Izvestia Vysshikh Uchebnykh Zawedeniy. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Bulk electrolysis of cooling system water of production plants and NPP reactors and its impact on safety

6/21/2017 2017 - #02 Global safety, reliability and diagnostics of nuclear power installations

Kulakov A.V. Rantsev-Kartinov V.A. Mel’nikov V.P. Papovyants A.K.

DOI: https://doi.org/10.26583/npe.2017.2.01

UDC: 622.276:658.58;622.279:658.5

The paper presents a new theoretical model in the mechanism of NPP reactor cooling system pipelines’ corrosion damage based on taking account of the formation of polarized surface layer of water at its interface with a solid body.

As aqueous suspension is generated in the circulation loop containing solid-state nanoparticles of the structural material, which peel off as a result of this material «aging» and when exposed to neutron flux, favorable conditions are provided for implementation of bulk water electrolysis with the formation of «explosive mixture» nanobubbles (hydrogen, oxygen). Due to microscopic accumulation of this mixture in the areas of local near-wall laminar water layer disturbance, microexplosions of the «explosive mixture» occur, which intensify corrosion. Under close consideration of the physico-chemical process at the interface, the water molecules are represented as a «spring pendulum», and their intercollision results in vibrational excitation of hydrogen ions (HI) relative to oxygen ions (OI), that differ greatly in the frequencies, specified by the differences in the mass of these ions.

When solving the OI motion equation in the oscillating field of vibrating HI, it was found that a potential field emerged, that prevented the entry of the «heavy» component (OI) to the oscillation center of the «light» component (HI). Oxygen with its high electron affinity forms the electrons’ surface density, providing the field strength equal to ~ 2.6 MV/cm, which induces water electrolysis on each nanoparticle with the production of gas components (H2, O2). The presence of hydrogen and hydrogen saturation of the structural material with increased alloying elements grains intensifies the process of material peeling with the formation of nanoparticles.

The safety measures should involve the need of diagnostics of the pipes and the presence of «nanopowders» in the water for timely replacement of pipes with the new ones, which is of vital importance for long operational life reactors.

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NPP safety reactor cooling system water molecule oxygen ions hydrogen water electrolysis corrosion resistance stainless steel detonation waves