The core engineering metric for measuring a motor’s radiation resistance is the cumulative absorbed dose, measured in gray (Gy), rather than the “number of irradiation cycles” or “years of service.” Radiation damage to the motor’s internal insulation materials and lubricating grease is an irreversible, cumulative process. The key premise behind the question customers often ask—“How many times can it withstand irradiation?”—is a clear understanding of the absorbed dose per irradiation cycle.

2.What is the typical magnitude of the “radiation resistance” of radiation-resistant motors?

Conventional motors may fail at doses as low as a few hundred gray (Gy), whereas truly radiation-resistant motors must meet different radiation resistance levels depending on the application:

Conventional nuclear industry applications: Typically require resistance to 10⁶ Gy (1 MGy) or higher.

High-demand scenarios (such as fusion devices): Technology exists to achieve radiation resistance of 10⁷ Gy (10 MGy) or even higher.

Limitations of drive circuits: It is important to note that while the motor itself is radiation-resistant, the radiation resistance of traditional drive circuits is often less than 10⊃3; Gy; therefore, hardened solutions such as FPGAs or gallium nitride (GaN) devices must be selected.

3.In a radiation environment, what is the component of an electric motor most prone to damage?

The most vulnerable parts of an electric motor are usually not the metal components, but rather the numerous organic material parts. These primarily include:

Insulation system: When exposed to radiation, the insulation varnish on enameled wire and insulation paper undergo molecular chain breakage, causing a sharp drop in insulation resistance.

Lubrication system: Ordinary grease can carbonize, form coke deposits, or volatilize in a radiation field, causing bearings to seize due to dry friction.

Seals and cables: Sealing rings and the insulation layers of lead wires are prone to hardening and cracking under radiation.