO responsible for the thyroid cancer they developed. Two have had one side of their thyroid removed and four others have had a complete thyroidectomy and are planning or undergoing radiation therapy. The treatment has forced them to drop out of school or college and give up on their dreams. The plaintiffs argue that their thyroid cancer has created barriers to their education and employment as well as marriage and starting a family.
The Fukushima Daiichi meltdown was the worst nuclear accident since Chernobyl in 1986, which was followed by a spike in cancer cases in the region. In Japan a health survey conducted by the Fukushima prefecture found 266 cases of cancer among the 380,000 people aged under 18 at the time of the accident. The lawyers representing the plaintiffs argue that pediatric thyroid cancer is extremely rare, with an annual incident rate of two cases in one million people
The plaintiffs added that in the past decade they have been forced to stay silent due to social pressure and the risk of public outrage over speaking out about the connection between the Fukushima nuclear accident and their thyroid cancer.
The Federation of Promotion of Zero-Nuclear Power and Renewable Energy, a civic group that includes five former Japanese prime ministers, sent a letter to the EU urging the elimination of nuclear power. In the letter, they stated that many children are suffering from thyroid cancer as a result of the Fukushima nuclear power plant accident.
However, the Japanese government believes there is no causal link between exposure to radiation from the accident and the children developing thyroid cancer. Prime Minister Kishida Fumio said at a House of Representatives Budget Committee meeting that “it is not appropriate to spread false information that children from Fukushima are suffering from health problems.”
At a press conference Takaichi Sanae, chairperson of the ruling LDP’s Policy Research Council refuted the letter sent by the federation. She stressed the government’s position that the cases of childhood thyroid cancer have been assessed by experts who have determined the accident is unlikely to have caused cancer.
Fukushima prefecture’s expert panel say there could be the possibility of “over-diagnosis” due to increased vigilance after the disaster, suggesting that some patients diagnosed with cancer did not need treatment. They say they are continuing to investigate the nature of each diagnosis. The Ministry of Environment also said they will continue to disseminate knowledge based on scientific findings to dispel rumors about the health effects of radiation.
Last week, the Fukushima reconstruction and revitalization council met to discuss the “diverse needs of the prefecture” and a long term response to support evacuees. Governor of Fukushima Uchibori Masao acknowledged that the prefecture is “facing many difficulties including the reconstruction and rehabilitation of evacuated areas and rebuilding the lives of evacuees and victims of the disaster.” There are also plans to establish a new national research and education organization in Fukushima that will devise measures to prevent and dispel rumors fueling discrimination toward evacuees and Fukushima food.
Taiwan recently lifted its blanket food import ban on Fukushima produce introduced in the wake of the disaster but there are 14 countries and regions that still maintain import restrictions. Additionally, Japan’s decision to discharge more than one million tonnes of low-level radioactive water from the crippled Fukushima nuclear power plant into the sea is another issue attracting negative publicity abroad.
UN to review Japan’s plan to release Fukushima water into Pacific
UN to review Japan’s plan to release Fukushima water into Pacific
Taskforce will ‘listen to local people’s concerns’, as government plans to release more than 1m tonnes, Guardian, Justin McCurry in TokyoFri 18 Feb 2022
A UN nuclear taskforce has promised to prioritise safety as it launches a review of controversial plans by Japan to release more than 1m tonnes of contaminated water into the ocean from the wrecked Fukushima Daiichi nuclear plant.
Japan’s government announced last April that it had decided to release the water over several decades into the Pacific Ocean, despite strong opposition from local fishers and neighbouring China and South Korea……………
The Tokyo Electric Power company (Tepco) says its treatment technology can remove all radioactive materials from water except tritium, which is harmless in small amounts. It said the gradual release of the water, diluted with seawater, would not pose a threat to human health or the marine environment. In 2020, however, Greenpeace said the water still contained contaminants beside tritium and would have to be treated again.
The wastewater is being stored in about 1,000 tanks that officials say need to be removed so the plant can be decommissioned, an operation expected to take several decades. The tanks are expected to reach their capacity of 1.37m tonnes this summer.
The liquid includes water used to cool the damaged reactors, as well as rain and groundwater that seeps into the area.
Shaun Burnie, a senior nuclear specialist for Greenpeace East Asia, said he did not believe the IAEA would fully investigate and address safety and environmental concerns in its report.
Noting that the agency had welcomed the discharge option when it was announced last year, Burnie said: “The IAEA is not an independent agency in nuclear affairs – under statute its mission is to promote nuclear power. It has sought to justify radioactive marine pollution as having no impact and safe. But the IAEA is incapable of protecting the environment, human health or human rights from radiation risks – that’s not its job.
“The IAEA taskforce should be investigating the root cause of the contaminated water crisis and exploring the option of long-term storage and the best available processing technology as an alternative to the deliberate contamination of the Pacific.”
The IAEA team, which includes experts from South Korea and China, will report its findings at the end of April.
South Korea, which has yet to lift an import ban on Fukushima seafood introduced in 2013, has said that discharging the water would pose a “grave threat” to the marine environment. Pacific peoples have challenged Japan to prove the water is safe by dumping it in Tokyo.
Local fishers also oppose the water’s release, saying it would undo a decade’s work to rebuild their industry and reassure nervous consumers their seafood is safe………https://www.theguardian.com/environment/2022/feb/18/un-to-review-japans-plan-to-release-fukushima-water-into-pacific
Robots used to remove Fukushima’s highly radioactive used nuclear fuel, but they’re still problematic.
Plutonium problems won’t go away, By Chris Edwards, Engineering and Technology, February 15, 2022 ”’………………………………………At a conference organised by the International Federation of Robotics Research on the 10th anniversary of the accident, Toyota Research chief scientist Gill Pratt said the first robots “got there in the overhead luggage of commercial flights”. For all of them it was a baptism of fire.
Narrow staircases and rubble turned into insurmountable obstacles for some. Those that made it further failed after suffering too much radiation damage to key sensors and memories. Finally, some developed by the Chiba Institute of Technology were able to explore the upper floors of Reactor 2. The researchers designed their Quince to work for up to five hours in the presence of a cobalt-60 source that would generate an average dose of 40 grays per hour.
Direct radiation damage was not the only problem for the Fukushima robots. Reactors are protected by thick concrete walls. Wireless signals fade in and out and fibre-optic cabling becomes an impediment in the cluttered space of a damaged building.
To be close enough to the machines, operators had to wear bulky protective clothing that made teleoperation much harder than it would be in other environments. Several robots went into the building only to fail and get stuck, turning into obstacles for other machines.
The risk of these kinds of failure played into the nuclear industry’s long-term resistance to using robots for repair and decommissioning. Plant operators continued to favour mechanical manipulators operated by humans, separated by both protective clothing and thick lead-heavy glass.
Since Fukushima, attitudes to robots in the nuclear industry have changed, but remote control remains the main strategy. Pratt says humans remain generally better at control and are far better at dealing with the unstructured environments within many older and sometimes damaged installations.
The long-term aim of those working on these systems is to provide robots with greater degrees of autonomy over time. For example, surveillance drones will be flown with operator supervision but the machines are acquiring more intelligence to let them avoid obstacles so they need only respond to simpler, high-level commands. This can overcome one of the problems created by intermittent communications. One instance of this approach was shown when UK-based Createc Robotics recently deployed a drone at Chernobyl and Fukushima, choosing in the latter case to survey the partly collapsed turbine hall for a test of its semi-autonomous mapping techniques.
To get more robots into play in the UK, the NDA has focused its procurement more heavily on universities and smaller specialist companies, some of which are adapting technologies from the oil and gas industry.
The NDA expects it will take many years to develop effective robot decommissioning and handling technologies. It has put together a broad roadmap that currently extends to 2040. Radiation susceptibility remains an issue. Visual sensors are highly susceptible to damage by ionising radiation. However, a mixture of smarter control systems and redundancy should make it possible to at least move robots to a safe point for repair should they start to show signs of failure.
Another design strategy being pursued both in the UK and Japan is to build robots as though they are a moving, smart Swiss-army knife: armed with a variety of detachable limbs and subsystems so they can adapt to conditions and possibly even perform some on-the-fly repairs to themselves.
Slowly, the technology is appearing that can handle and at least put the waste out of harm’s way for a long time, though you might wonder why the process has taken decades to get to this stage of development. ……………. (Goes on to laser developments, again, far from a sure thing.) https://eandt.theiet.org/content/articles/2022/02/plutonium-problems-won-t-go-away/
Latest look inside Fukushima ruins show mounds of melted nuclear fuel
A remote-controlled robot has captured images of melted nuclear fuel
inside Japan’s wrecked Fukushima nuclear plant. A massive earthquake and
tsunami in 2011 damaged cooling systems at the power plant, causing the
meltdown of three reactor cores. Most of their highly radioactive fuel fell
to the bottom of their containment vessels, making its removal extremely
difficult. A previous attempt to send a small robot with cameras into the
Unit 1 reactor failed, but images captured this week by a ROV-A robot show
broken structures, pipes and mounds of what appears to be melted fuel.
Metro 16th Feb 2022 https://metro.co.uk/2022/02/16/take-a-look-inside-the-radioactive-ruins-of-fukushima-nuclear-plant-16113689/
Russia, China concerned over Japan’s plans to dump Fukushima radioactive wate
Russia, China concerned over Japan’s plans to dump Fukushima radioactive water — statement, BEIJING, February 4. /TASS/. Russia and China are concerned over Japan’s plans to dump contaminated water from the wrecked Fukushima nuclear power plant into the ocean, both countries said in a joint statement on Friday.
“Japan’s plans to release nuclear contaminated water from the destroyed Fukushima nuclear plant into the ocean and the potential environmental impact of such actions are of deep concern to the sides,” the statement reads.
In this regard, Moscow and Beijing emphasized that “the disposal of nuclear contaminated water should be handled with responsibility” and carried out in a proper manner based on arrangements between the Japanese side, neighboring states and international organizations………..
At present, over 1.25 million tonnes of water are being stored in steel tanks on the territory of the accident-hit power plant. The water has reportedly been purified of all harmful radioactive substances except for tritium, as there is no technology to rid the water of it. The Japanese government officially permitted to release a significant amount of Fukushima-1 water into the ocean. The water is expected to be dumped into the ocean gradually in small amounts over 30 years. The International Atomic Energy Agency has already announced that it will control this process on a permanent basis…………….
Tokyo Electric Power (TEPCO) specialists constantly pump away this water and put it into special steel reservoirs located on the plant’s territory. However, more than a thousand of them have already been piled up there. The space for these tanks is running out and the limit may be reached already in the summer of 2022. About 140 tonnes of specially treated water are being pumped into them daily. As the Japanese side says, the liquid will be further treated to reduce the amount of tritium before its release into the ocean. https://tass.com/world/1398125
Doubts grow on water-release schedule at Fukushima plant
Doubts grow on water-release schedule at Fukushima plant cTHE ASAHI SHIMBUN, January 31, 2022 Shovel loaders digging pits at the Fukushima No. 1 nuclear power plant on Jan. 17 were a rare sign of progress in the government’s contentious water-discharge plan at the stricken site.
Under the plan, millions of tons of treated but still contaminated water stored at the plant will be released into the sea over decades starting in spring 2023.
However, opposition to the plan remains fierce among local residents, the fishing industry and even overseas governments.
The pits being dug will temporarily hold radioactive water right before the release. But other preparatory work has already been stalled.
The government plans to create an undersea tunnel through which the treated and diluted radioactive water will be released into the sea about 1 kilometer from the plant.
Drilling work for the tunnel was initially scheduled to start early this year, but it was delayed to June.
Some government officials now doubt that the tunnel can be completed in time for the planned water release.
“It would be impossible to construct the underwater tunnel in less than a year,” one official said.
The government in April last year decided to discharge the contaminated water stored at the plant to move forward the decades-long process of decommissioning of the plant.
The accumulation of highly contaminated water has been a serious problem for the government and plant operator Tokyo Electric Power Co. since the Great East Japan Earthquake and tsunami in March 2011 caused the triple meltdown there.
An average of 150 tons of such water was produced each day last year as rainwater and groundwater keeps flowing into the damaged reactor buildings and mixing with water used to cool the melted nuclear fuel.
The contaminated water is treated by a multi-nuclide removal facility, known as ALPS, and stored in tanks. ALPS, however, cannot remove tritium, a beta-emitting radioactive isotope of hydrogen, and others.
The pits are being built to ensure that tritium levels in the treated water after dilution with a large amount of seawater are low enough to be sent to the planned tunnel for discharge into the sea.
Disposal of the contaminated water has become an urgent matter.
TEPCO said the existing 1,061 tanks at the plant are capable of holding a total of 1.37 million tons of water and would be full by around spring next year.
As of Jan. 20, the plant had reached 94 percent of capacity.
The government fears that continuing to add more storage tanks at the plant could jeopardize the overall decommissioning work.
EFFORTS TO EASE CONCERNS DELAYED
The government asked the International Atomic Energy Agency to send an inspection team to examine the safety of the treated radioactive water.
A seal of approval from a credible international body could go a long way in easing domestic and international opposition about the water release plan.
The IAEA team of researchers from 11 countries, including China and South Korea, which are opposed to the water release, was expected to visit Japan in December to begin its on-site inspection.
But that trip was scrapped after a new wave of novel coronavirus infections hit the global community.
Government officials are negotiating with the IAEA for a visit in spring by the team. But it remains unclear when the trip will finally materialize.
The government and TEPCO have also made little progress in gaining support from fishermen and the public, despite holding numerous briefings about the water release plan.
Distrust of the government and the utility remain high in Fukushima Prefecture over their series of mishandling of the nuclear disaster.
Fishermen, in particular, are adamantly opposed to the release of the water into areas where they make their living.
“If you insist on the safety of treated water, why don’t you spray it in your garden or dump it in a river flowing into Tokyo Bay?” Toru Takahashi, a fisherman in Soma, asked government officials at a recent briefing session.
The officials brought with them a huge stack of documents to emphasize the safety of the treated water.
But they lowered their eyes and clammed up when Takahashi and other opponents challenged their view.
“I will never ever drop my opposition,” Takahashi said.
Such opposition has created a headache for leaders of the towns hosting the plant.
They are eager to see progress in the decommissioning work, and getting rid of the huge amount of contaminated water at the plant would be a big step toward rebuilding their affected communities.
After the government’s decision to release the water, Shiro Izawa, mayor of Futaba, a town that co-hosts the plant along with Okuma, called on then industry minister Hiroshi Kajiyama to gain support for the water discharge plan from the public and fisheries to advance the decommissioning process.
Futaba, a town with a population of nearly 7,000 before the nuclear disaster, is the only municipality in Fukushima Prefecture that remains entirely under an evacuation order.
In 2015, Futaba grudgingly became the storage site of contaminated soil and debris gathered in the cleanup of municipalities in the prefecture on the pretext of “moving forward rebuilding.”
If the planned water release is further delayed because of opposition from other municipalities, the future of rebuilding Futaba will remain in doubt.
(This story was compiled from reports by Takuro Yamano, Keitaro Fukuchi, Tsuyoshi Kawamura and Mamoru Nagaya.)
The more radiation, the weirder Fukushima’s fir trees became.
NUCLEAR DISASTER IN JAPAN DID SOMETHING STRANGE TO TREES https://futurism.com/the-byte/nuclear-japan-trees
SOMETHING IS UP WITH THOSE TREES. by ABBY LEE HOOD ( Journalist) They didn’t grow any larger or suddenly become sentient, but the trees outside the Fukushima Daiichi Nuclear Power Plant are definitely acting weird, according to a new study published earlier this month in the journal Plants.
Researchers from multiple universities in Italy and Brazil studied fir trees growing near the plant, which was destroyed in 2011 following a severe earthquake. The scientists studied whorls — nodes where leaves, branches or other plant parts grow from a central point — and found that fir trees around Fukushima exhibited weird growth patterns around them.
“These conifers showed irregular branching at the main axis whorls,” reads the study, spotted by Newsweek. “The frequency of these anomalies corresponded to the environmental radiation dose rate at the observed sites.”
The more radiation, in other words, the weirder the trees got.
Circle of Life
It’s pretty interesting that trees affected by nuclear radiation grow in funky patterns and are still affected by material in the soil near Fukushima. But even more important is the team’s goal of learning how to better take care of people caught up in similar, future disasters, and to create better emergency management plans.
“Ten years have passed since the FNPP accident, and still the large-scale effects are visible,” the researchers concluded. “Learning from past incidents and implementing this knowledge can make a significant difference in terms of lives and costs in healthcare management.”
We may not always be good stewards of the environment around us, but nature seems happy to provide cautionary tales for humanity to learn from all the same.
More on Fukushima weirdness: Scientists Monitoring Radioactive Snakes Near Fukushima Meltdown Site
Fukushima nuclear radiation has had strange effects on plants and trees
Fukushima Radiation Made Japanese Fir Trees Go Haywire After Nuclear Disaster Newsweek, BY ORLANDO JENKINSON ON 1/27/22 Plants in Fukushima are growing in abnormal ways because of the radiation left over from the 2011 nuclear accident, a study suggests.
In a study published on January 15 in the journal Plants, scientists described changes to the structure of plants and trees in areas close to where a partial meltdown occurred at Fukushima Dai-ichi Nuclear Power Plant (FNPP) after an earthquake caused a tsunami that overwhelmed the plant’s cooling systems.
………….. To come to their conclusion, researchers examined the whorls—the places on plants where foliage like leaves, petals or needles spread out from a central point.
Instead of branching out in the expected way, the whorls showed irregular growths and even elimination of some shoots in ways not seen on trees that avoided radiation.
What is more, the number of strange mutations like this corresponded with the amount of radiation the trees were hit with. Researchers said that the rate of mutations was “directly proportional to the dose of ionizing radiation to which the conifers had been exposed.”
The authors of the paper said that another abnormality they found was the “deletion” of shoots of Japanese fir and red pine trees. This happened most often after the spring of 2012, and peaked in 2013, though precisely why remains a mystery.
The paper consequently offered further evidence that ionizing radiation like that produced by nuclear accidents can alter the structure of conifer trees.
The authors noted that the abnormalities they uncovered were like those found on Scots Pine trees in the Chernobyl Exclusion Zone, the 18.6-mile radius surrounding the site of the Chernobyl nuclear disaster in the former Soviet Union in 1986. https://www.newsweek.com/fukushima-radiation-japanese-fir-trees-haywire-nuclear-disaster-1673577
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14 May – online event From Bombs to Data Centres: the Face of Nuclear Colonialism
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