Radiation explosion

Different materials pose different hazards, including thermal radiation, explosion overpressure, and toxic and flammable vapor clouds. Some materials pose only one hazard, while others may pose all four. For the purposes of ranking facilities you will need to estimate the laigest area affected by the potential hazards. You can arrive at such an estimate by calculating the greatest downwind distance to a particular level of hazatd. The following thresholds are commonly applied ... 

Facilities can be ranked based on the sum of the maximum hazard distances for each release. Only one hazard distance should be used for each release, even if there is the potential for more than one hazard (thermal radiation, explosion overpressure, toxic cloud and flammable vapor cloud). The highest-ranked facility will be the one whose potential releases would reach the greatest total distance. 

Fire and explosion models describe the magnitude and physical effects (heat radiation, explosion overpressure) resulting from a fire or e.xplosion. 

Fire, fire spread, fireballs, radiation Explosion, secondary explosion, domino effects Noise, smoke, toxic fumes, exposure effects Collapse, falling objects, fragmentation... 

D. B. Sciafe, The Electrostatic Spark Sensitiveness of Initiators Part IV-Initiation of Explosion by Spark Radiation, Explosives Research and Development Establishment Report 9/R/59, Waltham Abbey, Essex, 1959. 

Physical Models Models that provide quantitative information on source rates and extent of damage (thermal radiation, explosion overpressure, or concentration of dispersing vapor clouds). 

Measuring method of explosion temperature is to determine the color temperatures of instant explosion products. The spectra are used to smdy the distribution of energy in the spectra, and this energy distribution is compared with that in absolute blackbody specttum to obtain explosion temperature data. However, because the actual radiator explosion product is not an ideal blackbody, the calculated temperature is called color temperature, and this color temperature is generally slightly higher than the actual temperature. And measured explosion temperatures of some explosives are fisted in Table 3.10. 

Furthermore a radioactive source may heat up by self-absorption so that the ignition temperature of the surrounding explosible atmosphere is exceeded. By impact with ionizing radiation explosible substances and mixtures, especially if highly reactive radicals are formed, may be produced. The causes are radiolysis and chemical decomposition which thus create further explosion hazards. ... 

Certain types of equipment are specifically excluded from the scope of the directive. It is self-evident that equipment which is already regulated at Union level with respect to the pressure risk by other directives had to be excluded. That is the case with simple pressure vessels, transportable pressure equipment, aerosols and motor vehicles. Other equipment, such as carbonated drink containers or radiators and piping for hot water systems are excluded from the scope because of the limited risk involved. Also excluded are products which are subject to a minor pressure risk which are covered by the directives on machinery, lifts, low voltage, medical devices, gas appliances and on explosive atmospheres. A further and last group of exclusions refers to equipment which presents a significant pressure risk, but for which neither the free circulation aspect nor the safety aspect necessitated their inclusion. 

Copolymerization is effected by suspension or emulsion techniques under such conditions that tetrafluoroethylene, but not ethylene, may homopolymerize. Bulk polymerization is not commercially feasible, because of heat-transfer limitations and explosion hazard of the comonomer mixture. Polymerizations typically take place below 100°C and 5 MPa (50 atm). Initiators include peroxides, redox systems (10), free-radical sources (11), and ionizing radiation (12). 

The reaction with fluorine occurs spontaneously and explosively, even in the dark at low temperatures. This hydrogen—fluorine reaction is of interest in rocket propellant systems (99—102) (see Explosives and propellants, propellants). The reactions with chlorine and bromine are radical-chain reactions initiated by heat or radiation (103—105). The hydrogen-iodine reaction can be carried out thermally or catalyticaHy (106). 

Low Level Waste. The NRC 10CFR61 specifies the nature of the protection required for waste containers (20). Class A wastes must meet minimum standards, including no use of cardboard, wastes must be solidified, have less than 1% Hquid, and not be combustible, corrosive, or explosive. Class B wastes must meet the minimum standards but also have stabiHty, ie, these must retain size and shape under soil weight, and not be influenced by moisture or radiation. Class C wastes must be isolated from a potential inadvertent intmder, ie, one who uses unrestricted land for a home or farm. Institutional control of a disposal faciHty for 100 years after closure is requited. 

MicrobaUoons have been used for gap filling, where the spheres dampen sound or vibration in the stmcture. In the medical area, microbaUoons have been evaluated as a skin replacement for bum victims and phantom tissue for radiation studies. An important appHcation is in nitroglycerin-based explosives, in which microbaUoons permit a controUed sequential detonation not possible with glass spheres. 

Criticality Precautions. The presence of a critical mass of Pu ia a container can result ia a fission chain reaction. Lethal amounts of gamma and neutron radiation are emitted, and a large amount of heat is produced. The assembly can simmer near critical or can make repeated critical excursions. The generation of heat results eventually ia an explosion which destroys the assembly. The quantity of Pu required for a critical mass depends on several factors the form and concentration of the Pu, the geometry of the system, the presence of moderators (water, hydrogen-rich compounds such as polyethylene, cadmium, etc), the proximity of neutron reflectors, the presence of nuclear poisons, and the potential iateraction with neighboring fissile systems (188). As Httle as 509 g of Pu(N02)4 solution at a concentration Pu of 33 g/L ia a spherical container, reflected by an infinite amount of water, is a critical mass (189,190). Evaluation of criticaUty controls is available (32,190). 

Explosives. Explosives can be detected usiag either radiation- or vapor-based detection. The aim of both methods is to respond specifically to the properties of the energetic material that distinguish it from harmless material of similar composition. A summary of techniques used is given ia Table 7. These techniques are useful for detecting organic as well as inorganic explosives (see Explosives and propellants). 

Volume of vessel (free volume V) Shape of vessel (area and aspect ratio) Type of dust cloud distribution (ISO method/pneumatic-loading method) Dust explosihility characteristics Maximum explosion overpressure P ax Maximum explosion constant K ax Minimum ignition temperature MIT Type of explosion suppressant and its suppression efficiency Type of HRD suppressors number and free volume of HRD suppressors and the outlet diameter and valve opening time Suppressant charge and propelling agent pressure Fittings elbow and/or stub pipe and type of nozzle Type of explosion detector(s) dynamic or threshold pressure, UV or IR radiation, effective system activation overpressure Hardware deployment location of HRD suppressor(s) on vessel... 

The seal must also resist the vibrations from the explosions of internal combustion in the engine, chassis and wheel vibrations, and even potholes in the road. This seal must resist strong chemicals (anti freeze, anti-rust agents, radiator stop-leak and sealant chemicals, gasoline and lubricant residuals), and also solid particles (rust, iron slag, minerals, asbestos fibers, and silica from the engine casting mold). In spite of all this, the mechanical seal on the water pump of your car can run 7, 10, even 15 years without problems. 

Flare Gas - Molecular weight, lower explosive limit, density at flare tip, fraction F of heat release radiated by the flame. 

The ineident eommander may rely on visual observation of plae-ards, labels, and manifests and information gathered during the response. Obtaining air measurements with monitoring equipment for toxie eon-eentrations of vapors, partieulates, explosive potential, and the possibility of radiation exposure is important for determining the nature, degree, and extent of the hazards [2]. 

Requirements on parameters that may influence the building and its performance and target levels to be determined for occupational zones and non-occupational zones are the following temperature, humidity, air velocity, contaminant concentration (particles, gases), odors, biocontamination (in air and on surfaces), fire/explosion risk, noise, vibrations, radiation (IR, UV, radioactive, etc.), sunshine, loading on floors, and pressure differences (in,side-outside and between rooms). 

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