Targeting HSP90 suppresses STAT1/CCL8-driven inflammation and mitigates mitochondrial dysfunction to attenuate hypertension-induced atrial fibrillation.

A thermodynamic model of the molten salt system (Na,Cs,Mg,Pu,Nd)(Cl,I) has been developed in this work to assess the effect of CsI on the melting and vaporization behavior of the nuclear fuel in molten salt reactors. Investigation using X-ray diffraction (XRD) and differential scanning calorimetry (DSC) of the binary systems NdCl3-NdI3 and MgI2-NdI3, as simulant systems for the analogous Pu system, is presented for the first time. Both systems were found to be binary eutectic systems, with solid solutions NdCl3-3xI3x (hexagonal in space group P63/m) and NdCl3yI3-3y (orthorhombic in space group Cmcm) in the NdCl3-NdI3 system, and Mg1-xNdxI2+x (hexagonal in space group P 3 m1) in the MgI2-NdI3 system. Additionally, the system CsI-MgI2 was scrutinized using DSC, confirming the available experimental data in the literature. Furthermore, the investigation of the reciprocal diagonals in the systems (Na,Nd)(Cl,I), (Cs,Mg)(Cl,I), (Mg,Nd)(Cl,I), and (Cs,Nd)(Cl,I) is presented, allowing the characterization of the quaternary behavior of these salts. Based on the experimental data obtained in this work, a CALPHAD model is presented using the quasi-chemical formalism in the quadruplet approximation for the liquid solution. With the aim of modeling the complete (Na,Cs,Mg,Pu)(Cl,I) system, the binary systems NaCl-CsCl, CsCl-MgCl2, CsCl-NdCl3, NaI-CsI, and CsI-NdI3 were reassessed based on data from the literature. Furthermore, a CALPHAD model of the PuCl3 and PuI3 systems is also presented using Nd as a simulant for Pu in molten halide salts. With the developed thermodynamic models, calculations were finally performed to assess the fission product retention of Cs and I in a molten chloride environment. As opposed to their behavior in molten fluorides, the fission products are well retained in the fuel matrix up to concentrations of at least 5 mol%.

High-performance multiple parallel plate avalanche counter (PPAC) used for prompt fission neutron spectrum measurement: superior fission fragment identification and nanosecond-scale response

Computational prediction of structural and physicochemical properties of molten salts plays a vital role in advancing spent nuclear fuel reprocessing, as it circumvents the experimental challenges imposed by extreme operation conditions. Here, first-principles molecular dynamics simulation is employed to investigate the influence of the fission product europium (Eu) on the local structure and transport properties of the LiF-BeF2 (FLiBe) molten salt. It is discovered that the spatial distribution of solute Eu significantly modulates ionic self-diffusivity, introducing a striking 60% uncertainty in the diffusivity of Eu2+ as it transitions from an isolated to a clustered configuration. A clear correlation emerges between the system free energy and the Eu-Eu distance, wherein cluster formation confers lower energy and stronger stability. A comparison of Eu oxidation states reveals that Eu(III) markedly suppresses both ionic self-diffusion and total conductivity relative to Eu(II) due to compromised charge transport efficiency. Structural analysis further indicates strengthened Be-F and Eu-Be interactions in the Eu(III) system, rationalizing the depressed mobility of Eu3+ and Be2+. Together, Bader charge and phonon calculations establish connections between the ion migration behavior and charge transfer, polarization strength, and vibrational characteristics. These findings provide fundamental atomic-scale insights into ionic conduction mechanisms, advance the predictive modeling of fission product behavior, and establish a quantitative basis for assessing their separation rates.

First-principles molecular dynamics simulations systematically elucidate the influence of atomic structure on ionic conductivity in BeF2-NdF3 (FBeNd) molten salt, a key constituent salt in electrochemical pyroprocessing for the molten salt reactor. The increase in ionic conductivity with Nd concentration is explained by multilevel structural analyses encompassing phonon modes, ionic pair structures, network architectures, and electronic characteristics. Phonon dispersion analysis demonstrates that high- and low-frequency vibrational modes are governed by Be and Nd ions, respectively. Detailed structural analyses confirm that enhanced Nd diffusivity correlates with improved Nd-Nd interactions manifested through shortened Nd-Nd distances, distorted Nd-F-Nd angles, emergent edge/face-sharing clusters, and intensified electronic polarization. Conversely, Be-F tetrahedra retain structural integrity with increasing Nd concentrations, and network fragmentation accelerates Be and F diffusion. The dual enhancement effect of ionic self-diffusion coefficients and charge carrier concentration synergistically elevates the bulk ionic conductivity of molten FBeNd. Overall, a composition-structure-property framework spanning macroscale conductivity to atomistic features is established, offering foundational insights for the predictive modeling of fission product accumulation effects and the rational design of separation protocols in pyroprocessing.

Excitation energy of fission fragments within nuclear time-dependent density functional theory

Sensitization of the PADC detector through a wide wavelength UV exposure, in a study utilizing irradiation with relativistic 300 MeV/n Ni ions.

Independent isomeric yield ratios of 131m,gTe and 133m,gTe in the quasi-mono-energetic neutron induced fission of 238U.

Optimization and re-operation of the fission fragment spectrometer VERDI

Nearly four decades after the Chornobyl accident, the structural stability of dispersed nuclear fuel particles is still not fully understood, limiting accurate environmental risk assessment. To date, no phase analyses of these particles have been published. We present a comprehensive phase analysis of individual nuclear fuel hot particles and crystal diffraction data that have not been previously reported in literature. By combining high-resolution synchrotron X-ray diffraction with triple-axis rotation, we were able to collect full Bragg reflection data and determine which phases remained stable in real-world conditions. The analysis revealed the presence of UO2, U3O8, U4O9 and Zr-mixed phases. The detection of largely intact UO2 and U4O9 suggests their structural frameworks have remained stable and are likely to continue acting as containment matrices for incorporated fission products and actinides in the near future. These results provide a basis for further investigation into the extent to which uranium oxide matrices have retained their integrity after long-term environmental exposure in soil and asphalt within the Chornobyl Exclusion Zone (CEZ) and support further development of contamination models and waste management strategies at nuclear accident sites.

Mechanistic modelling of chemically reactive fission product release during power ramps

In – situ chlorination of simulated fission products from light water reactor fuel using ZrCl4

This work presents the neutron-induced transmutation of long-lived fission products (LLFPs) in an accelerator-driven transmuter (ADT) that is not loaded with any nuclear fuel and therefore is free of fission reactions producing additional fission products. The ADT couples a 1-GeV and 30-mA proton accelerator to a blanket made of LLFP rods immersed in heavy water moderator, coolant, and reflector. The proton beam impinges against a lead-bismuth windowless target and produces, on average, ~29 neutrons per incident proton by a spallation reaction. The heavy water moderator slows down the spallation neutrons to enhance the transmutation of LLFP isotopes by higher neutron capture cross sections at thermal energies. Argonne National Laboratory has been actively working on the design of the linac proton accelerator. At present, no software can directly model the fixed-source transmutation of LLFPs from a spallation reaction; therefore, this work externally couples MCNP and FISPACT codes using a Python script. At the beginning of each burnup step, MCNP simulates proton, pion, neutron, gamma, and electron transport and tallies the neutron flux in 12 burnable material regions with 1102 energy groups. Then, FISPACT simulates the fixed-source transmutation using MCNP output data. At the end of the burnup step, burnable materials are shuffled to maximize the transmutation of the LLFPs.

The object of this study is a small modular gas-cooled fast reactor (GFR) fuelled by UN-PuN with minor actinides (MA) addition. The problem solved in this study is the identification of the impact of MA addition on the criticality, fuel burnup stability, and nuclear waste transmutation of the small modular GFR. The parameters studied include k-eff, macroscopic cross-section, conversion ratio (CR), heavy nuclides inventory, and the probability of radiopharmaceutical isotope production. The study was conducted using SRAC-COREBN computational analysis, and the MA used in this study were Pa-231, Am-241, and Np-237. The results obtained that the MA addition, on average, results in a decrease in k-eff, the magnitude of which depends on the type and concentration of MA. Macroscopic cross-section analysis reveals shifts in values, such as an increase in the Macroscopic cross-section absorption, particularly in the case of Am-241. Then, an increase in the macroscopic cross-section of fission is passed at high energies. The CR > 1 and inversion ratio of heavy nuclide approximately are observed at 50% in all configurations. Furthermore, the evolution of fission products such as Tc-99, Rh-105, and I-135 suggests the chance production of radiopharmaceutical isotope. Interpretation of the results show that adding MA effect k-eff and CR because isotopes such as Am-241, Np-237, and Pa-231 actively participate in fission and conversion of fissile material using fast neutron spectrum. A key feature of obtained results is a stable burnup profile, where the MA effectively functions in target transmutation without disrupting the consumption of the primary fissile fuel. These findings could be a technical basis for supporting national energy security and sustainable nuclear waste management.

This work reports high-precision cumulative yield measurements of key isotopes from 235U(nth,f) reactions using the FIPPS (FIssion Product Prompt γ-ray Spectrometer) at ILL, representing the first dedicated cumulative fission yield campaign in the facility. In this work, advanced spectroscopic techniques were employed to reduce nuclear data uncertainties, while evaluating FIPPS capabilities for fission yield measurements. A pre-irradiated 235U target was exposed to a high neutron flux, and the resulting γ-rays were recorded using a 16-element HPGe Clover array. A 7-day irradiation at a thermal neutron flux of ~3.3 x 107 n/s/cm2 was followed by a 23-day decay period. The multi-parameter FIPPS setup, providing data from 64 detector channels, enabled detailed reconstruction of the entire fission process from irradiation to decay. Our analysis framework combined machine learning-based spectral analysis with γ-emission simulations, establishing new benchmarks for fission yield measurements. The approach demonstrates the strength of integrating high-precision γ-spectroscopy with advanced computational methods. Cumulative yields for key isotopes were determined with small uncertainties and showed good agreement with evaluated libraries. The developed methodology offers a robust foundation for future fission product studies and nuclear data improvements, applicable to both short- and long-lived isotopes of nuclear relevance.

Transforming "waste" material into "wealth" emphasises reclaiming its remaining energy and precious isotopes while minimising long‑term ecological impact. Nuclear reactors produce radioactive waste, but this waste can be viewed as a source of uranium and plutonium, in which certain percentages can be retrieved using chemical techniques and thereby allowing the production of new ones, such as mixed-oxide (MOX) fuels and advanced fast-thermal-reactor-fuels, which, in turn, plant uranium and dramatically reduce high-level waste. The latest furnace designs, like molten-salt systems, for instance, have won over many supporters by claiming to totally occlude actinides, thus making them into innocuous or short-lived isotopes which will, in due course, lighten the burden of radiotoxicity and storage facilities. Meanwhile, the isotopes of caesium-137 and strontium-90, the main fission products, which were labelled under the waste category, have indirectly been utilised by the medical as well as the energy sector, thereby proving that there are multiple avenues for value creation apart from electricity generation. Even though there are concerns regarding the potential for the production of explosive materials, as well as high capital and processing costs, the generation of secondary waste and the complexity of regulations, these factors still pose considerable challenges to the widespread use of the recycling techniques. The review outlines the current and near-market options for reprocessing, partitioning, and transmutation, as well as isotopic reuse, assessing their technological maturity, sustainability metrics, safety implications, and nuclear economy loop. Starting from a critical angle, the paper takes the reader through the different possibilities and eventually questions whether the nuclear “waste” could be redefined as a strategic resource for producing long-lasting carbon-free energy.

Nondestructive assay (NDA) techniques for special nuclear materials (SNMs) are increasingly vital for nuclear security and safeguards. Among various NDA techniques, the photofission reaction rate ratio (PFRR) method offers a promising approach to estimate the isotopic compositions of SNMs by comparing photofission reaction rates under different photon energy spectra. However, with this method, it is challenging to accurately detect photofission events because of detector dead time due to gamma flash and the simultaneous occurrence of other photonuclear reactions such as (γ,n) and (γ,2n). To overcome these limitations, this study proposes a novel approach utilizing delayed neutrons emitted from fission products as indicators of photofission reactions. Delayed neutrons, released after irradiation, allow for measurement outside the detector’s dead time and are temporally separated from prompt neutrons and photons, allowing for cleaner signal acquisition. Theoretical formulations are developed to model the production and decay of delayed neutron precursor nuclides, and their neutron emission is linked to photofission reaction rates. The method is validated through simulations using a 235U/238U system irradiated with 6- and 11-MeV photons. Nuclear data from the fifth version of the Japanese Evaluated Nuclear Data Library and Evaluated Nuclear Structure Data File are employed to estimate delayed neutron yields. The simulation results demonstrate that the total delayed neutron production ratio correlates well with uranium enrichment, achieving an average estimation error of less than 2.5%. This confirms the feasibility of using delayed neutrons to infer photofission reaction rates and isotopic compositions. Furthermore, the approach does not require specialized neutron detectors, enhancing its practicality for field deployment. The delayed neutron–based PFRR method thus represents a robust, accurate, and accessible technique for SNM characterization, contributing to the advancement of nuclear security technologies.

Monte Carlo simulations with the CRISP code were conducted to study spallation and fission fragment distributions induced by intermediate- and high-energy protons and photons on actinide and pre-actinide nuclei. The model accounts for intranuclear cascade, pre-equilibrium, and evaporation-fission competition, enabling the consistent treatment of both residues and fission products. Comparisons with experimental data show good agreement in mass and charge distributions, with minor deviations for light fragments. The results highlight the reliability of Monte Carlo approaches for predicting residual nuclei and fragment yields under accelerator-driven system (ADS) conditions. This work provides nuclear data relevant to ADS design, safety, and transmutation analysis

Long-lived fission products represent a major challenge in nuclear waste management due to persistent radiotoxicity over very long timescales. This study focuses on six of these fission products: Se-79, Zr-93, Tc-99, Sn-126, I-127, Cs-135. This study investigates the feasibility of spallation-driven transmutation, in which a high energy proton beam strikes a heavy spallation target to generate neutrons that induce transmutation in the fission products surrounding the target. Lead and depleted uranium are identified as the principal spallation target candidates, reflecting contrasting trade offs in neutron yield, secondary reactions, and heat generation. Simulations assess nuclide specific behavior under reactor scale inventories and practical geometric constraints. Results demonstrate that technetium, iodine, and selenium are strong candidates for transmutation using this pathway, while tin shows partial resistance but benefits from thermal flux. By contrast, zirconium is inefficient to transmute, and cesium suffers from low net reduction due to competition with lighter isotopes. Cost effectiveness is highly isotope-dependent: technetium is most favorable, whereas cesium and zirconium remain expensive. These findings highlight the advantages and limitations of spallation driven systems and motivate strategies with optimized target-blanket designs.

Tellurium is a volatile fission product and a considerable danger in case of a nuclear accident. It has a branch of organic chemistry that is a relatively unexplored part of its accident chemistry. Irradiation of an aqueous solution containing tellurium and organics can give rise to organic tellurides, which are highly volatile species and therefore represent a potential component of the tellurium source term. Iodine behaves similarly and has a well-established interaction with organic species in accidents. In this paper, the formation of organic iodides and tellurides is investigated using various organic species for precursors: acetaldehyde, methyl isobutyl ketone, Texanol ester, and solid flakes of paint representative of what is used in nuclear containments. The results imply that, while both organic tellurides and iodides can form, the presence of iodide serves to suppress the formation of tellurides. Considering this, it appears unlikely that organic tellurides are a practical concern in nuclear accidents, with the possible exception of very early in the accident sequence, when the fission yields of the fuel result in much more tellurium being present than iodine.