Studsvik (Sweden)

SIMULATE5-K (S5K) is the newest state-of-the-art, best-estimate, transient reactor analysis software developed by Studsvik Scandpower, Inc. (SSP). When used in conjunction with CASMO5 to generate multi-group neutronic data for steady-state and transient calculations, S5K can be used to accurately model reactor transient conditions in Pressurized Water Reactors (PWRs) and Boiling Water Reactors (BWRs). Recently, the methods in S5K and CASMO5 were validated by simulating reactor transients from the SPERT-III E-core experiments. These experiments were performed on a small Light Water Reactor (LWR) core and were designed to resemble Reactivity Insertion Accidents (RIAs) in PWRs. Overall, the results calculated with S5K agree well with the experimentally measured data and any differences are much smaller than the reported uncertainties in the measurements, especially the uncertainty in the initial condition. Additionally, S5K supports general multi-group time-dependent neutron diffusion calculations and the SPERT-III E-core experiments were used to show that there were no obvious trends or discrepancies when the two-, four-, and eight-group calculations were compared.

This study investigates Helle Virkner’s role as First Lady to the Danish Prime Minister Jens Otto Krag (1962-1972) – a role that was not fully established at Virkner’s time. The study examines how she formed and modernized the role of the First Lady through her actions, media awareness, and strategic staging. The analysis is divided into a private and public part based on Virkner’s memoirs and contemporary newspaper and magazine articles. The study investigates Virkner’s perception of the role, the press’ framing, and public expectations. While fulfilling traditional duties, Virkner also challenged them through her active societal engagement and strategic media use. The press portrayed her through gendered stereotypes and Americanized ideals. Judith Butler’s theory of performativity and Lisa M. Burns’ concepts of framing and feminization are introduced in the discussion to bring a new perspective on Virkner’s role as First Lady. The theories explain how her actions reproduce and challenge contemporary gender norms. The study concludes that Virkner was a central actor in defining the Danish First Lady balancing tradition and modernity while reshaping public perceptions of women’s roles. Her political influence was greater than previously assumed contributing to Krag’s successes and marking her as Denmark’s first modern First Lady.

Selectively separating Am(III) from nuclear waste streams is an extremely challenging task due to the presence of the trivalent lanthanides and Cm(III). 1,10-Phenanthroline ligands decorated with 1,2,4-triazines or 1,2,3-triazoles have emerged as promising extractants for achieving such separation. In this article, a new robust synthetic pathway towards the hydrophilic, CHON compliant bistriazoylphenanthroline ligand BTrzPhen-tetraol is reported. BTrzPhen-tetraol was synthesised both as the hydrochloride and as a free base with overall yields of 66% and 48%, respectively. The ligand demonstrated excellent solubility and stability in dilute nitric acid solutions, with no observable decomposition after three days in 0.5 mol L-1 HNO3 at 50 °C. Additionally, it exhibited rapid stripping kinetics for Am(III) and Eu(III). Liquid-liquid extraction experiments conducted with BTrzPhen-tetraol, TODGA, and radiotracers of Am(III), Cm(III), and Eu(III) yielded maximum Eu(III)/Am(III) and Cm(III)/Am(III) separation factors of 84 and 2.4, respectively, at 0.26 mol L-1 HNO3. Notably, the separation factors achieved with BTrzPhen-tetraol are comparable to those of existing systems. While only a minor influence of the BTrzPhen concentration on the distribution ratios of Am and Cm was observed under the given conditions, these results highlight the effectiveness of hydrophilic BTrzPhen ligands for selective americium stripping and encourage further optimisation to enhance performance.

Nuclear industry workers exposed to uranium aerosols may risk kidney damage and radiation-induced cancer. This warrants the need for well-established dose and risk assessments, which can be greatly improved by using material-specific absorption parameters in the ICRP Human Respiratory Tract Model. The present study focuses on the evaluation of the slow dissolution rate (ss, d−1), a parameter that is difficult to quantify with in vitro dissolution studies, especially for more insoluble uranium compounds. A long-term follow-up of urinary excretion after the cessation of chronic inhalation exposure can provide a better estimate of the slow-rate dissolution. In this study, two workers, previously working for >20 y at a nuclear fuel fabrication plant, provided urine samples regularly for up to 6 y. One individual had worked at the pelletizing workshop with the known presence of uranium dioxide (UO2) and triuranium octoxide (U3O8). The second individual worked at the conversion workshop where multiple compounds, including uranium hexafluoride (UF6), uranium dioxide (UO2), ammonium uranyl carbonate, and AUC [UO2CO3·2(NH4)2CO3], are present. Data on uranium concentration in urine during working years were also available for both workers. The daily excretion of uranium by urine was characterized by applying non-linear least square regression fitting to the urinary data. Material-specific parameters, such as the activity median aerodynamic diameter (AMAD), the respiratory tract absorption parameters, rapid fraction (fr,), rapid dissolution rate (sr, d−1), and slow dissolution rate (ss, d−1) and alimentary tract transfer factor (fA) acquired from previous work along with default absorption types, were applied to urine data, and the goodness of fit was evaluated. Thereafter intake estimates and dose calculations were performed. For the ex-pelletizing worker, a one-compartment model with a clearance half-time of 662 ± 100 d (ss = 0.0010 d−1) best represented the urinary data. For the ex-conversion worker, a two-compartment model with a major [93% of the initial urinary excretion (A0)] fast compartment with a clearance half-time of 1.3 ± 0.4 d (sr = 0.5 d−1) and a minor (7% of A0) slow compartment with a half-time of 394 ± 241 d (ss = 0.002 d−1) provided the best fit. The results from the data-fitting of urinary data to biokinetic models for the ex-conversion worker demonstrated that in vitro derived experimental parameters (AMAD = 20 μm, fr = 0.32, sr = 27 d−1, ss = 0.0008 d−1, f A = 0.005) from our previous work best represented the urinary data. This resulted in an estimated intake rate of 0.66 Bq d−1. The results from the data-fitting of urinary data to biokinetic models for the ex-pelletizing worker indicated that the experimental parameters (AMAD = 10 μm and 20 μm, fr = 0.008, sr = 12 d−1, fA = 0.00019) from our previous dissolution studies with the slow rate parameter step-wise optimized to urine-data (ss = 0.0008 d−1) gave the best fit. This resulted in an estimated intake rate of 5 Bq d−1. Experimental parameters derived from in vitro dissolution studies provided the best fit for the subject retired from work at the conversion workshop, where inhalation exposure to a mix of soluble (e.g., AUC, UF6) and relatively insoluble aerosol (e.g., UO2) can be assumed. For the subject retired from work at the pelletizing workshop, which involved exposure to relatively insoluble aerosols (UO2 and U3O8), a considerably higher ss than obtained in dissolution studies provided a better representation of the urinary data and was comparable to reported ss values for UO2 and U3O8 in other studies. This implies that in vitro dissolution studies of insoluble material can be uncertain. When evaluating the results from the retrospective fitting of urine data, it is evident that the urine samples acquired after cessation of exposure provide less fluctuation. Long-term follow-up of uranium excretion after cessation of exposure is a good alternative for determining absorption parameters and can be considered the most viable way for determining the slow rate for more insoluble material.

Neuroinflammation during the neonatal period has been linked to disorders such as autism and epilepsy. In this study, we investigated the early life behavioral consequences of a single injection of lipopolysaccharide (LPS) at postnatal day 10 (PD10) in mice. To assess deficits in communication, we performed the isolation-induced ultrasonic vocalizations (USVs) test at PD12. To determine if early life immune stimulus could alter seizure susceptibility, latency to flurothyl-induced generalized seizures was measured at 4 hours(hrs), 2days, or 5days after LPS injections. LPS had a sex-dependent effect on USV number. LPS-treated male mice presented significantly fewer USVs than LPS-treated female mice. However, the number of calls did not significantly differ between control and LPS for either sex. In male mice, we found that downward, short, and composite calls were significantly more prevalent in the LPS treatment group, while upward, chevron, and complex calls were less prevalent than in controls (p< 0.05). Female mice that received LPS presented a significantly higher proportion of short, frequency steps, two-syllable, and composite calls in their repertoire when compared with female control mice (p< 0.05). Seizure latency was not altered by early-life inflammation at any of the time points measured. Our findings suggest that early-life immune stimulation at PD10 disrupts vocal development but does not alter the susceptibility to flurothyl-induced seizures during the neonatal period. Additionally, the effect of inflammation in the disruption of vocalization is sex-dependent.

This paper presents the results of a comparative analysis of corrosion-state studies of E110opt alloy fuel rod claddings carried out in the Studsvik “hot cells” after irradiation in the Halden reactor as well as after 3 years of operation at the Ringhals-3 nuclear power plant (NPP). The experimental fuel rods in the Halden were operated in a water-chemistry regime with increased lithium content (10 ppm lithium). During operation of the TVS-K fuel design in the PWR reactor at the Ringhals-3 NPP, the lithium content in the coolant was at the level of 3.5 ppm. The corrosion state of the fuel rod claddings was estimated from the results of eddy-current liftoff studies, metallographic analysis, transmission electron microscopy/scanning electron microscopy studies of the structural-phase state of oxide film, and lithium distribution over the oxide layer thickness studies by laser ablation inductively coupled plasma mass spectrometry. The results obtained show that increased values of the lithium content in the coolant (10 ppm) lead to an increase in the oxidation state of the fuel rod claddings that is associated with prolonged exposure to an aggressive environment. The lithium content in the fuel rod cladding oxide film after irradiation in the Halden reactor is over two times higher than the typical values obtained during industrial operation in the PWR reactor. The results of TVS-K operation at the Ringhals-3 NPP showed a high corrosion resistance of fuel rod claddings made from E110opt alloy. The maximum oxide film thickness values do not exceed 9 μm, which is consistent with the results obtained after industrial operation in VVER reactors. Thus, the PWR water chemistry (with a standard lithium content ≤5 ppm) has no effect on the corrosion intensification of the fuel rod claddings made from E110opt alloy.

&amp;lt;p&amp;gt;Coastal resources are productive drivers of the so-called blue economy, impacting rapidly growing industries, as the Seawater desalination. Yet, the efficiency of desalination operations is at stake as a result of an imminent operational threat at a global scale, i.e., the proliferation of microscopic algae in seawater. Algal blooms are associated with operational difficulties in the desalination industry, i.e., clogging and bio-fouling, which increase the costs of chemicals, energy and maintenance.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;To alleviate the impact of algal blooms, desalination could be supported by innovative tools that foretell the onset and evolution of bloom events. However, the desalination sector lacks near-real time decision-support tools. This work aims to address this gap. To this end, an operational forecasting service was developed, deployed and tested in a seawater desalination plant,&amp;amp;#160; located at the Saronic Gulf (Greece).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The operational forecasting service comprises three components: (a) a hydrodynamic component, (b) a water quality component, and (c) an early warning system for algal bloom events.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The hydrodynamic model predicts the hydrodynamic regime in the Gulf, including vertical mixing, circulation patterns, temperature and salinity profiles. The hydrodynamic model accounts for the heat exchange between the water body and the atmosphere, the salinity, wind and wave action. Both the hydrodynamic and the wave component have been calibrated and validated using satellite-derived and reanalysis data for the first and in situ data for the latter. Specifically, on the validation of the hydrodynamic component, comparisons with satellite-derived water temperatures proved the model&amp;amp;#8217;s ability to accurately predict water temperature profiles in the domain, with MAE=1.11oC and MAPE=4% at the validation period from 01/07/2018 to 30-11-2018. To further improve the predictive capacity of the forecast model, the service assimilates satellite-derived sea surface temperature (obtained by Landsat-8 imagery) using the Ensemble Kalman Filtering method.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The prediction of algal-related water quality attributes (i.e., chlorophyll-a) is based on a data-driven approach. An ensemble learning method (i.e., a random forest) was trained to map hydrodynamic data (temperature, mixed layer thickness), biogeochemical data (inorganic nutrients) and meteorological data (air temperature, wind speed, solar radiation) to chlorophyll-a concentrations at the area of interest. The random-forest-based model produced accurate predictions in hindcast (the mean absolute percentage error was 14% for the held-out data), allowing for its further deployment in an operational setting.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Ultimately, forecasted hydrodynamic and water quality attributes of the coastal zone are integrated into an early warning system that generates and disseminates readily interpretable warning information to enable operators threatened by a probable shift in the regime of the coastal environment to act promptly and appropriately to reduce the vulnerability of those due to be impacted.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;In conclusion, this work delivers an operational platform that predicts accurately algal-related parameters in coastal waters. Following its deployment and testing in hindcast, the service line will be tested and validated in operational conditions, aiming to assess the limitations in its forecasting abilities.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Acknowledgements:&amp;lt;/strong&amp;gt; This work is supported by a grant from Iceland, Liechtenstein and Norway through the EEA Financial Mechanism 2014-2021, within the framework of the Programme &amp;amp;#8220;Business Innovation Greece&amp;amp;#8221;.&amp;amp;#160;&amp;lt;/p&amp;gt;

For a future deep repository for spent nuclear fuel, the rate and mechanism for dissolution of fission products and actinides from the fuel is a key parameter for the safety assessment of the disposal concept. Although the behavior of spent nuclear fuel under deep repository conditions has been studied extensively, studies of failed fuel are relatively scarce. However, at the Studsvik laboratory, aerated leaching tests of spent fuel started in the 1980s and two of these were finalized only recently. This provides an opportunity to investigate the effects of long-term contact with water under aerated conditions similar to wet interim storage conditions. In this study, surface investigations have been performed on two fuel pellet samples which have been exposed to leaching solutions for over 30 years. Furthermore, the fuel samples have been exposed to carbonate solutions in an effort to dissolve the secondary phases formed during the extended leaching time.