Izvestiya vuzov. Yadernaya Energetika

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

An experimental study into the solubility of boric acid in steam during boiling in conditions of atmospheric pressure

3/25/2019 2019 - #01 Nuclear power plants

Pityk A.V. Morozov A.V. Shlepkin A.S. Sahipgareev A.R.

DOI: https://doi.org/10.26583/npe.2019.1.03

UDC: 621.039.58:532.77

The paper presents the results of experimental studies into the solubility of boric acid in steam in conditions of atmospheric pressure in a concentration range of 16 to 240 g/kg of H2O. The problem of accumulation and crystallization of boric acid in accidents with disruption of the main circulation pipeline and the operation of passive safety systems (hydraulic accumulators of the first, second and third stages, as well as the passive heat removal system) is formulated.

An overview of the available literature data on the solubility of boric acid in steam depending on its initial concentration in solution is provided. It has been found that the available results do not cover the whole range of parameters (temperature, pressure, concentration of acid) typical of a potential emergency at an NPP with the VVER reactor. The experimental facility and the investigation procedures are described. The results of processing data obtained in the course of the experiments confirm the existing literature evidence that the change in the concentration of boric acid is described by a linear law. The application scope of the known dependence that makes it possible to calculate the solubility of H3BO3 in steam is extended to the boric acid concentration in solution of 240 g/kg which is close to the solubility of H3BO3 in water in conditions of atmospheric pressure.

The data obtained as the result of the experiments can be used for the computational simulation of emergency processes in the VVER reactor plant during operation of integrated passive safety systems such as the passive core flooding system, the passive steam generator heat removal system, and the system of stage III accumulators (HA-3 system).

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boric acid solubility steam accumulation VVER emergency mode

Link for citing the article: Pityk A.V., Morozov A.V., Shlepkin A.S., Sahipgareev A.R. An experimental study into the solubility of boric acid in steam during boiling in conditions of atmospheric pressure. Izvestiya vuzov. Yadernaya Energetika. 2019, no. 1, pp. 30-40; DOI: https://doi.org/10.26583/npe.2019.1.03 (in Russian).

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