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Radioactive Micro-particles at Fukushima Daiichi

Caesium-rich micro-particles: A window into the meltdown events at the Fukushima Daiichi Nuclear Power Plant
Abstract
The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors. During the meltdowns, a type of condensed particle, a caesium-rich micro-particle (CsMP), formed inside the reactors via unknown processes. Here we report the chemical and physical processes of CsMP formation inside the reactors during the meltdowns based on atomic-resolution electron microscopy of CsMPs discovered near the FDNPP. All of the CsMPs (with sizes of 2.0–3.4 μm) comprise SiO2 glass matrices and ~10-nm-sized Zn–Fe-oxide nanoparticles associated with a wide range of Cs concentrations (1.1–19 wt% Cs as Cs2O). Trace amounts of U are also associated with the Zn–Fe oxides. The nano-texture in the CsMPs records multiple reaction-process steps during meltdown in the severe FDNPP accident: Melted fuel (molten core)-concrete interactions (MCCIs), incorporating various airborne fission product nanoparticles, including CsOH and CsCl, proceeded via SiO2 condensation over aggregates of Zn-Fe oxide nanoparticles originating from the failure of the reactor pressure vessels. Still, CsMPs provide a mechanism by which volatile and low-volatility radionuclides such as U can reach the environment and should be considered in the migration model of Cs and radionuclides in the current environment surrounding the FDNPP.
The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors1,2,3, which caused the second-most serious nuclear accident in history4, resulting in serious environmental threats with the release of ~5.2 × 1017 becquerels (Bq) of radionuclides5 in Fukushima prefecture. Many of the resulting problems, including radioactive caesium contamination of the surface environment, have yet to be resolved6. The most challenging issue remaining is the treatment of the four damaged reactors. Decommissioning of Units #1–4 is currently ongoing7, although the properties of the melted fuels mixed with reactor components, referred to as debris, and the conditions inside the reactors remain unknown because the high-radiation field prevents access7.
Until now, the reactions that occurred in the FDNPP reactors have been only inferred based on indirect evidence3. It is believed that radioactive Cs was liberated from the irradiated fuel when the temperature of the fuel rose above 2,200 K8 after the cooling systems shut down in Units #1–3. Other radionuclides were released in amounts depending on their respective volatilities9 rather than in amounts based on their estimated presence in the nuclear fuel, which was primarily composed of UO28,10. Thus, a large portion of the fission products (FPs), including radioactive Cs still remain in the damaged reactors and in contact with the cooling water11. To carry out an adequate decommissioning process, it is of critical importance to understand the physical and chemical state of the radionuclides inside the reactors12. In particular, most of the irradiated fuels melted in Units #1 and #3, while a lesser amount or none of the fuels underwent melting in Unit #23,13. Melted fuel accumulated at the bottom of the reactor pressure vessels (RPVs), which eventually caused the RPVs to rupture, leading to reactions with the concrete pedestals of the primary-containment vessels (PCVs)14, a process known as molten core concrete interaction (MCCI)15. There remains considerable uncertainty about the extent of the MCCI in the reactors and the state of the melted fuel.
Caesium-rich micro-particles (CsMPs) originating from the FDNPP were first found in atmospheric particles some 170 km southwest of the FDNPP16,17. These particles represent condensed matter that formed within the reactors during meltdown, and they provide important information on the physical and chemical characteristics of the radioactive material inside the reactors. This study unravels the formation process of the CsMPs based on their chemical and structural properties at the atomic scale utilizing a high-resolution transmission electron microscopy (HRTEM) in conjunction with conventional radio-analytical techniques.
Methods
Sample description
The sampling campaign was conducted on 16 March 2012. The Ottozawa soil sample (OTZ) was collected from the top ~1 cm of soil in a paddy located ~4 km west of the FDNPP in Okuma Town, Futaba County, Fukushima. The soil was primarily composed of clay minerals, quartz and feldspars. Because entering the area was still restricted due to the high radiation dose, the locality had not been artificially disturbed. The radiation dose ~1 m above the ground was 84 μSv/h. The gravel sample from Koirino (KOI) was collected under the drainpipe of the assembly house. The house is located 2.9 km southwest of the FDNPP. The radiation dose beneath the drainpipe was extremely high compared with the surroundings, with a sampling area dose as high as 630 μSv/h. The gravel samples were carefully collected from the surface of the ground using a hand shovel, and placed in plastic bags. The aquaculture centre (AQC) soil samples were collected from the side ditch of an aquaculture centre located ~2 km south of the FDNPP.
Separation of CsMPs
The procedure for separating CsMPs from the soil samples is schematically illustrated in Fig. S1. Prior to the procedure, both samples were sieved through a 114 μm mesh. The powder samples were dispersed on grid paper and covered with a plastic sheet, and an imaging plate (Fuji film, BAS-SR 2025) was placed on the samples for 5–25 min. Autoradiograph images with pixel sizes of 50–100 μm were recorded using an imaging-plate reader. After the positions of intensely radioactive spots were identified, droplets of pure water were added to these positions and then drawn using a pipette to produce suspensions with small amounts of soil particles by dilution with pure water (Procedures 3–9 in Fig. S1). This procedure was repeated until the suspension did not contain a significant amount of soil particles. Subsequently, positions containing hot spots were selected using pieces of double-stick carbon tape that were cut as small as possible with a blade. The pieces of tape were checked by autoradiograph imaging so that scanning electron microscopy (SEM) observation could be performed to obtain the CsMPs with maximum efficiency. Prior to SEM analysis, the pieces of tape were placed on an aluminium plate and coated with carbon using a carbon coater (SANYU SC-701C). The CsMPs were found using an SEM (Shimadzu, SS550 and Hitachi, SU6600) equipped with an energy dispersive X-ray spectrometer (EDX, EDAX Genesis) using acceleration voltages of 5–25 kV for imaging details of the surface morphology and 15–25 kV for elemental analysis, including area analysis and elemental mapping.
Preparation of the TEM specimen
A focused ion beam (FIB) instrument (FEI, Quanta 3D FEG 200i Dual Beam) was utilised to prepare a thin foil of individual CsMPs with diameters of a few μm. Gallium was used as an ion source, and W deposition was used to minimise damage from the ion bombardment. Prior to application of the FIB, each SEM specimen was coated with ~40 nm-thick gold. The current and accelerating voltage of the ion beam were adjusted from 100 pA to 30 nA and 5–30 kV, respectively, depending on the progress of the thinning and on sample properties such as hardness and size. Each thinned piece was attached to the semilunar-shaped Cu grid for FIB and further thinned by an ion beam operating at 5 kV.
TEM analysis
HRTEM with EDX and a high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) were performed using a JEOL JEM-ARM200F and JEM-ARM200CF with an acceleration voltage of 200 kV. The JEOL Analysis Station software was used to control the STEM-EDX mapping. To minimise the effects of sample drift, a drift-correction mode was used during acquisition of the elemental map. The STEM probe size was ~0.13 nm, generating ~140 pA of current when 40 μm of the condenser lens aperture was inserted. The collection angle of the HAADF detector was ~97–256 mrad.
Gamma spectrometry
The 134Cs and 137Cs radioactivities of the CsMPs were determined using gamma spectrometry. The radioactivity of an additional micro-particle with a size of ~400 μm obtained from the surface soil in Fukushima was precisely determined at the radioisotope centre in Tsukuba University, Japan, and utilised as a standard point specimen for 134Cs and 137Cs. The radioactivity of the point source standard was 23.9 Bq for 134Cs and 94.6 Bq for 137Cs as of 29 September 2015. The measurement of radioactivity was performed on the CsMPs and the point source standard using germanium semi-conductor detectors GMX23, GMX30 and GMX40 (all from SEIKO E&G) at the centre for radioisotopes in Kyushu University, Japan. The acquisition times were: 12,305 s for the KOI sample, using GMX30; 86,414 s for the OTZ sample, using GMX40; and 263,001 s for the AQC sample, using GMX23.
Results
The CsMPs were discovered in three samples within ~4 km of the FDNPP: in gravel soil at the assembly house in Koirino, in soil from a side ditch at an aquaculture centre and in paddy soil in Ottozawa (Fig. 1). The samples are hereafter labelled KOI, AQC and OTZ, respectively. The radioactivity of the CsMPs and the relevant parameters are summarised in Table 1. The 134Cs/137Cs radioactivity ratio of the samples is 0.97–1.1, with an average of 1.04, which approximately corresponds to ~26 GWd/tU according to OrigenArp calculations18. Because of the heterogeneity within even the irradiated fuels in a single reactor, the source reactor unit could not be determined based only on the isotopic or radioactivity ratios. The radioactivity per unit mass of the CsMPs calculated assuming that the radioactivity for SiO2 glass19 with a density of 2.6 g/cm3 varies from 9.5 × 1010 to 4.4 × 1011 (Bq/g), which is comparable with values reported for CsMPs from Tokyo20.
1
Figure 1
Locations of the samples used in this study.
2
Table 1
Summary of the radioactivity and the associated parameters of three CsMPs in the present study.
 
The KOI CsMP was mainly composed of Si, Fe, Zn and Cs (Fig. 2 and Table S1). A HAADF-STEM image of the cross section shows two large pores of approximately 500 nm and numerous small pores in sizes ranging from 10–200 nm, indicating that some gases (such as H2, H2O, CO and CO2) were trapped through sparging during the MCCI (Fig. 3a). Selected area electron diffraction (SAED) patterns revealed diffuse diffraction maxima that correspond to an amorphous structure (Fig. 3b). Trace elements, including K, Cl, Sn, Rb, Pb and Mn, were detected by STEM energy dispersive X-ray (EDX) area analysis (Table S1).
3.jpg
Figure 2
Secondary electron images of three CsMPs; KOI, OTZ, and AQC, associated with the energy dispersive X-ray spectrum (EDX) maps of the major constituents.
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Figure 3
(a) HAADF-STEM image of the focussed ion beam (FIB)-prepared specimen of the KOI Cs-rich micro-particle, with its original shape traced by a white dotted line. The yellow and orange open triangles indicate rod-like nanoparticles consisting primarily of Cs. (b) SAED pattern of the area indicated in (a). (c) A HAADF-STEM image associated with elemental maps of the major constituents. (d) HAADF-STEM image with the elemental maps of the CsMP at high resolution, showing the heterogeneous occurrence of Fe–Zn-oxide nanoparticles associated with Sn and Cs. (e) HRTEM image of the Fe–Zn oxide and the fast Fourier transformed (FFT) image. (f) A HRTEM image of a rod-shaped Cs nanoparticle present in a pore indicated by the yellow arrow in (a).
 
An elemental map of the CsMP constituents shows the synchronised distribution of Si, O, Fe and Zn, although only Cs is concentrated in the particle cores (Fig. 3c). Although the SAED exhibits diffuse diffraction maxima (Fig. 3b), a magnified image reveals that Zn, Fe, Sn and Cs are associated with nanoparticles as small as <10 nm distributed within the SiO2 matrix (Fig. 3d) that were identified to be franklinite structures (ZnFe2O4, Fd3m, Z = 8)21 (Fig. 3e). Several rod-like nanoparticles, indicated by yellow arrows, are present (Fig. 3a). An HRTEM image of the rod-shaped nanoparticle reveals a mostly amorphous contrast, with a small portion that is still crystalline (Fig. 3f). Based on the d-spacing in the HRTEM image (Fig. 3g) and the composition of primarily Cs and O (Fig. 4a–c), these rod-shaped particles were identified as Cs hydroxides, CsOH•H2O22. Nano-sized inclusions of ZnCl2 and CsCl were also identified (Fig. 4d,e).
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Figure 4
(a) The STEM-EDX spectrum of a rod-like nanoparticle shown in Fig. 3a. (b) HAADF-STEM image of the core region in the KOI obtained in the second session, showing that the rod-like Cs nanoparticle in the large pore degraded. (c) EDX spectrum of the area indicated by the red square in the left image. The composition of the degraded particle also revealed the Cs as the major constituent. (d) HAADF-STEM image of nano-sized inclusion of ZnCl2. (e) HAADF-STEM image of nano-sized inclusion of CsCl.
 
In the OTZ CsMP, there are no pores, and the particle appears to have a homogeneous composition except for an Fe-oxide inclusion (Fig. 5a,b). However, like the KOI CsMP, the OTZ CsMP is composed of an amorphous SiO2 glass matrix along with Fe–Zn-oxide nanoparticles of <10 nm in size (Fig. 5c); these nanoparticles were identified as franklinite, based on the FFT image and SAED pattern (Fig. 5d,e). Franklinite was the only nanomaterial for which the structure was convincingly characterized. Caesium, Cl and Sn were associated with the franklinite for the most part; however, an inclusion of CsCl associated with ZnCl is also present (Fig. 5f). Remarkably, the area indicated by the yellow square in Fig. 5a contains nanoparticles with peaks of U Mα, Lα and Lβ in the EDX spectrum (Fig. 5g). Point analyses of the particles (edx1 and 2) exhibited further distinctive U peaks without interference from Rb (red line in the spectrum). The HAADF-STEM image resolved no UO2 crystal, only franklinite associated with a small amount of U.
6
Figure 5
(a) HAADF-STEM image of the FIB-prepared OTZ CsMP. The inset is the SAED pattern obtained from the top thin area. White dotted curves represent the original shape of the particle before FIB thinning. (b) Elemental maps of the CsMP showing the distribution of major constituents. (c) Enlarged HAADF-STEM image with the elemental maps of major constituents, showing numerous Fe–Zn nanoparticles associated with Sn, Cs and Cl in the Si matrix. (d) Fe–Zn-oxide nanoparticle identified as franklinite. (e) SAED pattern exhibiting faint diffraction rings in diffuse halo, which are confirmed to be caused by franklinite. (f) HAADF-STEM image with elemental maps revealing the presence of CsCl domains. (g) HAADF-STEM image of the area indicated by the yellow square in (a) showing aggregation of franklinite nanoparticles. Comparison of edx spectra (edx1 and 2 in red line) of the point analysis with the spectrum obtained by the area analysis (black line) reveals the presence of U peaks.
 
The AQC CsMP exhibits a spherical shape (Fig. 6a) containing a spherical W oxide core as large as ~1 μm in diameter (Fig. 6b), which indicates that W oxide initially melted to form a droplet that served as a nucleation centre for CsMP formation. Otherwise, the AQC CsMP has a composition similar to that of the KOI and OTZ CsMPs, that is, Zn–Fe-oxide nanoparticles embedded in an SiO2 glass matrix (Fig. 6c–e). Some fission-product nanoparticles consisting of Ag and Sb were characterized in the CsMP as well (Fig. 6f).
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Figure 6
(a) A HAADF-STEM image of the cross-section of AQC CsMP prepared by FIB. (b) The STEM-EDX elemental maps of the major constituents. (c) SAED pattern of top thin area of FIB specimen shown in (a). (d) Magnified HAADF-STEM image of the thin area of FIB specimen associated with STEM-EDX elemental maps. (e) HRTEM image of a Zn–Fe oxide and the FFT image of the area outlined by the white square. (f) HAADF-STEM image of a fission product nanoparticle consisting of Ag and Sb.
 
The STEM-EDX area analysis (~100 × 100 μm) and point analyses of individual Zn–Fe oxides revealed that the Si concentrations are linearly correlated with the Zn + Fe content (Fig. 7a,b), indicating that the CsMPs are essentially composed of SiO2 glass and Fe–Zn-oxide nanoparticles, with the number of nanoparticles directly reflecting the concentrations of Fe and Zn. The Cs concentration derived from the area analysis also has a linear correlation with the Si content (Fig. 7c), whereas the Cs concentrations in the individual Fe–Zn oxide particles are scattered without correlation to the Si content (Fig. 7d). Such differences can be attributed to either variations in the concentration of Cs associated with Fe–Zn-oxide nanoparticles and/or intrinsic Cs species such as Cs(OH) and CsCl. Indeed, some area analyses of the KOI CsMP tended toward high Cs content (yellow circles) because of the presence of intrinsic Cs particles trapped inside the CsMP. The Zn concentration is positively correlated with Fe concentration towards the ideal Zn/Fe ratio of franklinite, as indicated by the solid line (Fig. 7e). The deviation toward a higher amount of Zn is a result of the presence of ZnCl2 inclusions.
8.jpg
Figure 7
(a–d) Diagrams showing compositional relationship between Si and Fe + Zn (a,b), and between Si and Cs (c,d). (a,c): results of area analysis. (b,d): results of point analysis. (e) Correlation between Zn and Fe contents with a line of ideal composition of franklinite (ZnFe2O4). Correlations between all other elements measured in the CsMPs are given in Figs S2 and S3. *The TKY data are from Imoto et al. (2017)20.
 
Discussion
As was shown in previous experiments15,23,24, the occurrence of Cs and other FP nanoparticles strongly suggests that volatile FPs (Cs, I, Xe, Te, Ag and Rb)9, which accumulated in the gap between the fuel and the cladding during reactor operation, were released either immediately after cladding failure or during the melting of the fuel rods in the FDNPP prior to MCCI. Thus, the atmosphere inside the RPVs must have been filled with aerosol particles associated with Cs, gaseous Cs species, water vapour and hydrogen gas. Interactions between the melted core and Fe in the structural materials of the reactor during vessel failure then produced large amounts of Fe–Zn-oxide nanoparticles.
As recent results20,25 showed, the major and trace elements of the CsMPs were derived from elements inside the reactor during the meltdowns; however, the compositions are markedly different from those in the debris12, which consists of a mixture of melted core, reactor materials and concrete. Possible sources of the constituent elements are as the follows: Sn was part of a Zr–Sn alloy; Fe and Mn were constituents of the reactor pressure vessel; Si was derived from siliceous concrete released during the molten-core–concrete interaction3,23; Cs, Rb, Pb and Sn were fission products contained in the irradiated fuels; Cl was from seawater and Zn was routinely added to the reactor water to prevent radioactive corrosion of steel by formation of a protective oxide layer. Tungsten is present as an impurity in zircaloy and most stainless steels26. Although W is a promising element with extremely high heat resistance (a melting temperature of 3687 K), the oxidized form can be easily melted at relatively low temperature of ~1746 K19. It is plausible that the presence of water vapour dramatically enhanced the oxidation of the stainless steel26.
As reported in the MCCI experimental study22,23, when the melted cores hit the siliceous concrete pedestal, SiO(g) was generated as a consequence of Zr oxidation at a temperature >2,143 K. In this study, it was found that SiO(g) eventually condensed to SiO2 glass rather than forming Si metal or SiC, indicating that there was some oxygen within the reactor PCVs at the FDNPP. The presence of oxygen affects the volatilization temperature of radionuclides in the fuel such as U27. The oxidised form of U oxide fuel can volatilise at ~1,900 K by 10% of the total UO2, whereas for non-oxidized form of UO2 the figure is nearly 0% at 2,700 K28. Thus, it is plausible that the trace amounts of U associated with franklinite are evidence of the volatilisation of slightly oxidised UO2. The absence of UO2 fragments in the CsMPs suggest that fuel fragments were not directly incorporated into the CsMPs during the MCCI.
The airborne CsOH nanoparticles that formed in the PCVs prior to MCCI were trapped during the MCCI events. Considering that CsOH is stable as a solid at temperatures <615 K19, which is much lower than the temperature of SiO2 solidification, ~1995 K19, it is likely that the CsMP rapidly cooled and solidified without degrading the CsOH particles, which is consistent with the glassy structure of the SiO2 matrix. The CsOH particles might have decomposed if they were trapped in pores that contained water vapour and then recrystallized while the CsMP cooled down.
In addition, at the time of MCCI, the other gases (H2, H2O, CO and CO2) are typically sparged from the molten corium pool and must have been trapped in the micro-particles during the condensation of SiO(g). The trapped gases created the porous texture, and the SiO2(l) rapidly solidified into glassy SiO2, thus retaining numerous pores. Thus, the pore found within the KOI CsMPs was probably filled with CO2 and water vapour, in addition to possible gaseous decay daughters, due to the oxidizing conditions. The difference in the micro-texture with (KOI) or without (OTZ and AQC) pores possibly represents a local variation in the amount of vapours trapped during condensation of the SiO(g).
The formation process of CsMPs in the FDNPP was clearly different from that of the micro-particles reported in the previous MCCI experiments23,29,30. The nanoscale textures of the CsMPs revealed several processes during meltdown: (i) FPs, such as Cs, were released to form nanoparticles or were present in mist droplets during the meltdown; (ii) many Zn–Fe-oxide nanoparticles formed during the failure of the RPVs, and Cs dissolved in mist droplets attached to the surfaces of airborne Zn–Fe-oxide nanoparticles; (iii) the molten fuels that melted through the RPVs hit the concrete pedestal and generated SiO gas at >2,000 K, which immediately condensed as SiO2 over the Zn–Fe-oxide nanoparticles and incorporated the FP nanoparticles.
A recent study reported interesting phenomena during a laboratory experiment involving CsOH adsorption onto a stainless-steel surface at an elevated temperature31. The authors found that CsOH can easily adsorb onto an Fe-oxide surface. Their results are consistent with our results revealing a close association of CsOH with Fe–Zn-oxide nanoparticles. However, the resulting product of chemisorption, CsFeSiO4, which was characterized in their study, was not observed in the present study; Si occurs as pure SiO2. The difference strongly suggests that the CsMP did not form in the process where the melted fuel encountered the material of the RPV, but instead formed via another reaction process, most likely interaction with the concrete pedestal, as suggested in the present study.
As a recent study reported that ~90% of the Cs radioactivity derived from CsMPs during the initial fallout of radioactive Cs in Tokyo20, CsMPs with FP nanoparticles are significant sources of radioactive Cs and FPs for the surface environment in Fukushima. Although the contribution of the CsMPs to the total inventory of radioactivity in the contaminated area in Fukushima remains to be determined, the nanoscale physical and chemical properties of the CsMPs provide clues for understanding the mechanisms of Cs release and the stability of Cs after dispersal to the environment. Although their total activity is low, CsMPs are yet another vector for the dispersion of low-volatility radionuclides, such as U, in addition to volatile radionuclides, to the surrounding environment. Thus, the migration of CsMPs in the environment should be taken into account in the Cs transport model of the Fukushima environment in order to gain a better understanding of the impact and dynamics of radionuclide contamination.
Conclusions
The sequence of chemical and physical processes inside the reactors during the meltdowns in the FDNPP have been unravelled based on state-of-the-art atomic-resolution electron microscopy of CsMPs. The CsMPs are as small as a few microns and comprise SiO2 glass matrices and ~10 nm-sized Zn–Fe-oxide nanoparticles associated with up to ~20 wt% of Cs, occasionally accompanied by trace amounts of U. The micro-texture of the CsMPs reveals that various airborne fission-product nanoparticles were first released from the fuels before and during meltdowns. Subsequently, RPV failure occurred and a large number of Zn–Fe-oxide nanoparticles were produced. Finally, the melted core interacted with concrete and the MCCI proceeded via SiO2 condensation encompassing the Zn–Fe-oxide nanoparticles, incorporating the fission-product nanoparticles. The present study demonstrates that the CsMPs provide an important clue for understanding the reactions and conditions inside the reactors. On the other hand, because of the extremely high radioactivity per unit mass, ~1011 Bq/g, CsMPs can be a significant source of the radiation dose in the ambient environment in Fukushima. In addition, CsMPs are an important carrier by which volatile and low-volatility radionuclides such as U reach the environment.
 
Acknowledgments
This study is partially supported by JST Initiatives for Atomic Energy Basic and Generic Strategic Research and by a Grant-in-Aid for Scientific Research (KAKENHI) from the Japan Society for the Promotion of Science (16K12585, 16H04634, No. JP26257402). SU is also supported by ESPEC Foundation for Global Environment Research and Technology (Charitable Trust) (ESPEC Prize for the Encouragement of Environmental Studies). The authors are grateful to Dr. Watanabe for her assistance on SEM analyses at the Centre of Advanced Instrumental Analysis, Kyushu University. The findings and conclusions of the authors of this paper do not necessarily state or reflect those of the JST.
Footnotes
The authors declare no competing financial interests.
Author Contributions S.U. conceived the idea, designed all experiments, and wrote the manuscript. G.F. and J.I. performed measurements and data analysis. A.O. conducted TEM analysis. T.O. and K.N. provided navigation during field research in Fukushima. S.Y. performed gamma spectroscopy at Tsukuba University. B.G. and R.C.E. provided constructive comments and thorough editing on the manuscript.
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February 5, 2018 Posted by | Fukushima 2018 | , | Leave a comment

Shipments of green laver seaweed from Fukushima resume after seven-year hiatus

As usual I would strongly recommend you to stay away from Japanese food products for safety’s sake. For the ones among you fond of sushi, if you eat sushi in a restaurant please make sure that they are using a non Japanese origin nori wrapping for their sushi, if you make your own sushi at home you better use non Japanese nori, Korean or Taiwanese…
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Green laver, known as aonori (アオノリ; 青海苔) in Japan and parae (파래) in Korean, is a type of edible green seaweed, including species from the genera Monostroma and Enteromorpha. It is commercially cultivated in some bay areas in Japan, Korea, and Taiwan.
It is used in its dried form for Japanese soups, tempura, and material for manufacturing dried nori and tsukudani and rice.
Nori is familiar in the United States and other countries as an ingredient of sushi, being referred to as “nori” (as the Japanese do) or simply as seaweed. Finished products are made by a shredding and rack-drying process that resembles papermaking.
 
SOMA, FUKUSHIMA PREF. – Shipments of green laver from Fukushima Prefecture restarted Monday for the first time in about seven years.
 
Radiation levels for the green laver, a kind of seaweed, were confirmed to be far below the government limit despite concern about contamination due to the crisis at the Fukushima No. 1 nuclear plant, officials said.
 
About 740 kilograms of green laver harvested Monday at aqua farms near Matsukawaura fishing port in the city of Soma was delivered to a local processing plant after being dehydrated to remove pebbles and other objects.
 
Fukushima was a major production area for green laver until the March 2011 tsunami caused major damage to local aqua farms and the port. The Fukushima product is used mainly for ramen and tsukudani (preserved foods), boiled down in soy sauce.
 
“Matsukawaura green laver features a good scent,” said Yuichi Okamura, a 62-year-old member of a local fisheries cooperative. “It’s as beautiful as before the disaster.”
 
Green laver from the prefecture is expected to be available only locally for the time being, as farming it will be on a trial basis for now.
 
Following the March 2011 tsunami and nuclear crisis, the Fukushima Prefectural Federation of Fisheries Co-operative Associations refrained from coastal fishery operations.
 
The test farming, carried out by local fishermen, is taking place more than 10 kilometers from the crippled nuclear plant.
 

February 5, 2018 Posted by | Uncategorized | 1 Comment

Once again, they’re contemplating a WINNABLE WAR !

They’re Talking About “Winnable” Nuclear War Again, February 03, 2018, By William Rivers Pitt, Truthout | “……… The missiles are still there. Thousands and thousands of them, marking time in their holes like funnel-web spiders. The astonishingly toxic byproduct left by their creation is still there, entombed in places like Yucca Mountain, and will be there for thousands of years unless it leaks or is stolen. The ability of a sitting president to use them is still there.

Some 25 years ago, we mostly broke the habit of building and testing more of these engines of annihilation, an absolute good in every sense. Not entirely, to be sure: The nuclear weapons program had its own gravity long before Trump came along, and it was President Obama who first put the trillion dollar weapons modernization program on the table. Still, it feels as if we’ve forgotten the things still exist and are existentially lethal…….

Not even Trump’s ongoing middle school shoving match with North Korea’s Kim Jong-un and his growing nuclear toybox appears to have ruffled a great many feathers around here. Perhaps it’s the surreal nature of this president and his administration that explains our national shrug at this incredibly dangerous, feckless faceoff. It’s a strange plot twist in a weird animation starring two cartoon characters ordering bombs from the Acme catalog. Who could take these guys seriously?

Enter Robert R. Monroe, Vice Admiral, US Navy (Ret.) and his recent article in The Hill titled, “Only Trump Can Restore America’s Ability to Win a Nuclear War.” Vice Admiral Monroe, former director of the Defense Nuclear Agency, is the kind of man Curtis LeMay would have recognized as a brother on sight. “When the Cold War ended in 1991,” laments Monroe in his opening line, “America made an unwise decision.”

It goes downhill from there. “Ongoing nuclear programs were stopped,” seethes Monroe. “Budgets were cut. New nuclear capabilities were prohibited by law. A presidential moratorium denied underground nuclear testing. No research into advanced nuclear technology was allowed. Essentially, America went into an unannounced a nuclear freeze, and we have progressively increased its restrictions and denials for a quarter-century.”

These are all good things, unless you are one of those interesting individuals who still believe a nuclear war can be won………

Donald Trump has already announced his desire to increase the massive US nuclear arsenal tenfold. The draft of his soon-to-be-released Nuclear Posture Review seeks significant production of so-called “low-yield” nuclear weapons, because our current weapons are theoretically too big to use with any degree of tactical success. It should be noted that, according to modern metrics, the bombs dropped on Hiroshima and Nagasaki were also “low-yield.” An arsenal of smaller bombs is key to Admiral Monroe’s fever dream of a winnable nuclear war. It is a dream Trump appears to share.

The world is dangerous enough as it is, one would think. It is so dangerous, in fact, that a great many people are frozen to near-immobility by it, by the sheer immensity of the perils we face. Where to even begin?

If you seek a place to lay your chisel, I have two words: “No Nukes.”

Should you choose this path, your first task is to remind everyone that the threat not only still exists, but is growing again. White House officials were concerned about Richard Nixon’s mindset during the 1973 crisis, mired as he was in the Watergate scandal. Donald Trump makes Richard Nixon look like Marcus Aurelius. We are all in a great deal of trouble, and no one seems to care.

Make them care, please and thank you. Let’s go find that peace dividend they were talking about on my birthday. I think we’ve earned it. http://www.truth-out.org/opinion/item/43446-they-re-talking-about-winnable-nuclear-war-again

February 5, 2018 Posted by | general | Leave a comment

The penultimate storage of contaminated waste

From Pierre Fetet Fukushima Blog, translation Hervé Courtois
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Contaminated waste storage in Minamisoma in 2012 next to a primary school
 
 
On 28 October, nuclear waste was temporarily stockpiled at a site that is expected to be the penultimate (perhaps the last and perpetual) site in the cities of Ōkuma and Futaba, where the Fukushima Daiichi nuclear power plant is located.
 
The bottom of a large storage basin was lined with waterproof canvas to prevent groundwater pollution. The rainwater collected at the bottom will be purified by a machine and released into the rivers. This storage area covers an area of 16,000 hectares, but constitutes only 39% of the planned land. It is difficult to get the agreement of the landowners.
ob_709ebc_1.JPG
 
On this land, an incinerator will be built for the uprooted plants and felled trees, and a storage area for highly radioactive ashes. According to the law, the government has promised that after 30 years (before 2045) this storage will have to be moved out of the Fukushima Prefecture, but nobody of course believes it, because no one will accept these dangerous installations near his house.
 
In Fukushima, 15.2 million cubic meters of contaminated soil are temporarily stored on sports fields, in car parks and even in private gardens. According to the plan, most of this contaminated land will be transported to the new storage site by 2020.
 
 
 

February 5, 2018 Posted by | Fukushima 2018 | , , , | Leave a comment

Fukushima 49.17% thyroid deficiency in the 295 000 young people under 18 years examined between 2011 and 2014 …

thyroid fukushima.jpg
Findings of thyroid ultrasound examination within three years after the Fukushima Nuclear Power Plant accident: The Fukushima Health Management Survey
 
Abstract
Context
Childhood thyroid cancer is of great concern after the Fukushima Nuclear Power Plant accident. The baseline analytical data on thyroid ultrasound examination in children is quite important for future examination.
Objective
We analyzed the age and sex distribution of findings from the thyroid ultrasound examinations of children and adolescents in the Fukushima Health Management Survey (FHMS).
Design, Setting, and Participants
From October 2011 through March 2014, 294,905 participants aged 18 years or younger at the earthquake voluntarily had thyroid ultrasound examinations in the first round of the FHMS. A secondary confirmatory examination was performed in 2,032 subjects. Age- and sex-dependent prevalence and size of thyroid cysts, nodules, and caners were analyzed.
Main Outcome Measures
Age, sex, and size distribution of findings were analyzed.
Results
Thyroid cysts, nodules, and cytologically suspected cancers were detected in 68,009, 1,415, and 38 subjects in males and 73,014, 2455, and 74 subjects in females, respectively. There was an age-dependent increase in the detection rate of thyroid nodules and cancer, but that of cysts reached a peak at 11–12 years. Sex affected the prevalence of thyroid nodules and cancers after the onset of puberty, but only a small difference was exhibited in that of cysts.
Findings of thyroid ultrasound examination within three years after the Fukushima Nuclear Power Plant accident: The Fukushima Health Management Survey
Hiroki Shimura Tomotaka Sobue Hideto Takahashi Seiji Yasumura Tetsuya Ohira Akira Ohtsuru Sanae Midorikawa Satoru Suzuki Toshihiko Fukushima Shinichi Suzuki
https://academic.oup.com/jcem/advance-article-abstract/doi/10.1210/jc.2017-01603/4630428?redirectedFrom=fulltext

February 5, 2018 Posted by | Fukushima 2018 | , | Leave a comment

‘Global Consequences’ of Lethal Radiation Leak at Destroyed Japan Nuclear Plant

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Lethal levels of radiation have been observed inside Japan’s damaged Fukushima nuclear power plant. And they are arguably way higher than you suspect.
According to Tokyo Electric Power Company (Tepco), radiation levels of eight Sieverts per hour (Sv/h) have been discovered within the Fukushima nuclear power plant, which was destroyed after a massive earthquake and a tsunami in March 2011.
Tepco, the company that operated the plant and is now tasked with decommissioning it, reported the discovery after making observations in a reactor containment vessel last month.
Eight Sv/h of radiation, if absorbed at once, mean certain death, even with quick treatment. One Sv/h is likely to cause sickness and 5.5 Sv/h will result in a high chance of developing cancer.
While 8 Sv/h is deadly, outside of Fukushima’s Reactor Number 2 foundations of a much higher level of 42 Sv/h was detected.
A strange occurrence, and experts are still arguing what caused the discrepancy. One possible explanation is that cooling water washed radioactive material off debris, taking it somewhere else.
But here’s a truly terrifying catch: according to the report, Tepco highly doubts the new readings, because, as was discovered later, a cover was not removed from the robot-mounted measurement device at the time of the inspection, NHK World reports.
Exactly one year ago, Sputnik reported that Tepco engineers discovered absolutely insane levels of radiation of about 530 Sv/h within the reactor. Such levels of radiation would kill a human within seconds. By comparison, the Chernobyl reactor reads 34 Sv/h radiation level, enough to kill a human after 20 minutes of exposure.
The levels of radiation within Fukushima reactor number 2 were so high that Tepco’s toughest robot, designed to withstand 1000 Sv/h of radiation, had to be pulled out, as it started glitching due to high radiation levels. Nuclear experts called the radiation levels “unimaginable” at the time.
On November 2017, the New York Times and other news outlets reported a much smaller figure of 70 Sv/h of radiation, more or less on par with a 74 Sv/h reading gathered before an anomalous 530 Sv/h spike.
While that radiation dosimeter cover negligence prevents precise calculations, the actual picture inside Unit 2 is thought to be much worse.
Japanese state broadcaster NHK World quoted experts saying that if the cleaning of the stricken power plant is not properly addressed, it will result in major leak of radioactivity with “global” consequences.
Richard Black, director of the Energy and Climate Intelligence Unit, says that while the readings are not reliable, they still “demonstrate that, seven years after the disaster, cleaning up the Fukushima site remains a massive challenge — and one that we’re going to be reading about for decades, never mind years.”
Mycle Schneider, independent energy consultant and lead author of the World Nuclear Industry Status Report, criticized Tepco, saying the power company has “no clue” what it is doing.
“I find it symptomatic of the past seven years, in that they don’t know what they’re doing, Tepco, these energy companies, haven’t a clue what they’re doing, so to me it’s been going wrong from the beginning. It’s a disaster of unseen proportions.”
In observing the poor maintenance of plant radiation leaks, Schneider also pointed out that the company stores nuclear waste at the site in an inappropriate way.
“This is an area of the planet that gets hit by tornadoes and all kinds of heavy weather patterns, which is a problem. When you have waste stored above ground in inappropriate ways, it can get washed out and you can get contamination all over the place.”

 

February 5, 2018 Posted by | Fukushima 2018 | , | Leave a comment

Fukushima operator aims to double visitors by Tokyo Olympics

A lot of minimizing PR propaganda in this article, only one line states the real situation though:
“However, levels of radiation in areas around the three melted-down reactors remain extremely high, hampering the plant’s decommissioning process, which is expected to take decades.”
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The reactor number 2 building at the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power plant in Okuma, Fukushima, Japan, on Jan 31, 2018.
FUKUSHIMA DAIICHI NUCLEAR PLANT, JAPAN (AFP) – Fukushima’s nuclear power operator is hoping to double the number of visitors to its tsunami-ravaged facilities by 2020, seeking to use the Olympic spotlight to clean up the region’s image.
A massive undersea earthquake on March 11, 2011 sent a tsunami barrelling into Japan’s northeast coast, leaving more than 18,000 people dead or missing and sparking the Fukushima crisis, the worst nuclear accident since Chernobyl in 1986.
Initially, visitors to Fukushima Daiichi Nuclear Power plant were strictly limited to a handful of nuclear experts, lawmakers, government officials and selected media.
Visitor numbers have gradually increased as levels of radiation in most of the compound have dropped low enough to allow workers to operate without special protective equipment.
Tokyo Electric Power Co. (Tepco), which runs the plant, is now accepting requests for tours from groups of local residents, embassy officials and school students, although it has yet to accept individual applications.
The number of visitors for the fiscal year to March last year rose to around 10,000 – a figure the operator aims to double to 20,000 in 2020 when Tokyo hosts the Summer Games, said Takahiro Kimoto, a Tepco official.
“Our objective is not to send a message saying ‘It’s safe. It’s secure’,” Kimoto told AFP.
“It is more important for us to have people watch what’s really going on… without a prejudiced eye,” he said.
“The inspections will help revitalise the region and reduce reputational damage,” Kimoto said, adding that the company would be happy to show around International Olympic Committee officials.
Next era
Fukushima is expected to be in the spotlight during the Games as it will stage Olympic baseball and softball matches as part of Japan’s effort to regenerate the area.
Tepco also hopes that a football training centre used as a base for the plant’s workers after the disaster will host teams competing in the 2019 Rugby World Cup.
Kimoto stressed that the company is responsible for not only reviving the region but also conveying bitter lessons to future generations.
Decontamination work is under way inside the plant, with thousands of workers enjoying hot meals, taking showers and buying sweets at a convenience store.
However, levels of radiation in areas around the three melted-down reactors remain extremely high, hampering the plant’s decommissioning process, which is expected to take decades.
The scars of the catastrophe remain visible – steel frames are gnarled and walls are missing, ripped off by the tsunami and hydrogen explosions.
‘Strictly controlled’
With the seventh anniversary of the disaster looming, AFP journalists given exclusive access to the roof of the plant’s No. 3 reactor saw stagnant water stored inside a deep pool under which lay more than 560 fuel rods.
Each worker is required to wear a protective suit, three sets of gloves and a heavy-duty mask and carry a dosimeter, used to measure exposure to radiation.
Workers only stay a maximum of two hours per day on the roof where electric gauges showing current radiation levels hang on every corner.
A gigantic steel dome is now being built on the roof to prevent radiation leaking when the fuel rods are transferred from the pool to remote storage later this year.
As the initial stages of decommissioning the plant draw to a close, the biggest challenge is a protracted battle against high radiation, said Daisuke Hirose, a plant official.
“We have to lower radiation exposure to workers, but this prevents them from working for a long time up there,” Hirose said.
“We want them to work under strictly controlled exposure plans. That’s the big difference from working conditions at ordinary sites,” he said.
The total costs for decommissioning, decontamination and compensation are estimated to reach 21.5 trillion yen (US$255 billion) and Tepco aims to dismantle the plant in three to four decades.

February 5, 2018 Posted by | Fukushima 2018 | | Leave a comment

Fukushima nuclear disaster: Lethal levels of radiation detected in leak seven years after plant meltdown in Japan

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Workers of theTokyo Electric Power Co, which is tasked with the job to decommission the nuclear power plant in Okuma, Fukushima
 
Lethal levels of radiation have been detected at Japan’s Fukushima nuclear power plant, seven years after it was destroyed by an earthquake and tsunami. 
The Tokyo Electric Power Company (Tepco), which operated the complex and is now responsible for its clean up, made the discovery in a reactor containment vessel last month. 
The energy firm found eight sieverts per hour of radiation, while  42 units were also detected outside its foundations. 
A sievert is defined as the probability of cancer induction and genetic damage from exposure to a dose of radiation, by the International Commission on Radiological Protection (ICRP). One sievert is thought to carry with it a 5.5 per cent chance of eventually developing cancer. 
Experts told Japanese state broadcaster NHK World that exposure to that volume of radiation for just an hour could kill, while another warned the leaks could lead to a “global” catastrophe if not tackled properly.
It came as Tepco said the problem of contaminated water pooled around the plants three reactors that is seeping into the ground has caused a major headache in its efforts to decommission the plant.
Thousands of workers have been hired by the company to as it attempts to secure the plant, which was the scene of the most serious nuclear accident since Chernobyl in 1986. 
Three of its reactors went into a meltdown after the earthquake and tsunami which killed at least 15,000 people.
Tepco has admitted that it could be until 2020 until the contamination issue is resolved. Only then can it move onto the second stage of removing nuclear debris at the site, including the damaged reactors.
Richard Black, director of the Energy and Climate Intelligence Unit, said the high levels of radiation found in and around the reactor last month were “expected” and unlikely to pose a danger. 
He told The Independent: “Although the radiation levels identified are high, a threat to human health is very unlikely because apart from workers at the site, no-one goes there.
“The high readings from fuel debris would be expected – the higher reading from the foundations, if confirmed, would be more of a concern as the cause is at present unclear. But as officials indicate, it might not be a genuine reading anyway.
“What this does demonstrate is that, seven years after the disaster, cleaning up the Fukushima site remains a massive challenge – and one that we’re going to be reading about for decades, never mind years.”
But Mycle Schneider, an independent energy consultant and lead author of the World Nuclear Industry Status Report, said that Tepco “hasn’t a clue what it is doing” in its job to decommission the plant.
He added that the contaminated water that is leaking at the site could end up in the ocean if the  ongoing treatment project fails and cause a “global” disaster, he told The Independent. 
“Finding high readings in the reactor is normal, it’s where the molten fuel is, it would be bizarre if it wasn’t,” he said. 
“I find it symptomatic of the past seven years, in that they don’t know what they’re doing, Tepco, these energy companies haven’t a clue what they’re doing, so to me it’s been going wrong from the beginning. It’s a disaster of unseen proportions.”
Mr Schneider added that the radiation leaks coupled with the waste from the plant stored in an “inappropriate” way in tanks could have global consequences.
“This is an area of the planet that gets hit by tornadoes and all kinds of heavy weather patterns, which is a problem. When you have waste stored above ground in inappropriate ways, it can get washed out and you can get contamination all over the place.
“This can get problematic anytime, if it contaminates the ocean there is no local contamination, the ocean is global, so anything that goes into the ocean goes to everyone.”
He added: “It needs to be clear that this problem is not gone, this is not just a local problem. It’s a very major thing.”
The Independent contacted Tepco for comment, but the energy giant had not responded at the time of publication.

February 5, 2018 Posted by | Fukushima 2018 | , | Leave a comment

Britain’s costly gamble with Hinkley point C nuclear project, as the renewables revolution gather speed

there will be no room in this new world of flexible, decentralised generation for large, rigid nuclear reactors. “There are going to be increasingly frequent periods when we have too much power,” says Mr Burke. “But if you are the energy minister, how do you explain to people why you are having to switch off cheap renewables in order to use the much more expensive nuclear power which you have committed to pay for over the next 35 years?”

FT 4th Feb 2018, The UK’s Hinkley Point C has become a critical test of developers’ ability to compete with cheap gas and renewables. Across an expanse of scarred earth the size of 250 football pitches beside the Bristol Channel in south-west England, 3,000 workers are building what will be, by some estimates, the most expensive structure on the planet.

At a cost of almost £20bn, the Hinkley Point C power station in Somerset is the first nuclear plant to be built in the UK since the 1990s. Clusters of cranes and cement silos loom over a warren of earthworks crawling with excavators and
100-tonne dumper trucks. At the centre of the site, foundations are taking shape for two 1.6 gigawatt reactors intended to meet 7 per cent of UK electricity demand, with a target for completion by the end of 2025.

Hinkley is crucial to UK energy security as the country faces the closure of old coal and nuclear plants accounting for about 40 per cent of the country’s reliable electricity generating capacity by 2030. But it also has wider significance as a test of the industry’s ability to compete in a rapidly changing energy landscape. Nuclear power has been under threat
since the meltdown at the Fukushima plant in Japan in 2011 revived safety fears.

But the biggest threat is now economic as the spiralling cost of building new reactors collides with a world of cheap and plentiful gas and renewable power. The UK is now one of the few western countries committed to renewing its ageing reactors. More than 70 per cent of the 448 reactors around the world are in the OECD club of wealthy nations, and more than half of them are at least 30 years old.

Many will reach the end of their operational lives in the next two decades, yet the prospects of replacing
them are uncertain, at best, in countries such as the US, Japan and France, while others including Germany, Switzerland and South Korea are planning to phase out nuclear power altogether. The days of networks dominated by a few large, centralised power stations are drawing to a close, according to many analysts. In their place will come more dispersed sources of renewable generation. Battery storage and digital “smart grid” technology will help smooth out supply and demand, and increase efficiency.

Tom Burke, chairman of E3G, an environmental think-tank, says there will be no room in this new world of flexible, decentralised generation for large, rigid nuclear reactors. “There are going to be increasingly frequent periods when we have too much power,” says Mr Burke. “But if you are the energy minister, how do you explain to people why you are having to switch off cheap renewables in order to use the much more expensive nuclear power which you have committed to pay for over the next 35 years?”

Progress at Hinkley, therefore, is being watched as closely in Beijing as in Paris and London. A repeat of the delays at Olkiluoto and Flamanville could sign the death warrant for western reactor developers, while dealing a setback for
China’s international expansion. Mr Rossi is aware of the high stakes: “We need to make sure that Britain will be happy about the choice it made.”  https://www.ft.com/content/8307c266-066b-11e8-9650-9c0ad2d7c5b5

February 5, 2018 Posted by | business and costs, politics, UK | Leave a comment

France’s nuclear industry – unsafe?

JDD 3rd Feb 2018, Nuclear: the book that undermines the safety of French power plants. The JDD publishes preview extracts of Nuclear, immediate danger , a survey book that challenges the dogma of the safety and profitability of French power stations.

At the forefront of concerns: the alarming state of severaltanks, which contain the heart of the reactors. “That’s it, we are there atthe age of 40. By 2028, 48 reactors [out of 58 in service in France] – those of the level of 900 MW and a part of the reactors of 1,300 MW – will reach this canonical age.

Since the mid-2000s, because of its financial difficulties that prevent it from investing in new means of production, EDF is asking for, calling for, even imposing, that all of its nuclear power stations be allowed to operate at the same time. beyond the age of forty, and prolonged by twenty years. […]

[Among the elements that will] determine the extension or the stop of the vats: do they have defects, of
origin or appeared with the time, which compromise the safety?

This is one of the biggest secrets of the nuclear industry in France. […] According to EDF, 10 tanks in operation have cracks that date from their manufacture. […] Tricastin, with its reactor 1, is the worst central of the country.

This reactor combines all the problems: defects under coating, no margin at break, and exceeding the fragility forecast at forty years! Not to mention the risk of catastrophic flooding in the event of an earthquake, as noted in September 2017 by the Nuclear Safety Authority (ASN), which has automatically stopped the operation of the four reactors of the plant while waiting for EDF finally, work to reinforce the dike of the Donzère-Mondragon canal. The plant is below the canal, 6 m below the water.

Pierre-Franck Chevet, the president of the ASN, told us’ that in the event of a strong earthquake we could go to a situation, with four simultaneous reactors merging, which potentially looks like a Fukushima type accident. EDF has found the immediate stoppage of the plant to carry out this unjustified work, I find it justified. ” http://www.lejdd.fr/societe/nucleaire-le-livre-qui-met-a-mal-la-surete-des-centrales-francaises-3564173

February 5, 2018 Posted by | France, safety | Leave a comment

Sweden agonises over nuclear waste burial project that no community wants

GDF Watch 2nd Feb 2018, A week on from the Environmental Court’s ruling, and it would seem nobody in Sweden is any the wiser about what happens next. The general view seems to be that this is a hiccup, and everything will eventually continue as planned.

But don’t expect that to happen anytime soon, and at least not until after this autumn’s national elections in Sweden. Anders Lillienau, who chaired the Court’s Hearings, is reported as saying that while they had significant concerns about the safety of the copper canisters, the Court did not otherwise see any barriers to the safety of the repository.

The Court has asked SKB, the organisation responsible for the repository, to provide further information on copper canisters to address their concerns. It is understood that SKB are preparing such information, and reportedly told a community meeting in Östhammar earlier this week that they intend to provide that information later this year.

Anders Lillenau has also made clear the ball is now in the Government’s court: “In the
end, it is still the case that the Government may make the overall assessment whether or not this will be allowed.” A Swedish Government spokesman, Magnus Blücher, explained that this was a complex issue and it was too soon to say what the Government might do, or when.

Back in Östhammar, the local referendum planned for 4 March has been postponed. The referendum was advisory, and any final decision on agreeing to host the repository has to be taken by the local council. A spokesman for Östhammar Municipality says that it is too soon to know when the referendum and council vote will now take place.

Local resident Åsa Lindstrand chairs a resident’s group opposed to the repository. She told the local newspaper that she was pleased but surprised by the Court’s decision, but feels little will change:

“Actually, nobody else in Sweden wants this nuclear fuel repository, so the rest of Sweden would probably be lucky if someone takes it. The municipality is so marinated by SKB that it is not easy to
say ‘no’. For us who live here, it’s more about noise and traffic than about the copper capsules, it’s happening before they get there at all.” Her sense of pyrhhic victory is shared by environmentalist Johan
Swahn, who added, “but only if the government stays passive and the copper canister issues raised by the Court become a matter solely for SKB.” His organisation, MKG, has raised concerns about the long-term
safety of copper canisters over many years.

While delighted that the Court accepted the case presented by leading corrosion scientists, he now wants
the Swedish Government to guarantee an open scientific re-evaluation of the issues relating to copper canister corrosion.  http://www.gdfwatch.org.uk/2018/02/02/sweden-update/

February 5, 2018 Posted by | Switzerland, wastes | Leave a comment

American companies’plans to market nuclear technology to India have come to nothing

The Hindu 3rd Feb 2018, Watching the Republic Day parade, where 10 ASEAN leaders were chief guests,
it was easy to miss the fact that the dates of their visit also marked the
anniversary of another big visit three years ago: the visit by then U.S.
President Barack Obama, when he announced a “breakthrough” in the
India-U.S. civil nuclear deal, to finally pave the way for a commercial
contract.

“The deal is done,” Sujatha Singh, who was Foreign Secretary
at the time, said as the government issued papers and held briefings
describing the nature of the agreement between India and the U.S. on
supplier liability and tracking requirements, which would enable American
companies to build nuclear power reactors in India.

Today, nearly a decade since the memoranda of understanding were inked, and three years after the
last wrinkles were ironed out, there is no sign yet of any concrete
contract between an American company and the Indian authorities to build a
reactor.

In 2009, both GE-Hitachi and Toshiba-Westinghouse had begun talks
on techno-commercial agreements for six reactors each in India. These
commercial contracts were to be the start of the ‘payoff’ for the U.S.
that had considerably shifted its stand on non-proliferation to give India
the waivers needed, and they were to herald India’s arrival on the global
nuclear power stage in return.

Instead, GE-Hitachi’s plans were shelved after it rejected the Obama-Modi agreement in January 2015, saying GE would
not accept the compromise formula on supplier liability. (While others have
indicated they would accept the liability offer, none of them has put that
on paper.) Toshiba-Westinghouse then carried the baton to actualise the
India-U.S. civil nuclear deal, but ran into a different storm as both
Toshiba and Westinghouse had major financial troubles last year. After a
near-bankruptcy, Toshiba jettisoned Westinghouse for just $4.6 billion to a
Canadian consortium, a deal that is now expected to be cleared by the end
of 2018.
http://www.thehindu.com/opinion/lead/forging-a-new-nuclear-deal/article22637628.ece

February 5, 2018 Posted by | business and costs, India, politics international, USA | Leave a comment

The mammoth task of cleaning up Fukushima’s radioactive nuclear reactor wrecks has only just begun

Power Engineering 31st Jan 2018, Worst-Hit Reactor at Fukushima May be Easiest to Clean Up. High atop Fukushima’s most damaged nuclear reactor, the final pieces of a jelly-roll shaped cover are being put in place to seal in highly radioactive dust.

Blown apart by a hydrogen explosion in 2011 after an earthquake and tsunamihit Japan’s Fukushima Dai-ichi plant, reactor Unit 3 is undergoing painstaking construction ahead of a milestone that is the first step toward dismantling the plant. The operating floor — from where new fuel rods
used to be lowered into the core — has been rebuilt and if all goes as planned, huge cranes will begin removing 566 sets of still-radioactive fuel
rods from a storage pool just below it later this year.

It has taken seven years just to get this far, but now the real work of cleaning up the Tokyo Electric Power Co. plant can begin. “If you compare it with mountain climbing, we’ve only been preparing to climb. Now, we finally get to actually start climbing,” said Daisuke Hirose, an official at the plant’s decommissioning and decontamination unit.

Cleaning up the plant’s three reactors that had at least partial meltdowns after the earthquake and tsunami is a monumental task expected to take three to four decades. Taking out the stored fuel rods is only a preliminary step and just removing the ones in Unit 3 is expected to take a year. Still ahead is the uncharted challenge of removing an estimated 800 tons of melted fuel and debris inside the cracked containment chambers — six times that of the 1979 Three Mile Island accident.  http://www.power-eng.com/articles/2018/01/worst-hit-reactor-at-fukushima-may-be-easiest-to-clean-up.html

February 5, 2018 Posted by | Fukushima continuing | Leave a comment

Artificial intelligence to enhance the thinking skills of nuclear submarine commanding officers,

China’s plan to use artificial intelligence to boost the thinking skills of nuclear submarine commanders
Equipping nuclear submarines with AI would give China an upper hand in undersea battles while pushing applications of the technology to a new level, SCMP, Stephen Chen,  05 February, 2018,  China is working to update the rugged old computer systems on nuclear submarines with artificial intelligence to enhance the potential thinking skills of commanding officers, a senior scientist involved with the programme told the South China Morning Post.

A submarine with AI-augmented brainpower not only would give China’s large navy an upper hand in battle under the world’s oceans but would push applications of AI technology to a new level, according to the researcher, who spoke on condition of anonymity because of the project’s sensitivity.

“Though a submarine has enormous power of destruction, its brain is actually quite small,” the researcher said.

While a nuclear submarine depends on the skill, experience and efficiency of its crew to operate effectively, the demands of modern warfare could introduce variables that would cause even the smoothest-run operation to come unglued.

For instance, if the 100 to 300 people in the sub’s crew were forced to remain together in their canister in deep, dark water for months, the rising stress level could affect the commanding officers’ decision-making powers, even leading to bad judgment.

An AI decision-support system with “its own thoughts” would reduce the commanding officers’ workload and mental burden, according to the researcher……….

Up till now, the “thinking” function on a nuclear sub, including interpreting and answering signals picked up by sonar, a system for detecting objects under water by emitting sound pulses, has been handled almost exclusively by human naval personnel, not by machines.

Now, through AI technology, a convolutional neural network undergirds so-called machine learning. This structure underpins a decision support system that can acquire knowledge, improve skills and develop new strategy without human intervention.

By mimicking the workings of the human brain, the system can process a large amount of data. On a nuclear submarine, data could come from the Chinese navy’s rapidly increasing observation networks, the submarine’s own sensors or daily interactions with the crew…….. http://www.scmp.com/news/china/society/article/2131127/chinas-plan-use-artificial-intelligence-boost-thinking-skills

February 5, 2018 Posted by | China, technology, weapons and war | Leave a comment

China wants USA to drop its “Cold War mentality

China accuses US of ‘Cold War mentality’ over nuclear policy BBC News 4 Feb 18 China has urged the US to drop its “Cold War mentality” after Washington said it planned to diversify its nuclear armoury with smaller bombs.”The country that owns the world’s largest nuclear arsenal, should take the initiative to follow the trend instead of going against it,” China’s defence ministry said on Sunday.

The US military believes its nuclear weapons are seen as too big to be used and wants to develop low-yield bombs.

Russia has already condemned the plan.

Iran’s foreign minister claimed it brought the world “closer to annihilation”……….

China said on Sunday it “firmly” opposed the Pentagon’s review of US nuclear policy.

The defence ministry in Beijing said Washington had played up the threat of China’s nuclear threat, adding that its own policy was defensive in nature.

“We hope that the United States will abandon its Cold War mentality, earnestly assume its special disarmament responsibilities, correctly understand China’s strategic intentions and objectively view China’s national defence and military build-up,” its statement said. …..http://www.bbc.com/news/world-asia-42935758

February 5, 2018 Posted by | China, politics international, USA | Leave a comment

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