[3E09-12] Corrosion Potential, Zinc Injection

[3E12] Applicability of the U.S. zinc injection management goal on dose rate suppression to Japanese BWR plants

*Gaku Yamazaki¹, Kazutoshi Fujiwara¹ (1. CRIEPI)

Keywords:Zinc injection, Cobalt 60, Dose rate, Water chemistry, BWR

For Japanese BWR plants that inject zinc into the reactor feedwater, the effect of a ⁶⁰Co/Zn concentration ratio (a value of soluble ⁶⁰Co activity concentration in the reactor water divided by soluble Zn concentration in the reactor water) on radiation dose rates has been investigated. No correlation was observed between the ⁶⁰Co/Zn concentration ratio and Primary Loop Recirculation (PLR) piping radiation dose rates. Further, even if the ⁶⁰Co/Zn concentration ratio deviates from the U.S. zinc management goal on dose rate suppression, PLR radiation dose rates can be lower.