SENSITIVITY OF EVACUATION TIME ESTIMATES TO CHANGES IN INPUT PARAMETERS FOR THE I-DYNEV COMPUTER CODE

A study performed by the Pacific Northwest Laboratory (PNL) with the assistance of the Texas Transportation Institute for the U.S. Nuclear Regulatory Commission (NRC) identifies the key input parameters to I-DYNEV affecting evacuation time estimates (ETEs). In addition, the study attempts to determine the sensitivity of ETEs to changes in those parameters when applied to two different evacuation networks. The information could then be used to determine parameters requiring additional research and to assist in the evaluation of ETEs submitted by licensees and applicants. The parameters analyzed for the study included vehicle population, network capacity, loading time, the capacity reduction factor, the time interval of processing, and free-flow velocity. These parameters were applied to two evacuation networks simulating a rural and an urban area. Changes in each of the six input parameters evaluated for the study affected to some degree the estimates of evacuation times. In general, however, the results obtained revealed that the sensitivity of the evacuation time estimates to changes in the input parameters is consistent wih traffic modeling theory and documented algorithms included in the model.