TABLE OF CONTENTS Safety is a prime consideration in plant siting. Other important factors include: access to raw materials and to markets; availability of land, labour and cooling water; means of effluent disposal; interlinking with other plants; and government policies, including planning permission and investment incentives. It is only safety aspects which are considered here.
As far as safety of the public is concerned, the most important feature of siting is the distance between the site and built-up areas. Sites range from rural to urban, with population densities varying from virtually zero to high. Separation between a hazard and the public is beneficial in mitigating the effects of a major accident. An area of low population density around the site will help to reduce casualties. In the ideal case, the works is surrounded by fields or waste land forming a complete cordon sanitaire. In many situations, however, it is unattractive to sterilize a large amount of land in this way, particularly in an urban area, where land is generally at a premium.
The physical effects of a major accident tend to decay quite rapidly with distance. Models for fire give an inverse square law decay, as do many of the simpler models for explosion and toxic release, though other explosion and toxic release models give different decay relations, some with less rapid decay. Decay laws were discussed in Chapter 9 and further treatments are given in Chapters 15 17.
Information on the potential effects of a major accident on the surrounding...
