Antinuclear

Australian news, and some related international items

Integrated wind and solar still cheapest, and green hydrogen costs falling fast: CSIRO — RenewEconomy

Wind and solar are still clearly cheapest form of new energy, even with storage and transmission, latest CSIRO report says. Cutting emissions goes hand in hand with lower costs. The post Integrated wind and solar still cheapest, and green hydrogen costs falling fast: CSIRO appeared first on RenewEconomy.

Integrated wind and solar still cheapest, and green hydrogen costs falling fast: CSIRO — RenewEconomy

July 11, 2022 Posted by | Uncategorized | Leave a comment

Edify lands ARENA and NSW funds for advanced battery inverter project in NSW — RenewEconomy

Edify lands ARENA and NSW government funds for part of the big 150MW/300MWh Darlington Point advanced battery project in south west NSW. The post Edify lands ARENA and NSW funds for advanced battery inverter project in NSW appeared first on RenewEconomy.

Edify lands ARENA and NSW funds for advanced battery inverter project in NSW — RenewEconomy

July 11, 2022 Posted by | Uncategorized | Leave a comment

Russia and other nuclear-armed parties must be held to account for violations of non-proliferation treaty

As a model, NPT states can look to the Vienna Declaration – adopted by state parties to another nuclear weapons treaty, the Treaty on the Prohibition of Nuclear Weapons – on June 23 where states condemned “unequivocally any and all nuclear threats, whether they be explicit or implicit and irrespective of the circumstances”.

Let’s not forget that there is a cycle of complicity when it comes to nuclear weapons.

A handful of companies have secured multi-decade, multibillion-dollar contracts to keep nuclear weapons around forever. These companies employ a virtual army of lobbyists and fund think tanks to undermine the long-term solutions that could reduce nuclear arsenals and nuclear risks.

The increase in the obscene amount of money spent on nuclear weapons flies in the face of a commitment to non-proliferationWhen parties meet in August, they must call out nuclear-armed states for violating the historic treaty and international law more broadly

 https://www.scmp.com/comment/opinion/article/3184443/russia-and-other-nuclear-armed-parties-must-be-held-account Alicia Sanders-Zakre and Susi Snyder 9 Jul, 2022

Every minute of 2021, the nine nuclear-armed countries spent US$156,000, almost twice the median US family income, on nuclear weapons designed to destroy cities in a flash of light.

This month, five of these countries – China, France, Russia, the United Kingdom and the United States – will join over 100 others at the United Nations in New York to discuss progress, or lack thereof, on a more-than-50-year-old treaty that commits countries party to the treaty with nuclear weapons to work towards disarmament and all others not to acquire nuclear weapons.

The 1970 Treaty on the Non-Proliferation of Nuclear Weapons (NPT) has 191 state parties, including five of the nine nuclear-armed states. Countries that have joined the treaty meet nearly every year to review its implementation, including month-long conferences every five years where they try to agree on a common plan of action to take it forward.

The 10th NPT Review Conference will be held in August. The last agreed plan of action was adopted over a decade ago, at the 2010 review, and remains largely unimplemented.

The countries getting together in New York should talk about how nuclear-weapon states have violated their commitments to the NPT and under international law more broadly.

The most egregious breach of international law, the threats to use nuclear weapons by Russia – a depositary of the NPT – and its invasion of a non-nuclear-armed state, should be universally and unequivocally condemned by all states parties and in a final outcome document.

As a model, NPT states can look to the Vienna Declaration – adopted by state parties to another nuclear weapons treaty, the Treaty on the Prohibition of Nuclear Weapons – on June 23 where states condemned “unequivocally any and all nuclear threats, whether they be explicit or implicit and irrespective of the circumstances”.

Instead of meeting their obligations under the treaty, nuclear-armed states are doubling down on nuclear spending and engaging in a new nuclear arms race, increasing their spending on nuclear weapons by US$6.5 billion in 2021 over the previous year – and that’s after adjusting for inflation.

Why would these countries blatantly disrespect international law and their obligation to pursue nuclear disarmament? Let’s not forget that there is a cycle of complicity when it comes to nuclear weapons.

A handful of companies have secured multi-decade, multibillion-dollar contracts to keep nuclear weapons around forever. These companies employ a virtual army of lobbyists and fund think tanks to undermine the long-term solutions that could reduce nuclear arsenals and nuclear risks.

New contracts for nuclear-weapons-related manufacturing and development actually increased in 2021 from 2020. Companies in France, the UK and the US were awarded US$30 billion in new contracts – some spanning decades into the future – twice as much as they received in 2020.

At least 12 major think tanks that research and write about nuclear weapons in India, France, the UK and the US collectively received between US$5.5 million and US$10 million from companies that produce nuclear weapons. The CEOs and board members of companies that produce nuclear weapons sit on some of their advisory boards, serve as trustees and are listed as “partners” on their websites.

Nuclear-armed states spent an obscene amount of money on illegal weapons of mass destruction in 2021, while most of the world’s countries support a global nuclear weapons ban. This spending failed to deter a war in Europe and squandered valuable resources that could be better used to address current security challenges, or cope with the outcome of a still raging global pandemic.

This corrupt cycle of wasteful spending must be put to an end, and the first step is calling out the problem. In August, nuclear-armed states must be held to account for their flagrant violation of this historic nuclear weapons treaty and for broader violations of international law.

July 11, 2022 Posted by | Uncategorized | Leave a comment

Nuclear myopia — Promoting nuclear power as a solution to climate change is short-sighted

Contrary to public perception, nuclear power is a significant source of greenhouse gas emissions when considering the amount of fossil fuels required for mining, uranium enrichment, building and decommissioning of power plants, and processing and storing radioactive waste. In fact, nuclear power emits twice as much carbon as solar photovoltaics and six times as much as onshore wind power, according to the nonprofit organization Beyond Nuclear.

If the potentially catastrophic risks to nuclear power plants posed by political instability and military conflict were not apparent prior to Russia’s recent invasion of Ukraine, they are abundantly clear now.

Bright future for clean energy must be holistic and long-term

Nuclear myopia — Beyond Nuclear International Promoting nuclear power as a solution to climate change is short-sighted
By Kim Friedman
We must think holistically about what constitutes “clean energy” when we consider climate change investments and our energy future. President Biden’s recent announcement of his $6 billion effort to save “distressed” nuclear (fission) power plants is misguided and short-sighted.

Although reducing carbon emissions is critical to slowing the pace of climate change, it must not be our only litmus test for moving toward a “clean” energy future, similarly to how our overall health cannot be measured solely by our blood pressure or weight.

In the case of nuclear power, we must consider its high cost compared to renewable energy sources, such as wind and solar. According to Climate Nexus, the minimum cost per megawatt hour to build a new nuclear plant is almost 3 times higher than utility-scale solar ($112 vs. $46, respectively) and almost 4 times higher than wind power ($122 vs. $30, respectively). That’s like paying $70,000 for a car when you could purchase an equivalent car, in terms of its overall value, for one-third or one-quarter of the cost.

There are also numerous environmental and community-based reasons to wean ourselves off of nuclear power. Intercontinental Cry, a non-profit newsroom that produces public-interest journalism centered on Indigenous Peoples, states that 75 percent of uranium mining worldwide occurs on Indigenous land, including in the United States. Furthermore, unlike solar and wind power, uranium reserves are not a renewable resource; eventually, we will run out of uranium.

We have spent over half a century trying to find a suitable storage option for spent fuel rods and have failed miserably. Consequently, these rods, which remain radioactive for as long as 10,000 years, are generally stored on site at active or shuttered plants all over this country. They are sitting ducks for domestic or international terrorists, and they pose a serious potential threat to surrounding communities’ drinking water supplies if radioactive water leaks and makes its way into the ground.

Contrary to public perception, nuclear power is a significant source of greenhouse gas emissions when considering the amount of fossil fuels required for mining, uranium enrichment, building and decommissioning of power plants, and processing and storing radioactive waste. In fact, nuclear power emits twice as much carbon as solar photovoltaics and six times as much as onshore wind power, according to the nonprofit organization Beyond Nuclear. …………………… more https://beyondnuclearinternational.org/2022/07/10/nuclear-myopia/

July 11, 2022 Posted by | Uncategorized | Leave a comment

Not responsible — Beyond Nuclear International

Court says Japan government could not have prevented Fukushima tsunami damage

Not responsible — Beyond Nuclear International

July 11, 2022 Posted by | Uncategorized | Leave a comment

Where to in 2045? Contaminated Soil from the Nuclear Power Plant Accident: The Present Location of Interim Storage Facilities, Fukushima.

July 3, 2022
Contaminated removed soil and other materials generated by decontamination following the accident at TEPCO’s Fukushima Daiichi Nuclear Power Plant are temporarily stored at an interim storage facility adjacent to the plant. Decontamination outside of the difficult-to-return zones has been largely completed, and decontamination is also progressing in the specified restoration and rehabilitation base areas (restoration bases) within the difficult-to-return zones where evacuation orders are expected to be lifted this spring or later. However, there is no concrete plan for the decontamination of areas outside of the restoration centers that are difficult to return to, and there has been no progress in discussions regarding the removal of contaminated soil outside of Fukushima Prefecture. Eleven years after the accident, the problem of radioactive waste remains unresolved. (The problem of radioactive waste remains unresolved even 11 years after the accident.)

◆Total amount of contaminated waste is not foreseeable
 According to the Ministry of the Environment, the amount of contaminated soil generated by decontamination in areas other than the difficult-to-return zones is estimated to be 14 million cubic meters, an enormous amount equivalent to 11 times the size of the Tokyo Dome. The soil is scheduled to be delivered to an interim storage facility by March 2010. In the remaining difficult-to-return zones in the seven municipalities of Fukushima Prefecture, six municipalities (excluding Minamisoma City) have been designated as “specific restoration base areas (restoration bases)” where decontamination work will be carried out ahead of other areas. It is estimated that 1.6 to 2 million cubic meters of contaminated soil will be generated in the decontamination of the reconstruction bases.
 In addition, the government decided in August 2009 to lift the evacuation order for difficult-to-return zones outside of the restoration centers by decontaminating homes and other structures on request of those who wish to return. The Ministry of the Environment said, “We will proceed with the acquisition of land and the construction of storage facilities while keeping a close eye on the amount of soil that can be brought in. We do not know the maximum amount that can be brought in.

◆Unclear whether the waste will be transported out of Fukushima Prefecture
 As the name implies, storage at interim storage facilities is considered “temporary” for final disposal. The government has promised to remove the contaminated soil to a final disposal site outside of Fukushima Prefecture in 2045, 30 years after the storage began in 2015. However, it is not known whether there are municipalities that will accept the waste contaminated by the nuclear accident, and the candidate site has not yet been decided.
 In addition, three-quarters of the total amount of contaminated soil in storage currently contains less than 8,000 becquerels of radioactive cesium per kilogram of soil, which is the same level as that of the soil that is normally incinerated or landfilled. The government plans to reuse contaminated soil with less than 8,000 becquerels per kilogram in public works projects such as road construction. However, the use of contaminated soil is strongly opposed by local residents, and efforts to put this into practical use have run into difficulties. The Ministry of the Environment states that it will “continue its efforts to develop technologies and gain the understanding of related parties.

Interim storage facilities are located around the Fukushima Daiichi Nuclear Power Plant and cover an area of 1,600 hectares. Of the privately owned land, which accounts for about 80% of the total area, 93% has been acquired by the government. The delivery of contaminated soil generated outside of the difficult-to-return zone is expected to be completed by the end of FY2022.

福島第一原発を囲むようにして汚染土を一時保管する中間貯蔵施設が広がる=福島県大熊町で(2022年1月25日、本社ヘリ「おおづる」から伊藤遼撮影)

https://www.tokyo-np.co.jp/article/161520?fbclid=IwAR1aeeM_DVPdjUmckTFzItQfpsfj9wKIRu9IbxaiTzDwnqK50g3THWmCd_0

July 11, 2022 Posted by | Uncategorized | Leave a comment

Decadal trends in 137Cs concentrations in the bark and wood of trees contaminated by the Fukushima nuclear accident.

Published: 04 July 2022

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.

Locations of the monitoring sites and initial deposition densities of 137Cs (decay-corrected to July 2, 2011) following the Fukushima nuclear accident in Fukushima and Ibaraki Prefectures. Open circles indicate the monitoring sites and the cross mark indicates the Fukushima Dai-ichi Nuclear Power Plant. Data on the deposition density were provided by MEXT19,20 and refined by Kato et al.21. The map was created using R (version 4.1.0)22 with ggplot2 (version 3.3.5)23 and sf (version 1.0–0)24 packages.

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.

https://www.nature.com/articles/s41598-022-14576-1

July 11, 2022 Posted by | Uncategorized | Leave a comment

Fears that UK environment bills could be sidelined in Tory leadership race

 Greg Clark is now being given the task of deciding on the proposed
Whitehaven coalmine in Cumbria but has not worked in the department for
years. On Thursday the government also announced it was postponing for a
second time a decision on whether to approve the £20bn Sizewell C nuclear
power plant in Suffolk.

The treasury, with its new chancellor, Nadhim
Zahawi, is to decide whether to go ahead with a windfall tax on oil and gas
companies. A decision on this is due next week, and while it is a popular
measure with voters it is unknown whether Zahawi will press ahead with it,
and whether he will remove the loophole that would provide tax relief for
new oil and gas.

There could also be a wait of some time for a government
response to the fracking review. The British Geological Survey has given
its report on the safety and feasibility of fracking to the Department for
Business, Energy and Industrial Strategy (BEIS), but the results will not
be seen until the government responds to it, with BEIS sources saying they
do not know when that will be.

BEIS will also have to deal with the cost of
living and energy crises, with insulation measures and direct support for
the poorest households the most urgent priority. The energy security bill
is also coming, with an opportunity to overhaul the energy market so the
low cost of renewable electricity feeds through to consumers.

Greenpeace
UK’s policy director, Doug Parr, said: “No matter how dire things may
seem in Westminster right now, when it comes to the climate crisis things
risk getting much worse without immediate action. However, delays to
decisions on whether or not to backtrack on coal and build a new mine, or
waste untold time and money on a new nuclear power station that will only
distract from genuine energy solutions, could be taken as positive, if they
were set to be given the green light as rumours suggest. “This
parliamentary reset must deliver a new prime minister that will take bolder
action on climate and nature. They must invest in real solutions like
cheap, clean, homegrown renewables and fixing the vast number of cold,
damp, energy-wasting homes. If not, we may lose even more time and find
ourselves in a far worse position than we already are.”

 Guardian 9th July 2022

https://www.theguardian.com/environment/2022/jul/09/fears-environment-bills-could-sidelined-tory-leadership-race

July 11, 2022 Posted by | Uncategorized | Leave a comment

Alaska burning

America’s great northern expanse is burning. Alaska, the US’s largest
state, is experiencing an extreme fire season with wildfires scorching over
2.3million acres since January – an area roughly two and a half times the
size of Rhode Island. That’s far more land burned than the state normally
sees in a year, and fire season is far from over.

 Independent 8th July 2022

https://www.independent.co.uk/climate-change/news/alaska-wildfire-climate-danger-b2118449.html

July 11, 2022 Posted by | Uncategorized | Leave a comment

July 10 Energy News — geoharvey

Opinion:  ¶ “How Inflation Could Be Cut By FERC And Renewable Energy Doubled” • Inflation is one of the chief financial challenges in America. A solution lies in plain sight, because technologies like wind and solar power can help stabilize domestic energy prices and prevent future price spikes due to over-reliance on volatile international fuel […]

July 10 Energy News — geoharvey

July 11, 2022 Posted by | Uncategorized | Leave a comment