Radioactive Cesium Research Articles

Radiocesium-bearing microparticles discovered on masks worn during indoor cleaning

A decade has passed since the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident on March 11, 2011. However, radioactive particles have recently been detected in the indoor air of some residences near the FDNPP. Following the recommendations of previous research, we determined the presence of radiocesium-bearing microparticles (CsMPs) and measured the radioactivity of radiocesium that adhered on non-woven face masks worn by six persons during the indoor cleaning of 59 residences in Namie, Futaba, Okuma, and Tomioka towns in Fukushima Prefecture. Of the 284 masks worn in this study, significant 137Cs radioactivity was detected in 268, and 44 new CsMPs were discovered in 28. The results of this study also suggest the presence of highly concentrated soluble radiocesium particles or soluble radioactive cesium aerosols adhered to house dust. This implies that the CsMPs constituted a large proportion of radioactivity in the indoor air contamination for particles in the 1.0–2.5 µm size range due to the radioactive radiocesium particles. It is desirable to wear masks during cleaning to prevent inhalation of CsMPs.

Molecular dynamics study on the adsorption of radioactive ions by geopolymers

The construction of nuclear power plants necessitates careful consideration of the discharge and fixation of nuclear waste. Geopolymers are new cement-based materials (CBMs) with three-dimensional cage-like structures that enable effective nuclear waste fixation. In this work, the adsorption of radioactive caesium and strontium ions by sodium aluminosilicate hydrate (NASH) gel, the main component of geopolymers, was investigated using molecular dynamics simulations to obtain nanoscale insights into the ions’ interactions with the gel. The formation of strong ion–oxygen bonds allowed both ions to be effectively adsorbed on the NASH surface, but the adsorption ratio of strontium ions (17.2%) was slightly lower than that of caesium ions (21.0%). Because strontium ions are divalent, they can form stronger electrostatic interactions with water molecules and chloride ions, which hinders their approach to the interface. For the same reason, the diffusion coefficient of strontium ions in solution is lower than that of caesium ions. These results provide new insights into the nuclear waste fixation capacity of NASH gel and guidance for the design of new CBMs for radioactive waste disposal.

SYSTEM OF PHYSICAL PROTECTION DURING TRANSPORTATION OF SOURCES OF IONIZING RADIATION OF THE FIRST CATEGORY

The discovery of radioactivity by Antoine Henri Becquerel in 1896 was a major achievement. Today, radioactive substances are used in medicine, agriculture, heavy industry, and power generation. But while radioactivity has a wide range of useful applications, this discovery also has a flip side - the misuse of ionizing radiation that can lead to burns, radiation sickness, death, cancer, tumors and genetic mutations. A source of ionizing radiation (IRS) is a physical object containing radioactive material or a technical installation that generates or is capable of generating ionizing radiation under certain conditions. In order to ensure compliance with the permissible limits of radiation exposure of people, the population and the natural environment, as specified in codes, rules and safety standards, there is a national regulatory body. In Ukraine, since 2007, state registration of sources of ionizing radiation has been a part of licensing activities in the field of nuclear energy use. Those radioactive sources that are not or have never been under regulatory control, or are left unattended, lost, misplaced, diverted without proper government authorization, or stolen, are called "abandoned sources." The problem with "abandoned sources" is their potential danger to public health and the difficulty of detection. As a rule, sources of ionizing radiation are located in metal containers with thick walls, which makes it difficult to identify the presence of a radioactive source inside with the help of appropriate equipment. Furthermore, they are objects of different shapes and sizes, and as such they are often objects of interest to different groups of people with different purposes. Getting an "abandoned source" into the hands of ordinary citizens can have catastrophic consequences. An example of a similar situation is the radioactive contamination of the Brazilian city of Goiânia in 1987. After the theft, the perpetrators dumped radiation therapy equipment components containing the radioactive isotope cesium-137 into the trash. Later, this source was discovered by a local resident, whose actions and careless handling led to the spread of radioactive contamination, as a result of which four people died from radioactive contamination, and the area where this source is located is not suitable for life. the next 300 years.

Fabrication of self-assembled Prussian blue graphene hydrogel for highly selective removal of radioactive cesium in water: Adsorption study

This paper reports a simple and cost-effective method for fabrication of a 3D porous and redox-active Prussian blue-graphene (PBG) hydrogel using ferrous ions to reduce graphene oxide sheets. The hydrogel was obtained via sonication for 5 min only at a low temperature of 40 °C without the need of purification or centrifugation. The hydrogel exhibited high selectivity for cesium ions due to the cubic framework of iron centers bound by cyanide bridges, which allows for intercalation of additional cations. The hydrogel's centered-cubic phase of Prussian blue was confirmed through XRD, and its existence was demonstrated through FTIR and XPS. The BET surface area measurements revealed that the composite's adsorptive surface area increased as compared to magnetic PBGO. Furthermore, the hydrogel's adsorption potential for cesium ions increased to 4.67 mmol/g (621.11 mg/g) compared to the previous work, fitting well with the Langmuir isotherm and the pseudo-second order kinetic model. Moreover the optimal values for temperature and pH for cesium ions removal were found to be 30 °C and neutral, respectively.

Release of radioactive cesium to the environment during standard npp operations

Release of radioactive cesium to the environment during standard npp operations

New insight into polystyrene ion exchange resin for efficient cesium sequestration: The synergistic role of confined zirconium phosphate nanocrystalline

Polystyrene resins (PS) have been practical ion exchangers for radionuclides removal from water. However, nonspecific effects of ion exchange groups continue to be a major obstacle for emergency treatment with coexisting ions of high concentrations. The selectivity for Cs+ enables zirconium phosphate (ZrP) to be the most promising inorganic sorbent for radioactive cesium extraction, despite being difficult to synthesize and causing excessive pressure loss in fixed-bed reactors due to fine powder. Herein, through facile confined crystallization in host macropores, we prepared PS confined α-ZrP nanocrystalline (ZrP-PS). Size-screen sorption of layered α-ZrP and sulfonic acid group preconcentration of PS synergistically enable a considerably higher Cs+ affinity of ZrP-PS than PS, as confirmed by X-ray photoelectron spectroscopy (XPS) analysis. ZrP-PS demonstrated remarkable cesium sequestration performance in both batch and continuous experiments, with a high adsorption capacity of 269.58 mg/g, a rapid equilibrium within 80 min, and a continuous effluent volume of 2300 L/kg sorbents. Given the excellent selectivity for Cs+ and flexibility to separate from treated water, ZrP-PS holds great promise as purification packages for the emergency treatment of radioactively contaminated water.

Simultaneous removal of Cs(I) and U(VI) by a novel magnetic AMP@PDA@Fe3O4 composite

The development and use of clean energy produced by nuclear power plants is becoming a major international trend, but it will inevitably lead to the problem of radionuclide pollution. Radioactive nuclear wastewater containing Cs and U and produced as a byproduct of coastal nuclear power production can cause substantial environmental pollution. In order to simultaneously remove radioactive cesium and uranium, polydopamine (PDA) inlaid ammonium phosphomolybdate (AMP) has established a hydrophilic functional structural film on the surface of Fe3O4, forming AMP@PDA@Fe3O4 (APF) which is used to simultaneous remove Cs(I) and U(VI). Using the pH sensitive range of APF adsorption in the process of adsorbing Cs(I) and U(VI), synergistic adsorption can be achieved under the condition of weak acidity to neutral. The effects of temperature, and common cations on Cs(I) and U(VI) adsorption by APF were investigated, the adsorption was found to be sensitive to the presence of K+. The efficiency of Cs(I) and U(VI) adsorption by APF was 99.88% and 98.39%, respectively. The Cs(I) adsorption process was primarily ion exchange with NH4+ within APF composite, whereas that for U(VI) was primarily C-O complexation. Both the Cs(I) and U(VI) adsorption reactions were consistent with second-order kinetic and Langmuir isothermal adsorption models. After five cycles of experiments the removal efficiency of Cs(I) and U(VI) can reach 64.88% and 79.81%, respectively. APF was also found to have high selectivity for Cs and U in seawater with high salt content at pH 6.0–7.0. In mimic contaminated seawater, the efficiency of Cs(I) and U(VI) removal was 97.65% and 84.63%, respectively. These findings provide references for the remove of Cs(I) and U(VI) from radioactive wastewater, making the process of energy production safer.

Interactions between micaceous minerals weathering and cesium adsorption

The environmental behavior of radioactive cesium (RCs) in contaminated areas is generally governed by soil and sediment components and natural weathering conditions. In this study, desorption tests and spectroscopic approaches were used to explore the interaction between the weathering of micaceous minerals (i.e., biotite and phlogopite) and the adsorption of Cs+ and the critical role of weathering in the environmental behavior of RCs. Results showed that the reaction sequence between weathering and Cs+ adsorption significantly affected the surface species of Cs+ and the structure of biotite and phlogopite. Regardless of whether it occurred before, after, or during Cs+ adsorption, weathering generated more high-affinity adsorption sites, namely, interlayer sites (ITs) and frayed edge sites (FESs), to different extents, and then facilitated the uptake of Cs+ at FESs and ITs on micaceous minerals in a poorly exchangeable state. Cs+ stabilized the micaceous mineral structure once it was absorbed within collapsed interlayers by hindering cation exchange and preventing further destruction during weathering. As important weathering factors, high temperature and Ca2+ content promoted the binding of Cs+ in the interlayers of biotite and phlogopite by enhancing interlayer cation exchange. These findings are beneficial for a better understanding of the environmental behaviors of RCs in the hydrosphere and pedosphere.

Перспективы использования метода фиторемедиации для дезактивации загрязненных радионуклидами территорий

Soil contamination with radionuclides, the main cause of which is the accident at the Chernobyl nuclear power plant, is one of the most dangerous negative environment impact factors. Phytoremediation including cultivation of «energy» crops is an effective method for decontamination of territories contaminated with radionuclides. The advantage of this approach is the possibility of using biomass as a renewable source of green energy in combination with the gradual reclamation of polluted soils. A promising crop for the purposes of phytoremediation is willow, the fast-growing species of which provide a high yield of biomass from a production plantation. A problematic issue is the safe use of willow biomass. The assessment of the conditions for the transition of radioactive cesium into willow biomass was carried out on the territories of Belarus contaminated after the Chernobyl accident. Experiments have shown that the predicted content of 137Cs in the wood of a fast-growing willow is significantly lower than the level allowed for wood fuel according to the standards established for the Republic of Belarus (740 Bq/kg). Even at the level of soil pollution at which they are removed from agricultural use (40 Ci/km2), the content of 137Cs in wood will be from 35 to 120 Bq/kg (depending on the dose of potash fertilizers).

Solidification of cesium containing magnetic zeolite sorbent by spark plasma sintering

The possibility of effective solidification of spent sorbents containing radioactive cesium by spark plasma sintering (SPS) technology for their safe and long-term disposal was studied. The kinetics of consolidation spent sorbent based on magnetic zeolite after adsorption saturation with cesium (∼23 wt %) under SPS conditions in the range of 700–950 °C was carried out. The structural, elemental and phase composition changes during high-rate (minutes) heating of zeolite powder saturated with Cs+ ions was studied by SEM, EDX and XRD methods. As a result, ceramic samples with mineral-like structure of Fe-substituted pollucite CsFeSi2O6 were successfully obtained. It was determined that the optimal temperature of SPS consolidation was 900 °C, at which the formation of CsFeSi2O6 ceramics with a relative density of 91.2%, compressive strength of 497.6 MPa, Vickers microhardness of 1019 HV, rate of cesium leaching of 2.33 × 10−8 g/cm2 × day was reached. It was found that the mechanism of cesium diffusion from the volume of ceramics corresponded to flushing from the available surface of the sample, the lowest diffusion coefficient was 2.71 × 10−16 cm2/s, as well as the lowest penetration depth of the solution into the volume of ceramics was 1.04 × 10−5 cm. The adsorbents prepared by SPS up to 900 °C retained the magnetization, and at higher temperature the magnetization decreased, which was caused by phase and structural changes of ceramics. The characteristics of ceramic obtained from spent adsorbent complied with the requirements of GOST R 50926–96 and ISO 6961:1982 for solidified Cs-containing radioactive waste.

Long-Term Analysis of Internal Exposure Dose-Reduction Effects by Food Regulation and Food Item Contribution to Dose after the Fukushima Daiichi Nuclear Power Plant Accident.

Over 10 years have passed since the Fukushima Daiichi Nuclear Power Plant accident. This study verifies the efficacy of longitudinal regulation on internal exposure doses and analyzes food group contributions to radiation doses using accumulated monitoring test results. The committed effective doses in 10,000 virtual persons from fiscal year (FY) 2012 to 2021, with and without regulation, were estimated as products of radioactivity concentrations randomly sampled from the test results, food intake, and dose coefficient. The distributed values of food intake rather than a mean value in dose estimation were assumed to reflect food intake variations and avoid underestimation of internal exposure doses for high-intake consumers. Furthermore, the ingestion of radioactive cesium from the calculation was analyzed per food group. The 95th percentile of the internal exposure dose (the dose of a "representative person") was less than 1 mSv/year in both FYs. The regulation effect was substantial in FY 2012, and no noticeable difference in radiation doses was found between the regulation and no regulation conditions after FY 2016. Internal exposure doses decreased until approximately FY 2016 and then remained constant. It was also shown that not only radioactivity concentration but also food intake is a major factor affecting cesium intake. In summary, it was confirmed that Japan had ensured food safety regarding radioactive materials.

Efficient and selective removal cesium from strong acidic medium by novel butenyl-calix [4]-crown 6 functionalized millimeter-sized mesoporous carbon spheres sorbent: Experimental and theoretical study

Eliminating the radioactive Cesium from high level waste (HLW) is crucial to avoid the radioactive pollution. Herein, a novel carbon-based recognizable material, butenyl-calix [4]-crown 6 functionalized millimeter-sized mesoporous carbon spheres (ButC[4]C6/MMCs), was prepared via “interpenetrating functionalization” strategy to remove Cs(I) from strongly acidic solution. ButC[4]C6 supramolecular was incorporated into the channels of MMCs and polymerized to form cross-linked IPN structure. The morphology and microstructure of the final product were characterized by SEM, NMR, FT-IR, TG-DSG and N2 adsorption–desorption isotherms. The adsorption behaviors of Cs(I) onto ButC[4]C6/MMCs were systematically investigated. ButC[4]C6/MMCs displayed an astonishing adsorption capacity (55.22 mg g−1), high selectivity and reusability at a low dose (2.0 g L-1) under 3.0 M HNO3 medium. Pseudo-second-order kinetic model, Brouers-Sotolongo model and thermodynamic study revealed that the adsorption process is a spontaneous endothermic chemical and heterogeneous adsorption process. Theoretical study revealed that the Cs(I) was tightly fixed in the calixarene cavity via cation-π interaction. This work proposes an effective approach to selectively remove Cs(I) from HLW by skillfully coupling supramolecular recognizer with millimeter-sized porous material to address radioactive pollution issue.

Adsorption of radioactive cesium using synthesized chitosan-g-poly(acrylic acid/N-vinylcaprolactam) by γ-irradiation

To remove radioactive cesium ions from wastewater, graft copolymer of chitosan-g-poly(acrylic acid/N-vinylcaprolactam) [CTS-P(AA/VC)] was synthesized. The shape, thermal stability, and structure of the graft copolymer were all successfully characterized by SEM, TGA, and FT-IR. Batch sorption experiments were carried out in order to evaluate the effects of various parameters such as pH, contact time, adsorbate initial concentration, and temperature. The kinetics data of batch interaction were also extensively covered with various (linear and non-linear) models of sorption kinetic such as pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. Langmuir and Freundrich equations isotherm models were studied by linear and non-linear equations. To determine the best-fitting equations, the correlation coefficient (R2) and the normalized standard deviation Δq (%) were used as error analysis methods. It appeared briefly that the linear and non-linear forms of pseudo-second order and the Langmuir model are better fitted for kinetic and isotherm models, respectively. The elimination capability for cesium-134 radionuclides was ∼115 mg g-1. Thermodynamic parameters showed exothermic, spontaneous nature and decreased randomness during the adsorption process. After the adsorption studies, the elution process was successfully proceeds by using different eluting agents. The findings suggested that CTS-P(AA/VC) graft copolymer could be a useful material for treating cesium-134 ions-containing liquids.

Important roles of surface functionalized groups of MXenes on adsorption capacities of Sr and Cs: A theoretical study

It is important and challenging to capture the radioactive strontium (90Sr) and cesium (137Cs) from nuclear wastes for radionuclide remediation due to their long half-lives and hazardous nature. Adsorption method has been widely used to remove radioactive nuclides as it's low-cost and easy operation. Transition metal carbide and nitride (MXenes) nanomaterials with functional groups possess excellent properties, which can be used as promising adsorbents. However, the influence of surface functional groups of MXenes on adsorption properties of radioactive nuclides is not clear. In this work, a serial of surface functional groups (O/OH) decorated MXenes have been systematically investigated to adsorb Sr and Cs based on density functional theory calculations. The best O/OH (3/16) ratio of MXenes has been used to remove Sr and Cs, and we have found that Sr and Cs can adsorb on the surfaces of MXenes with the adsorption energies ranging from −2.07 ∼ −4.34 eV and −1.42 ∼ −2.58 eV, respectively. Among these MXenes, Sc2C monolayer exhibits the strongest adsorption capacity for Sr and Cs with the largest value of electron transfers, which can be achieved by forming three SrO and CsO covalent bonds between the radioactive nuclides and O atoms of Sc2C monolayer.

Lipophilic Guanidine with Enhanced Stability for Use in Cesium Separation from Legacy High-Level Nuclear Waste

Guanidine functional groups are found in a variety of biologically active molecules and specialized molecules used in industrial applications but often suffer from instability because of their tendency to hydrolyze. Here, guanidines with differently structured alkyl groups were synthesized and their stabilities tested to determine if there is a relationship between the locus of branching in the alkyl groups attached to a guanidine and its hydrolytic stability under the hypothesis that increased steric hindrance to hydrolytic attack will increase stability. The guanidines examined in this work are pertinent to the next-generation caustic-side solvent extraction (NG-CSSX) process, which was developed for the removal of radioactive cesium from highly radioactive and complex alkaline solutions. In the NG-CSSX process, a lipophilic alkylguanidine solvent component is highly important to maintain the effectiveness of the Cs+ stripping of the loaded organic solvent putatively by sequestering extractable anions. Currently used for this purpose, N,N′,N″-tri(3,7-dimethyloctyl)guanidine (TiDG) succumbs to slow hydrolysis under process conditions. Guided by quantum chemical calculations, two new guanidines with large, sterically bulky alkyl substituents have been designed, synthesized, and tested. More sterically hindering alkyl groups were found to increase the stability of guanidines, particularly for the guanidine with branching closest to the guanidine N atom: N,N′-dicyclohexyl-N″-(10-nonadecyl)guanidine (DCNDG). DCNDG was found to have a stability toward hydrolysis 8 to 44 times greater than that of TiDG under different simulated NG-CSSX process conditions, making it one of the most hydrolysis-resistant guanidine molecules reported to date.

Tannic acid-assisted prussian blue anchoring on membranes for rapid and recyclable removal of cesium

As an effective adsorbent, prussian blue (PB) has been used to selectively eliminate radioactive cesium from the complex and change wastewater. Multiple attempts were introduced to refrain from the recovery difficulty of direct application of PB. This study designed a novel strategy of tannic acid (TA) assisted multilayer PB immobilization on a commercial substrate for cesium adsorption. As an effective binder, TA-Fe was successfully applied to immobilize and disperse PB to increase the number of active particles. The resulting composite membrane (MTA-PB) showed excellent cesium selectivity with a high Kd value of 8986 mL/g in geothermal water and maintained its cesium adsorption ability after 5 cycles. Compared with the reported PB powder, the loaded PB gave full play to the adsorption performance. The convenient fabrication method and effective removal of Cs from complex solutions demonstrated that the MTA-PB has excellent potential for practical application in low wastewater concentrations.

Comparative study of the cesium adsorption behavior of montmorillonite and illite based on their mineralogical properties and interlayer cations

Among clay minerals, montmorillonite (MMT) and illite are generally used to remove radioactive cesium (137Cs) from radioactive wastewater. The objectives of this study were to investigate the mineralogical properties of MMT and illite with their Cs adsorption behavior and then demonstrate the type of clay mineral that should be used for removing high- and low-concentrations of Cs. The Ca-type MMT used in this study was exchanged with sodium (Na), magnesium (Mg), and potassium (K) to compare the Cs adsorption behavior based on the interlayer cation type, including that of illite. The basal d-spacing (d001) of MMTs (swelling) ranged from 1.011 to 1.396 according to the interlayer cation type. Illite (non-swelling) had d001 of about 1.0 nm. Among the types, Na-MMT had the highest Cs adsorption capacity (204.67 mg/g), while illite exhibited the highest Cs distribution coefficient (Kd) (161.1 mL/g). The results indicated that the relative charge density of cations and interlayer properties, such as swelling and non-swelling, of clay minerals significantly affect Cs adsorption capacity and selectivity. Therefore, the selection of clay minerals should vary according to the type of high- and low-concentrated Cs wastewater. MMT and illite are advantageous for removing Cs from high- and low-concentration radioactive wastewater, respectively.

Potassium applications reduced cesium uptake and altered strontium translocation in soybean plants

ABSTRACT After the Tokyo Electric Power Company’s Fukushima Dai-ichi Nuclear Power Plant accident in 2011, radioactive cesium (RCs) was released in greater concentrations than radioactive strontium (RSr) in the surrounding environment. Most of the countermeasures were developed to mitigate the RCs transfer from the soil to plants. However, to avoid what has happened after the Chernobyl and Mayak accidents, preventing the transfer of RSr from soil to plants should be a priority. Although the application of potassium (K) fertilizers is the most effective method for preventing agricultural crops from absorbing RCs in contaminated fields, this implementation increases the cost and labor requirements. Considering the preparedness for nuclear accidents, it remains unclear how this countermeasure will be affected if RCs and RSr are released simultaneously. We aimed to explore the effect of K applications on cesium (Cs) and strontium (Sr) uptake and their interaction with and correlation to other elements in the soybean plants and soil. The field experiments were conducted in Fukushima Prefecture, Japan, using different K applications (i.e., no, normal, and high K applications). The dry weight and mineral concentrations of K, Cs, Sr, calcium (Ca), magnesium (Mg), and nitrogen (N) concentration in plants and exchangeable K (ExK), exchangeable Cs (ExCs), exchangeable Sr (ExSr), exchangeable Ca (ExCa), exchangeable Mg (ExMg), NH4+ (ammonium), and NO3- (nitrate) concentrations in the soils were evaluated. This study revealed that K application reduced Cs, Ca, and Mg uptake but did not affect the ExSr, ExCa, and ExMg concentrations in the soil and did not change the uptake of Sr. On the other hand, K concentration of the plant especially at later growth stage, which indicates re-translocation of Sr was negatively regulated by K concentration.

Applicability of non-destructive equipment for radioactivity measurement to screening radio-cesium in foods

This study aimed to evaluate the applicability of non-destructive radioactivity measurement equipments for screening radio-cesium in whole foods without sample preparation procedures. Wild mushrooms and bamboo shoots were collected and studied using five different non-destructive radioactivity devices, and activity concentration was determined by conventional gamma-ray spectrometry using a Ge-detector. Linear regression analyses of activity concentrations were conducted and prediction intervals determined as uncertainties. Overall, non-destructive radioactivity measurement devices found to be suitable for screening radioactive cesium contamination in foods with an effective screening level.

New Approach To Understanding the Experimental 133Cs NMR Chemical Shift of Clay Minerals via Machine Learning and DFT-GIPAW Calculations.

Structural determination of adsorbed atoms on layered structures such as clay minerals is a complex subject. Radioactive cesium (Cs) is an important element for environmental conservation, so it is vital to understand its adsorption structure on clay. The nuclear magnetic resonance (NMR) parameters of 133Cs, which can be determined from solid-state NMR experiments, are sensitive to the local neighboring structures of adsorbed Cs. However, determining the Cs positions from NMR data alone is difficult. This paper describes an approach for identifying the expected atomic positions on clay minerals by combining machine learning (ML) with experimentally observed chemical shifts. A linear ridge regression model for ML is constructed from the smooth overlap of atomic position descriptor and gauge-including projector augmented wave (GIPAW) ab initio data. The constructed ML model predicts the GIPAW data to within a 3 ppm root-mean-squared error. At this stage, the 133Cs chemical shifts can be instantaneously calculated from the Cs positions on any clay layers using ML. The inverse analysis, which derives the atomic positions from experimentally observed chemical shifts, is developed from the ML model. The input data for the inverse analysis are the layer structure and the experimentally observed chemical shifts. The Cs positions for the targeted chemical shifts are then output. Inverse analysis is applied to montmorillonite, and the resultant Cs positions are found to be consistent with previous results (Ohkubo, T.; et al. J. Phys. Chem. A 2018, 122, 9326-9337). The Cs positions on saponite clay are also clarified from experimentally observed chemical shifts and inverse analysis.