Inherently Safer Plant Design
Publication Date: 2012-May-04
The IP.com Prior Art Database
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lNHERENTLY SAFER PLANT DESIGN
R. C. Frey
The M. W. Kellogg Company
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Every aspect of our lives is associated with risks. Presumably the risk of traveling to safety seminars is outweighed by the benefits associates with attendance.
The past summer has again brought to our daily attention the many disasters possible; the devastating floods in the Mississippi Valley. It is a certainty that they are coming and impressive measures had been taken to mitigate the effects, but they never appear to suffice. This not new.
Pliny the elder noted the Egyptian authorities had successfully devised an elaborate system to deal with the overflow of the Nile, two millennia before the birth of Christ. The Nile begins its rise in mid-summer, rising gradually and subsiding again in 100 days. The rise is detected by means of wells marked with scales. The variations ranged from 7% ft. to 27 ft. The Egyptian beauracrats used this data to adjust taxes. We don't know if they provided government support as well.
Another of society's means of dealing with risk is insurance. It's early employment in the form of interest rates on crops and trade can be traced to the Mesopotamia and Babylonian era's. Risk premiums on cargo often included premiums of 200%, due to bandits, pirates, storms and other assorted misfortunes. Borrowers often posted all their properties and families as collateral. The Code of Hummurabi established the doctrines of risk management that laid the basis for insurance.
From the 17th century, the insurance industry flourished in England. Lloyds was established in 1688. Fire insurance developed after the great London fire of 1666. Life insurance developed at the same time in the form of Friendly Societies, which failed miserably due to lack of proper probabalistic assessment and actuarial data.
These developments in the 17thto 19th centuries precede the modern concern with the value of life, what is the acceptable monetary value of the loss of human life. The church raised serious questions about the morality of life insurance. For the church, life insurance was an immoral wager on human life. Although this aspect is no longer debated, we see daily concern with the implied value of life.
A recent U.K. study shows the implied levels of investment to save a human life. It shows orders of magnitude variations for each category and between industries. It is not unreasonable or immoral to put a monetary value on human life for safety investment purposes, not to do so could be regarded as irresponsible and wasteful. This provides a measure of what can be considered as a reasonable investment for a safe plant.
The concept of inherent safety or an inherently safer plant has developed in the last several years. Inherently safer plants rely on basic engineering, chemistry and physical processes rather than rely on control systems, interlock, alarms or administrative procedures to stop incipient accidents....