An assessment of a partial pit ventilation system to reduce emission under slatted floor – Part 1: Scale model study

2012 ◽  
Vol 83 ◽  
pp. 127-133 ◽  
Author(s):  
Wentao Wu ◽  
Peter Kai ◽  
Guoqiang Zhang
Keyword(s):  
Ventilation System ◽  
Scale Model ◽  
Model Study

A Research Reactor Source Term and Dose Results in the Event of a LOCA

2014 ◽  
Author(s):  
Charalampos Pappas ◽  
Andreas Ikonomopoulos ◽  
Athanasios Sfetsos ◽  
Spyros Andronopoulos ◽  
Melpomeni Varvayanni ◽  
...  
Keyword(s):  
Research Reactor ◽  
Source Term ◽  
Dispersion Model ◽  
Ventilation System ◽  
Atmospheric Dispersion ◽  
Reactor Core ◽  
Forecast Model ◽  
Scale Model ◽  
Continuous Reactor ◽  
Reactor Building

The present study discusses the source term derivation and dose result calculation for a hypothetical accident sequence in the Greek Research Reactor – 1 (GRR-1). A loss-of-coolant accident (LOCA) has been selected as a credible accident sequence. The source term derivation has been based on the GRR-1 confinement performance where the inventory has been computed assuming continuous reactor operation. A core damage fraction of 30% has been considered for the calculations while conservative core release fractions have been employed. The radionuclides released from the reactor core to the confinement atmosphere have been subjected to natural decay, deposition on and resuspension from various internal surfaces before being led to the release pathway. It has been assumed that an emergency shutdown is initiated immediately after the beginning of the accident sequence and the emergency ventilation system is also activated. Subsequently, the source term has been derived comprising of noble gases, iodine and aerosol. The JRODOS computational software for off-site nuclear emergency management has been utilized to estimate the dose results from the LOCA-initiated source term that is released in its entirety from the reactor stack at ambient temperature. The Local Scale Model Chain in conjunction with the DIPCOT atmospheric dispersion model that is embedded in JRODOS have been used with proper parameterization of the calculation settings. Five weather scenarios have been selected as representative of typical meteorological conditions at the reactor site. The scenarios have been assessed with the use of the Weather Research and Forecast model. Total effective, skin, thyroid, lung and inhalation doses downwind of the reactor building and up to a distance of 10 km have been calculated for each weather scenario and are presented. The total effective gamma dose rate at a fixed distance from the reactor building has been assessed. The radiological consequences of the dose results are discussed.

scholarly journals THE EFFECT OF WAVE DIRECTION ON SHIP MOTIONS IN A HARBOUR ENTRANCE CHANNEL - MODEL STUDY APPROACH

1984 ◽  
Vol 1 (19) ◽  
pp. 217
Author(s):  
A.C. Van Wyk ◽  
J.A. Zwamborn
Keyword(s):  
Channel Model ◽  
Basic Knowledge ◽  
Scale Model ◽  
Ship Motions ◽  
Wave Direction ◽  
Extreme Wave ◽  
Essential Requirement ◽  
Study Approach ◽  
Model Study ◽  
Bulk Carriers

Basic knowledge of a ship's vertical motions in waves of different angles of approach is an essential requirement in the formulation of allowance criteria on which to base harbour accessibility under extreme wave conditions. A comprehensive series of scale model tests are being undertaken to establish minimum underkeel clearance for given channel depths and sea states using two models representing typical 150 000 and 270 000 dwt bulk carriers.

scholarly journals A Scale Model Study of the Bosomtwe Crater.

1965 ◽  
Vol 70 ◽  
pp. 324
Author(s):  
G. H. S. Jones ◽  
C. H. H. Diehl
Keyword(s):  
Scale Model ◽  
Model Study

Reduced-scale model study on cable heat dissipation and airflow distribution of power cabins

2019 ◽  
Vol 160 ◽  
pp. 114068 ◽  
Author(s):  
Jiaxu Wang ◽  
Xuefeng Liu ◽  
Siwei Chen ◽  
Hanghang Jiang ◽  
Guanyu Fang ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Scale Model ◽  
Model Study ◽  
Airflow Distribution ◽  
Distribution Of Power ◽  
Reduced Scale

Acoustical scale model study of the attenuation of sound by wide barriers

1977 ◽  
Vol 62 (3) ◽  
pp. 601-606 ◽  
Author(s):  
Elizabeth S. Ivey ◽  
G. A. Russell
Keyword(s):  
Scale Model ◽  
Model Study

scholarly journals Impacts of climate and emission changes on nitrogen deposition in Europe: a multi-model study

2014 ◽  
Vol 14 (5) ◽  
pp. 6663-6720 ◽  
Author(s):  
D. Simpson ◽  
C. Andersson ◽  
J.H. Christensen ◽  
M. Engardt ◽  
C. Geels ◽  
...  
Keyword(s):  
Critical Loads ◽  
N Deposition ◽  
Scale Model ◽  
Gaseous Ammonia ◽  
Nh3 Emission ◽  
Model Study ◽  
Emission Changes ◽  
Emission Change ◽  
The Impact ◽  
Oxidised Nitrogen

Abstract. The impact of climate and emissions changes on the deposition of reactive nitrogen (Nr) over Europe was studied using four offline regional chemistry transport models (CTMs) driven by the same global projection of future climate over the period 2000–2050. Anthropogenic emissions for the years 2005 and 2050 were used for simulations of both present and future periods in order to isolate the impact of climate change, hemispheric boundary conditions and emissions, and to assess the robustness of the result across the different models. The results from these four CTMs clearly show that the main driver of future N-deposition changes is the specified emission change. Under the specified emission scenario for 2050, emissions of oxidised nitrogen were reduced substantially, whereas emissions of NH3 increase to some extent, and these changes are largely reflected in the modelled concentrations and depositions. The lack of sulphur and oxidised nitrogen in the future atmosphere results in a much larger fraction of NHx being present in the form of gaseous ammonia. Predictions for wet and total deposition were broadly consistent, although the three fine-scale models resolve European emission areas and changes better than the hemispheric-scale model. The biggest difference in the models is for predictions of individual N-compounds. One model (EMEP) was used to explore changes in critical loads, also in conjunction with speculative climate-induced increases in NH3 emissions. These calculations suggest that the area of ecosystems which exceed critical loads is reduced from 64% for year 2005 emissions levels to 50% for currently estimated 2050 levels. A possible climate-induced increase in NH3 emissions could worsen the situation, with areas exceeded increasing again to 57% (for a 30% NH3 emission increase).

Geotechnical synthesis of 2D_Electrical resistivity tomography of geomaterial_laboratory model study

2011 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Zainab Mohamed ◽  
Nurbaiyah Mohamad Noh
Keyword(s):  
Electrical Resistivity ◽  
Cement Mortar ◽  
Clay Fraction ◽  
Soil Mass ◽  
Mass Scale ◽  
Scale Model ◽  
Hard Material ◽  
Residual Soil ◽  
Hard Layer ◽  
Model Study

In this paper, a laboratory scale model study was conducted on interbeded geomaterial using electrical resistivity instrument. The electrical resistivity value of individual material was determined and modeled as mass scale. The tank was filled with composite geomaterial constituted of interbedding of cement mortar as hard layer and residual sedimentary soil. Forty-one copper electrodes of 15 cm long were used and installed at 4 cm spacing in the tank. The composite geomaterials were labeled as Model 1, Model 2 and Model 3, where they were referred respectively to interbedding of hard layer and layers of residual soil at natural dry state and wet state. The electrical resistivity terrameter was used to obtain the georesistivity pseudo-section by adopting Werner protocol. The georesistivity pseudo-sections were derived from 3 models simulated the subsurface of rock mass in humid tropic environment. The objective was to synthesize the composite georesistivity pseudo-section based on geo-engineering principle. It was observed that the pseudo-section of the composite geomaterial was represented by range of colors with range of georesistivity values. The horizontal bands of color differentiated the georesistivity of models vertically but constant in horizontal direction. The georesistivity value at material scale was comparable to the range of georesistivity values derived from the 2D electrical resistivity pseudo-sections. The contrasts in the conductivity of clay fraction, silica and electrolytes have differentiated the electrical resistivity pseudo-section of sandy soil mass and cement mortar hard material.

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