Following the Fukushima Daiichi Nuclear Power Plant accident in March 2011, radionuclides such as iodine-131, cesium-134 and cesium-137 were released into environment. In this study, we collected ...wild mushrooms from the Kawauchi Village of Fukushima Prefecture, located less than 30 km southwest of the Fukushima nuclear power plant, to evaluate their radiocesium (134Cs+137Cs) concentrations and the risk of internal radiation exposure in local residents. 342 mushroom samples were collected from 2016 to 2019. All samples were analysed for radiocesium content by a high-purity germanium detector. Among 342 mushroom samples, 260 mushroom samples (76%) were detected the radiocesium exceeding the regulatory limit of radiocesium (100 Bq/kg for general foods in Japan). The median of committed effective dose from ingestion of wild mushrooms was in the range of 0.015-0.053 mSv in 2016, 0.0025-0.0087 mSv in 2017, 0.029-0.110 mSv in 2018 and 0.011-0.036 mSv in 2019 based on the assumption that Japanese citizens consumed wild mushrooms for 1 year. Thus, our study showed that although radiocesium is still detected in mushrooms collected in Kawauchi village even after 5 to 9 years later, the committed effective dose due to consuming mushrooms was lower than 1 mSv per year. Long-term comprehensive follow-up should monitor radiocesium concentrations in wild mushrooms to support the recovery of the community after the nuclear disaster.
Purpose
To investigate the potential use of Prussian blue-coated magnetic nanoparticles, termed “Prussian blueberry”, to bring about the magnetic elimination of cesium.
Methods
Prussian blueberry ...were prepared by a layer-by-layer assembly method. The morphology, structure and physical properties of the Prussian blueberry were investigated as was their ability to magnetically eliminate cesium.
Results
We confirmed that Prussian blueberry were composed of a magnetite nanoparticle-core and a Prussian blue-shell. Under a magnetic field, Prussian blueberry (5 mg) reduced the cesium concentration of seawater (3 ml) from 150 ppm to about 50 ppm; but regular Prussian blue could not magnetically eliminate cesium. Moreover, Prussian blueberry removed a similar proportion of cesium from a larger volume of seawater, and from fetal bovine serum and cow’s milk.
Conclusions
Under a magnetic field, Prussian blueberry was able to rapidly eliminate cesium from seawater and from biological matrices such as serum and milk.
This study assesses the sorption characteristics of Punica granatum (pomegranate) peel as an economical sorbent, to decontaminate radioisotopes cesium and europium from aqueous solutions. In this ...respect, Punica granatum peel (virgin and modified by sodium dodecyl sulfate) had been prepared from the byproduct of numerous industries. The physical and chemical characteristics of prepared sorbents were determined using FTIR, TGA, DTA, SEM, XRD, and pH
PZC
. The effects of process parameters comprising medium pH, initial concentration, contact time and temperature on
137
Cs and
152+154
Eu sorption efficiency were investigated. Desorption of the investigated radioactive materials increased as the concentration of desorbing agent increased especially NaOH more than HNO
3
. Kinetic analysis study showed that the chemical reaction is the rate-determining step. Reaction equilibrium isotherm for both studied ions follows the Langmuir and Temkin model and the sorbent has a higher affinity to stabilize Europium more than Cesium ions.
Schematic representation of possible mechanisms determining the Cs extraction and immobilization in fly ash during water, methanol or n-MCaS extraction.
•nMCaS suspension for cesium extraction and ...immobilization in fly ash was developed.•Enhanced cesium immobilization was done by nanometallic Ca/CaO methanol suspension.•By SEM analysis the amount of cesium detectable on soil particle surface decreases.•Leachable cesium concentrations reduced, lower than the standard regulatory limit.•nMCaS unique and a highly potential amendment for the remediation of Cs.
In this work, the capability of nanometallic Ca/CaO methanol suspension in removing and/or immobilizing stable (133Cs) and radioactive cesium species (134Cs and 137Cs) in contaminated fly ash was investigated. After a first methanol and second water washing yielded only 45% of 133Cs removal. While, after a first methanol washing, the second solvent with nanometallic Ca/CaO methanol suspension yielded simultaneous enhanced removal and immobilization about 99% of 133Cs. SEM-EDS analysis revealed that the mass percent of detectable 133Cs on the fly ash surface recorded a 100% decrease. When real radioactive cesium contaminated fly ash (containing an initial 14,040Bqkg−1134Cs and 137Cs cumulated concentration) obtained from burning wastes from Fukushima were reduced to 3583Bqkg−1 after treatment with nanometallic Ca/CaO methanol suspension. Elution test conducted on the treated fly ash gave 100BqL−1 total 134Cs and 137Cs concentrations in eluted solution. Furthermore, both ash content and eluted solution concentrations of 134Cs and 137Cs were much lower than the Japanese Ministry of the Environment regulatory limit of 8000Bqkg−1 and 150BqL−1 respectively. The results of this study suggest that the nanometallic Ca/CaO methanol suspension is a highly potential amendment for the remediation of radioactive cesium-contaminated fly ash.
Halide perovskite semiconductors are poised to revitalize the field of ionizing radiation detection as they have done to solar photovoltaics. We show that all-inorganic perovskite CsPbBr3 devices ...resolve 137Cs 662-keV γ-rays with 1.4% energy resolution, as well as other X- and γ-rays with energies ranging from tens of keV to over 1 MeV in ambipolar sensing and unipolar hole-only sensing modes with crystal volumes of 6.65 mm3 and 297 mm3, respectively. We report the scale-up of CsPbBr3 ingots to up to 1.5 inches in diameter with an excellent hole mobility–lifetime product of 8 × 10−3 cm2 V−1 and a long hole lifetime of up to 296 μs. CsPbBr3 detectors demonstrate a wide temperature region from ~2 °C to ~70 °C for stable operation. Detectors protected with suitable encapsulants show a uniform response for over 18 months. Consequently, we identify perovskite CsPbBr3 semiconductor as an exceptional candidate for new-generation high-energy γ-ray detection.Energy resolution of high-energy photon detectors is desired for applications ranging from biomedical imaging to homeland security. In this work, perovskite-based γ-ray detection with 1.4% energy resolution is demonstrated.
Abstract
Gamma-ray detection and spectroscopy is the quantitative determination of their energy spectra, and is of critical value and critically important in diverse technological and scientific ...fields. Here we report an improved melt growth method for cesium lead bromide and a special detector design with asymmetrical metal electrode configuration that leads to a high performance at room temperature. As-grown centimeter-sized crystals possess extremely low impurity levels (below 10 p.p.m. for total 69 elements) and detectors achieve 3.9% energy resolution for 122 keV
57
Co gamma-ray and 3.8% for 662 keV
137
Cs gamma-ray. Cesium lead bromide is unique among all gamma-ray detection materials in that its hole transport properties are responsible for the high performance. The superior mobility-lifetime product for holes (1.34 × 10
−3
cm
2
V
−1
) derives mainly from the record long hole carrier lifetime (over 25 μs). The easily scalable crystal growth and high-energy resolution, highlight cesium lead bromide as an exceptional next generation material for room temperature radiation detection.
The isoguanosine self-assembled pentamer (isoG-star) exhibits remarkable selectivity for Cs
+
binding over competing alkali and alkali earth metal cations, rendering it a promising extractor for ...radioactive waste
137
Cs separation. However, to make isoG-star a practical material for Cs
+
isolation, the development of a recyclable isoG-star material is required. In this study, a systematic screening of functional isoG derivatives was performed. By employing well-defined complex formation and post-assembly modification, a covalently tethered isoG
5
-star was prepared through olefin metathesis, utilizing a designed isoG monomer. The application of this newly developed covalently linked isoG-star enabled selective Cs
+
extraction, followed by controlled solvent-induced H-bond dissociation. This resulted in the creation of a recyclable Cs
+
extractor, demonstrating excellent cation selectivity and good reusability (over seven cycles) for the first time. Consequently, this new supramolecular macrocycle offers a practical new platform for the treatment of radiocesium (
134
Cs and
137
Cs) in an environmentally friendly and highly effective manner.
By employing well-defined isoguanosine self-assembled pentamer formation and post-assembly modification, covalently tethered isoG-star through olefin metathesis was prepared as a recyclable receptor for selective cesium separation.
•Incorporation in a glass of a dismantling waste rich in Zr, P and Mo•Impact of waste composition variation and waste loading on glass microstructure•P and Mo are the only elements that may lead to ...phase separation or crystallization•For Mo-rich compositions Cs may enter into molybdate crystals (CsLiMoO4)
Dismantling nuclear facilities leads to radioactive waste less active but which may have highly variable compositions compared to the high-level radioactive wastes recovered after the reprocessing of spent nuclear fuel. In this work, we studied the ability of an alkali-rich glass matrix belonging to the SiO2-B2O3-Al2O3-Fe2O3-Na2O-Li2O-CaO system to solubilize P2O5, MoO3, ZrO2 and Cs2O by melting at 1100°C. Phosphorus, molybdenum, zirconium and cesium are present as a mixture of complex compounds in the real radioactive dismantling waste containing 137Cs considered here. To determine the capacity of the matrix to accept a wide range of variations of waste composition and the solubility limits of P2O5, MoO3, and ZrO2, several glass series were prepared by melting mixtures of raw materials (oxides, carbonates, phosphates) and by increasing the total amount of oxides representing the waste and varying their relative proportions. Their incorporation in the melt was studied by analyzing the microstructure of quenched glasses by XRD and SEM-EDS. In addition, the phase separation and crystallization tendencies during cooling were studied by analyzing the microstructure of glasses cooled at 1°C.min-1 from 1100°C (representative of cooling in industrials steel canisters). It is shown that the glass can accept a wide range of waste compositions without exhibiting heterogeneities. For all compositions the melt remained homogeneous (study of quenched samples). However, during slow cooling, P2O5 and MoO3 may lead to phase separation and crystallization of Na2MoO4, CsLiMoO4, NaCaPO4, NaLi2PO4, and Li3PO4. Cs can be partially incorporated into the molybdenum-rich phase CsLiMoO4 when MoO3 content is higher than 1.3wt%. ZrO2 never lead to phase separation or crystallization, possibly because of the existence of strong connections between Zr and Si through Zr-O-Si bonds whereas P and Mo would be present as PO43− and MoO42− mobile entities. The increasing order of oxides solubility in the glass is the following: MoO3<P2O5<ZrO2.
Radionuclide contamination is a serious health issue caused by nuclear experiments and plant accidents, as seen for the Chernobyl and Fukushima nuclear plants. Italy has been especially interested in ...northwestern alpine regions, as have several other nations. The aim of this work was to indagate 134Cs and 137Cs contamination in wild boars, which were considered bioindicators sampled in the Chisone/Germanasca Valley and the Pellice Valley districts (Piedmont, Italy) in two hunting seasons (2014 and 2016). In the 2014 season, only the livers of the animals (n = 48) were sampled, whereas in 2016, five different anatomical sampling sites were sampled for each animal (n = 16). The analyses were conducted in an accredited laboratory (Agenzia Regionale per la Protezione dell'Ambiente-ARPA) by the aid of an HPGe detector (Ortec) with a relative efficiency of 50%. In general, the contamination levels registered in 2014 were under the detection limit for 134Cs and low for 137Cs (Chisone/Germanasca valley: min: 0.0, max: 23.9 median 11.0 Bq/kg vs Pellice valley: min 0, max: 31.7, median: 9.6 Bq/kg) and no health concern can be supposed. In the first-year samples, the liver showed a negative correlation between age and contamination level. In the second year of sampling, low levels were confirmed (min: 3.1 Bq/kg, max: 113.3; median 17.7 Bq/kg). Multiple sampling from the same animal showed that the diaphragm (median = 27.7 Bq/kg) kidney (27.4) and tongue (27.6) were more contaminated than the liver (17.7) and spleen (15.3). Moreover, a linear mixed model revealed a negative organ-by-age interaction, meaning that interorgan differences in contamination level were greater in younger (5-11 months) than in older (18-36 months) animals. Different feeding habits can be the explanation. Our paper shows that muscle sites (diaphragm and tongue) can be useful for radionuclide pollution surveillance in wild boar populations and that younger animals show more interorgan variability in contamination levels than older animals. More investigations are needed to confirm this correlation and to fulfill the request for more data to achieve better risk assessment.
Hrvatsko društvo za zaštitu od zračenja (HDZZ) održalo je 13. simpozij s medunarodnim sudjelovanjem u Poreču od 18. do 21. travnja 2023. godine. Suorganizatori simpozija bili su Institut za ...medicinska istraživanja i medicinu rada (IMI), Institut Ruder Bošković (IRB) te Hrvatsko društvo za medicinsku fiziku (HDMF). Branko Petrinec iz Instituta za medicinska istraživanja i medicinu rada. Brojni sponzori i izlagači dali su svoj doprinos simpoziju: glavni sponzor simpozija LKB Vertriebs GmbH, srebrni sponzori Radosys Dosimetric Microscopy i Nuklearna elektrana Krško, te brončani sponzori Dositracker Ltd., Mjerne tehnologije d.o.o., Jasika d.o.o. i Institut za medicinska istraživanja i medicinu rada. Opće teme u znanosti od zračenju, Nuklearne prijetnje - izazovi, Dozimetrija zračenja, Biološki učinci zračenja, Izloženost stanovništva zračenju, Zaštita od zračenja u medicini, Radioekologija, Radon, Neionizirajuća zračenja te Instrumentacija i mjerne tehnike. Ured za ISSN Nacionalne i sveučilišne knjižnice dodijelit će zborniku ISSN broj, što predstavlja priznanje HDZZ-u za redovno publiciranje ovakvog izdanja, a ujedno i obvezu za nastavak izdavačke djelatnosti Društva. Na izboru za nabolje izlaganje prvu je nagradu osvojio Luka Pasariček izlaganjem naziva „Utjecaj parametra „idelt" u programskom paketu phits i metode računanja na iznos linearnog prijenosa energije primarnih protona u radioterapiji" (IRB). Drugo mjesto dodijeljeno je Mihaeli Mlinarić za izlaganje „Kontrola kvaliteta terapijskih distribucija doze u robotiziranoj radiokirurgiji korištenjem dvodimenzionalnog diodnog detektora", dok je treće mjesto pripalo izlaganju Nikole Šegedina „Odredivanje korekcijskih faktora na volumno usrednjavanje za ionizacijske komore različitog volumena u uskim snopovima 60Co". Na izboru najboljeg postera prvu nagradu osvojio je poster „Koncentracija aktivnosti 137Cs u suhim i zamrznutim vrganjima" prve autorice Nore Miljanić (IMI), dok je drugu nagradu osvojio poster „Odredivanje radionuklida u površinskim i vodama za piće te atmosferskim precipitatima na širem području općine Dvor" Petre Tagliaretti (IMI). Održana je i redovita sjednica Zbora članova HDZZ-a, na kojoj je izloženo i prihvaćeno izvješće o radu i financijsko izvješće za proteklu godinu te plan rada i financijski plan za 2023. i 2024. godinu. Za vrijeme predsjedništva Márije Ranogajec-Komor, HDZZ je steklo medunarodni ugled u zajednici zaštite od zračenja kao rezultat znanstvene aktivnosti, uspješne organizacije i suorganizacije regionalnih kongresa IRPA-e i suradnje s drugim društvima za zaštitu od zračenja u Europi. Postignuta je financijska stabilnost Društva koja je omogućila mnogobrojne aktivnosti, izmedu ostalog i provedbu programa za potporu pri sudjelovanju mladih znanstvenika na kongresima IRPA-e. Rad Márije Ranogajec-Komor medunarodno je prepoznat te je 2006. godine primila nagradu „Počasna igla" Austrijskog društva za zaštitu od zračenja za dugogodišnji doprinos medunarodnoj zajednici za zaštitu od zračenja. Madarska akademija znanosti za unapredenje znanstvenog i umjetničkog životu Madara u Hrvatskoj te značajni doprinos suradnji izmedu hrvatskih i madarskih znanstvenika-istraživača 2009. dodijelila joj je medalju „Arany János".
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