Primary container sealing

The differences in primary container sealing are based on how energy is transferred or applied. Energy transfer can be accomplished via the following ... 

The primary objective of miniature battery design is to maximize the energy density in a small container. A compromise must be reached, however, since volumetric energy density decreases as cell volume decreases and the dead volume due to containers, seals, etc. becomes increasingly significant. A plot of energy density as a function of total volume is given in Fig. 3.28 for the zinc-mercuric oxide and zinc-silver oxide systems. 

Biological materials to be removed from the Class III cabinet or from the Biosafety/Laboratory Containment Level 4 laboratory in a viable or intact state are transferred to a nonbreakable primary container and then enclosed in a nonbreakable, sealed secondary container. This is removed from the facility through a disinfectant dunk tank, fumigation chamber or an airlock designed for this purpose. 

Ethylene oxide is penetrative (but less penetrative than gamma radiation). On an industrial scale this allows devices sealed within primary containers to be packed into shelf packs or shippers and palletized before sterilization. Product is normally sterilized on pallets. 

For safety and to prevent cross-contamination, the target is almost always sealed in a primary container and sometimes in a secondary as well. The container should be leak-free and not corrode or overheat during irradiation. For reactor irradiation at low neutron flux and short periods, small plastic tubes (e.g., polypropylene) are useful as they do not activate appreciably... 

Primary containment consists of the provision of immediate physical barriers to release and is represented by the basic design and structure of the equipment item. A glass bottle filled with a screw cap and elastomeric seal can be seen to represent an example of primary containment. In the same sense, a more complex container, such as a bioreactor fitted with appropriate seals and gas filters, serves as a primary container of the fermentation process. Whilst some primary containers may be intrinsically robust, the main feature of primary containment is that in the event of failure of the containment system, there would be release of contents. 

In some cases of pilot scale filtration, entire units have been enclosed as a secondary containment precaution (see Chapter 8). A recent commercial development is the MBR-Sultzer dynamic filter which is available in three sizes. Dynamic filtration is the same as cross flow filtration with little or no recirculation. The cross flow effect is derived from the spinning of the inner surface filter. This type of filter is more efficient, has a lower pump rate and a much higher linear velocity across the filter surface, than conventional cross flow filtration units. There is also little or no damaging effect on sensitive cells. The medium size has the same capacity as the Westfalia SA-7 separator. Van Hemert and Tiesjema concluded that the dynamic filter is suitable for work requiring strict aseptic and primary containment conditions. The use of a double mechanical seal on the rotating shaft could offer a higher degree of containment if required. 

The closure system seals the container, completing the barrier between the container content and the outside world. Labels belong to a special group of secondary packaging materials. A product s packaging system is tailored to meet the required level of protection and is comprised of the complete set of packaging materials primary container, closure system, secondary containers when necessary, and labelling. 

The container closure system seals the primary container after fiUing, protecting the contents from interactions with the external environment. In the majority of cases, the... 

Single-dose oral powders in powder paper can be packaged in a plastic bag with a clip. Single-dose oral powders can also be packaged in small sealed pouches from a laminate foil material including an aluminium layer. These primary containers are called sachets. Next to the use as primary container, bags are also used as secondary container. 

Concerning the On Ag activity in the primary coolant of several plants, silver-containing sealings were identified as the main source, from which traces were released to the coolant by corrosion or mechanical wear. Usually, does not... 

Total containment volume - the total internal (void) volume of the containment without the internal equipment. For double containment, the volume of the primary containment should be entered. For confinement, the total volume of the confinement (hermetically sealed -hermetic) areas should be entered. The appropriate value should be indicated in m. ... 

Containment The primary containment comprises the containment vessel, the reactor head closure and fittings, and the intermediate heat exchangers (Fig. 9.61). There are no penetrations in the reactor vessel below the closure head. During power operation, the reactor is hermetically sealed, all sodium and cover gas service lines (in the head closure) are closed with double isolation valves, and all other penetrations are seal-welded. The pressure of the reactor cover gas is approximately atmospheric during normal power operation. The leak... 

The core, steam generators, and helium circulators are enclosed within a reactor vessel of concrete reinforced by bonded reinforcement steel and prestressed by steel tendons. The top head houses a number of penetration channels which are used for refueling and as housings for the control rod drives. The walls of the vessel have an internal water-cooled liner of carbon steel. The liner forms a gas-tight seal and acts as the primary containment for the reactor, while the secondary containment is provided by the concrete vessel itself. All penetrations of the walls have two independent closures to maintain the principle of the double containment. 

Vented containment was adopted for the Winfrith SGHWR. It comprises a primary containment situated within a secondary containment and connected to it but sealed from it by water lutes. The concrete biological shield surrounding the core and primary circuit is utilised to form the primary containment but the boundary is extended to envelop that part of the refuelling machine above the rotating shield. The power hall, which houses the reactor, turbo-alternator and fuel pond is utilised to form the secondary containment. 

Access through the containment seid, which consists of welded pans, can be made easier through the use of mechanical seals with organic gaskets. These would not be subject to severe radiation damage since the containment seal is itself shielded from primary radiation. 

Container. The battery container is made up of a cover, vent caps, lead bushings, and case. Cost and appHcation are the two primary factors used to select the materials of constmction for container components. The container must be fabricated from materials that can withstand the abusive environment the battery is subjected to in its appHcation. It must also be inert to the corrosive environment of the electrolyte and soHd active materials, and weather, vibration, shock, and thermal gradients while maintaining its Hquid seal. 

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