Upper dome

Fig. 5. Schematic diagram summarizing the available structural information on the Halobacterium cell envelope from X-ray studies of the envelopes (Blaurock el al., 1976), from the primary structure of the surface glycoprotein (Lechner and Sumper, 1987), and from the three-dimensional structure described by Kessel el al. (1988). The three-dimensional structure determined by electron microscopy depicts only the upper dome-shaped region of the structure, which is separated from the cell membrane by the spacer elements. As indicated by the crystallographic symbols, the section runs from sixfold to sixfold axis via the twofold axis. From Kessel et al., (1988), with permission.

The stratification test program described here utilized a 70-ft vacuum-jacketed test vessel. The test vessel was a 4-ft-diameter x 6-ft-long stainless steel inner tank supported within a 6-ft-diameter outer tank by means of four legs, several tie rods, and a sway bar. The inner tank was designed for a working pressure of ISOpsig at liquid-hydrogen temperature. Its upper and lower domes w ere insulated with 1 in. of multilayer insulation to minimize inadvertent heat leak to the test fluid. Removal of the outer tank dome (Fig. 2) provides ready access to the inner tank. A 14-in. manhole in the upper dome of the inner tank provides access to the tank interior. 

Three hydrogen sensors in the upper dome monitor the bulk hydrogen concentration and alert the operators to the need for remedial action. 

Automobile suspension units include a number of elements which possess nonlinear characteristics in either displacement or velocity. It has been noted that correct modeling of these nonlinear characteristics is indispensable [1] when studying the dynamic behavior of a suspension unit, and hence its contribution to overall vehicle vibrational comfort. It has also been shown [2] that the most important nonlinearity is that of the shock absorber damping characteristic. The importance of the damper has stimulated a number of studies regarding the modeling and specification of shock absorbers [3-9]. The objective of the present study is to quantify the influence of the damper curve on the vertical force transmissibility from the wheel hub to the upper dome. The upper McPherson dome was chosen as the output measurement point because it is the location at which the greatest static and dynamic forces enter the car body from the suspension unit. The vertical direction has been isolated for the purposes of this study because it is the principal vibrational direction for an automobile on a typical road. 

In IET-1 the steam explosion in the cavity registered on the pressure transducer in the seal table room. The pressure differential across the seal table room walls caused some damage to the seal table room. The seal tcdile room was separated from the crane wall on one side and also had a large crack in the inner wall. In addition, the concrete plug in the seal table room ceiling was violently ejected into the upper dome of Surtsey. 

Figure 12 shows the pressure measured in the seal table room cuid the pressure measured in the upper dome of Surtsey plotted against time for IET-3. The pressure in the seal table room was greater them the pressure in Surtsey between 0.02 and 0.2s and between 0.4 and 0.7s. These intervals... 

Pressure data measured inside the subcompartment structures for IET-1, IET-3, and IET-6 showed similar behavior. The fuel coolant interactions (FCIs) that occurred at 0.06 s in these experiments caused the pressure in the subcompartment structure to be higher than the pressure in the upper dome of the Surtsey vessel. The pressure measured inside the subcompartment structures followed the pressure measured in Surtsey after about 0.1 s. There was no differential pressure between the structures and Surtsey due to the debris entrainment that occurred between 0.4 and 0.8 s. Differential pressure across the walls of the structures was caused by the FCIs. All of the pressure transducers showed an oscillatory behavior caused by the FCIs that damped out after approximately 2 s. The shock wave from the steam explosion may have caused the Surtsey vessel to resonate. 

In IET-1/ the highest gas temperature was measured at level 3, cind the second highest was measured at level 1. The gas temperature was higher at level 3 than at level 1 because there was a direct path for debris ejected from the seal table room to flow past level 3. Level 1 was below the operating deck and thus there was no direct path for debris to flow past the aspirated thermocouple at that level. The gas temperature at level 5, which is relatively high in the vessel, was barely above the ambient temperature. This is an indication that not much debris was ejected into the upper dome of the vessel. 

Figure 14. Gas temperatures measured in the upper dome of the Surtsey vessel with aspirated thermocouples in the IET-3 experiment.

The peak gas temperatures at level 5 in the Surtsey vessel were substcmtially lower than the temperatures measured at levels 1 and 3. The peetk temperature at level 1 was 1128 K at 1.0 s, and at level 3 was 1033 K at 1.0 s. The aspirated thermocouple temperature at level 5 peaked at 700 R at 4.3 s. The level 5 peak temperature in IET-6 was much greater than the tenqperatures in either IET-1 or IET-3, probably because of the high driving pressures in the cavity caused by the steam explosion and hydrogen combustion in the upper dome. 

High gas temperatures iii the vent spaces of IET-3 and IET-6 (cuid video analyses) indicate that hot jets of hydrogen produced by debris oxidation in the cavity and subcompartment structures burned as a diffusion flame as it was pushed into the air/nitrogen atmosphere in the upper dome of Surtsey. The hydrogen combustion contributed significantly to containment pressurization. 

The basic SPRAT was modified to deal with water rods cooled by downward flow [6]. It is called SPRAT-DOWN [7-9], The coolant flow scheme is shown in Fig. 4.3. The fuel channel and the water rod chaimel are modeled as single channels with 20 meshes. At normal operation, 30% of the feedwater is led to the water rod channel through the upper dome and the control rod guide tube. The lower plenum, including the downcomer, is divided into 20 meshes. The upper plenum, including the main steam line, is also divided into 20 nodes. The main feedwater line and the... 

A conceptual design of a 1,400 MWe reactor core with a solid moderator, ZrH2, has shown reasonable results [80-83, 85-87]. The idea of a solid moderator was introduced since it was believed to simplify the coolant passage in the reactor upper dome. A conceptual design study for a 1,700 MWe core has been also started with a sensitivity study [87]. 

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