GENERAL IMPLEMENTATION GUIDANCE.
This chapter provides an overview of the approach described in this standard. The approach is
summarized in the flowchart in Figure 1. The flowchart depicts an approach that provides
maximum flexibility in implementing this standard. The components of the approach are
modular, so they may be used in a different order and still be applicable. For example, a facility
that is located relatively far from airports with limited operations may decide that the best route
through the approach is to begin with impact frequency evaluation. Likewise, a facility with a
low quantity of hazardous material may decide to start with exposure screening. In fact, the
analyst is not limited to these selections and can start the implementation anywhere in the
flowchart. The chronological order of activities presented in Figure 1 is believed to provide the
most efficient method for implementing the approach.
As can be seen by the boxes in Figure 1, the approach consists of three distinct phases, which
aim to answer the following three questions:
Does the total hazardous material in the facility pose a threat to the
Does aircraft crash impact pose a threat to the facility?
What is the extent of the threat posed to the facility and the public?
The steps in the first phase are intended to determine whether the facility in question contains
sufficient inventory of hazardous radioactive or chemical material to pose a potential hazard if
an aircraft crash could result in the release of the available material. If the steps in this phase
indicate that the facility contains sufficient inventory to pose such a hazard, then the analysis
moves to the second phase. The second phase is intended to demonstrate whether an aircraft
crash poses a significant threat of release from the facility. This phase primarily considers
whether the frequency of aircraft impact into the facility is significant and whether those aircraft
that have a high impact frequency could actually do damage to the facility. If the steps in this
phase indicate that aircraft crash poses a threat of release from the facility, the analysis moves
to the third phase. The third phase comprises a "graded" analytical approach for assessing the
extent of the damage to the facility, the extent of any release associated with the damage, and
the exposures associated with the release. In this context, a "graded" analysis means