Events dangerous

Identification of critical events dangerous for the structural safety of the cryogenic tank... 

The transparency of methanol flames is usually a safety advantage in racing. In the event of fires, drivers have some visibiUty and the lower heat release rate of methanol provides less danger for drivers, pit crews, and spectators. 

Magnesium anodes must not be used in tanks. Aluminum anodes may be installed in all tanks according to the agreements of the International Association of Classification Societies, which are included in the individual regulations [5,6], but in tanks (b) in the event of the anode falling off, the kinetic energy must not exceed 275 J, i.e., a 10 kg anode must not be fixed more than 2.8 m above the bottom of the tank. There are no restrictions on the use of zinc anodes. The restrictions on the use of aluminum anodes are due to the possible danger of sparks if the anode falls off. 

Early in the Corrective Action process, a decision may be made concerning whether or not containment is necessary to protect human health and the environment (HHE). If the release or threatened release presents danger to HHE, immediate action must be taken to halt migration. Under these circumstances, actions termed "Interim Measures" may be required, and excavation or containment measures may be directed by the regulatory agency. However, the Owner/Operator will be responsible for their implementation. In the event that containment is not required as an interim measure, containment may still be needed as part of the overall Corrective Action to halt the pollution migration if wastes or contaminants are to be left on-site. 

Because the hazard is still present, there is always a danger that its potential impacts could be realized by some unanticipated route or mechanism. Nature may be more creative in inventing ways by which a hazardous event can occur than experts are in identifying them. Accidents can occur by mechanisms that were unanticipated or poorly understood. 

The chemical process environment which refers to the complexity and novelty of the process events, their perceived danger, and the imposed time constraints on the workers... 

Another danger of an inadequate appreciation of human causes of hazards is that the HAZOP analyst may consider a particular high risk event (identified by a guide word and deviation) to be noncredible, because he or she only takes into accoimt the hardware failures (with an extremely low probability) that could give rise to the event. When human causes are taken into accoimt, the likelihood of the event may actually be quite high. 

Hazard or event identifiealion provides information on possibly dangerous silualions lhal ean oecur when dealing witli ehemieals. There are several different methods that are used in hazard or event idenlifiealion. 

Hazard, risk, failure, and reliability are interrelated concepts concerned witli uncertain events and tlierefore amenable to quantitative measurement via probability. "Hazard" is defined as a potentially dangerous event. For example, tlie release of toxic fumes, a power outage, or pump failure. Actualization of the potential danger represented by a hazard results in undesirable consequences associated with risk. 

Part of the concern about global climate change stems from the human tendency to seek meaniiig in events that may or may not be more than simply a random event. A particularly cold winter, a particularly hot summer, an especially rainy season, or an especially severe drought will all send people off on a search for the greater meaning of the phenomenon. Is it a pattern, or a one-time event Must we build a dike, or has the danger passed Since the summer of... 

In the event of an earth fault the difference in potential between any point which may be touched and the ground (touch potential) should not reach dangerous levels. 

VasU ev (Ref 36) impacted various explosives with steel plates and followed events with a framing camera. PA at 1,59g/cc impacted with a 3-mm thick steel plate at 430m/sec showed only deflagration and no expins. Initially the burning rate was low but reached 600m/sec in about 65 microseconds after impact C. Potential Hazards. The main danger of accidental expln of PA appears to be in fires. There appears to be uncertainty if explns result if PA bums out of contact with metals. On p 494, Urbanski (Ref 35) states ... 

The main danger in the operation of a nuclear power plant is potential loss of control over the nuclear reaction. If the core overheats, it may either explode or melt down. In either event, radioactive materials escape Irom the reactor to contaminate the environment. Designers attempt to make nuclear reactors fail-safe by providing mechanisms that automatically shut the core down on overheating. One way this has been done is to design the control rods to fall into the core if their control mechanism fails. 

The object of this exercise is to identify the dangerous steps in the sequence of events. 

Ask patients and family members about any bothersome or dangerous sleepwalking episodes since the last visit and if therapy has reduced the frequency of these events. 

These models employ continuous, rather than single event, simulation. The advantage is that continuous output can be analyzed statistically. The user can obtain answers to questions such as "For what fraction of time will the concentration of X be above Y mg/1 at point Z in the system " Or, "What danger does chemical X pose to species A at locations B and C ". These are the kinds of answers needed if he is to make rational decisions regarding the permissible uses of chemicals for agricultural purposes. 

---