The accuracy of calculated dependencies for determination of passive catalytic hydrogen recombiners RVK-3 and RVK-4 capacity

The accuracy of calculated dependencies for determination of passive catalytic hydrogen recombiners RVK-3 and RVK-4 capacity

The fourth physical safety barrier of the NPP-2006 unit is the sealed containment. Passive catalytic hydrogen recombiners implement its protection and belong to localizing safety systems. Recombiners of the RVK-3 and RVK-4 brands are installed at the first and second units of the Belarusian NPP. The capacity of the devices depends on external parameters, the most important of which are the hydrogen concentration, pressure and temperature of the atmosphere in the localization zone. The specifications for the RVK recommend calculated dependencies for determining the capacity of the recombiners, no information on the accuracy is provided. The dependencies are established by processing the experimental data obtained at the facility for testing.
To determine the accuracy, the data from calculations by dependencies and modeling of physical and chemical processes in the device are compared. The discrepancy in data is confirmed to be no more than 13 % under normal conditions and under accident conditions, when the pressure and temperature of the atmosphere in the localization zone are proportionally related. With independent variation of these parameters, the accuracy of the match worsens. The reason is determined to be the method of mounting the recombiner on the facility for testing, which affects the value of the measured capacity due to a change in draft when a temperature difference appears in the facility room and at the entrance to the recombiner.

► Keywords: NPP-2006, localizing safety systems, passive catalytic hydrogen recombiner, capacity, calculations, accuracy.

Article language: Russian. Pp. 81–89. [in Russian]. DOI: 10.26277/SECNRS.2025.117.3.006.