NSUF 24-5130: Unveiling Long-Term Irradiation and Thermal Aging Effects on Solute Segregation in Commercial Reactor Pressure Boundary Material

We will seek in both the pressurizer and surveillance material to select APT specimens from differing grain character regions of the HAZ for a more comprehensive understanding of the interplay between microstructure and microchemistry. The results of the APT analysis for segregation and cluster size/density will be compared to archival literature of thermally aged and irradiated LAS, as well as yet unpublished TEM microstructural characterization by WEC. We hypothesize that the segregation and clustering behavior will directly correlate to impurity content, grain character, and fluence, and that the neutron-irradiated coarse grain HAZ will have the greatest extent of segregation. To test this hypothesis, we propose to examine base metal, weld, and HAZ material from both Indian Point 2 pressurizer and SONGS surveillance. The outcome of this study will be a hierarchical understanding of the interplay of microstructure, chemistry, and fluence on embrittlement mechanisms of RPV material. The microstructural and microchemical results will be contextualized using hardening and segregation models and compared to mechanical testing data produced by WEC through its routine surveillance program and prior collaborations with EPRI. The direct comparison of microstructural and microchemical evolution via thermal aging and thermal aged plus irradiation materials will provide context to the embrittlement and hardening observed in mechanical tests, and the data generated will improve upon existing structure-property correlation models.

추가 정보

필드	값
Award Announced Date	2024-09-23T12:14:30.427
Awarded Institution	Westinghouse Electric Company
Facility Tech Lead	Catou Cmar, Yaqiao Wu
Irradiation Facility
PI	Caleb Clement
PI Email	[email protected]
Project Type	RTE
RTE Number	None