Numerical Investigation of a Class of Accidents in the Generation IV Brest Reactor Involving the Formation of a Solid Phase in the Lead Coolant

2019 ◽  
Vol 66 (8) ◽  
pp. 543-549
Author(s):  
A. S. Chistov ◽  
O. G. Savikhin ◽  
V. F. Ovchinnikov ◽  
E. V. Kiryushina
Author(s):  
A. V. Lvov ◽  
P. A. Bokov ◽  
A. I. Shumilkov ◽  
O. O. Novozhilova ◽  
A. V. Beznosov

The purpose of this paper is optimization of methods for calculating of flow parts of impeller pumps for high-temperature lead coolant, taking into account specific cavitation performance of the lead coolant [1]. The article presents the studies of cavitation performance of the high-temperature coolant. The studies were conducted in the lead coolant medium at 450–550 °C, flow rate up to 25–30 m/s and lead flow pressure from 0 to 5.0 kgf/cm2 (atm), at oxygen content in lead from 10−5–10−4 up to saturation, as well as in the presence of solid phase of lead oxides in the flow and in the experimental loop with such coolant. With a view to improving the representativeness of the research results, conditions of occurrence and characteristics of gaseous cavitation in the lead coolant flow were determined using three independent methods [2, 3]. The research showed that gas cavitation can take place in lead flows in the vane-type pumps and other components of circulation loops followed by apertures of lead flow discontinuity (bubbles, caverns, etc.), filled up with diluted gas with subsequent disappearance of these apertures of flow discontinuity. Traditional cavitation with formation and subsequent collapse of lead vapors in reactor loops with lead and lead-bismuth coolant is not possible. Cavitation performance of lead coolant is identified.


2015 ◽  
Vol 267 ◽  
pp. 207-220 ◽  
Author(s):  
Kun Luo ◽  
Fan Wu ◽  
Shiliang Yang ◽  
Jianren Fan

Author(s):  
K. Pegg-Feige ◽  
F. W. Doane

Immunoelectron microscopy (IEM) applied to rapid virus diagnosis offers a more sensitive detection method than direct electron microscopy (DEM), and can also be used to serotype viruses. One of several IEM techniques is that introduced by Derrick in 1972, in which antiviral antibody is attached to the support film of an EM specimen grid. Originally developed for plant viruses, it has recently been applied to several animal viruses, especially rotaviruses. We have investigated the use of this solid phase IEM technique (SPIEM) in detecting and identifying enteroviruses (in the form of crude cell culture isolates), and have compared it with a modified “SPIEM-SPA” method in which grids are coated with protein A from Staphylococcus aureus prior to exposure to antiserum.


Author(s):  
Charles D. Humphrey ◽  
E. H. Cook ◽  
Karen A. McCaustland ◽  
Daniel W. Bradley

Enterically transmitted non-A, non-B hepatitis (ET-NANBH) is a type of hepatitis which is increasingly becoming a significant world health concern. As with hepatitis A virus (HAV), spread is by the fecal-oral mode of transmission. Until recently, the etiologic agent had not been isolated and identified. We have succeeded in the isolation and preliminary characterization of this virus and demonstrating that this agent can cause hepatic disease and seroconversion in experimental primates. Our characterization of this virus was facilitated by immune (IEM) and solid phase immune electron microscopic (SPIEM) methodologies.Many immune electron microscopy methodologies have been used for morphological identification and characterization of viruses. We have previously reported a highly effective solid phase immune electron microscopy procedure which facilitated identification of hepatitis A virus (HAV) in crude cell culture extracts. More recently we have reported utilization of the method for identification of an etiologic agent responsible for (ET-NANBH).


Author(s):  
C.D. Humphrey ◽  
T.L. Cromeans ◽  
E.H. Cook ◽  
D.W. Bradley

There is a variety of methods available for the rapid detection and identification of viruses by electron microscopy as described in several reviews. The predominant techniques are classified as direct electron microscopy (DEM), immune electron microscopy (IEM), liquid phase immune electron microscopy (LPIEM) and solid phase immune electron microscopy (SPIEM). Each technique has inherent strengths and weaknesses. However, in recent years, the most progress for identifying viruses has been realized by the utilization of SPIEM.


Author(s):  
C. Hayzelden ◽  
J. L. Batstone

Epitaxial reordering of amorphous Si(a-Si) on an underlying single-crystal substrate occurs well below the melt temperature by the process of solid phase epitaxial growth (SPEG). Growth of crystalline Si(c-Si) is known to be enhanced by the presence of small amounts of a metallic phase, presumably due to an interaction of the free electrons of the metal with the covalent Si bonds near the growing interface. Ion implantation of Ni was shown to lower the crystallization temperature of an a-Si thin film by approximately 200°C. Using in situ transmission electron microscopy (TEM), precipitates of NiSi2 formed within the a-Si film during annealing, were observed to migrate, leaving a trail of epitaxial c-Si. High resolution TEM revealed an epitaxial NiSi2/Si(l11) interface which was Type A. We discuss here the enhanced nucleation of c-Si and subsequent silicide-mediated SPEG of Ni-implanted a-Si.Thin films of a-Si, 950 Å thick, were deposited onto Si(100) wafers capped with 1000Å of a-SiO2. Ion implantation produced sharply peaked Ni concentrations of 4×l020 and 2×l021 ions cm−3, in the center of the films.


Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.


1998 ◽  
Vol 184-185 (1-2) ◽  
pp. 1021-1025
Author(s):  
G Geoffroy
Keyword(s):  

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