Contents I. Introduction
Nowadays shift for the spent nuclear fuel (SNF) processing with partial burial instead of its full burial was outlined in nuclear power, which means transition from an open nuclear fuel cycle to the closed nuclear fuel cycle. It means processing technologies development and new recycling plants construction. The existing plants and recycling units for SNF and nuclear waste processing use as drives for the rotating mechanisms generally low power electric motors with organic insulation which can be settled close to and even in radioactive zones. Service life of these electromechanical devices is reduced from several years in normal conditions to several months in radioactive environment. Service life reduction is caused by the accelerated ageing of the organic insulation applied in classical design motors that leads to short circuits in the motor winding and its rapid failure. Such short service life of electric motors results in need of their replacement each several months that essentially increase service costs of entire plant. Inorganic insulation, for example, ceramic insulation usage in the electric motors intended for working in the radioactive environment can become one of possible solutions of this problem. However inorganic insulation is very brittle that complicates its application in general industrial use low power motors with mush windings. Development of electric motor stator design which would allow applying of a wire with the inorganic insulation steady against radiation influence can become the solution of this problem. The synchronous motor with ring windings may become one of motors with such design [1].
