Study on life estimation of cable insulation by gas evolution and oxygen consumption during radiation and thermal aging

Ethylene-propylene rubber (EP rubber), as cable insulating material used in Japanese domestic nuclear power plants, is exposed to /spl gamma/-rays, and aged in an oxygen atmosphere. Oxygen consumption and CO/sub 2/ evolution during /spl gamma/-radiation and thermal aging are measured by gas chromatography. Elongation at the break of aged EP rubber is found to be related to oxygen consumption and CO/sub 2/ evolution during the degradation, and is scarcely affected by radiation dose and temperature. These O/sub 2/ and CO/sub 2/ measurements may be useful to estimate quantitatively the degree of polymer degradation.