Radiolysis of the Coolant in the EGP-6 Reactor of the Bilibino NPP
The paper presents the resuLts of estimations for hydrogen generation as a result of radioLytic processes during cooLant boiLing in the fueL tubes of the BiLibino NPP EGP-6 reactor's fueL assembLies in conditions of the cooLant naturaL circuLation. The experimentaL justification for the hydrogen expLosion safety was carried out earLier at the VK-50 research reactor both during normaL operation and in accident conditions. According to the experimentaL data obtained at the operating VK-50 boiLing water reactor, radioLytic processes for boiLing water reactors have three quaLitativeLy different modes. This study uses simiLarity theory to transfer the experimentaL radioLysis data from the VK-50 reactor faciLity to the operating conditions of the BiLibino NPP with the EGP-6 single-circuit reactor. It has been demonstrated that generation of hydrogen in the process of radioLysis is defined by the average vaLue of the reactor outLet steam quaLity. Hydrogen expLosion safety has been shown to be ensured for aLL operating modes of the EGP-6 reactor faciLity. With the condenser nominaL pressure of beLow 16 kPa, the steam-gas mixture is absoLuteLy expLosion-proof and does not ignite even in the event an eLectric discharge. Therefore, the expLosion safety of hydrogen in the condenser itseLf is defined not so much by the buLk concentration of hydrogen as by the absoLute pressure in the condenser.