Probabilistic Risk Assessment

Risk

Risk management is the ongoing process to identify, analyze, assess, and treat loss exposures and monitor control and financial resources to mitigate the adverse effects of loss.

Acceptable risk

The degree of potential losses that a society considers acceptable given existing social, financial, political, social, technical and environmental conditions.

In engineering terms, acceptable risk is likewise used to evaluate and characterize the structural and non-structural measures that are required to reduce possible damage to individuals, property, services and frameworks to a chosen tolerated level, as indicated by codes or "accepted practice" which are based on known probabilities of hazards and other factors.

Probabilistic Risk Assessment

This is generally called core damage frequency (CDF)

A Level 2 PRA, which begins with the Level 1 core damage accidents, estimates the frequency of accidents that discharge radioactivity from the nuclear power plant.

A Level 3 PRA, which begins with the Level 2 radioactivity release accidents, evaluates the results concerning injury to the public and harm to the environment.

Various techniques used in PRA

Probabilistic Risk Assessment normally answers three essential questions:

What can turn out badly with the examined technological entity, or what are the initiators or starting events that prompt adverse consequence(s)?

What and how extreme are the potential detriments, or the adverse outcomes that the technological entity might be inevitably subjected to as a result of the occurrence of the initiator?

How likely to happen are these undesirable outcomes, or what are their probabilities or frequencies?

Two common techniques for answering this last question are Event Tree Analysis and Fault Tree

Core damage accidents are viewed serious because harm to the core may avoid control of the nuclear reaction, which can prompt a nuclear meltdown.

• Large Early Release Frequency(LERF) It is defined as the recurrence of those accidents leading to important releases from containment in a time frame before effective evacuation of the close-in population such that there is a potential for early health impacts. Such accidents generally involve un-scrubbed releases connected with early containment failure at or shortly after vessel breach, containment bypass events, and loss of containment isolation.

Conclusion

It is very important and necessary to know how to deal with risks in the nuclear power plant, so that we can avoid potential problems that may damage and harm employees in the labor sector.

In this report, I defined the terms risk and acceptable risk; explained the Probabilistic Risk Assessment approach; described the various methods used in PRA, and defined as well the Core Damage Frequency and Large Early Release