Study of electric strength of electromagnetic pump insulation under thermal radiation ageing

Methods and results of measurements of electric strength of electroinsulation materials for electromagnetic pump windings after thermal radiation ageing in the BOR-60 reactor channel are presented. Test duration is approximately 25.000 hrs at 410±10 deg C and neutron fluence 8.7x1019m-2. It is established that electric strength of compositions investigated decreases at the initial stage of the tests and then, as a rule, is stabilized and later on even increases a little