NSUF 25-5377: Individual and Synergistic Effects of Solutes on Precipitate Phase Selection in Neutron Irradiated RPV Model Alloys
The structural integrity of reactor pressure vessels (RPVs) is critical to the safe and extended operation of light-water reactors (LWRs). RPVs, composed of low-alloy ferritic steels, are vulnerable to neutron irradiation-induced embrittlement, primarily due to the formation of nanoscale precipitates containing manganese (Mn), nickel (Ni), silicon (Si), phosphorous (P), and copper (Cu); thus they are called MNSPs. A high density and volume fraction of MNSPs leads to hardening and upward shifts in the brittle-to-ductile transition temperature (ΔT), which must be accurately predicted to extend the life of LWRs. This proposal will characterize the individual and synergistic effects of key solutes (Mn, Ni, Si, Cu) on the MNSPs. The proposed study will use atom probe tomography (APT) to quantify the MNSPs characteristics, including their number density, size, volume fraction, composition, and morphology. The specific alloys to be studied are split melt model ferritic steels with systematic variations in Cu, Ni, and Si at fixed levels of Mn and P. The simple annealed ferritic microstructures are intended to increase radiation enhanced diffusion (RED) rates, thus accelerating MNSP evolutions, compared to those that occur in complex steels, without changing their basic character. State-of-the-art algorithms will be used to analyze the APT data, providing new insights on MNSPs at high fluence conditions. The proposed work will be completed in nine months from the time of the award.
Additional Info
| Field | Value |
|---|---|
| Awarded Institution | Idaho National Laboratory |
| DOI | 10.46936/NSUF/60015370 |
| Embargo End Date | 2027-09-03 |
| Facility Tech Lead | Mukesh Bachhav, Peter Hosemann |
| NSUF Call | FY 2025 RTE 2nd Call |
| PI | Anshul Kamboj |
| PIE Facilities | Microscopy and Characterization Suite |
| Prep Facilities | Nuclear Materials Laboratory |
| Project Member | Dr. Takuya Yamamoto, Professional Research - University of California-Santa Barbara (https://orcid.org/0000-0002-6480-5225) |
| Project Member | Professor G. Robert Odette - University of California-Santa Barbara (https://orcid.org/0000-0002-7700-9391) |
| Project Member | Dr. Anshul Kamboj, Distinguished Postdoc - Idaho National Laboratory (https://orcid.org/0009-0001-2576-5478) |
| Project Type | RTE |
| Sample Identifiers | 11196,11197,11200,11201,11203,11202,11198,11199,11192,11193,11184,11204,11185,11190,11191,11186,11187,11194,11195,11189,11188 |