Can RADAR cause SEUs or similar transient faults?
SEU is used to describe the impact of ionising radiation, or potentially other low probablity interactions. High field strength EMF can affect electronic devices (for example the old EEPROM erase using UV light), but radar has far lower energy.

Radar will have an effect on the circuit signal levels, in the same way as any other radio interference, the impact of this will be far more significant than any transistor level interactions.