Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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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

  • Bottomley P.D.W. (European Commission, JRC, Institute for Transuranium Elements (ITU)) ;
  • Gregoire A.C. (Institut de radioprotection et de surete nucleaire (IRSN)) ;
  • Carbol P. (European Commission, JRC, Institute for Transuranium Elements (ITU)) ;
  • Glatz J.P. (European Commission, JRC, Institute for Transuranium Elements (ITU)) ;
  • Knoche D. (European Commission, JRC, Institute for Transuranium Elements (ITU)) ;
  • Papaioannou D. (European Commission, JRC, Institute for Transuranium Elements (ITU)) ;
  • Solatie D. (European Commission, JRC, Institute for Transuranium Elements (ITU)) ;
  • Van Winckel S. (European Commission, JRC, Institute for Transuranium Elements (ITU)) ;
  • Gregoire G. (Institut de radioprotection et de surete nucleaire (IRSN)) ;
  • Jacquemain D. (Institut de radioprotection et de surete nucleaire (IRSN))
  • Published : 2006.02.01
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Abstract

The $Ph{\acute{e}}bus$ 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, I) were nearly complete and comparable to those obtained during $Ph{\acute{e}}bus$ tests performed with a fuel bundle geometry (FPT1, 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 FPT1. Release of Ru was comparable to that observed during FPT1 and FPT2. As in other $Ph{\acute{e}}bus$ tests, the Ru distribution 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. The revaporisation testing under different atmospheres (pure steam, $H_2/N_2$ and steam /$H_2$) and up to $1000^{\circ}C$ was performed on samples from the first upper plenum. These showed high releases of Cs for all the atmospheres tested. However, different kinetics of revaporisation were observed depending on the gas composition and temperature. Besides Cs, significant revaporisations of other elements were observed: e.g. Ag under reducing conditions, Cd and Sn in steam-containing atmospheres. Revaporisation of small amounts of fuel was also observed in pure steam atmosphere.

Keywords

References

  1. B. Clement, N. Hanniet-Girault et al., The First International PHEBUS Fission Product Program for Investigation of Phenomena of Severe Water Reactor Accidents, Nucl. Eng. Des., 226, 5-82 (2003) https://doi.org/10.1016/S0029-5493(03)00157-2
  2. P. Von Der Hardt, M. Schwarz, Proc. TOPSAFE '98, 15-17 April, Valencia, Spain (1998)
  3. J. Abrefah, A. De Aguiar Braid et al., High temperature oxidation of UO2 in steam ？hydrogen mixture, J. Nucl. Mater., 208, 98 (1994) https://doi.org/10.1016/0022-3115(94)90201-1
  4. H. Manenc, P.K. Mason et al., The modelling of fuel volatilisation in accident conditions, J. of. Nucl. Mater., 294, 64-68 (2001) https://doi.org/10.1016/S0022-3115(01)00459-7
  5. N. Hanniet, G Repetto, FPT0 Final Report, Phebus PHPF Report, IP/99/423 (1999)
  6. P.D.W. Bottomley, A.D. Stalios, et al., Examination of melted fuel rods and released core material from the first Phebus FP reactor accident experiment, J. of Nucl. Mater., 278, 136-148 (2000) https://doi.org/10.1016/S0022-3115(99)00257-3
  7. D. Jacquemain, S. Bourdon, et al., FPT1 Final Report, Phebus PHPF report, IP/00/479 (2000)
  8. P. Chapelot, A.C. Gregoire et al., FPT4 Final Report, Phebus PHPF report, IP/04/553 (2004)
  9. Z. Hozer et al., CODEX and RUSET air oxidation experiments, Proc. of the 5th Technical Seminar Meeting, 24-26 June, Aix en Provence, France (2003)
  10. P. D. W. Bottomley, T. Gouder et al., Examination of the Plenum & Deposition Coupon of the FPT4 Test by Scanning Electron Microscopy and Photoemission Spectroscopy, Microchim. Acta, 145, 3-12 (2004) https://doi.org/10.1007/s00604-003-0119-9
  11. G. Ritter, M. Zabiego, FPT2 preliminary report, Phebus PHPF Report IP/02/514 (2002)
  12. B. Andre, G. Ducros et al., Nucl. Technol. 114, 23 (1996) https://doi.org/10.13182/NT96-A35221
  13. G. Ducros, P.P. Malgouyres et al., Fission products release and fuel behaviour under severe accidental conditions : synthesis of the VERCORS 1-6 experimental program, Proc. of the International Topic Meeting on LWR Fuel Performance, 1100, Park City, Utah (2000)
  14. R. Dubourg, P. Taylor, A qualitative comparison of barium behaviour in the Phebus FPT0 test and analytical test, J. of Nucl. Mater., 294, 32 (2001) https://doi.org/10.1016/S0022-3115(01)00471-8
  15. A.B. Anderson, A. Auvinen, et al., Revaporisation Tests on Samples from Phebus Fission Products: Final report. Report produced for the Commission of the EC, AEAT/R/NS/0124- issue2 (2000)
  16. A. Auvinen, J.K.Jokiniemi, et al., A test facility to measure fission product revaporisation in severe reactor accident conditions, J. Aerosol Sci., 28,-1, S713-S714 (1997) https://doi.org/10.1016/S0021-8502(97)85355-4