Nuclear reactors, applications

Aerospace and Nuclear Reactor Applications Chemical Applications and Mechanical Applications)... 

Nuclear reactor applications, artificial graphite in, 72 741-744 Nuclear reactor control rods, indium in, 74 195... 

Aerospace and nuclear reactor applications of graphite demand high reliability and reproducibility of properties, physical integrity of product, and product uniformity. The manufacturing processes require significant additional quality assurance steps that result in high cost. 

As of file early 1990s the hislnrieal importance of coball ill alloys for reducing wear resistance was markedly diminished by the development of Norem alloys, which were derived from stainless steel, particularly the Armco Nitronic 60. admittedly one of the few stainless steels that has excellent wear resistance. This is an outgrowth of research conducted by EPRI (Electric Power Research Institute) in an effort to lower equipment costs. Initial uses of the new cobalt-frec alloys will he power plant valves and turbines. Also. In nuclear reactor applications, the Nnrem alloys will not become activated [Co does), reducing worker-protection and maintenance costs. Tests have confirmed that the new cobalt-free alloys retain their wear-resistant properties when produced as rods and powders, the most common forms used by welders. 

When rhenium is added to other refractory metals, such as molybdenum and tungsten, ductility and tensile strength are improved. These improvements persist even after heating above the rccrystallization temperature. An excellent example is the. complete, ductility shown by a molybdenum-rhenium fusion weld. Rhenium and rhenium alloys have gained some acceptance in semiconductor, thermocouple, and nuclear reactor applications. The alloys also axe used in gyroscopes, miniature rockets, electrical contacts, electronic-tube components, and thermionic converters. 

In the past ten years the number of chemistry-related research problems in the nuclear industry has increased dramatically. Many of these are related to surface or interfacial chemistry. Some applications are reviewed in the areas of waste management, activity transport in coolants, fuel fabrication, component development, reactor safety studies, and fuel reprocessing. Three recent studies in surface analysis are discussed in further detail in this paper. The first concerns the initial corrosion mechanisms of borosilicate glass used in high level waste encapsulation. The second deals with the effects of residual chloride contamination on nuclear reactor contaminants. Finally, some surface studies of the high temperature oxidation of Alloys 600 and 800 are outlined such characterizations are part of the effort to develop more protective surface films for nuclear reactor applications. ... 

Reviews of BeO for nuclear reactor applications were persented at several international conferences. The literature on BiO up to 1966 has been reviewed in several papers... 

Some of the most important properties of sodium and lithium for high-temperature nuclear-reactor applications are listed in Table I. Several other popular and potential heat-transfer fluids are shown for comparison purposes. The advantages and disadvantages of various coolants are considered in relation to their application at temperatures in excess of 1200 °F. The undesirable properties of a particular coolant are underlined. Water is not particularly suitable because of its very low boiling point and its poor thermal conductivity. Sodium and the sodium-potassium alloy have properties to which there are no major objections. (Any statement made in this paper concerning the corrosiveness of sodium may be considered as applicable to the sodium-potassium alloys, as differences found... 

Remote operation (simulating nuclear reactor applications)... 

Gas Cost Data and Gas Requirements for Nuclear Reactor Applications... 

Simnad, M.T., Meyer, R.A. Beiylliumoxide - Review af Properties fan Nuclear Reactor Application", Part E, Chapt. 38 Reactor Handbook, Materials 1968 zitiert nach [71 Bu 18]. 

Additional literature reviews that generally predate those mentioned will be noted in the following discussions. The discussions in this report will focus more on nuclear reactor applications instead of the general case of parallel channels and NCLs. However, both situations arise in nuclear power applications. The general cases have been extensively covered by the literature just cited. 

Nb-alloys were examined for space nuclear reactor applications and Nb-lZr alloy is one of the remaining candidates having a fair amount of database including irradiation properties [50]. Ta-aUoys have had a similar history, being developed for space... 

Because there is no precedent for using ceramic composites in a nuclear reactor, standard test procedures will be established to qualify ceramic composites for nuclear reactor applications. In order to use SiCf/SiC in applications of structural components, it is necessary for well-established testing standards and material codes to be in place. CMCs have different mechanical behaviors than those of organic matrix composites and monolithic ceramics. Thus, new test methods are required. Some standards for the thermomechanical properties of CMCs already exist, as summarized in Table 12.9. 

Many of the HEAs contain cobalt, which is not a desirable material for in-core nuclear reactor applications due to the neutron-induced transmutation to produce °Co that can make some plant maintenance activities more difficult (due to normal corrosion processes that cause atomic deposition of core materials throughout the primary coolant loop, particularly in the cooler regions). Some single-phase HEAs with attractive mechanical properties that do not contain cobalt have been manufactured [116]. Tensile properties for a single-phase fee high-entropy alloy are summarized in Fig. 16.6. 

P.J. Maziasz, J.T. Busby, Properties of austenitic steels for nuclear reactor applications, in R. Konings (Ed.), Comprehensive Nuclear Materials, Elsevier Ltd., 2012. 

This can be seen in Fig. 16.24 for type A 533 GrB Cll steel and welds for nuclear reactors applications tested in demineralized water at 288 °C [24]. The testing frequency was 1 cpm and the load form sinusoidal. While the weld metal does not seem to experience any SCC event, the base metal is sensible to SCC that appears already at R = 0.2 (see also Fig. 16.14) but becomes particularly heavy for R = 0.7. At the same time, the threshold stress intensity factor decreases from about 18 to about 10 MPa,ym. 

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