[3H06-09] Development of Test Facility and Technology

[3H09] Development of fuel degradation and relocation test equipment under severe accident

(2)Degradation behavior of test bundle in steam environments at high temperature

*Kinya Nakamura¹, Takanari Ogata¹, Shigeru Kurematsu², Toshiya Kido², Masaki Kurata³ (1.CRIEPI, 2.NDC, 3.JAEA)

Keywords:fuel rod, control rod, fuel degradation, severe accident, Zircaloy oxydation

In order to clarify process of degradation and relocation behavior of fuel and control rod during early phase of severe accidents in LWR, test fuel bundles were heated in steam environment above 1800 ℃ at a different steam rate and heating rate. The selected test conditions and applied measurement techniques made possible the observation of some specific phenomena, such as the Zr-O melt formation, relocation and blockage, the protection of the oxide scale from melt relocation, and the reaction of stainless steel-clad FeB compound with Zircaloy-4 in steam environments at high temperature.