[2F07-11] Fuel Cladding and Dose Rate Reduction

[2F08] Development of Dose Rate Reduction Technology for Improving LWR Utilization

(9)Results of crud deposition/dissolution test on fuel cladding for normal water chemistry and hydrogen water chemistry

*Hideyuki Hosokawa¹, Masahiko Tachibana¹, Kazushige Ishida¹, Ryousuke Shimizu², Makoto Nagase², Hiromitsu Inagaki³ (1. Hitachi, 2. HGNE, 3. Chubu Electric Power)

Keywords:Fuel crud, Zinc injection, Noble Metal Chemical Addition, Cobalt 60, Ferrite

In order to improve the accuracy of the corrosion product behavior evaluation model for boiling water reactors, the effect of Zn injection on the deposition and dissolution behavior of Co to the fuel cladding tube was investigated. The water chemistry conditions used in the test were normal water chemistry (NWC), hydrogen injection water chemistry (HWC) and noble metal chemical addition (NMCA) of the Fe/Ni ratio control plant and the ultra-low iron and high Ni plant. Fe, Co, Ni, Cr, and Zn simulating impurities in the reactor water were added to the high-temperature water under these water chemistry conditions at a predetermined concentration. The fuel cladding tube attached to the heater pin was dipped in this high-temperature water and kept under boiling conditions for 250 hours. After the immersion, the amount of oxide depositing to the surface of the cladding tube was quantified to determine the deposition density.