scholarly journals NUCLEAR DATA SENSITIVITY/UNCERTAINTY PRE-ANALYSIS OF FNG WCLL FUSION BENCHMARK

2021 ◽  
Vol 247 ◽  
pp. 15004
Author(s):  
Ivan A. Kodeli ◽  
Maurizio Angelone ◽  
Davide Flamini

To assure tritium self-sufficiency in future fusion reactors such as DEMO the accuracy of TRP calculations has to be demonstrated within the design uncertainties. A new neutronics experiment representing a mock-up of the Water Cooled Lithium Lead (WCLL) Test Blanket Module (TBM) is under preparation at the Frascati neutron generator (FNG) with the objective to provide an experimental validation of accuracy of nuclear data and neutron transport codes for the tritium production rate (TPR) calculations. The mock-up will consist of LiPb bricks, EUROFER plates and Perspex substituting water. The mock-up will be irradiated by 14 MeV neutrons at the FNG facility, and the TPR and detector reaction rates will be measured using Li2CO3 pellets and activation foils placed at different positions up to about 55 cm inside the mock-up. Computational pre-analyses for the design of the WCLL neutronics experiment using the SUSD3D sensitivity/uncertainty (S/U) code system is described and compared with the results of some similar FNG experiments performed in the past, in particular the FNG HCPB Tritium Breeder Module Mock-up (2005) and FNG-HCLL Tritium Breeder Module Mock-up (2009). The objective of the pre-analysis is to provide the calculated nuclear responses including the uncertainties due to the uncertainties in nuclear data and thus contributes to the optimisation of the design of the experimental set-up.

2020 ◽  
Vol 225 ◽  
pp. 04021 ◽  
Author(s):  
Y. Jiang ◽  
A. Laureau ◽  
V. Lamirand ◽  
P. Frajtag ◽  
A. Pautz

The present article describes the preliminary validation study of simulated in-core and reflector n eutron spectra in preparation of oncoming experimental programs in the zeropower reactor CROCUS at EPFL. For this purpose, a set of activation foils were irradiated at three characteristic positions in the CROCUS reactor, and the subsequent activities were analyzed via γ spectrometry. The experimental setup was then modeled with the Monte Carlo neutron transport code Serpent2 and associated with an analysis tool to include the effect of the reactor power history during experiments. The comparison of calculated and measured reaction rates (C/E) indicates a general consistency (at 2σ) between calculated and measured spectra. However, offsets of C/E values were observed in (n, γ) reactions, up to 18% for 115In and 8% for 63Cu dosimeters. This could be caused by an unexpected isotopic composition, uncertainties in nuclear data, or the spectrometry analysis. In addition, a 100-groups spectrum unfolding was performed using the experimentally determined reaction rates and the Serpent2 spectra as the prior knowledge. The unfolded spectra were mainly adjusted in the thermal and fast ranges, while few modifications w ere m ade i n t he e pithermal r egion d ue t o the low contribution of epithermal neutrons in activation processes. Moreover, within energy groups where the capture reactions show resonant behavior, flux depletion (up to 38% as compared to the prior spectra) is observed due to the absence of self-shielding effect in the unfolding process. For this purpose, an unfolding method based on energy groups weighting is developed and tested.


2021 ◽  
Vol 247 ◽  
pp. 10021
Author(s):  
A. Vasiliev ◽  
M. Pecchia ◽  
D. Rochman ◽  
H. Ferroukhi

The CASMO/SIMULATE/MCNP/FISPACT-II calculation route has been established at the Paul Scherrer Institute (PSI) for reactor dosimetry and activation studies. Furthermore, the in-house tool NUSS is in use at PSI for nuclear data (ND) related uncertainties quantifications with Monte Carlo neutron transport calculations. The use of randomly sampled ACE-formatted ND files not only allows propagation of the ND uncertainties, but also can serve for assessing the applicability of different types of experimental data for validation of calculation predictions of parameters of interest. In the present work an application of the PSI calculation scheme for analysis of activation reaction rates and the fast neutron fluence (FNF), throughout the Swiss pressurised water reactor (PWR) and simplified containment building models, is demonstrated. As particular examples of potentially available experimental data, two kinds of the neutron flux monitors are considered: a) the reactor pressure vessel scraping samples and detectors placed in the dosimetry channels, mounted at the core barrel and designed for validation of FNF calculations, and b) the ex-vessel dosimeters, specifically used by the Swiss waste management organisation (NAGRA) for validation of bio-shield activation predictions. The calculations were done with the ENDF/B-VII.1 library. The obtained results demonstrate importance of the ND uncertainties for the dosimetry evaluations. The assessment of the applicability of the selected experimental information for validation of the bio-shield irradiation calculations was done based on evaluation of the ND-related Pearson correlation coefficients.


Technology united with research and development has evolved as a grave differentiator of the agriculture sector in India including production, processing, and agriculture packing and marketing of given crops. Near about 50 percent of the Indian workforce was engaged in the agriculture sector but its share in GDP was only 14 percent, much lower in comparison to former. Though, certain agriculture items showed a steady annual increase in terms of kilograms per hectare. Agriculture transformed significantly over the past few decades but when it comes to investment in research and development there is a lot more which needs to be done. The paper analyzes the role of various research and development institutions in boosting the growth of the agriculture sector that helps in attaining sustainable agriculture development and self-sufficiency in the production process since independence. It also focusesed on the various issues faced by these development institutions. The findings unveiled that since independence a lot more was done to boost the research and development in the agriculture sector at both the center and state levels but a proper implementation of these policies along with transparency could bring more desirable outcomes than were gained at present.


2021 ◽  
Vol 13 (8) ◽  
pp. 4592
Author(s):  
Fabio Bothner

The number of emission trading and carbon taxation schemes implemented has grown rapidly over the past decade. Together, they cover approximately 16% of global greenhouse gas (GHG) emissions. Although more than two-thirds of global GHG emissions are related to household consumption, approaches that directly target households, such as personal carbon trading (PCT), do not play a role in the fight against climate change. This is especially puzzling as measures taken so far are not sufficient to reach the 2 °C target. One clue to solving this puzzle comes from political science in the form of the multiple streams approach, which defines criteria that a policy proposal must meet to become part of the political agenda. Based on these criteria, this article conducts a systematic review on PCT to clarify why PCT does not play a role in the reduction of GHG emissions. The results show that there are three main problems with the PCT proposal. First, scholars often criticize the set-up costs as well as the running costs of such a system. Second, there is no clear consensus within the research community on public acceptance of PCT. Third, it is still unclear whether politicians are receptive to PCT or not.


Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 614
Author(s):  
Ayan Orazov ◽  
Liudmila Nadtochii ◽  
Kazybay Bozymov ◽  
Mariam Muradova ◽  
Araigul Zhumayeva

This paper examines the problem of food security in the Republic of Kazakhstan over the past 10 years. Based on statistical data, an assessment was made of the prevalence of malnutrition among the population of the country, including children under 5 years of age. There has been a trend towards for an improvement in the nutrition of the population for a few indicators; however, further optimization of food security indicators is required to achieve the goals of sustainable development (SDGs) of the FAO WHO Agenda for the period up to 2050 in Kazakhstan and in its individual regions. The paper reflects data on demographic changes over the past 10 years and its self-sufficiency in basic foods for 2019. A high degree of self-sufficiency in meat products (117.6%) is revealed in the population of the Republic of Kazakhstan. However, self-sufficiency in dairy products is at an extremely low level (0.1%). Camel breeding has been successfully developing in the country over the past 10 years. However, the number of camels in the country is still at a low level. Camel milk can be considered as a great source of macronutrients, its daily consumption partially facilitates the problem of Food Security in Kazakhstan.


2018 ◽  
Vol 15 (3) ◽  
pp. 49-51 ◽  
Author(s):  
Nick Bouras ◽  
Silvia Davey ◽  
Tracey Power ◽  
Jonathan Rolfe ◽  
Tom Craig ◽  
...  

Maudsley International was set up to help improve people's mental health and well-being around the world. A variety of programmes have been developed by Maudsley International over the past 10 years, for planning and implementing services; building capacity; and training and evaluation to support organisations and individuals, professionals and managers to train and develop health and social care provisions. Maudsley International's model is based on collaboration, sharing expertise and cultural understanding with international partners.


1921 ◽  
Vol 15 (2) ◽  
pp. 233-252
Author(s):  
Harold M. Vinacké

It is now nine years since the outbreak of the Chinese revolution. It is fifteen years since the Manchus attempted to maintain their control by introducing representative institutions into China. The development toward constitutional and representative government under the Manchus was checked in 1911 by the revolutionary movement. When the Chinese Republic was established as the successor to the alien Manchu Empire it was felt that the problem of modernizing China bade fair to be solved, and that in an orderly way her political institutions would be brought into harmony with western standards. Unfortunately that orderly progress has not come. Parliamentary government under the Nanking (provisional) Constitution was replaced by the dictatorship of Yuan Shih-kai under the arrangements of the so-called constitutional compact, which in turn was followed by the attempt to reëstablish the monarchy. The failure of the monarchy movement brought back parliamentary government, but before a permanent constitution could be adopted Parliament was again dissolved, and a government controlled by a military clique set up in its place. Since this military government was unacceptable to the southern provinces, the country became divided. So far it has not been possible for the country to reconcile its differences. Instead of an ordered constitutional progress, has come apparent failure in the effort to establish representative government. The name of a republic has been maintained, it is true, and the forms of constitutional government have been retained, but a permanent national government has not been set up, nor has popular government replaced the paternal despotism of the past.


Author(s):  
Cécile-Aline Gosmain ◽  
Sylvain Rollet ◽  
Damien Schmitt

In the framework of surveillance program dosimetry, the main parameter in the determination of the fracture toughness and the integrity of the reactor pressure vessel (RPV) is the fast neutron fluence on pressure vessel. Its calculated value is extrapolated using neutron transport codes from measured reaction rate value on dosimeters located on the core barrel. EDF R&D has developed a new 3D tool called EFLUVE3D based on the adjoint flux theory. This tool is able to reproduce on a given configuration the neutron flux, fast neutron fluence and reaction rate or dpa results of an exact Monte Carlo calculation with nearly the same accuracy. These EFLUVE3D calculations does the Source*Importance product which allows the calculation of the flux, the neutronic fluence (flux over 1MeV integrated on time) received at any point of the interface between the skin and the pressure vessel but also at the capsules of the pressurized water reactor vessels surveillance program and the dpa and reaction rates at different axial positions and different azimuthal positions of the vessel as well as at the surveillance capsules. Moreover, these calculations can be carried out monthly for each of the 58 reactors of the French current fleet in challenging time (less than 10mn for the total fluence and reaction rates calculations considering 14 different neutron sources of a classical power plant unit compared to more than 2 days for a classic Monte Carlo flux calculation at a given neutron source). The code needs as input: - for each reaction rate, the geometric importance matrix produced for a 3D pin by pin mesh on the basis of Green’s functions calculated by the Monte Carlo code TRIPOLI; - the neutron sources calculated on assemblies data (enrichment, position, fission fraction as a function of evolution), pin by pin power and irradiation. These last terms are based on local in-core activities measurements extrapolated to the whole core by use of the EDF core calculation scheme and a pin by pin power reconstruction methodology. This paper presents the fundamental principles of the code and its validation comparing its results to the direct Monte Carlo TRIPOLI results. Theses comparisons show a discrepancy of less than 0,5% between the two codes equivalent to the order of magnitude of the stochastic convergence of Monte Carlo results.


Author(s):  
Matthias Golz ◽  
Florin Boeck ◽  
Sebastian Ritz ◽  
Gerd Holbach

The efforts to discover the world’s oceans — even in extremely deep-sea environments — have grown more and more in the past years. In this context, unmanned underwater vehicles play a central role. Underwater systems that are not tethered need to provide an apparatus to ensure a safe return to the surface. Therefore, positive buoyancy is required and can be achieved by either losing weight or expanding volume. A conservative method is the dropping of ballast weight. However, nowadays this method is not appropriate due to the environmental impact. This paper presents a ballast system for an automated ascent of a deep-sea seabed station in up to 6000 m depth. The ballast system uses a DC motor driven modified hydraulic pump and a compressed air auxiliary system inside a pressure vessel. With regard to the environmental contamination in case of a leakage, only water is used as ballast fluid. The modification of an ordinary oil-hydraulic radial piston pump and the set-up of the ballast system is introduced. Results from sea trials in the Atlantic Ocean are presented to verify the functionality of the ballast system.


2011 ◽  
Vol 1 ◽  
pp. 3-8
Author(s):  
Cong Zhao ◽  
Wei Guo

To achieve the goal that anybody could communicate with anyone at anytime in anyplace and in anyway, many technologies, such as GSM、CDMA、WCDMA、CDMA2000、TD-SCDMA、802.11a/b/g and so on, come true in the past years. And now, many B3G or 4G technologies are being studied. It is well-known that the future network would be heterogeneous networks. It is studied in this paper the mobility management of wireless heterogeneous network and a reversing paging process of callee is proposed which integrates paging and handoff. In the process when the caller pages the callee choosing its best suited network on one end, the callee chooses its own best network to begin a reversing paging process to set up the communication. The simulation tells that the proposed process has better performances in the call delay, the call succeeding rate and the wireless signal cost than that of the existing process in which it sets up the call first and then does vertical handoff independently.


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