The Evaluation Method of Uranium Hexafluoride Leakage Accident Release Source Term

2017 ◽  
Author(s):  
Chen Lei ◽  
Wang Ning
Keyword(s):  
Evaluation Method ◽  
Source Term ◽  
Chemical Properties ◽  
Uranium Hexafluoride ◽  
Chemical Toxicity ◽  
Uranium Enrichment ◽  
Uranium Fuel ◽  
Nuclear Fuel Element ◽  
Active Chemical ◽  
Enrichment Process

Uranium hexafluoride is the intermediate material of uranium fuel enrichment process, which is widely used in uranium conversion plant, uranium enrichment plant and nuclear fuel element plant[1]. Because of its active chemical properties and its radioactive and chemical toxicity, great importance should be attached to the uranium hexafluoride release accident. This paper describes the possible leakage scenarios for uranium hexafluoride accident. And the general step of the evaluation for uranium hexafluoride leakage accident release source term is given, as well as an application example for the feed facility of a gaseous diffusion plant.

scholarly journals Back Calculation of Leakage Accident Source Term of Liquid Ammonia Gas Storage Tank

2021 ◽  
Vol 267 ◽  
pp. 01012
Author(s):  
Chang Liu ◽  
Teng Su ◽  
Ru Zhou
Keyword(s):  
Optimization Algorithm ◽  
Storage Tank ◽  
Liquid Ammonia ◽  
Source Term ◽  
Chemical Properties ◽  
Calculation Model ◽  
Source Information ◽  
Concentration Data ◽  
Ammonia Storage ◽  
Back Calculation

Ammonia is a colorless and toxic gas. Due to its fast leakage rate, the leakage port is not easy to detect, and it is often difficult to seal it, causing more serious personal injuries and property losses. So it is a key problem to predict the intensity and location of toxic and harmful gas leakage quickly and accurately. Then it needs to combine the atmospheric diffusion model and optimization algorithm to establish the source term information back calculation model, and solve the location and intensity of the leakage source based on the concentration data of the downwind direction of the leakage source. Based on the analysis of the physical and chemical properties of ammonia, according to Wilson plume rising experience formula and Gauss plume model, the leakage model of liquid ammonia storage tank is established, and the effective monitoring points are extracted. According to the concentration of simulated monitoring points, the source information is calculated by particle swarm optimization algorithm. The feasibility of this method in the leakage of liquid ammonia storage tank is verified, which can help emergency response of accidents.

Research and Design of the Sodium Steam Filter System in Large Liquid Metal Cooled Fast Reactors

2017 ◽  
Author(s):  
Wang Leijian ◽  
Lu Yuan ◽  
Xiao Changzhi
Keyword(s):  
Free Surface ◽  
Chemical Properties ◽  
Liquid Sodium ◽  
Thermal Calculation ◽  
Piping System ◽  
Filtration Process ◽  
Active Chemical ◽  
High Boiling Point ◽  
Research And Design ◽  
Thermal Physical Properties

This reactor uses liquid sodium as coolant owing to its good thermal physical properties, high boiling point and compatibility of cladding material. However, the sodium has a very active chemical properties, for which the free surface of sodium must be protected by inert gas. In the high temperature environment, the sodium atoms diffusion to cover gas slowly, forming a mixed atmosphere that contained large amount of sodium steam. Sodium steam is covered with the free surface of sodium. Then metal sodium will solidify in the inner wall of the pipe or correlative valves with the reduced temperature. This reactor needs to collect and filter sodium steam in order to reduce the hazards to the equipment, piping system, valves and the other devices. Based on the previous research about the purification process of sodium, this paper compared different steam trapping filtration process and carried out the thermal calculation providing basis for research and design of large sodium cooled fast reactor sodium steam trapping filtration process and establishing a reliable sodium steam filtering system.

Effect of zinc enriched farm yard manures on yield of mung bean and Physico-Chemical Properties of soil

2018 ◽  
Author(s):  
N. R. Meena ◽  
M. K. Meena ◽  
K. K. Sharma ◽  
M. D. Meena
Keyword(s):  
Seed Yield ◽  
Block Design ◽  
Chemical Properties ◽  
Available N ◽  
Loamy Sand Soil ◽  
Randomized Block Design ◽  
Physico Chemical ◽  
Average Improvement ◽  
Enrichment Process ◽  
Extractable Zn

The aim of this study was to investigate the effect of zinc enriched Farm Yard Manures (FYM) on zinc deficient loamy sand soil and yield of mungbean[Vigna radiata (L.) Wilczek.]. Treatments consisted of 15 combinations of three levels of FYM i.e. F0 (no FYM), F1 (FYM @ 5 t ha-1) and F2 (FYM @ 10 t ha-1) and five treatments of enrichment i.e. Zn enrichment (EnZn1, EnZn2, and EnZn3) at three levels of Zn (2.5, 5.0 and 7.5 kg Zn ha-1) @ 500 kg ha-1 FYM and without enrichment (Zn0 and Zn1) at two levels of Zn (inorganic salts) i.e. 0 kg and 5 kg Zn ha-1, replicated thrice in factorial randomized block design (FRBD)during 2012. The enrichment process was started 50 days before their use in kharif season experiment on mung bean.The average improvement in seed yield of mungbean was 1179 kg ha-1. Zinc-enriched FYM and their straight application produced (10983kgha-1) 31.86 and 22.83% higher grain yield, respectively, relative to control Zn0 (8959kg ha-1).The yield was increased due to enrichment and it was achieved by 9.04 % over straight application of zinc. Zn uptake was recorded significantly higher under the EnZn2 (143.96 g ha-1) which was at par with EnZn3 (148.23 g ha-1) followed by EnZn1 (118.50 g ha-1) all these values are significantly higher than Zn0 (92.02 g ha-1).The average improvement in total uptake of Zn by mungbean was 48.71%higher due to zinc enriched FYM than the straight application of zinc. The application of zinc enriched FYM significantly increased available N, organic carbon andDTPA-extractable Zn with increasing the level of enrichment.The application of zinc enriched FYM had non-significant effect on bulk density, saturated hydraulic conductivity and moisture retention at 1/3 and 15 bar and CEC than control.Application of 2.5 kg Zn ha-1which wascomparable to enriched with FYM,in terms of higher seed yield of mungbean.

Study results of hydrocarbon drilling mud in the context of Bulla-deniz field wells

2020 ◽  
pp. 23-27
Author(s):  
N.M. Aliyev ◽  
◽  
R.M. Zeynalov ◽  
E.A. Kazimov ◽  
A.M. Ashurova ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Evaluation Method ◽  
Chemical Properties ◽  
Expert Evaluation ◽  
Drilling Rate ◽  
Drilling Mud ◽  
Study Results ◽  
Expert Evaluation Method

The paper presents the main advantages of hydrocarbon-based drilling mud. It is shown that mentioned types of drilling mud are produced both on the mineral and diesel fuel basis and positively impact the overall drilling rate of the wells. Alongside with this, the information on existing complications in the drilling of V and VII horizons of Bulla-deniz field has been generalized, in the context of which improved recipes of drilling mud proposed. Using expert evaluation method, the structural-mechanical and colloid-chemical properties of the drilling mud types have been compared. A new structure for wells of Bulla-deniz field has been offered.

Study on the Corrosion Resistance of ZrN Films on the Aluminium Alloys Surface

2012 ◽  
Vol 252 ◽  
pp. 245-249
Author(s):  
Hui Qiang Wang ◽  
Wei Lian Sun ◽  
Yan Qiu Xing ◽  
Sun Bo
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Flow Rate ◽  
Chemical Properties ◽  
Nitrogen Flow ◽  
Corrosion Performance ◽  
Performance Study ◽  
Nitrogen Flow Rate ◽  
Active Chemical ◽  
Flow Rate Increase

Aluminum alloy have the active chemical properties,low standard electrode potential, and the surface will be easily forming about 1-3nm oxide film in dry air, therefore aluminum alloy have the poor corrosion resistance.ZrN film deposited by mid frequency reactive magnetron sputtering process on aluminium alloy surface in order to improve the corrosion performance. Study the influences of nitrogen flow rate, sputtering time and temperature to the corrosion performance. The results show that: The corrosion performance of ZrN films will be improved with the nitrogen flow rate increase,but when the nitrogen flow rate was more than 18sccm, ZrN film corrosion resistance will be reduce;The corrosion performance improved with the sputtering time increase,when the time reach 15min, ZrN film corrosion resistance was no longer increase;The corrosion performance improved with the temperature, when the temperature reach 130°C, the corrosion resistance was no longer increase.The best process parameters was: nitrogen flow rate 18sccm, sputtering time 15min, temperature 130°C.

scholarly journals Direct simulation Monte Carlo for modeling spatially homogeneous multi-component aerosols

2018 ◽  
Author(s):  
◽  
Issac Saldivar
Keyword(s):  
Monte Carlo ◽  
Large Scale ◽  
Source Term ◽  
Chemical Properties ◽  
Fission Products ◽  
Direct Simulation Monte Carlo ◽  
Direct Simulation ◽  
Experimental Database ◽  
Aerosol Dynamics ◽  
Simulation Monte Carlo

Nuclear aerosols generated under normal operational and post-accident reactor environments are of particular importance in estimation of the nuclear source term. Several light water reactor aerosol containment experiments provided an experimental database for verification and validation of thermal-hydraulic and aerosol transport codes. The Direct Simulation Monte Carlo (DSMC) technique has been shown to model multicomponent aerosol dynamics accurately while maintaining greater fidelity to actual aerosol physics than its sectional, moments, and finite element predecessors. This research focuses on the development of a comprehensive n-component source term code for modeling the behavior of aerosolized fission products based on the DSMC technique. Effective DSMC benchmarks provided further confidence in the technique's capabilities for modeling exceedingly complex systems. With the inclusion of the Knudsen, Kelvin, and solute effects in the Mason model, the role of condensation on aerosol evolution showed the differentiation of particles by physical size and chemical properties. High fidelity large-scale simulations posed evident but considerable challenges to computational runtime. Developments in the simulation scaling theory for coagulation, condensation, deposition, and generation processes showed to give comparable results while simultaneously reducing simulation time significantly. The evolution of aerosols coupled to environments was explored, and benchmark simulations provided further evidence that DSMC accurately models aerosol dynamics when coupled with containment thermal-hydraulics.

scholarly journals Quantitative Assessment of Environmental Soil Functions in Volcanic Zones from Mexico Using S&E Software

2019 ◽  
Vol 11 (17) ◽  
pp. 4552
Author(s):  
Ángeles Gallegos ◽  
Dante López-Carmona ◽  
Francisco Bautista
Keyword(s):  
Hydraulic Conductivity ◽  
Evaluation Method ◽  
Sustainable Use ◽  
Chemical Properties ◽  
Nutrient Retention ◽  
Field Capacity ◽  
Soil Profiles ◽  
Volcanic Area ◽  
Positive Effects ◽  
Environmental Functions

Making quantitative evaluations of the environmental functions of the soil in a quantitative way is an urgent necessity for transitioning towards the sustainable use of soils. The objective of this work was to use and improve the Soil and Environment software for soils of volcanic areas, for which the software was not designed to work on. The study was conducted in the volcanic area of Michoacan, Mexico. Nine soil profiles were described; samples were taken from each horizon and the physical and chemical properties of each sample were analyzed. The Soil and Environment software was used to conduct pedoecological evaluations of the soil samples and, subsequently, an evaluation of the environmental functions of the soils and the modeling of scenarios was carried out. The soil profiles studied showed variable properties of hydraulic conductivity, field capacity, air capacity, effective cation exchange capacity, and soil organic carbon. The soils showed very high nutrient retention, high naturalness and sorption of heavy metals, and low cultural and natural archive properties. The Soil and Environment software generally works well with soils of volcanic areas; however, we suggest improvements in the evaluation method of the following functions: naturalness and agricultural quality. Additionally, the estimating method of aeration capacity and hydraulic conductivity should be calibrated for the properties of the volcanic soils. The modeling of scenarios allowed us to identify the soil profiles that are most vulnerable to degradation. The modeling of scenarios provided a clear idea of the negative and positive effects that a change in soil use would have.

The Development of the Advanced Method for the Source Term Evaluation Applicable to the Dynamic PRA

2018 ◽  
Author(s):  
Koichi Nakamura ◽  
Sunghyon Jang ◽  
Akira Yamaguchi
Keyword(s):  
Power Plants ◽  
Evaluation Method ◽  
Source Term ◽  
Fission Products ◽  
Accident Risk ◽  
Branch Points ◽  
Event Tree ◽  
Term Evaluation ◽  
Accident Scenarios ◽  
Level 2

Useful insights on nuclear safety are provided by the level 2 probabilistic risk assessment (PRA), which evaluates the risk of fission products (FP) released in the environment during an accident in nuclear power plants (NPPs). The containment event tree method is generally employed for level 2 PRA. In this method, the accident scenarios are expressed by the combination of a number of branch points. The possible accident scenarios are approximately or representatively dealt with in this method. Dynamic PRA can evaluate the accident risk with complex changes or composition of various accident events dynamically. A reasonable source term evaluation method, which can be conducted with a small computational load, is developed for the establishment of dynamic PRA method focused on the risk of the release of FP in the environment. The proposed study aims to develop a reasonable source term evaluation method by applying phenomenological relationship diagram (PRD) method applicable to the dynamic PRA is developed.

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