The Characterization of the CLADS-MADE-01 and -02 BWR control blade degradation test debris by Raman spectroscopy

Pshenichnikov, A. ; Nagae, Yuji ; Kurata, Masaki 

One of the promising methods of debris characterization - a Raman spectroscopy was utilized for investigation of simulated debris obtained after two control blade degradation tests CLADS-MADE-01 and CLADS-MADE-02. New results allowed to refine a mechanism of the BC degradation during the beginning phase of a severe accident. A partial transformation of BC granules into pure graphite promotes formation of particular phases in the debris based on the oxidative or reducing environment. This knowledge would provide new insights for understanding of the absorber blade degradation mechanism under specific accident conditions close to 1F Unit 2 and Unit 3 reactors.