Analysis of data about emergency evacuation plan
Answers
Explanation:
The probability of a nuclear accident, while small, is not zero (Collins, et al., 1978). Measures to improve public safety have tended to favor reductions of this probability and its consequences as opposed to planning for large scale evacuations. This approach was logical given the characteristics of the design basis loss-of-coolant accident, but is
not consistent with the current goal of protecting the public in the event of a core melt accident. Moreover, most existing reactor site evacuation models appear to be overly abstract models of the evacuation problem that cannot be considered adequate under NRC's revised
requirements for evacuation planning. It is appropriate, first, to digress briefly and define some key terms.
The term "evacuation time" is used by different analysts to represent different components of the time between detection of an incident and the completion of an evacuation. It is essential to use other terms to describe the components of evacuation time. Our definition of evacuation time" will represent the interval of time from the detection of an incident which ultimately requires evacuation to the end of the
period required for individuals to physically move out of an area.
The components of evacuation time are as follows:
decision time = The time elapsed from detection of an incident until a decision is made by competent authority to order an evacuation.
notification time = The time required to get the evacuation notification to all individuals in the specified area.
preparation time = The time required for individuals to prepare to evacuate the specified area.
response time = The time required for individuals to physically
move out of a specified area.
For each individual evacuee, evacuation time is the sum of all the component times. In actuality, there may be different notification, preparation, and response times for each individual evacuee. Thus, in an area designated for evacuation there is a distribution of times for each of the components just defined rather than a single point in time. When viewed from the perspective of the agency responsible for the evacuation, this means that certain phases of the evacuation will overlap. That is, at any point in time, some residents may be in the process of being notified, others preparing to evacuate and still others in the process of leaving. Note that these components do not include confirmation time in the overall estimate of evacuation time.
Confirmation time--the period during which it is verified that the affected population has departed may occur concurrently with or subsequent to evacuation. It is important to understand that estimates of the length of the
time period from the decision to evacuate through clearance of the evacuation zone is significantly affected by the time required for both notification and preparation. That is to say, the length of time that it takes to clear the area cannot be calculated with any degree of certainty