Effects of Irradiation Temperature on Embrittlement of Nuclear Pressure Vessel Steels

This paper uses ABI® to characterize how irradiation temperature affects embrittlement in reactor pressure vessel (RPV) steels by measuring DBTT (ductile-to-brittle transition temperature) shifts. Published in the proceedings of the 16th International Symposium on Effects of Radiation on Materials — the premiere conference in this field — the work demonstrates ABI®'s sensitivity to radiation-induced hardening and its potential as a nondestructive surveillance technique.

Irradiation temperature is a critical variable in RPV embrittlement because it determines the types and mobility of radiation-induced defects. At lower irradiation temperatures, point defect clusters and copper-rich precipitates form more readily, accelerating embrittlement. Understanding this temperature dependence is essential for predicting embrittlement in reactor vessels that operate at varying temperatures around their circumference.

The study demonstrates that ABI® can detect the embrittlement differences caused by different irradiation temperatures — a sensitivity requirement that validates ABI® as a credible technique for reactor vessel surveillance. The ability to make this measurement nondestructively, without consuming irreplaceable irradiated surveillance specimens, has significant practical and economic value for the nuclear power industry.