scholarly journals Void Reactivity Coefficient Analysis during Void Fraction Changes in Innovative BWR Assemblies

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Andrius Slavickas ◽  
Raimondas Pabarčius ◽  
Aurimas Tonkūnas ◽  
Gediminas Stankūnas ◽  
Eugenijus Ušpuras
Keyword(s):  
Void Fraction ◽  
Functional Module ◽  
Decomposition Analysis ◽  
Section Data ◽  
Mox Fuel ◽  
Fuel Assemblies ◽  
High Enrichment ◽  
Reactivity Coefficient ◽  
The Impact ◽  
Data Library

The study of the void reactivity variation in innovative BWR fuel assemblies is presented in this paper. The innovative assemblies are loaded with high enrichment fresh UO2and MOX fuels. UO2fuel enrichment is increased above existing design limitations for LWR fuels (>5%). MOX fuel enrichment with fissile Pu content is established to achieve the same burnup level as that of high enrichment UO2fuel. For the numerical analysis, the TRITON functional module of SCALE 6.1 code with the 238-group ENDF/B-VI cross section data library was applied. The investigation of the void reactivity feedback is performed in the entire 0–100% void fraction range. Higher values of void reactivity coefficient for assembly loaded with MOX fuel are found in comparison with values for assembly loaded with UO2fuel. Moreover, coefficient values for MOX fuel are positive over 75% void fraction. The variation of the void reactivity coefficient is explained by the results of the decomposition analysis based on four-factor formula and neutron absorption reactions for main isotopes. Additionally, the impact of the moderation enhancement on the void reactivity coefficient was investigated for the innovative assembly with MOX fuel.

scholarly journals Decomposition Analysis of Void Reactivity Coefficient for Innovative and Modified BWR Assemblies

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Andrius Slavickas ◽  
Raimondas Pabarčius ◽  
Aurimas Tonkūnas ◽  
Gediminas Stankūnas
Keyword(s):  
Cross Section ◽  
Safety Concern ◽  
Functional Module ◽  
Decomposition Analysis ◽  
Fuel Burnup ◽  
Mox Fuel ◽  
High Enrichment ◽  
Reactivity Coefficient ◽  
The Impact ◽  
Irradiation Cycle

The decomposition analysis of void reactivity coefficient for innovative BWR assemblies is presented in this paper. The innovative assemblies were loaded with high enrichment UO2and MOX fuels. Additionally the impact of the moderation enhancement on the void reactivity coefficient through a full fuel burnup discharge interval was investigated for the innovative assembly with MOX fuel. For the numerical analysis the TRITON functional module of SCALE code with ENDF/B-VI cross section library was applied. The obtained results indicate the influence of the most important isotopes to the void reactivity behaviour over a fuel burnup interval of 70 GWd/t for both UO2and MOX fuels. From the neutronic safety concern positive void reactivity coefficient values are observed for MOX fuel at the beginning of the fuel irradiation cycle. For extra-moderated assembly designs, implementing 8 and 12 water holes, the neutron spectrum softening is achieved and consequently the lower void reactivity values. Variations in void reactivity coefficient values are explained by fulfilled decomposition analysis based on neutrons absorption reactions for separate isotopes.

scholarly journals Comparison of Deterministic and Stochastic Depletions in Graphite-Filled MOX Fuel Assembly Design

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Thanh Mai Vu ◽  
Donny Hartanto
Keyword(s):  
Fuel Assembly ◽  
Nuclear Data ◽  
Absolute Difference ◽  
Assembly Design ◽  
Mox Fuel ◽  
Nuclear Data Library ◽  
Calculation Results ◽  
The Impact ◽  
Data Library ◽  
Good Agreement

A comparison between stochastic and deterministic depletion calculations based on a graphite-filled MOX fuel assembly configuration is presented in this paper. The infinite multiplication factors and isotope inventory changes as a function of burnup obtained by Monte Carlo method module SCALE/KENO and deterministic method module SCALE/NEWT are compared with those obtained by deterministic code HELIOS. The impact in calculation results by using different nuclear data library is also investigated. The SCALE/KENO results show a good agreement with SCALE/NEWT results in the eigenvalue as a function of burnup (less than 0.1%). However, the absolute difference in the initial k¥ between SCALE/KENO and NEWT modules and HELIOS results is quite large (around 1.1%) and the isotope inventory changes show quite differently at the end of cycle. The uranium and plutonium depletion rates calculated by SCALE/KENO and SCALE/NEWT have quite good agreement. By using the same data library, the good agreement between stochastic and deterministic code’s results were confirmed.

How Does Public Debt Affect the Indian Macroeconomy? A Structural VAR Approach

2020 ◽  
Vol 14 (3) ◽  
pp. 253-284
Author(s):  
Ranjan Kumar Mohanty ◽  
Sidheswar Panda
Keyword(s):  
Economic Growth ◽  
Interest Rate ◽  
Public Debt ◽  
Positive Impact ◽  
Decomposition Analysis ◽  
Structural Var ◽  
Adverse Impact ◽  
Mixed Effect ◽  
Domestic Debt ◽  
The Impact

The study investigates the macroeconomic effects of public debt in India during 1980–2017 using a structural vector autoregression framework. The objective is to examine the impact of public debt on the interest rate, investment, inflation and economic growth in India. The results of the impulse response functions show that public debt has an adverse impact on economic growth but a positive impact on the long-term interest rate in the short run and a mixed effect (both negative and positive) on investment and inflation. We also find that domestic debt has a more adverse impact on the economy than external debt. The estimated variance decomposition analysis finds that much of the variation in selected macro variables are explained by public debt and growth in India. This study suggests that public debt especially domestic debt should be controlled and channelled productively to have a favourable impact on the economy. JEL Classification: H63, O40, C40

scholarly journals Analysis of the Accelerator-Driven System Fuel Assembly during the Steam Generator Tube Rupture Accident

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1818
Author(s):  
Di-Si Wang ◽  
Bo Liu ◽  
Sheng Yang ◽  
Bin Xi ◽  
Long Gu ◽  
...  
Keyword(s):  
Fuel Assembly ◽  
Steam Generator ◽  
Metal Flow ◽  
Maximum Temperature ◽  
Steam Generator Tube ◽  
Driven System ◽  
Fuel Assemblies ◽  
Accelerator Driven System ◽  
The Impact ◽  
Steam Bubble

China is developing an ADS (Accelerator-Driven System) research device named the China initiative accelerator-driven system (CiADS). When performing a safety analysis of this new proposed design, the core behavior during the steam generator tube rupture (SGTR) accident has to be investigated. The purpose of our research in this paper is to investigate the impact from different heating conditions and inlet steam contents on steam bubble and coolant temperature distributions in ADS fuel assemblies during a postulated SGTR accident by performing necessary computational fluid dynamics (CFD) simulations. In this research, the open source CFD calculation software OpenFOAM, together with the two-phase VOF (Volume of Fluid) model were used to simulate the steam bubble behavior in heavy liquid metal flow. The model was validated with experimental results published in the open literature. Based on our simulation results, it can be noticed that steam bubbles will accumulate at the periphery region of fuel assemblies, and the maximum temperature in fuel assembly will not overwhelm its working limit during the postulated SGTR accident when the steam content at assembly inlet is less than 15%.

scholarly journals Decomposition Analysis of the Evolution of the Local Energy System as a Tool to Assess the Effect of Local Actions: Methodology and Example of Malmö, Sweden

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 461
Author(s):  
Isabel Azevedo ◽  
Vítor Leal
Keyword(s):  
Local Level ◽  
Ghg Emissions ◽  
Decomposition Analysis ◽  
Specific Effect ◽  
Energy System ◽  
Local Energy ◽  
Total Change ◽  
The Impact ◽  
Change Mitigation

This paper proposes the use of decomposition analysis to assess the effect of local energy-related actions towards climate change mitigation, and thus improve policy evaluation and planning at the local level. The assessment of the impact of local actions has been a challenge, even from a strictly technical perspective. This happens because the total change observed is the result of multiple factors influencing local energy-related greenhouse gas (GHG) emissions, many of them not even influenced by local authorities. A methodology was developed, based on a recently developed decomposition model, that disaggregates the total observed changes in the local energy system into multiple causes/effects (including local socio-economic evolution, technology evolution, higher-level governance frame and local actions). The proposed methodology, including the quantification of the specific effect associated with local actions, is demonstrated with the case study of the municipality of Malmö (Sweden) in the timeframe between 1990 and 2015.

scholarly journals Growth and Weight Status in Chinese Children and Their Association with Family Environments

Children ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 397
Author(s):  
Xu Tian ◽  
Hui Wang
Keyword(s):  
Weight Status ◽  
Family Income ◽  
Decomposition Analysis ◽  
Overweight And Obesity ◽  
Chinese Children ◽  
Nutrition Survey ◽  
Growth Status ◽  
Health And Nutrition ◽  
The Impact ◽  
Over Time

The growth status and weight status of Chinese children have experienced remarkable changes in the past decades. Using China Health and Nutrition Survey (CHNS) data, this paper examines the secular trends and disparity of the growth status and weight status in Chinese children and further investigates the impact of various family environments on children’s growth from 1991 to 2011. We found an increasing trend in standardized growth indicators (height, weight, and BMI), overweight, and obesity from 1991 to 2011. We also observed an increasing disparity in overweight and obesity over time. Family environments had a significant impact on children’s growth status and weight status. In particular, children that live in families with a small size, higher family income, better sanitary conditions, and with well-educated parents or overweight parents tended to be taller and heavier and have a higher BMI, lower risk of being underweight, and higher risk of exhibiting overweight and obesity. Further decomposition analysis showed that more than 70% of the disparity in standardized height, weight, and overweight and around 50% of the disparity in standardized BMI, underweight, and obesity could be attributed to heterogeneity in family environments. Moreover, the disparity associated with family environments tended to increase over time.

Relation Between Flow Velocity and Impact Pressure in a Green Water Flow

2013 ◽  
Author(s):  
Kusalika Ariyarathne ◽  
Kuang-An Chang ◽  
Richard Mercier
Keyword(s):  
Kinetic Energy ◽  
Void Fraction ◽  
Pressure Rise ◽  
Impact Pressure ◽  
Breaking Wave ◽  
Wave Condition ◽  
Wall Impingement ◽  
Impact Coefficient ◽  
The Impact ◽  
Mean Kinetic Energy

Impact pressure due to plunging breaking waves impinging on a simplified model structure was investigated in the laboratory based on two breaking wave conditions: the wall impingement wave condition and the deck impingement wave condition. Pressure, void fraction, and velocities were measured at various locations on the deck surface. Impact pressure was correlated with the mean kinetic energy calculated based on the measured mean velocities and void fraction to obtain the impact coefficient. For the wall impingement wave condition, the relationship between impact pressure and mean kinetic energy is linear with the impact coefficient close to unity. For the deck impingement wave condition, the above relationship does not show good correlation, whereas the impact coefficient was found to be a function of the rate of pressure rise.

scholarly journals Key Factors Influencing the Achievement of Climate Neutrality Targets in the Manufacturing Industry: LMDI Decomposition Analysis

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8006
Author(s):  
Kristiāna Dolge ◽  
Dagnija Blumberga
Keyword(s):  
Energy Efficiency ◽  
Co2 Emissions ◽  
Manufacturing Industry ◽  
Decomposition Analysis ◽  
Clean Energy ◽  
Industrial Activity ◽  
Intensity Effect ◽  
Wood Processing ◽  
Activity Effect ◽  
The Impact

The manufacturing industry is often caught in the sustainability dilemma between economic growth targets and climate action plans. In this study, a Log-Mean Divisia Index (LMDI) decomposition analysis is applied to investigate how the amount of industrial energy-related CO2 emissions in Latvia has changed in the period from 1995 to 2019. The change in aggregate energy-related CO2 emissions in manufacturing industries is measured by five different factors: the industrial activity effect, structural change effect, energy intensity effect, fuel mix effect, and emission intensity effect. The decomposition analysis results showed that while there has been significant improvement in energy efficiency and decarbonization measures in industry, in recent years, the impact of the improvements has been largely offset by increased industrial activity in energy-intensive sectors such as wood processing and non-metallic mineral production. The results show that energy efficiency measures in industry contribute most to reducing carbon emissions. In the future, additional policies are needed to accelerate the deployment of clean energy and energy efficiency technologies.

scholarly journals Impact of Multitemporal Land Use and Land Cover Change on Land Surface Temperature Due to Urbanization in Hefei City, China

2021 ◽  
Vol 10 (12) ◽  
pp. 809
Author(s):  
Jing Sun ◽  
Suwit Ongsomwang
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Urban Areas ◽  
Decomposition Analysis ◽  
Lulc Change ◽  
Main Components ◽  
The Impact

Land surface temperature (LST) is an essential parameter in the climate system whose dynamics indicate climate change. This study aimed to assess the impact of multitemporal land use and land cover (LULC) change on LST due to urbanization in Hefei City, Anhui Province, China. The research methodology consisted of four main components: Landsat data collection and preparation; multitemporal LULC classification; time-series LST dataset reconstruction; and impact of multitemporal LULC change on LST. The results revealed that urban and built-up land continuously increased from 2.05% in 2001 to 13.25% in 2020. Regarding the impact of LULC change on LST, the spatial analysis demonstrated that the LST difference between urban and non-urban areas had been 1.52 K, 3.38 K, 2.88 K and 3.57 K in 2001, 2006, 2014 and 2020, respectively. Meanwhile, according to decomposition analysis, regarding the influence of LULC change on LST, the urban and built-up land had an intra-annual amplitude of 20.42 K higher than other types. Thus, it can be reconfirmed that land use and land cover changes due to urbanization in Hefei City impact the land surface temperature.

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