Positron Annihilation Measurements on Nuclear Reactor Pressure Vessel Steels

Positron Annihilation Spectroscopy is a valuable microscopic method to study radiation damage in nuclear reactor pressure vessel steels.At SCKoCEN, a new positron lifetime setup, suited to measure positron lifetimes in irradiated steel, is being constructed.The particularity of this setup is that the prompt count rate originating from the induced 60Co-activity in the steel is highly reduced.Some preliminary results obtained for unirradiated SA-508 steel are discussed.