Effects of dissolved hydrogen on fuel crud deposition and subcooled nucleate boiling in PWR primary water at 328 °C

Abstract

This work aimed to evaluate the effects of dissolved hydrogen (DH) on the crud deposition and subcooled nucleate boiling (SNB) behavior of fuel cladding tubes in a simulated primary coolant of a pressurized water reactor at 328 °C and 13 MPa. The SNB characteristic occurring on the fuel cladding tubes was periodically observed using an acoustic emission method during the deposition tests. There was little difference in the energy distribution and hit number of the boiling acoustic signals at three difference DH concentrations ranging from 0 to 70 cm3/kg H2O. The difference in the amount of crud particles on the cladding tube at each DH condition was also minor. The effect of DH on crud deposition is discussed from the viewpoint of the SNB behavior, the solubility of Ni and Fe, and the change in the crud morphology.