Experimental verification of phase diagram calculations of zr-based alloys after high-temperature oxidation

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F26722445%3A_____%2F20%3AN0000046" target="_blank" >RIV/26722445:_____/20:N0000046 - isvavai.cz</a>

Result on the web

<a href="https://www.scientific.net/DDF.405.351" target="_blank" >https://www.scientific.net/DDF.405.351</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4028/www.scientific.net/DDF.405.351" target="_blank" >10.4028/www.scientific.net/DDF.405.351</a>

Result language

angličtina

Original language name

Experimental verification of phase diagram calculations of zr-based alloys after high-temperature oxidation

Original language description

Zirconium-based alloys are commonly used as a material for nuclear fuel claddings in the light water reactors. The cladding material must function to fix a huge number of pellets, while conducting heat into the coolant that flows turbulently around the fuel rods. Cladding tubes can contain gaseous fission products that escape the fuel. Thus, by functioning as a sealed unit, it prevents a contamination of the coolant water with high-radioactive fission products. The integrity of claddings is always a critical issue during reactor operation and wet or dry storage and transport of the spent fuel rods. Moreover, the role gains importance at Loss of Coolant Accidents (LOCA). After Fukushima accident, cladding materials are widely studied with the purpose to reduce the high-temperature oxidation rate and enhance accident tolerance. In our contribution, we introduce the studies on Zr-1Nb (E110) cladding tubes after high-temperature steam oxidation at 1350 °C. During the testing of claddings, microscopy analytical methods play an important role in experimental verification of pseudo-binary phase diagram Zr1Nb-O, i. e. particularly in oxygen content determination at phase transitions. Wave Dispersive Spectroscopy (WDS) with complementary nano-indentation method were used to characterize the Zr1Nb microstructure formed after LOCA. It includes the regions from an oxide and oxygen-stabilized α-Zr(O) to the acicular prior β-Zr phase. The decrease of hardness and Young's modulus corresponds with oxygen content measured in line-profiles by WDS. The oxygen level at transition points was partly determined from Fe, Nb β-stabilizers and significant change in mechanical properties in fine-grained prior β-Zr. The slight fluctuation of oxygen values in adjacent grains can be caused by preferential oxidation through the favorably oriented α-Zr(O) grains studied by WDS+EBSD. As well, the non-uniform oxygen-rich α-Zr(O) phase adjacent to the oxide was characterized by EBSD & WDS. Increasing hydrogen content in specimens, 10, 700 and 1000 ppm H, caused increasing solubility of oxygen in prior β-Zr phase upon high-temperature and the cladding material hardening.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20305 - Nuclear related engineering; (nuclear physics to be 1.3);

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

Defect and Diffusion Forum, vol. 405. 17th International Symposium on Metallography, Fractography and Materials Science, 2019; Nový Smokovec; Slovakia; 24 April 2019 through 26 April 2019; Code 252579

ISBN

978-303573612-0

ISSN

1012-0386

e-ISSN

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Number of pages

6

Pages from-to

351-356

Publisher name

Trans Tech Publications Ltd.

Place of publication

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Event location

Nový Smokovec, Slovakia

Event date

Apr 26, 2019

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

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