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• Flow and rupture study of liquid film on corrugated plate wall are reviewed. • Chaotic analysis of film thickness series will be a prospect research direction. • Film rupture mechanism cannot be explained by surface wave disturbance model. • More study will be focused on rupture phenomenon at the corrugated plate corner. Steam generated by steam generator in a nuclear power plant must firstly be subjected to steam-water separation treatment before entering the turbine. The research on flow and rupture characteristics of the liquid film on the wall surface of corrugated plate has important and practical significance for improving the separation efficiency. Since the 1940s, researchers from the United States, France, Japan and other countries have carried out related researches. With the rapid development of steam-water separation technology, many scholars have carried out a large number of experiments, theoretical study and numerical calculations on this phenomenon. Based on the published papers, the research progress and significant achievements of the flow and rupture characteristics of the liquid film on corrugated plate wall are reviewed. Shortcomings of past research and prospects for future research are summarized and proposed, respectively, which provides a reference for improvement of separation efficiency of the corrugated plate dryer. [ABSTRACT FROM AUTHOR]

• From one-quarter to two-thirds of the market in the US, France, and Japan show a strong preference for domestic farmed salmon. • From one-fifth to two-thirds of these markets prefers imported salmon from Norway. • Domestic preference extends to land-based production, especially in Japan. • Consumers infer multitudes of qualities from origin, including product's sustainability and healthiness. • It is important to provide consumers with reliable origin information for farmed seafood that also covers land-based production. Technological advancements that enable countries to produce farmed seafood domestically, including land-based production, could potentially improve sustainability measures. However, whether consumers prefer domestic farmed seafood to imported seafood is unclear. This paper aims to fill this gap by employing hypothetical choice experiments from the US, France, and Japan. We find that, in each country, there is a sizable consumer segment (varying from one-quarter to two-thirds of the market) with a strong preference for domestic farmed salmon, including those from land-based production. These consumers associate domestic origin with higher qualities in all relevant dimensions and are willing to pay a price premium. There is also a segment of consumers with a strong preference for imported Norwegian salmon (from one-fifth to two-thirds of the market), linking Norwegian origin to higher qualities, and willing to pay higher prices. Consumers' attitudes towards the environment and food, usage of label information, age, income, and consumption frequencies, are among the characteristics that explain consumer heterogeneity. Our results show the market potential for domestic farmed seafood, thus, providing consumers with reliable origin information for farmed seafood that also covers land-based production would be important. At the same time, the existence of a segment with a preference for imported seafood implies that active trade will remain, indicating the importance of continued international corporation for a holistic and transparent policy framework and common standards for a sustainable aquatic food system. [ABSTRACT FROM AUTHOR]

Abstract: The joint paper presents a common view of fast reactor specific missions in the development of nuclear energy and a cross-analysis of merits and demerits of several Fast Reactors concepts studied worldwide and especially in the Generation-IV International Forum (GIF) framework. The paper provides the context for fast reactors development in the United States, France and Japan and focuses on the comparison on Sodium-cooled Fast Reactor (SFR), Gas-cooled Fast Reactor (GFR), and Lead-cooled Fast Reactor (LFR), i.e. the three fast reactor concepts that have the potential to meet the nuclear fuel cycle sustainability goals. The information provided in the article permits the reader to understand each country''s objectives to see that not only the objectives searched for but also the technical orientations are converging. The authors underline that SFR technology evaluation relies significantly on the substantial base technology development programs within each country which is without comparison for the other two fast reactor technologies, e.g., SFR technology has already been developed to commercial or near commercial scale in each country whereas the performance of LFR and GFR technology is still uncertain. The main GFR merits are the potential for high temperatures and the easier possibilities for inspections and repairs. The main challenges are the fuel (fabrication, in-pile behavior), materials for high temperatures, and the implementation of mitigation means to manage severe core degradation. The main LFR merit is the lack of chemical reactivity of the lead coolant with air and water. The main challenges are the development of corrosion resistant structural and cladding materials, the implementation of mitigation means to manage severe core degradation, the density of the lead, and the comparably large core size. The selection of a reference fast reactor concept in view of possible industrialization is made on a national base, taking into account the each countries’ strategic objectives, existing technology base, the proven or expected technical performance, the R&D challenges and technical means to conduct that R&D, the possibility to share development costs and risks, etc. It is important to note that in different contexts, the U.S., French, and Japanese organizations have selected the SFR as their reference fast reactor concept. [Copyright &y& Elsevier]

Launched in 2014, Japan-France collaboration on the ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration) project is active both in reactor design and in R&D fields. CEA, Framatome, JAEA, MHI and MFBR are in charge of this collaboration. In the design field, Japan-France evaluates core assemblies with interferences on seismic events. The objectives of this collaboration are to determine the core assembly lattice displacements under seismic load in order to demonstrate the safe behavior of the core regarding control rod insertion, structural integrity, and reactivity variation, etc. From this point of view, the object of this study is to verify the seismic evaluation method on core assemblies between Japan and France by comparing the results. Using their evaluation method applied to common the ASTRID core input data, Japan and France will calculate a collision load, a horizontal displacement, and a vertical displacement for core assemblies. As the first step of this work, the comparison of each evaluation (modelling and calculation results) is carried out considering the horizontal seismic excitation and without including the vertical component. The analysis of this benchmark calculation shows a satisfactory agreement between the Japanese and French tools and the figures show a good behavior of the core in horizontal direction under French seismic condition. This paper describes the summary of horizontal seismic analysis comparison and the future analysis plan. [ABSTRACT FROM AUTHOR]

Abstract: Although MOX fuel coming from reprocessed depleted uranium fuels has been used as a recycling strategy by countries like France and Japan it is not a common policy in the 30 countries that uses nuclear power, nowadays it seems to be a more direct alternative to reduce the depleted fuel interim storage. Previously, the spent fuel pools of Laguna Verde Nuclear Power plant were redesigned to host the total operating life depleted fuel under its original nominal power condition, however the plant has been up-rated to 120% of its original nominal power increasing the number of depleted fuel forecasted. This new situation makes necessary the analysis of alternatives, being one of them recycling. The current paper assesses the viability of using MOX fuel in the up-rated Power Plant; the design of the boiling water reactor MOX fuel addresses the two main constraints of its use: shutdown margin and reactor stability. Fuel design proposed sets the appropriate MOX enrichment and the maximum MOX fuel batch reload that does not imply any modification to the reactor control systems to avoid an extra economical cost due to its use. [Copyright &y& Elsevier]

Abstract: The radioactivity levels in the air of the radionuclides released by the Fukushima accident were measured at the Laboratoire Souterrain de Modane, in the South-East of France, during the period 25 March–18 April 2011. Air-filters from the ventilation system exposed for one or two days were measured using low-background gamma-ray spectrometry. In this paper we present the activity concentrations obtained for the radionuclides 131I, 132Te, 134Cs, 137Cs, 95Nb, 95Zr, 106Ru, 140Ba/La and 103Ru. The activity concentration of 131I was of the order of 100 μBq/m3, more than 100 times higher than the activities of other fission products. The highest activities of 131I were measured as a first peak on 30 March and a second peak on 3–4 April. The activity concentrations of 134Cs and 137Cs varied from 5 to 30 μBq/m3. The highest activity concentration recorded for Cs corresponded to the same period as for 131I, with a peak on 2–3 April. The results of the radioactivity concentration levels in grass and mushrooms exposed to the air in the Modane region were also measured. Activity concentrations of 131I of about 100 mBq/m2 were found in grass. [Copyright &y& Elsevier]

Abstract: The mission of the JT-60SA Tokamak, to be built in Japan, is to contribute to the early realization of fusion energy by its exploitation in support of the ITER program. JT-60SA project is an important part of the “broader approach” activity as a satellite program for ITER. The toroidal field (TF) coils are a European “in kind” contribution and they will partly be built by France. JT-60SA TF coil uses the Cable In Conduit Conductor (CICC) with NbTi superconductor strands. TF conductors will have to operate at 5.7T, 5K and at current density of 450A/mm2 with sufficient margins. In the framework of JT-60SA TF coil manufacture, the variable temperature characterization is an important step to select NbTi strand. At an early stage of design, we had to choose the strand with acceptable performances. During the design qualification and validation stage, it is important to qualify strands in conditions close to the operation conditions. The industry has proposed various strands manufactured with different processes. This work and publication examines a strand with an internal CuNi barrier, which is expected to lead to better current distribution between strands, by more precise calibration and control of the inter-strand resistance. The strands were tested at the Grenoble High Magnetic Field Laboratory facility. The domain (B,T,J) explored was in the range of 4.5–11T for the magnetic field intensity, 4.2–6.5K for the temperature and between 40A/mm2 and 1200A/mm2 for the current density. For each strand, “critical current density” and “current sharing temperature” measurements have been carried out, with a temperature precision of few tens of mK. Once the measurements performed, the fitting parameters (of type J C =f(B,T)) of each strand have been found, by performing regression analysis. This work will lead to select the strand with the best characteristics. In this paper, we present the results of this measurement task, the data and regression analysis (fits, T cs, etc.) and the conclusion about the strand choice. [Copyright &y& Elsevier]

Abstract: This paper presents the results of a benchmark on thermal fatigue crack growth evaluation for a thick-wall cylinder subjected to cyclic thermal transients. The simplified crack growth evaluation methods of both JNC in JAPAN and A16 procedures proposed by CEA in France are presented. The predictions obtained using both methods are compared with the experimental data. The JNC method, which accounts for the non-linear stress component provides predictions of crack advance in a good agreement with the experimental data. In contrast, significant differences are observed between the A16 predictions and the experimental data. The discrepancies are mainly due to the non-linear stress component which is not accounted for in the A16 method. When using the JNC stress intensity factor solution determined by finite element analysis to account for the non-linear stress component, the A16 method well predicts the thermal fatigue crack growth behavior. [Copyright &y& Elsevier]

This paper presents the results of a benchmark on creep-fatigue crack growth evaluation for a plate subjected to cyclic bending loads with a 1 h dwell. The simplified creep-fatigue crack growth evaluation methods of JNC in Japan and A16 procedures proposed by CEA in France are presented. The methods, based on the reference stress approach, are compared each other. They are found to differ in the expression used for the reference stress solution used to estimate the creep strain. It is also pointed out that in contrast to the A16 procedures, the JNC method takes heterogeneous creep strain distribution into account for small scale yielding condition. The predictions obtained by the methods are also compared to the experimental data. It is found that the methods exhibit conservatisms which are significantly reduced when integrating the creep curve continuously without initialisation during the experiment [Proceeding of SMiRT 14(G13/2), Creep-Fatigue Crack Growth on CT25 Specimens in 316L(N) stainless steel at 650 °C]. [Copyright &y& Elsevier]

This paper presents the results of a benchmark on fatigue crack growth evaluation for plates subjected to cyclic bending loads. The simplified fatigue crack growth evaluation methods of JNC in Japan and A16 procedures proposed by CEA in France are presented. The methods, based on the reference stress approach, are compared with each other. They are found to differ in estimating crack closure, in the expression used for the reference stress solution and in the formulations used to take plasticity into account. The methods are then employed to predict the fatigue crack growth behavior observed experimentally. At R=0.1, the methods provide predictions of crack growth in good agreement with the experimental data. At R=−1.0, significant differences are observed between the predictions. The discrepancies are mainly due to the crack closure effect used to calculate the effective SIF range. [Copyright &y& Elsevier]

• Outcome of the France-Japan collaboration on R&D related to fuel discharge. • Study of efficiency of mitigation devices. • Unprotected Loss Of Flow simulation results in terms of mitigation efficiency. • Local calculations around one transfer tube. Sodium-cooled Fast Reactors (SFR) are investigated as future Generation IV reactor concepts. In SFR, the core configuration is not the most reactive during the nominal reactor operation, its geometry change or coolant voiding can induce a reactivity insertion. Within these considerations, mitigation devices should be implemented into the core in order to limit the thermal energy released into the fuel during a severe accident and thereby the possibility to induce mechanical loadings of the reactor structure when vaporized materials expand. Complementary safety devices called Transfer Tubes (TT) are studied in a French concept as an effective mitigation measure of severe accidents to reach a final reactor safe state, even in case of a failure of all shutdown systems including the passive shutdown safety rods. More precisely the TT, with their upper part located in and above the core, cross the core support structure and are linked to the core catcher zone situated in the main vessel bottom. Their purpose is to extract fissile materials from the core zone and secondly to favor the transfer of the molten fuel from the core region to the core catcher in case of severe core damage. The fuel discharge out of the core zone is necessary in order to lower the core reactivity, the relocation into the core catcher is necessary to enable the stabilization, the sub-criticality and the fuel cooling. An extensive work on severe accident calculations and phenomena identification related to fuel discharge through TT was performed. These studies represent the outcome of the work performed in 2014–2019, performed with collaboration of Japanese JAEA and MFBR and Framatome in the framework of the SFR project carried out by CEA. Calculations of fuel discharge were carried out with the mechanistic calculation code SIMMER and the main results are presented in this paper. Firstly, the whole unprotected loss of flow (ULOF) accident sequence was calculated with the SIMMER code. From these calculations, the power and flow evolution were set as boundary conditions for a more detailed model with six fuel assemblies around TT. This model was used to focus on key phenomena and to check impact of design parameter as local bottom restriction inside TT on fuel discharge way. [ABSTRACT FROM AUTHOR]