Radiation effects over time cannot be "assumed" very well: the difference between (very high) energy gamma, (medium energy) gamma, X-ray, thermal and high-energy neutrons, and simple heat stress over time gets very complicated: Different material react differently to each kind of different radiation damage.
Don't relate "biological equivalent radiation units" to simple metallic damage either: equal (or convertible) biological doses will still have physically different effects in different materials, and a material defect that a cell can "regrow" or "replace" will never go away in a crystal or plastic part.
If you can't duplicate your requirement in the literature, Run a simple test (at SWRI or someplace equal research institute) of "what radiation" at "what energy" at "what rate" hitting "what material" at "what temperature"?
Don't assume conditions: Higher temperatures might "repair" interstitial impact damage, or might make it worse. Higher energies will likely make damage worse, but higher energies might be between resonance points and be less damaging.