scholarly journals Safety Factors for Neutron Fluences in NPP Safety Assessment

2017 ◽  
Author(s):  
V. Diemiokhin ◽  
V. Bukanov ◽  
V. Ilkovych ◽  
A. Pugach
Keyword(s):  
Safety Factor ◽  
Safety Assessment ◽  
Neutron Fluence ◽  
Neutron Transport ◽  
Safety Factors ◽  
Neutron Fluences ◽  
Maximum Value ◽  
Transport Calculation ◽  
Calculation Code

In accordance with global practice and a number of existing regulations, the use of conservative approach is required for the calculations related to nuclear safety assessment of NPP. It implies the need to consider the determination of neutron fluence errors that is rather complicated. It is proposed to carry out the consideration by the way of multiplying the neutron fluences obtained with transport calculations by safety factors. The safety factor values are calculated by the developed technique based on the theory of errors, features of the neutron transport calculation code and the results obtained with the code. It is shown that the safety factor value is equal 1.18 with the confidence level of not less than 0.95 for the majority of VVER-1000 reactor places where neutron fluences are determined by MCPV code, and its maximum value is 1.25.

scholarly journals Uncertainty determination of fast neutron fluence onto the WWER pressure vessel metal surveillance specimens

2021 ◽  
Vol 22 (1) ◽  
pp. 42-47
Author(s):  
O.M. Pugach ◽  
◽  
S.M. Pugach ◽  
V.L. Diemokhin ◽  
V.N. Bukanov ◽  
...  
Keyword(s):  
Fast Neutron ◽  
Pressure Vessel ◽  
Neutron Fluence ◽  
Neutron Transport ◽  
Monte Carlo Code ◽  
Neutron Fluences ◽  
Surveillance Programs ◽  
Surveillance Specimens ◽  
Reactor Pressure

The standard surveillance programs of WWER reactors do not allow to measure the surveillance specimens irradiation conditions with the required accuracy. Therefore, the special methodology for the determination of the surveillance specimens irradiation conditions of the reactor pressure vessel metal has been developed by the specialists of the INR of NASU and is successfully applied. The developed methodology bases on the use of the Monte-Carlo code for neutron transport calculations to the surveillance specimens locations. The methodology improvement is described. The fundamentals of the calculation-experimental determination of the fast neutron fluences onto surveillance specimens and their uncertainties are presented.

scholarly journals Determination of Safety Factors for Mango Fruit Paperboard Transport Crates under Refrigerated Conditions

2018 ◽  
Vol 11 (1) ◽  
pp. 34-43
Author(s):  
Bernd Sadlowsky ◽  
Viktoria Köstner ◽  
Margot Mazur ◽  
Sina-Kristin Thun ◽  
Péter Böröcz
Keyword(s):  
Safety Factor ◽  
Food Industry ◽  
Safety Factors ◽  
Mango Fruit ◽  
Dynamic Stresses ◽  
Corrugated Board ◽  
Material Costs ◽  
The Stability ◽  
Industry Sectors

The use of corrugated board packaging is very popular in most industry sectors, but the food industry is one of the main consumers. Special requirements are placed on corrugated board in the food industry since the level of humidity necessary may be as high as 85-90% rH and this can greatly influence on the performance of the packaging. This influencing circumstance is taken into account in this paper when estimating a safety factor aimed at reducing risk. Knowing the safety factor can save transport and material costs, and can also prevent serious damage during the distribution of goods. The aim of this study is to determine the influence of humidity, pre-compression and load carriers on the stability of corrugated board mango fruit crates and thus to determine the safety factor. The results show that it is possible to calculate the safety factor by measuring realistic static stresses. Further researches into determining the dynamic stresses are required so as completing the calculation of the safety factor.

Determination of safety factor for defibrillator waveforms in cultured heart cells

1982 ◽  
Vol 242 (4) ◽  
pp. H662-H670 ◽  
Author(s):  
J. L. Jones ◽  
R. E. Jones
Keyword(s):  
Safety Factor ◽  
Heart Cells ◽  
Efficacy And Safety ◽  
Safety Factors ◽  
Electric Shocks ◽  
Rate Of Success ◽  
Cultured Heart Cells

We studied excitation thresholds and arrhythmias produced in cultured chick embryo myocardial cells subjected to electric shocks using rectangular, untruncated resistor-capacitor (RC), and critically damped resistor-inductor-capacitor (RLC) waveforms with variable intensities while photocell mechanograms were recorded. Strength-duration curves for excitation and production of a specific postshock arrhythmia (4-s arrest) were constructed. Excitation curves closely resembled those for in situ defibrillation threshold (or specific % success). The ratio between the shock intensity producing a 4-s arrest and that producing excitation at each duration (termed the "safety factor") was determined. Waveforms with a large safety factor in vitro defibrillated most effectively in situ with little postshock dysfunction. Waveforms with low safety factors had a low rate of success in situ and produced much postshock dysfunction. Safety factor of monophasic clinical waveforms were lower than that of the 5-ms rectangular wave. The close correspondence between in vitro safety factor and in situ defibrillating effectiveness, as reported in the literature, suggests that the cell culture system is an effective screening system for determining waveforms that will improve the efficacy and safety of defibrillation procedures.

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

Analysis of the Safety Factors of Municipal Road Undercrossing Existing Bridge Based on Fuzzy Analytic Hierarchy Process Methods

2021 ◽  
pp. 036119812110318
Author(s):  
Yonghong Yang ◽  
Yu Chen ◽  
Zude Tang
Keyword(s):  
Safety Assessment ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Safety Evaluation ◽  
Safety Factors ◽  
Analytic Hierarchy ◽  
Road Engineering ◽  
Existing Bridges ◽  
Hierarchy Process ◽  
Engineering Projects

Increasing traffic volume and insufficient road lanes often require municipal roads to be reconstructed and expanded. Where a road passes under a bridge, the reconstruction and expansion project will inevitably have an impact on the bridge. To evaluate the safety impact of road engineering projects on bridges, this paper evaluates the safety of the roads and ancillary facilities of highway bridges involved in municipal road engineering projects. Based on a comprehensive analysis of the safety factors of municipal roads undercrossing existing bridges, a fuzzy comprehensive analytic hierarchy process (AHP) evaluation method for the influence of road construction on the safety of existing bridges is proposed. First, AHP is used to select 11 evaluation factors. Second, the target layer, criterion layer, and index layer of evaluation factors are established, then a safety evaluation factor system is formed. The three-scale AHP model is used to determine the weight of assessment indexes. Third, through the fuzzy comprehensive AHP evaluation model, the fuzzy hierarchical comprehensive evaluation is carried out for the safety assessment index system. Finally, the fuzzy comprehensive evaluation method is applied to the engineering example of a municipal road undercrossing an existing expressway bridge. The comprehensive safety evaluation of the existing bridge reflects the practicability and feasibility of the method. It is expected that, with further development, the method will improve the decision-making process in bridge safety assessment systems.

Limit State Philosophy in Pipeline Design

1987 ◽  
Vol 109 (1) ◽  
pp. 9-22 ◽  
Author(s):  
C. P. Ellinas ◽  
P. W. J. Raven ◽  
A. C. Walker ◽  
P. Davies
Keyword(s):  
Structural Analysis ◽  
Safety Factor ◽  
Current Knowledge ◽  
Limit State ◽  
Structural Behavior ◽  
Major Conclusion ◽  
Safety Factors ◽  
Suitable Framework ◽  
General Aspects ◽  
Pipeline Design

This paper considers the application of the limit state philosophy of structural analysis to pipeline design. General aspects of the philosophy are discussed and the approach to the evaluation of safety factors is reviewed. The paper further considers the various limit and serviceability states which would be relevant to a pipeline and reviews the various factors which may require consideration, before a code embodying the limit state philosophy could be formulated. A review of the state of current knowledge on various aspects of geometry and material characteristics, loading and structural behavior is presented. It is intended that such a review can be used as the basis for a larger study to provide guidance and data for the evaluation of rational levels of safety factor. The major conclusion reached by the authors is that a limit state philosophy would be valuable in providing a suitable framework, which may highlight the significant aspects of pipeline design and which can most easily accommodate new requirements and results obtained from research.

Metrology of the photo-grid determination of fracture strain for a plate in bending

1968 ◽  
Vol 3 (2) ◽  
pp. 96-97
Author(s):  
R T Hartlen ◽  
L E Jones
Keyword(s):  
Circumferential Strain ◽  
Fracture Strain ◽  
Thickness Ratio ◽  
Grid Data ◽  
Fracture Location ◽  
Maximum Value

Aluminium plates (7/1 width/thickness ratio) were bent to fracture. Circumferential strain at fracture location (maximum value 0.26) was obtained by special plotting and extrapolation of (millimetre) photo-grid data.

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