Molten core

Itydrogen formation, and concrete ablation. Figure 8.1-3k shows the molten core pend ration of the basemat. 

These descriptions are conjecture and assume that the molten core is not dispersed by the steam explosions or geometry. The more it disperses, the better the heat transfer and ihe sooner ihe accident stabilizes. 

CORCON initially assumes that the molten core debris is stratified as a dense oxidic layer on the bottom and a less dense metallic layer on the top. Later, when molten concrete slag dilutes the heavy oxide layer, the lighter oxide layer than the metal layer rises to the top. Each layci is assumed to be isothermal and heat is exchanged between (1) the melt and the concrete, (2) layers of the melt, and (3) the top surface of the melt and the atmosphere above it. When the concrete heats up to about 2500 F, CORCON predicts the release of steam and COj from concrete decomposition. Tile lieat of reaction of the gases reacting with the materials of the melt are calculated. 

Nuclear PSAs contain considerable uncertainty associated with the physical and chemical processes involved in core degradation, movement of the molten core in the reactor vessel, on the containment floor, and the response of the containment to the stresses placed upon it. The current models of these processes need refinement and validation. Because the geometry is greatly changed by small perturbations after degradation has commenced, it is not clear that the phenomcn.i can be treated. 

The earth is assumed to contain a molten core therefore, it is logical to assume that the temperature should increase with depth below the surface. This temperature-depth relationship is commonly assumed to be a linear function. 

Iron is also necessary to life. Our blood uses iron compounds to help bring oxygen from the lungs to the cells. Iron compounds are found all over the world, in many forms. One compound of iron looks so much like gold that it is sometimes mistaken for gold, and is therefore called fool s gold. Many scientists believe that about 90 percent of the earth s molten core consists of iron. 

Iron catastrophe Melting and fractionation of the interior of a planet, resulting in a molten core in which the density of iron causes in to sink to the core of the planet... 

The reactor vessel is on top of a 20 foot concrete slab with a leaktight core catcher. In the event of a meltdown the molten core would collect there and cool down. Four safeguard buildings are also used with independent pressurizers and steam generators. Each of these buildings is able to provide emergency cooling for the reactor core. 

Cole, R. K., Kelley, D. P. and Ellis, M. A. (1984) CORCON-Mod 2 A computer programme for analysis of molten core-concrete interactions , NUREG/CR-3920, August. 

The Earth s core is composed of iron-nickel alloy, with an inner solid core surrounded by a molten outer core. A mismatch between the inferred density of the outer core and that predicted for iron-nickel metal at high pressure suggests that some light elements) must dilute the iron in the molten core. Some possibilities are oxygen, sulfur, silicon, and hydrogen, all elements with high cosmic abundances that can alloy with iron at very high... 

As an element, Na is the sixth most abundant in the Earth s crust, whereas it is 14th in the universe. This is because its oxide Na20 is so easily made and so tighdy bound into rocks thatNa remained in the crust when many metals sank to the molten core of Earth. 

Seismic experiments124 indicate that today the Moon must be solid down to a depth of 800 km, but they also suggest a small molten core. The positive gravity anomalies found for the circular maria also require a thick, solid lunar crust or mantle. If the whole Moon had a homogeneous distribution of radio-... 

The iron metal and troilite of mesosiderites are presumed to represent core materials of an asteroid. Mixing of this with crustal silicates requires an unusual formation process. Some have suggested that a naked molten core (a core with the sihcate crust and mantle largely stripped off) impacted a differentiated asteroid at low velocity (Wasson and Rubin, 1985). Others have suggested that an impact disrupted the differentiated, mesosiderite parent body, which reaccreted. This process mixed materials from different portions of the parent body, with mesosiderites representing a location where the core and crust were mixed together (Haack et al., 1996 Scott et al., 2001). 

Chabot N. L. and Drake M. J. (1999) CrystaUization of magmatic iron meteorites the role of mixing in the molten core. Meteorit. Planet. Sci. 34, 235—246. 

The Moon has no overall magnetic field. According to the currently favored model of planetary magnetic fields (the dynamo model), this means either that the Moon probably has no molten core or that only a very small part of the core is molten. There is a weak m net-ic field frozen into the rocks, however, or the rocks have a north pole and a south pole, so it s possible that the Moon cnce had a m nefic field surrounding it. 

There is a lot of oxygen in the atmosphere, and over the millions of years since the Earth was formed many metals have combined with oxygen to form compounds called oxides. Iron, for example, occurs in the molten core of our Earth, and is often found in the Earth s crust as the ore haematite, which is iron oxide. Iron oxide is a binary compound, which means it contains only two elements. Notice that its name ends with ide . This is true for all binary compounds. Metals tend to combine with non-metals. Where a binary compound is made up of a metal and a non-metal, the first name of the compound is simply the name of the metal it contains and the second is the name of the non-metal, changed to end in ide for example, the compound between copper and chlorine is copper chloride. 

In the arc fusion method, a large powder charge (typically 60 kg) is inserted into an insulated enclosure and a molten core is produced at the center by striking an arc between carbon electrodes. The melt is then solidified by slow reduction of the current between the electrodes, and the resulting mass may contain large crystals, although nucleation is uncontrolled. 

Discovered in 1751, nickel is rare in earth s crust, but is believed to be more common in molten core. 

In principle, the diameter of a silicon rod produced after the Siemens process (see part I) is limited. The endothermic deposition from SiHCl3 takes place at a temperature of the rod surface of >1,100°C and is established by an axial electric current. As the hottest region, the core region of the rod has the highest conductivity, which causes self-bunching of the heating current. If the rod diameter exceeds 160-180 mm, the silicon melting temperature can be reached in the core. When silicon melts, the electric conductivity jumps by a factor of about 30. Therefore, most of the current will be concentrated in the molten core. If that melt solidifies, the rod will brake by the specific volume expansion of ca. 8%. 

At only 2 percent abundance, the potassium content of Earths crust is much lower than the average measured in meteorites, most of which formed during the earliest stages of the solar system about 4.5 billion years ago. Since Earth formed at roughly the same time, the disparity means that some potassium-depleting process must have occurred as the planet evolved. Scientists have long speculated that much of the potassium may have moved into the molten outer core that surrounds the solid inner core of Earth. The molten core is composed primarily of... 

Since argon is inert, it remains intact until it is released, which is usually accomplished by heating the object of interest. There are important limitations to this method, so it can only be used under specific circumstances. Clearly, the scheme is viable only for samples that originally contained a considerable fraction of potassium 40. This is most common in volcanic rock and ash, as lava emerging from Earth s molten core carries a higher... 

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