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Implementing internal independent nuclear safety oversight – Insights from a Nordic empirical case study
Get PDFIndependent Nuclear Safety Oversight (INSO) is an internal organizational function that aims to provide nuclear licensee organizations an independent overview of their nuclear safety situation. This article provides an overview of the implementation and impact of INSO based on an empirical, qualitative case study in three Nordic nuclear power companies. INSO was perceived to contribute to nuclear safety by providing independent challenge of the line activities and decisions, advising and supporting the line organization and senior management, and providing an independent overview of nuclear safety. The implementation challenges were often managerial and included the underutilization of INSO recommendations by top management, lack of agreement between INSO and the line organization regarding INSO’s role, tasks, and results, and the unavailability of resources for conducting INSO activities. Our results also suggest that internal independence is not a black and white phenomenon and that there is no universally correct level of independence. Internal independence involves continuously and intelligently managing the tension between being isolated and losing perspective. The article concludes with recommendations for improving the effectiveness of INSO in global nuclear industry and suggests future development needs
Hydroxylamine grafting of periodate oxidized cellulose microfibrils and its impact on fibre adhesion
No full textIn this work, dialdehyde cellulose microfibrils (DA-CMFs) were reacted with O-substituted hydroxylamines, demonstrating an effective and versatile method for lateral functionalization of DA-CMFs using mild, aqueous reaction conditions. Depending on the conditions used, partial or complete substitution of the aldehydes could be achieved. The reaction was performed in the presence and absence of the reducing agent α-picoline borane (PB). DA-CMFs were reacted with O-(carboxymethyl) hydroxylamine (HAAA), and the adhesive properties of native and HAAA-conjugated DA-CMFs to fibres were studied. The adhesive properties were shown to depend on charge; while native DA-CMFs aggregate heavily in contact with the fibre surface, HAAA-conjugated DA-CMFs showed significantly improved adhesion. For a degree of substitution of 50% or higher, a sealed layer, without aggregates, could be observed using electron microscopy. Finally, a versatile protocol for co-insertion of HAAA (carboxylate) and aminooxy-PEG3-azide (hydroxylamine azide) was developed and demonstrated, with high yields of insertion. The modified DA-CMFs retained good adhesive properties to fibres, showing that the approach is general, and that the chemistry can be tuned depending on the target application
Effect of Boric Acid on Volatile Fission Products in Conditions Simulating a Severe Nuclear Accident
No full textBoric acid is expected to play a role in severe nuclear accident chemistry, raising questions about of how it affects the volatile fission products iodine, cesium, and tellurium. Since tellurium and iodine are radiologically related (132Te decays into 132I/132mI with a half-life of 3.17 days) interactions between them are always possible in a severe accident scenario, but research focusing on their interactions is surprisingly scant. Experiments were undertaken at the VTT Technical Research Center of Finland using a setup involving the volatilization of tellurium, the injection of iodine as a gas, and boric acid and/or CsI dissolved in water and injected with the help of an atomizer. Analysis of the results included measurements with inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicate that the volatility of tellurium is significantly increased if tellurium, iodine (I2), and boric acid are all present together, which was observed through a heightened concentration of tellurium in the liquid trap following such experiments. Furthermore, the formation of tellurium iodide is possible, as determined by SEM-Energy-dispersive X-ray spectroscopy (SEM-EDS) and supported by XPS. These results imply that studies of tellurium in combination with other relevant species should be continued. There is evidence that their volatility can be affected by one another, but the research into this type of interaction is scant.</p
Semi-quantitative Lateral Flow Assay Using a Handheld Device with a Transmissive Readout
No full textLateral flow assays (LFAs) are widely used for rapid and cost-effective diagnostic testing. The assays are often qualitative relying on a binary interpretation of the results on test strips. In many applications, however, quantitative or semi-quantitative readout is needed to define the analyte molecule concentration in a sample matrix, such as, saliva or urine. This study focuses on developing a semi-quantitative LFA test concept with a customized test strip cartridge and transmissive optical detection. LFA was developed to detect Covid-19 proteins and the coloration of the test line was induced by the concentration of plasmonic nanoparticles. Spectroscopic characterization of the test strips showed that the signal strength was enhanced by 82% on average when the conventional reflection-based detection was substituted by a transmission detection. When a set of LFA tests were read with the developed handheld optoelectronic device, the observed standard deviation was found to be below 3% meeting the requirements for semi-quantitative analyses.</p
Fast pyrolysis pathway for production of sustainable aviation fuel (SAF) from demolition wood: Experimental and process simulation approach
No full textThe escalating adverse climate impacts of aviation industry have attracted the attention of research towards the production of sustainable aviation fuels (SAF) for mitigating the climate change. This study aims to investigate the demolition wood as a potential feedstock to produce SAF through fast pyrolysis process. A steady-state process simulation model was developed in Aspen Plus® and validated experimentally. The simulation model developed for SAF production comprises pyrolysis process, hydrotreating of bio-oil, fractionation of hydrotreated-oil, production of H 2 gas through Proton exchange membrane (PEM) electrolyzer, purification of aqueous stream, and combustion of char blocks. The process simulation model has produced 52.8 wt% bio-oil, 20.5 wt% char, and 10.8 wt% gases by using yield-based pyrolysis reactor at operating temperature of 500 °C. Experimental results have demonstrated 49.9 wt% bio-oil yield at 500 °C pyrolysis temperature and 1 s reactants residence time. The simulation model indicated 12.2 wt% SAF yield, and physiochemical properties of SAF were also found consistent with the ASTM D7566 standard. It was also indicated that around 0.07 kg of H 2 per kg of bio-oil is needed for hydro-processing reactions at 99.9 % purity of H 2 gas. The process simulation model also estimated that 36.3 MW of electrical power, 6.9 MW of external heating utility and 11.7 MW of external cooling utility were required to produce 0.12 kg of SAF per kg of feedstock. Overall, the research provides a platform to examine the development of SAF production process through the fast pyrolysis of demolition wood, followed by hydro-processing and fractionation.</p
Degrowth and postgrowth:A systematic literature review of growth-critical science
No full textThis article is a systematic review of the bourgeoning field of studies employing growth-critical concepts, namely degrowth and postgrowth. First, it demonstrates how these concepts are used across disciplines, and how they consequently have varying approaches to theory, subject matter, and policy. Secondly, it maps the topography of growth-critical science to demonstrate the topical differences and similarities in these studies. By topic modelling, a natural-language processing machine-learning method, the study finds 20 focal topics from 943 articles. The critiques of growth appear in various combinations, allowing the article to compile the main topics and to demonstrate how they span across studies. The article challenges the assumption that growth-critical science forms a united political or scholarly agenda beyond being critical towards perpetual economic growth.<br/
Exploring the hydration potential and kinetics of Na-Ye'elimite and Ti-Ferrite solid solutions
Get PDFThe addition of Bauxite residue in the raw mix introduces Na+ and Ti4+ into the crystalline phases of calcium-sulfoaluminate (CSA) clinkers. To mimic such a system, Na-Fe-ye'elimite (C₃.₉N₀.₁A₂.₈F₀.₂Ŝ) and Ti-ferrite (C₂F₀.₇₆A₀.₂₄T₀.₁) were synthesized at 1285 °C, 2 h, and 1320 °C, 3 h, respectively. Quantitative X-ray diffraction (QXRD) revealed solid solutions with minor Ca-aluminates phases, whereas electron backscattered diffraction-energy dispersive spectroscopy (EBSD-EDS) could distinguish Na-rich orthorhombic and Fe-rich cubic ye'elimite polymorphs. Isothermal calorimetry showed the Na-Fe-ye'elimite phase drives early heat evolution, whereas higher ferrite and gypsum (M > 0) prolong induction and attenuate the main hydration peak. In ferrite-free mixes, the cubic-ye'elimite polymorph dissolves fastest, but when ferrite exceeds 33 wt%, its Fe3+ release accelerates orthorhombic-ye'elimite dissolution, as confirmed by pore-solution analysis. After 28d, Na-Fe-ye'elimite is fully consumed at M (sulfate to ye'elimite molar ratio) ≥ 2 for ye'elimite-ferrite mixes, while ferrite remains partly inert, possibly from Ca2+/SO₄2− adsorb onto its Fesingle bondAl surface. Limiting ferrite to ≤33 wt% is recommended to achieve more densification of the microstructure for better performance
Static Light Scattering for Lignin Particle Size Characterization
No full textLignin, a widely available and renewable organic polymer, has several desirable properties and applications. However, as a by-product of pulp and paper industry, it is mainly burned for energy. Limited understanding of the complex and heterogeneous structure and a shortage of tailored analysis methods hinder its utilization in higher value applications. This study describes and compares the use of two different static light scattering methods, laser diffraction and small-angle light scattering (SALS), for studying lignin particle size in suspension. The results from laser diffraction showed that the selected particle concentration and absorption coefficient affect the measured sizes especially for particles <1 µm in diameter. For irregularly shaped particles with broad size distributions, sampling is the most important parameter affecting the results. SALS proved an efficient method for obtaining information on particle aggregation by providing primary particle sizes as well as aggregate sizes. Characterization of samples with spherical particles and narrow size distributions is straightforward with both laser diffraction and SALS, whereas the interpretation of results for more heterogeneous samples is less obvious. Static light scattering methods could make lignin particle size analysis more rapid and automated, thus enhancing lignin valorization, but should be applied carefully to avoid systematic errors
Corrigendum to “A Novel Data-Driven Input Shaping Method Using Residual Impulse Vector Via Unscented Kalman Filter”:[Knowledge-Based Systems (2025), Volume 329, Part B, November 2025, 114385] (S0950705125014248), (10.1016/j.knosys.2025.114385)
No full textThe authors regret that there is an error in the affiliation listing. The first affiliation is currently merged as one entry, but it needs to be split into two separate ones to accurately reflect the first author's dual affiliations and, most importantly, to comply with the mandatory graduation requirements of her university. Requested Correct Format: Weiyi Yanga b, Yuqi Lic, Mingsheng Shanga b, Shuai Lid e, Shiping Wenf a. Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China b. Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China c. Institute of Computing Technology, Chinese Academy of Sciences, China d. Faculty of Information Technology and Electrical Engineering, University of Oulu, 90570 Oulu, Finland e. VTT-Technology Research Center of Finland, 90570 Oulu, Finland f. Australian AI Institute, Faculty of Engineering and Information Technology, University of Technology, Australia The authors would like to apologise for any inconvenience caused.</p
A state-of-the-art review of R&D for the supercritical water-cooled reactor technology. Part II materials & chemistry
No full textThis document presents a summary of the most relevant research and development (R&D) carried out to support the development of the only generation IV water-cooled reactor endorsed by the Generation IV International Forum (GIF).The coolant of the proposed reactor operates at supercritical water conditions, allowing for an increase in thermodynamic efficiency of the plant and the production of high-grade process heat. Several collaborations have been established to support this technology under the GIF umbrella as well as through other international avenues; as a result, the development work is bolstered by a collective effort between numerous R&D institutions across Asia, Europe, and North America. The Joint European Canadian Chinese development of Small Modular Reactor Technology (ECC-SMART) collaborative project was established to encompass the design and pre-licensing requirements as well as a roadmap demonstrating the safe operation of the supercritical water small modular reactor (SCW-SMR). One of the main challenges in the material and component aspect is the selection and qualification of a fuel cladding material that can withstand supercritical water conditions (beyond 374 °C and 22.1 MPa). The aim of the materials testing work package (WP2) in the ECC-SMART project is to achieve a deep understanding of the corrosion behavior of selected candidate cladding materials. Over 750 corrosion specimens were tested including those under nominal SCW-SMR operating conditions and also at simulated accident conditions. This article summarizes the findings from the study of corrosion behavior of non-irradiated and pre-irradiated candidate materials and from the study of the effect of chemistry and changes in the chemical properties of SCW.</p