METHODOLOGY FOR EVALUATING EXPOSURE DUE TO AIRCRAFT IMPACT
Purpose. This chapter provides the methodology for evaluating exposure resulting from
aircraft impact on a facility. The methodology by which exposure is assessed can be
divided into two broad areas: exposure screening and exposure evaluation.
Exposure Screening. The purpose of exposure screening is to determine, on the basis of
overall facility inventory and generic expected release mechanisms associated with aircraft
impact (e.g., fuel fire, missile impact shock, building collapse), whether a facility has the
potential for significant onsite or offsite exposure, given an aircraft impact.
Applicability. Exposure screening will be performed for all facilities subject to the
provisions of this standard.
Hazard Identification. Hazard identification will be performed to identify and
inventory hazardous materials and energy sources (in terms of quantity, form, and
location) associated with the facility processes or related operations. Standard
industrial hazards will be identified only to the degree that they may exacerbate a
postulated aircraft impact on the facility. Well-confined material may be excluded
from the hazardous materials inventory, but such exclusions should be justified
based on the robustness of the material containment in a postulated aircraft impact
environment (i.e., such assumptions should be shown to be valid for the class of
accidents being evaluated). References 1 and 2 may be used in performing
Radioactive Materials. This section summarizes the screening approach for
radioactive materials. More detail is provided in a separate report, Screening for
the Potential Consequences of Accidental Releases of Radioactive and Chemical
Materials to the Atmosphere (Reference 3).
Radioactive Material Source Term Determination. A bounding source
term will be developed based upon an assumed loss of containment for
all hazardous radioactive material associated with the facility, except the