Used Fuel Disposition Campaign: Embrittlement and DBTT of High-Burnup PWR Fuel Cladding Alloys

Technical Report · Mon Sep 30 04:00:00 EDT 2013

DOI:https://doi.org/10.2172/1096165· OSTI ID:1096165

Billone, M. C. ^[1]; Burtseva, T. A. ^[1]; Han, Z. ^[1]; Liu, Y. Y. ^[1]

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1. Argonne National Laboratory (ANL), Argonne, IL (United States)

Structural analyses of high-burnup (HBU) fuel require cladding mechanical properties and failure limits to assess fuel behavior during long-term dry-cask storage and transportation. Pre-storage drying-transfer operations and early stage storage subject cladding to higher temperatures and pressure-induced tensile hoop stresses relative to in-reactor operation and pool storage. Under these conditions, radial hydrides may precipitate during slow cooling and provide an additional embrittlement mechanism as the cladding temperature decreases below the ductile-to-brittle transition temperature (DBTT). On the basis of previous test results, susceptibility to radial-hydride precipitation depends on cladding material and microstructure, hydrogen content (CH), and pre-drying hydride distribution, as well as peak hoop stresses and temperatures during drying operations and storage. Susceptibility to embrittlement depends on the extent of radial-hydride precipitation, the number density of circumferential hydrides, and the thickness of the outer-surface hydride rim. The goal of the testing program is to determine drying-storage conditions for which the cladding remains ductile at ambient temperature, in other words, with the DBTT ≤20°C.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1096165
• Report Number(s): ANL--13/16; FCRD-UFD-2013-000401
• Country of Publication: United States
• Language: ENGLISH