Understanding the Zinc Behaviour in PWR Primary Coolant: A Comparison between French and German Experience

摘要

Since the 1980s the zinc injection has been applied in boiling water reactors (BWR) with the objective to reduce the dose rates and thereby to contribute to increase the radiation safety level of units. The positive BWR feedback [1] corroborating the theoretical hypothesis and the experimental laboratory results [2] has been the initial point to begin injecting zinc in pressurised water reactors (PWR). The first zinc was injected in a the PWR reactor of Farley 2, cycle 10, in June 1994. Fourteen years later, Farley 2 goes on with the zinc injection due to the progressive dose reduction and the positive effect on PWSCC. Biblis B started zinc injection in September 1996 and nowadays Biblis B [3 and 4] is the plant with the longest zinc exposure. The feedback of these first units have been widely analysed taking into account all the aspects: radiation fields, fuel and corrosion material.