Temperature study during the edge trimming of carbon fiber-reinforced plastic [0]8/Ti6Al4V stack material

Carbon Fiber-Reinforced Plastic (CFRP) and Titanium alloy (Ti6Al4V) stacks are used extensively in the modern aerospace industry thanks to their outstanding mechanical properties and resistance to thermal load applications. Machining the CFRP/Ti6Al4V stack is a challenge and is complicated by the differences in each constituent materials’ machinability. The difficulty arises from the matrix degradation of the CFRP material caused by the heat generated during the machining process, which is a consequence of the low thermal conductivity of Ti6Al4V material. In most cases, CFRP and Ti6Al4V materials are stacked and secured together using rivets or bolts. This results in extra weight, while the drilling process required for such an assembly may damage the CFRP material. To overcome these issues, some applications employ an assembly that is free of bolts or rivets, and which uses adhesives or an adapted curing process to bond both materials together. The present research analyzes a thermal distribution and its effect on quality during the edge trimming process of a CFRP/Ti6Al4V stack assembly. Different types of tools and cutting parameters are compared using thermocouples embedded within the material and others on the tool cutting edge. In contrast to previous studies, the feed rate was the most significant factor affecting the cutting temperature and quality of the workpiece, while the cutting speed had no significant impact. The temperature in the workpiece increases as the feed per tooth decreases

General Synthesis Report of the Different ADS Design Status. Establishment of a Catalogue of the R&D needs

This document is a General Synthesis Report of the Different ADS Design Status being designed within the EUROTRANS Integrated Project; an FP6 European commission partially funded programme. This project had the goal to demonstrate the possibility of nuclear waste transmutation/burning in Accelerator Driven Systems (ADS) at industrial scale.The focus is on a Pb-cooled ADS for the European Facility on Industrial scale Transmuter (ETD/EFIT) with a back-up solution based on an He cooled ADS.As an intermediate step towards this industrial-scale prototype, an eXperimental Transmuter based on ADS concept (ETD/XT-ADS) able to demonstrate both the feasibility of the ADS concept and to accumulate experience when using dedicated fuel sub-assemblies or dedicated pins within a MOX fuel core has been also studied.The two machines (XT-ADS and Pb cooled EFIT) have been designed in a consistent way bringing more credibility to the potential licensing of these plants and with sufficient details to allow definition of the critical issues as regards design, safety and associated technological and basic R&D needs. The different designs fit rather well with the technical objectives fixed at the beginning of the project in consistency with the European Roadmap on ADS development.For what concerns the accelerator, the superconducting LINAC has been clearly assessed as the most suitable concept for the three reactors in particular with respect to the stringent requirements on reliability. Associated R&D needs have been identified and will be focused on critical components (injector, cryomodule) long term testing.The design of the different ADS has been performed in view of what is reasonably achievable pending the completion of R&D programmes. The way the EUROTRANS Integrated Project has been organised with other domains than the DM1 Design being specifically devoted to R&D tasks in support to the overall ETD/EFIT and ETD/XT-ADS design tasks has been helpful. The other domains were centred on the assessment of reactivity measurement techniques (DM2 ECATS), on the development of U-free dedicated fuels (DM3 AFTRA), on materials behaviour and heavy liquid metal technology (DM4 DEMETRA) and on nuclear data assessment (DM5 NUDATRA). Pending questions associated to technology gaps have been identified through the different appropriate R&D work programmes and a Catalogue of the R&D needs has been established.Finally, the work within the EUROTRANS integrated project has provided an overall assessment of the feasibility at a reasonable cost for an ADS based transmutation so that a decision can be taken to launch a detailed design and construction of the intermediate step Experimental ADS now already launched within the 7th FP programme under the name of Common Design Team (CDT)

Nuclear Data for Sustainable Nuclear Energy

Final report of a coordinated action on nuclear data for industrial development in Europe (CANDIDE). The successful development of advanced nuclear systems for sustainable energy production depends on high-level modelling capabilities for the reliable and cost-effective design and safety assessment of such systems, and for the interpretation of key benchmark experiments needed for performance and safety evaluations. High-quality nuclear data, in particular complete and accurate information about the nuclear reactions taking place in advanced reactors and the fuel cycle, are an essential component of such modelling capabilities. In the CANDIDE project, nuclear data needs for sustainable nuclear energy production and waste management have been analyzed and categorized, on the basis of preliminary design studies of innovative systems. Meeting those needs will require that the quality of nuclear data files be considerably improved. The CANDIDE project has produced a set of recommendations, or roadmap, for sustainable nuclear data development. In conclusion, a substantial long-term investment in an integrated European nuclear data development program is called for, complemented by some dedicated actions targeting specific issues.JRC.D.5-Neutron physic

The GUINEVERE project at the VENUS facility

Proc. on CD Rom log315International audienceThe GUINEVERE project is an international project in the framework of IP-EUROTRANS, the FP6 program which aims at addressing the main issues for ADS development in the framework of partitioning and transmutation for nuclear waste volume and radiotoxicity reduction. The GUINEVERE project is carried out in the context of domain 2 of IP-EUROTRANS, ECATS, devoted to specific experiments for the coupling of an accelerator, a target and a subcritical core. These experiments should provide an answer to the questions of online reactivity monitoring, sub-criticality determination and operational procedures (loading, start-up, shutdown, …) in an ADS by 2009-2010. The project has the objective to couple a fast lead core, within the VENUS building operated by the SCK•CEN, with a neutron generator able to work in three different modes: pulsed, continuous and continuous with beam interruptions at the millisecond scale. In order to achieve this goal, the VENUS facility has to be adapted and a modified GENEPI-3C accelerator has to be designed and constructed. The paper describes the main modifications to the reactor core and facility and to the accelerator, which will be executed during the years 2008 and 2009, and the experimental programme which will start in 2009

a new approach for analysing the impact of nuclear data uncertainties on the astrid sodium void reactivity effect

International audienceFor ensuring sustainable nuclear energy, France has chosen to develop sodium cooled fast reactors. The ASTRID project is a demonstrator of such technology exhibiting innovative features such as the CFV core which has a negative sodium void reactivity effect. In order to study in details the uncertainty associated to this parameter, we split it into two components : the central component (CC) which is a positive reactivity effect due to spectrum changes and the leakage component (LC) which is a negative reactivity effect due to the increase of the neutron mean free path. This paper presents the development of an innovative GPT procedure for computing sensitivities of the CC and the LC. With such sensitivities and the use of the COMAC-V2 covariance matrix, we are able to calculate the uncertainties due to nuclear data on each component using JEFF-3.2 nuclear data. The application of the method to the ASTRID CFV core shows a 2.44% uncertainty on the CC, a 2.98percent uncertainty on the LC and a 14.8percent on the total sodium void reactivity effect. There is a correlation factor of -0.5776 between the LC and CC uncertainties. This approach gives perspectives in studying experimental programmes performed in zero power facilities such as MASURCA

Enhanced Simmer Neutronics Tool for Studying Fast Reactor Distorted Core Configurations

International audienceCore disruptive accidents in fast reactors need to bemonitored carefully since they may lead to possible criticalityconfigurations. However, the worst-case scenariomay have small probability occurrences, but the proof ofit requires multidisciplinary studies. Even with the upgradein computer performance, calculations would requireseveral months on several parallel computers.Accurate calculations with short running times are thusrequired. Updating the neutronics module of SIMMERset up in the 1970s was therefore carried out with thehelp of routines able to handle probability tables forgenerating broad group libraries. The use of such librariestogether with new SIMMER options is now able toproduce reliable results in all sorts of situations whilemaintaining reduced calculation times.Indeed, until now, neutronics calculations from SIMMERgave results quite far from ERANOS ones (differencesin reactivity larger than 1.5 $). The discrepancieswere mainly due to the libraries used. As a consequence,in 2000, an ERANOS module (BISIM) was created togenerate SIMMER nuclear data libraries ( for both crosssections and self-shielding factors) from the ERANOSnuclear data file, thereby reducing the major source ofinconsistencies. Other improvements were added by theJapan Atomic Energy Agency, on the way of calculatingthe transport cross section and on the library group schemeso as to better calculate the k-effective within a reasonabletime frame, but also at the Commissariat à l’EnergieAtomique et aux Energies Alternatives on the b-effectivecalculation. A new option (using the Keepin data) wasimplemented in 2010 in SIMMER.Once all these optimizations were carried out, a comparisonbetween the SIMMER (III for two dimensionsand IV for three dimensions) and ERANOS results wasperformed for a series of disruptive and representativeconfigurations. While the computation time has notchanged significantly, the differences on k-effective betweenERANOS reference route results and SIMMER 16energy-group calculations were drastically reduced by;0.8$

NEA SFR subassembly benchmark sensitivity/uncertainty propagation with depletion

International audienceFor the next generation of fast reactors, global objectives are required in terms of safety improvement, sustainability, waste minimization and non-proliferation. Concerning safety issues, particular efforts have been made in order to obtain core designs that can be resilient to accidental transients. Under the auspices of the Working Party on Scientific Issues of Reactor Systems (WPRS) an OECD/Nuclear Energy Agency (NEA) Expert Group Task Force on Uncertainty Analysis in Best-Estimate Modelling (UAM) for Design, Operation and Safety Analysis of Sodium-cooled Fast Reactors (SFR-UAM) has been initiated in 2015 with the objective to study the uncertainties in different stages of the next generation Sodium Fast Reactors. Among the identified topics of this expert group, a representative SFR fuel subassembly depletion benchmark has been set up in order to analyse the reactivity swing as well as the associated uncertainty level based on available nuclear data variance/covariance matrices coming from evaluations. The benchmark focuses on changes on number densities, on Doppler Effect and sodium void worth as well as kinetic parameters from the beginning of equilibrium cycle up to the end of cycle. For sensitivity/uncertainty estimation, two methods are tested a deterministic one based on sensitivities and a stochastic one using direct nuclear data sampling. In the deterministic approach, Boltzmann and Bateman equations are coupled at the sensitivity level with the help of the perturbation theory. This coupling is currently operational in ERANOS code system. The present implementation gives sensitivities for both reactivity coefficients and mass balance. For stochastic approach, relevant nuclear data set are directly sampled from variance/covariance data and used as input parameter for neutronic calculations. Both methods are found to be consistent

An in-depth analysis of Minor Actinide Fission Chambers Measurements in the FCA IX Experimental Programme.

International audienceFCA is a zero power facility located at Tokai in Japan. The FCA-IX experimental programme exhibits 7 different cores with a variety of different neutron spectra. This has been achieved through the use of different moderators and different Uranium enrichments (93% for most of them except FCA-IX-7 where it is 20%). Fission Chambers of seven different nuclides: $^{237}$Np, $^{238}$Pu, $^{239}$Pu, $^{242}$Pu, $^{241}$Am, $^{243}$Am and $^{244}$Cm were used to measure ratios of fission reaction rate. Mass quantitative determinations of the electrodeposited nuclides were carried out through spectral analysis using a surface barrier silicon detector and a pulse height analyzer. The quantitative determination errors for electrodeposited nuclides were 3% for $^{244}$Cm and 1.5% for the other