scholarly journals Tabulation of thermodynamic data for chemical reactions involving 58 elements common to radioactive waste package systems

1980 ◽  
Author(s):  
L.V. Benson ◽  
L.S. Teague
Keyword(s):  
Radioactive Waste ◽  
Chemical Reactions ◽  
Thermodynamic Data ◽  
Waste Package

Research on the Gold Ore Leaching in Iodine-Iodide System

2013 ◽  
Vol 634-638 ◽  
pp. 3227-3233
Author(s):  
Xian Ping Luo ◽  
Min Hu ◽  
Chang Li Liang ◽  
Qing Hai Ge
Keyword(s):  
Chemical Reactions ◽  
Thermodynamic Data ◽  
Influence Factors ◽  
Promising Method ◽  
Cyanide Leaching ◽  
Gold Ore ◽  
Leaching Experiments

Iodine-iodide leaching gold ore is a promising method alternative to cyanide leaching. In this paper, Eh—pH diagram of Au-I--I2-H2O system was established through calculating the equilibrium potentials of the main chemical reactions based on the thermodynamic data of the actual iodide leaching of gold system. Gold ore leaching experiments in iodine-iodide system under different influence factors were carried out to verify the effectiveness of the Eh-pH diagram. The results indicated the diagram of Eh-pH can effectively guide the actual gold ore leaching in iodine-iodide system.

scholarly journals Radiation Safety for Incineration of Radioactive Waste Contaminated by Cesium

2017 ◽  
Author(s):  
Yu. Veriuzhsky ◽  
O. Hrynko ◽  
V. Tokarevsky
Keyword(s):  
Radioactive Waste ◽  
Chemical Reactions ◽  
Contaminated Soil ◽  
Radiation Safety ◽  
Chemical Properties ◽  
Damage Effect ◽  
Gas Purification ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

Problems in the treatment of radioactive waste contaminated by cesium nuclides are considered in the paper. Chornobyl experience in the management of contaminated soil and contaminated forests is analyzed in relation to the accident at Fukushima-1. The minimization of release of cesium aerosols into atmosphere is very important. Radiation influence of inhaling atmosphere aerosols polluted by cesium has damage effect for humans. The research focuses on the treatment of forests contaminated by big volumes of cesium. One of the most important technologies is a pyro-gasification incineration with chemical reactions of cesium paying attention to gas purification problems. Requirements for process, physical and chemical properties of treatment of radioactive waste based on the dry pyro-gasification incineration facilities are considered in the paper together with the discussion of details related to incineration facilities. General similarities and discrepancies in the environmental pollution caused by the accidents at Chornobyl NPP and Fukushima-1 NPP in Japan are analyzed.

Photoacoustic Calorimetry

2008 ◽  
Author(s):  
José A. Martinho Simões ◽  
Manuel Minas da Piedade
Keyword(s):  
Thermal Expansion ◽  
Chemical Reactions ◽  
Thermodynamic Data ◽  
Chemical Species ◽  
Experimental Methods ◽  
Sound Waves ◽  
Ambient Conditions ◽  
Photoacoustic Effect ◽  
Photoacoustic Calorimetry ◽  
Present Understanding

“Any chemical species, which under ambient conditions (i.e., a temperature around 25°C, and a pressure close to 1 atm) will, for a combination of kinetic and thermodynamic reasons, decay on a timescale ranging from microseconds, or even nanoseconds, to a few minutes” can be classified as a short-lived compound. According to this definition, suggested by Almond, it is clear that the experimental methods described in previous chapters can only be used to study the thermochemistry of long-lived substances. The technique that we address here, known as photoacoustic calorimetry (PAC) or laser-induced optoacoustic calorimetry (LIOAC), is suitable for investigating the energetics of molecules with lifetimes smaller than about 1μs. It relies on the photoacoustic effect, which was discovered by Bell more than 100 years ago. With the assistance of Tainter, he was able to “devise a method of producing sounds by the action of an intermittent beam of light” and conclude that the method “can be adapted to solids, liquids, and gases”. Figure 13.1 shows a photophone, “an apparatus for the production of sound by light,” used by Bell to investigate the photoacoustic effect. The controversy around the origin of this phenomenon was settled by Bell himself and by Lord Rayleigh; their views were rather close to our present understanding: When a light pulse is absorbed by a substance, a given amount of heat is deposited, producing a local thermal expansion; this thermal expansion propagates through the medium, generating sound waves. The basic theory of the photoacoustic effect was described by Tam and Patel and some of its applications were presented in a review by Braslavsky and Heibel. The first use of PAC to determine enthalpies of chemical reactions was reported by the groups of Peters and Braslavsky. The same groups have also played an important role in developing the methodologies to extract those thermodynamic data from the experimentally measured quantities. In the ensuing discussion, we closely follow a publication where the use of the photoacoustic calorimety technique as a thermochemical tool was examined. Consider the elementary design of a photoacoustic calorimeter, shown in figure 13.3. The cell contains the sample, which is, for instance, a dilute solution of a photoreactive species.

scholarly journals Chemical reactions during sintering of Fe-Cr-Mn-Si-Ni-Mo-C-steels with special reference to processing in semi-closed containers

2015 ◽  
Vol 47 (1) ◽  
pp. 61-69 ◽  
Author(s):  
A. Cias
Keyword(s):  
Mechanical Properties ◽  
Carbon Monoxide ◽  
Special Reference ◽  
Water Vapour ◽  
Chemical Reactions ◽  
Thermodynamic Data ◽  
Alloying Elements ◽  
Bearing Steels ◽  
Kinetics Of

Sintering of Cr, Mn and Si bearing steels has recently attracted both experimental and theoretical attention and processing in semiclosed containers has been reproposed. This paper brings together relevant thermodynamic data and considers the kinetics of some relevant chemical reactions. These involve iron and carbon, water vapour, carbon monoxide and dioxide, hydrogen and nitrogen of the sintering atmospheres and the alloying elements Cr, Mn, Mo and Si. The paper concludes by presenting mechanical properties data for three steels sintered in local microatmosphere with nitrogen, hydrogen, nitrogen-5% hydrogen and air as the furnace gas.

Development of nuclear criticality safety controls on intermediate-level waste packages

2012 ◽  
Vol 76 (8) ◽  
pp. 2949-2956 ◽  
Author(s):  
T. W. Hicks ◽  
P. Wood ◽  
D. Putley ◽  
T. D. Baldwin
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Neutron Transport ◽  
Intermediate Level ◽  
Fissile Material ◽  
Radioactive Waste Management ◽  
Waste Package ◽  
Operational Phase ◽  
Nuclear Criticality Safety ◽  
Enriched Uranium

AbstractIntermediate-level wastes (ILW) include substantial quantities of fissile material and controls are required to ensure that its storage, transport and disposal does not present a nuclear criticality hazard. This paper describes the Radioactive Waste Management Directorate's research to develop package fissile material limits (in the form of screening levels) for four different categories of ILW, defined according to uranium or plutonium composition: (1) irradiated natural and slightly enriched uranium (uranium containing up to 1.9 wt.% 235U); (2) low-enriched uranium (uranium containing up to 4 wt.% 235U); (3) high-enriched uranium (uranium containing up to 100 wt.% 235U); and (4) separated plutonium (plutonium containing up to 100 wt.% 239Pu).The derivation of package screening levels was supported by neutron transport calculations that addressed conditions during waste package transport to a geological disposal facility (GDF), during the GDF operational phase and after GDF closure. The analysis included consideration of combinations of events and processes that could result in fissile material accumulation and concentration after GDF closure, when waste packages have deteriorated sufficiently for fissile material to be mobilized. The results of the calculations have provided input to Radioactive Waste Management Directorate's decision making on setting waste package screening levels.

The Next EDF Tracking System

2009 ◽  
Author(s):  
Emmanuelle Julli ◽  
Bertrand Lantes
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Tracking System ◽  
Treatment Plant ◽  
Computer Application ◽  
Pressurized Water ◽  
Waste Package ◽  
Additional Processing ◽  
Water Reactors

EDF’s network of nuclear power plants (NPP) comprises 58 pressurized water reactors. Solid waste arising during plant operation (mainly VLLW, LLW and ILW) are conditioned and sent either to interim storage, an off site treatment plant for additional processing (e.g. the Centraco incinerator or the melting facilities of SOCODEI) or directly to one of the two final repositories operated by ANDRA, the French national radioactive waste management agency. The tracking system allows: - the checking of waste package characteristics against acceptance criteria of the final disposal facilities or off site treatment facilities; and - the transmission of the waste package data to ANDRA and SOCODEI. Since 1992, the EDF computer application DRA has been run on networked computers at EDF and ANDRA, and more recently at SOCODEI. DRA is also a key element in the management of radioactive waste. It allows a large range of inter comparisons to be made between the NPPs in operation and is thus the principal tool used optimize technical and economic performance. After 15 years of use, DRA was technically obsolete and could no longer be successfully developed to meet evolving regulatory requirements. It was therefore decided to completely replace the DRA system and in so doing to introduce new functionality.

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