Evolution of the nanostructure OF VVER-1000 RPV materials under neutron irradiation and post irradiation annealing

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2009.01.299· OSTI ID:949993

Miller, Michael K ^[1]; Chernobaeva, A. A. ^[2]; Shtrombakh, Ya. ^[2]; Erak, D. ^[2]; Zabusov, Oleg O. ^[2]; Russell, Kaye F ^[1]; Nanstad, Randy K ^[1]

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1. ORNL
2. Russian Research Center, Kurchatov Institute, Moscow, Russia

A high nickel VVER-1000 (15Kh2NMFAA) base metal (1.34 wt% Ni, 0.47% Mn, 0.29% Si and 0.05% Cu), and a high nickel (12Kh2N2MAA) weld metal (1.77 wt% Ni, 0.74% Mn, 0.26% Si and 0.07% Cu) have been characterized by atom probe tomography to determine the changes in the microstructure during neutron irradiation to high fluences. The base metal was studied in the unirradiated condition and after neutron irradiation to fluences between 2.4 and 14.9 x 10{sup 23} m{sup -2} (E > 0.5 MeV), and the weld metal was studied in the unirradiated condition and after neutron irradiation to fluences between 2.4 and 11.5 x 10{sup 23} m{sup -2} (E > 0.5 MeV). High number densities of 2-nm-diameter Ni-, Si- and Mn-enriched nanoclusters were found in the neutron irradiated base and weld metals. No significant copper enrichment was associated with these nanoclusters and no copper-enriched precipitates were observed. The number densities of these nanoclusters correlate with the shifts in the {Delta}T{sub 41 J} ductile-to-brittle transition temperature. These nanoclusters were present after a post irradiOffice of Science (US)C, but had dissolved into the matrix after 24 h at 450 C. Phosphorus, nickel, silicon and to a lesser extent manganese were found to be segregated to the dislocations.

• Research Organization: Oak Ridge National Laboratory (ORNL); Shared Research Equipment Collaborative Research Center
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 949993
• Journal Information: Journal of Nuclear Materials, Journal Name: Journal of Nuclear Materials Journal Issue: 3 Vol. 385; ISSN 0022-3115; ISSN JNUMAM
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNEALING
ATOMS
COPPER
DISLOCATIONS
IRRADIATION
MANGANESE
MICROSTRUCTURE
NANOSTRUCTURES
NEUTRONS
NICKEL
PHOSPHORUS
PROBES
SILICON
TOMOGRAPHY
TRANSITION TEMPERATURE