SFP: Spent Fuel Pool activities

The SFP activities are connected with several international programs:
  • SFP PIRT - OECD/NEA Project
    A Priority Identification and Ranking Table has to be defined by international experts in the severe accident area for spent fuel pool accident boundary conditions. Identification of needs in experimental research and code modeling for long term station blackout scenarios in spent fuel pools.
  • Air-SFP - NUGENIA+ Project
    Experimental and theoretical investigations in the spent fuel pool severe accident area. The SACRE group is active in the coordination of a benchmark programme in the frame of the European Air-SFP project.
  • IAEA - Collecting and interpreting of Fukushima SFP data
    IAEA organised an international expert group to collect, analyse and interpret the spent fuel pool measurements connected with the Fukushima Dai-ichi nuclear accident. The SACRE group is participating in the expert group.
  • Spent fuel behaviour under severe accident conditions
    The severe accident code MELCOR was used to investigate the spent fuel in spent fuel pools under different severe accident conditions. The international Sandia Fuel Project delivered data for the code validation under spent fuel pool conditions and these knowledge was used to calculate and interpret the response of spent fuel elements under different loss-of-cooling conditions. The results of this work was presented at different international meetings.
  • Application of PSI air oxidation model on SFP accidents
    An air oxidation model developed at PSI was used to get best estimate results during a postulated spent fuel pool accident. Additional phenomena were found in seperate effect tests which leads to an enhancement of the oxidation velocity because of oxid-crust breakaway. Theese phenomena only occured during a low temperature oxidation of the zircaloy cladding of fuel rods. Under steam oxidation the oxide layer flakes off because of mechanical stress and under air oxidation the oxide crust becomes porous because of the zirconium nitriding under oxygen starved conditions. Both phenomena results in a stronger oxidation of the cladding material even under lower temperatures.