With respect to the B-52G nuclear turbojet testbed described HERE, some information about what the nuclear radiation was expected to do to various materials in use on the B-52.
The parameter proposed by Convair for the evaluation of radiation damage to materials
is the threshold of damage, the minimum amount of radiation that will change the properties of a material to the specification limit. The approximate thresholds of some of the
more common aircraft-system materials are listed in Table 2.12. In certain regions it
may be desirable to replace Teflon with polyethylene, which has a functional threshold
about 3000 times greater than Teflon. Polyurethane was also recommended as a replacement for Buna-N.
Except for semiconductors, gamma radiation causes most of the incipient damage to
the components. The neutron field causes only a small percentage of the damage. The
approximate isodose pattern of a 70-megawatt nuclear system is shown in Figure 2.18.
The operating lifetime of a component in this nuclear environment, designated by zones,
is calculated by dividing the functional threshold of the material by the radiation field
in the respective zones. The isodose patterns do not include air scattering, structural
scattering, nor absorption in the airframe structure.
The data is provided in ergs per gram (of the target material). This seems to be a not entirely spectacular way to present the data, since an erg is simply a unit of energy, not of power. Thus an erg could be deposited in a nanosecond or a millenium, and the table would indicate the same response. So I’m guessing that this refers to a specific radiation dose or environment. So while the *absolute* values don;t seem to be readily apparent, relative values can be determined.
