Protective and safety systems

Protective systems are employed to reduce/eliminate hazards and risks, and may be viewed as a special category of process equipment. Ten examples of protective systems are provided below. The management of protective systems information should occur within the management of systems for process and equipment. However, with protective systems equipment, it is particularly 

Provision for protection and safety equipment should be incorporated in the original plant design. The size of the plant, nature of the hazards, and the e.xposure will determine the amount, kind, and location of this equipment. 

Regarding fires, water is the primary extinguishing agent, and it should be available in adequate supply and pressure at all of the locations in the plant. The layout for various types of installations and the appropriate recommendations are found in the standards of the National Fire Protection Association. Fire hydrants, hose lines, automatic sprinkler and water spray systems should all be a part of the permanent equipment facilities of the plant. 

Fire extinguishing systems can include foam, carbon dioxide and dry chemical. Wetting agents and high e.xpansion foam have been used in some plant protection systems. All fire extinguishing systems should be evaluated for the potential health risks as well as overall effectiveness before incorporation into a plant. 

Since many chemical plants have severe health hazards, it is essential to provide medical facilities and first aid stations. In addition, showers and eye wash stations are necessary in certain hazardous areas. Also, guards and covers should be provided for all moving equipment. Ten of the key protective equipment are listed below. 

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Protection and safety systems should be used to reduce/eliminate hazards in a plant. 

Evaluation of the three principal safety functions shutting down the reactor, cooling the fuel and maintaining confinement of radionuclides, including an indication of both the correct functioning of reactor protection and safety systems and their failure ... 

Industrial fire protection and safety engineers attempt to eliminate hazards at their source or to reduce their intensity with protective systems. Hazard elimination may typically require the use of alternative and less toxic materials, changes in the process, spacing or guarding, improved ventilation or, spill control or inventory reduction measures, fire and explosion protective measures - both active and passive mechanisms, protective clothing, etc. The level or protection is dependent on the risk prevalent at the facility versus the cost to implement safety measures. 

Increasingly, newer fired process heater installations are adding more fuel-air combustion controls and safety instrumentation systems. However, the decision on the extent of fired heater combustion controls, instrumentation, and safety systems to employ is fundamentally a loss prevention and risk tolerance issue, rather than a fire protection one. The following recommended practices, codes and standards apply to fired heater and dryer controls and instrumentation ... 

Typical irradiation facilities consist of a process chamber containing the radiation source, some sort of conveyor systems to transport products inside and outside the shielding walls, and sophisticated control and safety systems. Irradiation facilities are built with several layers of redundant protection to detect equipment malfunctions and protect employees from accidental exposure. Technical details depend on the type of irradiation. Typical processing parameters are compared in Table 2 [7]. 

Annual report the annual report has a separate heading titled environmental protection and safety . In it the environmental report is discussed, and some of the detail from it is included, together with discussion on the financial costs of environmental protection and a description of how the HS E system is managed. 

The first approach is traditional and is based on increasing the amount and efficiency of various protecting and localizing systems which reduce the possibility of severe accidents and hazardous factor of their results. Practical realization of this approach, theoretically based on probabalistic safety analysis (PSA), results in more complicated and expensive installation, deterioration of its other characteristics and, nevertheless, in principle, does not exclude the possibility of severe accident with catastrophic consequences because there have not been eliminated the internal causes of arising the accident. 

The second approach is based on the concept of the RI with inherent safety ensuring its selfprotection in which the causes of arising the severe accidents witii catastrophic consequences have been deterministically eliminated by nature laws. This approach does not require the construction a lot of protecting and localizing systems, which, in some cases, themselves may become the causes of accidents. 

The Safety Protection Subsystem of the Plant Protection and Instrumentation System (PPIS) is that portion of the PPIS which performs lOCFRlOO-related functions. It includes the reactor trip Instrumentation hardware and associated system sensors which are used to detect abnormalities in the plant... 

There are other engineering factors that affect the fire and explosion hazard, e.g., engineering standards of the structural steel and foundations, process equipment, heat exchangers, feeding system, fan and blowers, storage vessels, electrical equipment, instruments, and fire protection and safety equipment. Considerable assistance in design also can be obtained from relevant codes of practice. The responsibility for safe operation rests with the manufacturers of equipment and products as required by national law (e.g.. Factories Act and Health and Safety at Work Act in the United Kingdom). 

Separation of Protection and Control Systems. The protection system shall be separated from control systems to the extent that failure of any single control system component or channel, or failure or removal from service of any single protection system component or channel which is common to the control and protection system leaves intact a system satisfying all reliability, redundancy, and independence requirements of the protection system. Interconnection of the protection and control systems shall be limited so as to ensure that safety is not significantly i mpa i red. 

Designing plant safety systems so that redundant safety equipment is protected by automatic fire suppression systems and separated from each other and from other plant areas by fire barriers such that a fire would not endanger other safety related equipment required for safe shutdown. Alternate or dedicated shutdown capability should be provided where the protection of safety systems required for safe shutdown is not provided by established fire suppression methods. 

The Basic Safety Standards [2] can be applied only by means of an effective infrastructure for radiation safety, which includes adequate legislation and regulations, an efficient regulatory system, supporting experts and services, and a commitment to safety shared by all those with responsibilities for protection and safety, including both management and workers. 

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