Location fire risk assessment

Identifying and analyzing fire hazards and scenarios is the next step in a fire risk assessment. The hazard identification should be structured, systematic, audit-able, and address all fire hazards, including nonprocess fires. The result of the hazard identification is a list of potential fire hazards that may occur at the facility, for example, jet, pool, flash, BLEVE, electrical, or Class A fires. This list should also include the location where each fire could occur. Hazard identification techniques used to identify potential hazards are shown in Table 6-1. 

A fairly detailed risk analysis of fires was in the Clinch River Breeder Reactor (CRBR) Risk Assessment Study, 1977. In this study, FMEA was used to identify important fire locations for a wide variety of combustibles, including cables, oil, and sodium. The resulting estimate of the frequency of fire-induced core melt, 5E-7 per reactor-year, is substantially below the estimates discussed above. 

Various risk assessments have been carried out over the years for the sea transport of radioactive materials, including those documented in the literature [39, 40]. These studies consider the possibiUty of a ship carrying packages of radioactive material sinking at various locations the accident scenarios include a collision followed by sinking, or a collision followed by a fire and then followed by sinking. 

Knowledge of the distribution and density of people is necessary to assess the impact of radiant heat and smoke from fires. This allows an estimate to be made of the risk to which the population in and around the facility may be exposed. Extensive population data is necessary where an estimate of societal risk is required. Where only an estimate of individual risk is desired, extensive population data may not be required. However, it is still necessary to determine the location of the people whose individual risk is being estimated. 

The exposure potential from adjacent facilities due to catastrophic incidents such as a fire, explosion, or a chemical release should be identified when conducting a site assessment. Reassessments of nearby facilities may also be warranted as changes to the surrounding exposures occur over time. High hazard or poorly protected operations may present a risk to a nearby chemical warehouse. The most effective approach for minimizing the exposure is usually sufficient spatial separation or fire walls. Locating a chemical warehouse adjacent to airports, highways and railroad lines may also result in an exposure, albeit remote. 

Sometimes, the risk to the public does not come from the area where the public resides. An example is the migration of mercury from coal-fired plants in the Midwest being carried into the atmosphere and deposited into lakes the Northeast. The mercury converts to methyl mercury and then bioaccumulates and eventually concentrates in fish in those lakes. This results in the issuance of fish consumption advisories in the affected areas. In developing the Clean Air Mercury Rule, the U.S. EPA modeled the location of mercury deposition using a spatially explicit air quality model to assess the magnitude of fish contamination and a behavioral model to assess population consumption patterns of these fish. EPA reported monetized benefits from implementing the Clean Air Mercury Rule, measured as decreases in IQ. 

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