Fission Product and Actinide Release from the Debris Bed Test PHEBUS FPT4 - Synthesis of the Post Test Analyses and of the Revaporisation Testing of the Plenum Samples

The Phebus FP project is an international reactor safety project. Its main objective is to study the release, transport and retention of fission products in a severe accident of a light water reactor (LWR). The FPT4 test was performed with a fuel debris bed geometry, to look at late phase core degradation and the releases of low volatile fission products and actinides. Post Test Analyses results indicate that releases of noble gases (Xe, Kr) and high-volatile fission products {Cs, Ī) were nearly complete and comparable to those obtained during Phėbus tests performed with a fuel bundle geometry (FPTI, FPT2). Volatile fission products such as Mo, Te, Rb, Sb were released significantly as in previous tests. Ba integral release was greater than that observed during FPTI. Release of Ru was comparable to that observed during FPTI andFPT2. As in other Phėbus tests, the Ru distiibution suggests Ru volatilization followed by fast redeposition in the fuelled section. The similar release fraction for all lanthanides and fuel elements suggests the released fuel particles deposited onto the plenum surfaces. A blockage by molten material induced a steam by-pass which may explain some of the low releases.

BOTTOMLEY Paul;  GREGOIRE A.C.;  CARBOL Paul;  GLATZ Jean-Paul;  KNOCHE Dietrich;  PAPAIOANNOU Dimitrios;  SOLATIE Dina;  VAN WINCKEL Stefaan;  GREGOIRE G.;  JACQUEMAIN D.; 

2006-06-06

Korean Nuclear Society (KNS)

JRC33604

https://publications.jrc.ec.europa.eu/repository/handle/JRC33604,