Hazardous operations , explosion

General Safety Precautions. The preparation and handling of the items covered by this specification, and the subassemblies thereof, involve hazardous operations and therefore require explosives safety precautions. Use of this specification will not be construed as to relieve the contractor or manufacturer of responsibility for the safety of his operations. Listed below are certain minimum provisions which a contractor or manufacturer (who prepares the item covered) should observe in order to fulfill his responsibility for safety. At Bureau of Naval Weapons, Navy Department, and other government plants, these provisions are mandatory. Such other warnings and precautions, pertinent to the operational effectiveness or safety during preparation of the specified items, are included in detailed technical requirements of the specification... 

Examples of common safe practices are pressure relief valves, vent systems, flare stacks, snuffing steam and fire water, escape hatches in explosive areas, dikes around tanks storing hazardous materials, turbine drives as spares for electrical motors in case of power failure, and others. Safety considerations are paramount in the layout of the plant, particularly isolation of especially hazardous operations and accessibility for corrective action when necessary. 

It becomes clear that the chances a single fire or explosion will spread to adjoining units can be reduced by careful plant layout and judicious choice of construction materials. Hazardous operations should be isolated by location in separate buildings or by the use of brick fire walls. Brick or reinforced concrete walls can serve to limit the effects of an explosion, particularly if the roof is designed to lift easily under an explosive force. 

Group 6 Shield. The Group 6 Shield is spherical. The requirement for this shield is that an operator be capable of transporting on a push cart small quantities of extremely hazardous primary explosive material. It is not feasible to vent this shield because of the hazardous material Involved and the close proximity of the operator. 

As this table indicates, suppressive shields are approved for use in hazardous operations involving explosive charge weights up to the equivalent of 57 pounds 50/50 pentollte for Group 5 and 50 pounds of lllumlnant mix for Group 5. 

At Pantex, the preliminary hazards analysis takes the form of a questionnaire (PX-1245), which is used to collect information about facility inventories of highly hazardous chemicals, explosives, and nuclear material. This information serves as an objective basis for facility hazard classification. The information also allows ranking of facilities based on the quantity and form of nuclear material the eonsequences associated with an explosive event, as well as the type of explosives operation and the eonsequences of a release of highly hazardous materials. 

YES / NO Procedures for controlling hazardous operations, such as cranes, scaffolding, trenches, confined spaces, hot work, explosives, hazardous materials, leading edges, etc. 

Working Alone You should not work alone in a laboratory. Use the buddy system. If you are separated by a wall or out of direct observation, then you must devise a system to periodically check your buddy. Your buddy should know what you are doing, particularly if this involves hazardous operations. Someone should always be in the near vicinity so that if something happens, an explosion or incident, your buddy can have an opportunity to get you assistance. Explosions, fires, splashes, spills, or contact with chemical or physical hazards could result in life-threatening incidents that require immediate action. If you are alone you are putting yourself at high and unnecessary risk. 

Fire prevention Extinguishers, alarms, sprinklers, smoking rules, exits, personnel assigned, separation of flanunable materials and dangerous operations, explosion-proof fixtures in hazardous locations, waste disposal, training of personnel. 

It may also be noted that a French assessment of the explosibility risk in a rather more potentially hazardous operation of incinerating spent nuclear graphite in a fluidized bed plant has also given a favourable result. It is considered that the procedures adopted for the trepanning of Piles graphite, particularly the controls on temperature and the presence of an inert atmosphere in the vicinity of the cutting operation, effectively eliminate the explosibility risk ... 

Program Elements 1. Written policy, purpose, scope Statement of objectives Standards compliance Responsibility/accountability assigned Implementation activities A. Training/certification Written procedures Hazardous operations Hazardous materials Hazardous operations permits Personal protective program Mishap/near-miss investigations Mishap/near-miss records and reports Fire/explosion safety Emergency preparedness Procurement and subcontract safety Safety representatives on-site Implementation of supplemental requirements... 

As opposed to alkaline azides which do not have properties of explosives, alkaline fulminates are mostly reported as highly sensitive and explosive substances [8,107, 108] even though one source mentioned sodium fulminate as not so sensitive (impact sensitivity for NaCNO to be 32 cm with 0.5 kg hammer compared to 7.5-10 cm MF under the same conditions) [27]. Sensitivity of these fulminates is reported as extreme and handling a hazardous operation [8, 107, 108]. Extreme sensitivity is further reported for the rubidium and cesium salts. Alkaline fulminates undergo explosion when initiated by flame, even in small amounts, whereas mercury fulminate only deflagrates. The exact sensitivity data are, however, not reported in this work [107]. Sensitivity of cadmium fulminate to impact is about the same as that of MF sensitivity of thallium fulminate is higher [15, 57]. 

The preventive strategies for reducing the risk of fire and explosion within the workplace can be equally applied across the majority of industry sectors as illustrated from the preceding section on arson prevention and control. The principal causes of fire generally only vary in very specific detail and more often than not relate to hazardous operations and sites, e.g. COMAH sites, otherwise the causes remain constant, particularly when it revolves around human factor . 

Location of the hood is also important from a safety viewpoint. Since fume hoods are utilized for some potentially hazardous operations, they should be located near the back of the laboratory and away from exits. Should a fire or explosion occur in the hood, the laboratory layout should never require personnel to pass in front of it to reach an exit. 

Here we shall restrict consideration to safety and health considerations that can be built in while the design is developing rather than the detailed hazard and operability studies that take place in the later stages of design. The three major hazards in process plants are fire, explosion, and toxic release. ... 

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