Influence of mixed core in the radionuclides releases and hydrogen production for VVER-1000

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F86652052%3A_____%2F24%3AN0000007" target="_blank" >RIV/86652052:_____/24:N0000007 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0029549323007070" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0029549323007070</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.nucengdes.2023.112858" target="_blank" >10.1016/j.nucengdes.2023.112858</a>

Result language

angličtina

Original language name

Influence of mixed core in the radionuclides releases and hydrogen production for VVER-1000

Original language description

This paper aims to compare the behaviour of VVER-1000 Nuclear Power Plants (NPPs) under DEC-A/B conditions, contemplating different fuel assemblies considered in mixed cores. The main characteristics of both fuel assemblies are described in this paper, with a focus on highlighting the key differences in mass composition. There are three models under consideration: Model A, Model B and Model C. Model A consists of a core entirely filled with fuel assemblies equipped with grids made of Zr-1 %Nb, referred to as “Type A” through the paper. Model B comprises a core filled with fuel assemblies that have grids made of Alloy 718 (aka Inconel), referred to “Type B”. Lastly, Model C features a mixed core of 151 fuel assemblies with Zr-1 %Nb grids and 12 fuel assemblies with Inconel grids. Initially, the primary distinctions between these fuel assemblies types are the number and composition of their spacer grids. Type A fuel assemblies have 13 grids made of Zirconium, while Type B fuel assemblies have 16 grids made of Inconel. It was initially anticipated that the reduction in the mass of zirconium available for oxidation would lead to lower hydrogen production in Model B compared to Model A. However, it was observed that the Inconel grids in Type B fuel assemblies provide enhanced structural support, prolonging the oxidation reaction and yielding more hydrogen during the initial oxidation phase compared to Type A fuel assemblies. Moving on to the mixed core configuration (Model C), the Inconel grids in Type B fuel assembly also offer superior structural support. This results in an extended oxidation process. The Type A fuel assemblies having a significant zirconium mass, oxidation in intensified, causing a rise in temperature due the exothermic reaction and leading to the producing of a greater amount of hydrogen compared to the other two models. This pattern is also observed in radionuclide releases. In conclusion, this study sheds light on the behaviour of VVER-1000 NPPs under DEC-A/B conditions, considering different fuel assembly types and mixed core configurations. The results indicate that the choice of grid materials significantly influences the oxidation process and hydrogen production, with Inconel grids exhibiting extended oxidation and hydrogen generation behaviour in both pure and mixed core setups.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

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

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

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

Name of the periodical

Nuclear Engineering and Design

ISSN

0029-5493

e-ISSN

1872-759X

Volume of the periodical

417

Issue of the periodical within the volume

February

Country of publishing house

CH - SWITZERLAND

Number of pages

16

Pages from-to

112858

UT code for WoS article

001147840900001

EID of the result in the Scopus database

2-s2.0-85180536167