Development of sealing insulator for electrical penetration assemblies

In chase of improvement of electric penetrations for nuclear power plants, especially in the heat-resistance of sealing, sodium-barium based glass was studied about whether to replace compound (epoxy resin). 'Compression Sealing Method' was used for sealing glass and metal. A production technique for 62 mm dia. glass sealing has been established. The glass sealant has been proved to have high temperature airtightness at 300degC. Environmental tests were conducted in terms of heat-cycle, vibration and LOCA etc. They were made certain of conformity to the design requirements for boiling water reactor operation. (author)