Accession Number : AD0766053

Title :   Discussion of the Possible Dose-Rate Effect in Irradiation of Pressure Vessel Steel.

Descriptive Note : Memorandum rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Serpan,C. Z. , Jr

Report Date : AUG 1973

Pagination or Media Count : 18

Abstract : A 'dose-rate effect' for low alloy steel is based on the premise that radiation damage will be greater for a given fluence of neutrons when irradiation takes place at a low flux level over a long time than for irradiation for a short time at a high flux level. These are the conditions under which accelerated irradiations are performed for short times to establish anticipated lifetime mechanical property changes in reactor vessel components that will be under irradiation for long times at low flux levels. The available theoretical and experimental evidence related to the dose-rate effect in low alloy steel has been reviewed and is discussed. The conclusion reached is that trends in steel hardening and embrittlement by neutron irradiation are not noticeably influenced by the rate of irradiation when the rates (fluxes) are between 10 to the 10th power and 10 to the fourteenth power n/sq cm per sec, and the fluence received is <1x 10 to the twentieth power n/sq cm >1 MeV. (Author)

Descriptors :   (*STEEL, *NEUTRON REACTIONS), (*DOSE RATE, STEEL), REACTOR MATERIALS, NUCLEAR REACTORS, PRESSURE VESSELS, NEUTRON FLUX, EMBRITTLEMENT

Subject Categories : Physical and Dynamic Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE