Mitigation combustion systems

This scaling problem is not unique, however, to fluidized-bed combustion systems that burn salty sludges. It is possible to reduce the combustion temperature below 612 C, but this temperature limit affects combustor efficiency. One currently demonstrated method of mitigating the problem without altering combustion conditions is to add a fine suspension of clay, lime compounds 05). 

Noise generated by the burners in a combustion system may be greatly mitigated by the combustion chamber. 

A more comprehensive disucssion of fouling and slagging in combustion systems as it affects mitigation, is to be found in Chapter 16, but for completeness, implications in respect of corrosion are discussed in this chapter. 

In general the techniques described in Chapters 14 and 15 for the mitigation of gas side fouling are employed in combustion systems to reduce or eliminate the accumulation of deposits on heat transfer surfaces. Soot blowing and sonic... 

Local containment systems within process structures or areas are intended to retain spills released from process systems within the immediate area of their release. Containment systems are passive mitigation systems usually employed to prevent the spread of spills and releases of flammable or combustible liquids and other materials. Local containment systems are also used for controlling spills of powders or dusts and for molten materials that solidify at ambient temperatures. Containment systems are commonly used to ... 

Local containment is a passive mitigation system intended to retain liquid spills or releases from process systems within the immediate area of the release. Local containment may be appropriate where the quantity of potential flammable or combustible liquid spills is well defined and small to moderate. Where larger quantities of liquids are involved, e.g. continuous process operations, local containment alone is usually not an appropriate design. Containment systems are commonly used for the following purposes ... 

The explosion of combustible gas is a very severe problem to keep the reactor safety. The problem can be considered as overpressure caused by blast to the safety-related components. There are three principal countermeasures against explosion, that is, i) place a distance between the reactor and the hydrogen production system enough to mitigate the overpressure within an allowable range, ii) limit the leak amount of combustible gas, and iii) protect blast with barriers such as wall, bank and so on. As for the hydrogen production system connected to HTTR, the countcnncasure-ii) was mainly considered. 

Dispersion of chemicals into the environment may occur via ground and surface water or sanitary and storm sewer systems. Gases, vapors and combustion products can be dispersed in the air. In addition, particulate matter and condensate can precipitate out of smoke plumes. The risks to the public will be the result of several variables, including quantities, physical properties and hazards, as well as the adequacy and effectiveness of mitigation measures. 

The use of additives was initially confined to the combustion of fuel oils, presumably because the system lent itself to the injection of suitable chemicals and compounds. In more recent times the use of additives has been applied to coal combustion and at present treatment of flue gases derived from waste combustion is being developed. For instance fluidised bed combustors for waste incineration are very suitable for fouling mitigation using additives. The mixing effect of the... 

Features for fire prevention were the mechanical properties of some metal material containers and radioactive material form to prevent or reduce the release, and sprinkler fire suppression systems to prevent or delay ignition of combustible materials. In addition, administrative operating procedures, hazardous materiai handling training and packaging requirements could also help prevent or mitigate a fire caused by an electrical wiring short or overheat. 

Unfortunately, it is also true that the containment could come under harsh assault at the time of vessel failure at high system pressure. This assault is then usually in the form of pressurisation and potential hydrogen combustion though in some cases it can include attack by expelled debris itself or even just elevated temperatures of the containment atmosphere. Accident management activities that can mitigate such potential threats to containment integrity are, of course, seriously considered, e.g. by primary system depressurisation in case of a high-pressure core melt sequence. 

The System 80+ Standard Design includes the Hydrogen Mitigation System (HMS) for control of combustible gas concentration in containment during and following a degraded core accident. The HMS, which is designed in accordance with the requirements of 10 CFR 50.34(f), is described in CESSAR-DC Section 6.2.5. 

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