Lab Scale Experimental Studies For Modeling Possible Zinc Removal Efforts in LOCA Situations


Lab Scale Experimental Studies For Modeling Possible Zinc Removal Efforts in LOCA Situations

Harm, U.; Kryk, H.; Hampel, U.; Seeliger, A.; Alt, S.; Kästner, W.

During the sump recirculation phase after a postulated LOCA in PWR, the coolant in the reactor sump is recirculated to the reactor core by residual-heat removal pumps as part of the emergency core cooling system. Long-term contact of the boric acid containing coolant with hot-dip galvanized containment internals (e.g. grating treads) is assumed to cause corrosion of corresponding materials with the consequence of rising concentrations of dissolved zinc in coolant. As it was shown in previous research projects, subsequently formed zinc borates may precipitate within hot spots of the reactor core in the late phase of the LOCA causing thermal hydraulic effects. In PWR, ion exchange columns are installed as part of the coolant cleaning system, having potential to be used to remove dissolved zinc ions.
For evaluation of such approach, lab scale investigations with ion exchange resins to remove dissolved zinc ions from the coolant are carried out under typical conditions of the post LOCA phase (sump recirculation). The usability of the coolant cleaning system for this purpose was proven successfully. The further aim is to model the zinc removal process by the coolant cleaning system by means of data of the ion exchange capacity of different ion exchange resins and kinetic data for the zinc removal under LOCA conditions.

The investigations are carried out as joint research project of Helmholtz-Zentrum Dresden - Rossendorf, TU Dresden, and Hochschule Zittau/Goerlitz. The goal is to build up a database for extensions of thermo-hydraulic simulation tools by the project partner GRS.

Keywords: PWR; LOCA; coolant cleaning system; zinc; modeling

  • Contribution to proceedings
    The 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19), 06.-11.03.2022, Brussels, Belgium
    Proceedings of NURETH-19
  • Lecture (Conference) (Online presentation)
    The 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19), 06.-11.03.2022, Brussels, Belgium

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Publ.-Id: 34289