Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
1999, Volume 2, Issue 3+4

The Role of Risk Analysis in Control of Complex Plants' Safety Operation

Abstract

The problem of risk estimation, assessment and control is necessary to be discussed in every decision level of an activity. In this way it qualitatively assess the performances of a system, action or technology, by indicating the possible consequences on environment, people or property. The paper presents methodologies of risk assessment successful applied on isotopic separation plants. The quantitative methodologies presented, use fault tree and event tree to determine the accident states frequency, physical models to analyse the dispersion in atmosphere of dangerous substances. The qualitative methodologies use the fuzzy models for the multicriterial decision making, models based on risk matrix build on the base of combination between the severity and the probability of maximum admissible consequence.
These methodologies present the following steps for applying: familiarising with the activity in study, establishing the adequate method of risk assessment, realising of the model of risk assessment for the activity or objective in study, developing of applications of the proposed model. Applying this methodology to isotopic separation plants have conducted to: analysis of operation events and establishing of principal types of events potential dangerous, analysis of human error in these plants operation and operating experience assessment, technical specifications opeimisation by probabilistic safety assessment, reliability analysis and development of reliability and exploitation events database, post accident events analysis (releases, fires, explosions) and mathematical modeling of dispersion in atmosphere of dangerous substances. The risk concept being complex and with multiple implications, is not the case of a rigid approaching neither of existence of some methods universal valuable. Because of these reasons, choosing of the most appropriate method for the risk assessment of an activity, conduct to a solution in useful time, of some problems with economic, social, ecological or moral implications.