An investigation of the applicability of existing core catcher proposals designed to mitigate the effects of a hypothetical reactor core meltdown on a presently envisioned offshore, barge-mounted nuclear power plant design is undertaken. In addition, a new core catcher concept employing a graphite pebble bed is described and evaluated. To establish the envelope of design parameter constraints necessary to both devise and evaluate core catcher concepts, a detailed description of the one offshore conceptual design which has progressed far enough to permit specific analysis is presented. Potential plant system interactions with a hypothetical core catcher are identified, and weight, moment, and volume limitations are described. An analytical evaluation of the meltdown sequence, from primary system blowdown to reactor vessel meltthrough, is carried out to develop the quantitative aspects of the accident necessary to assess the viability of the proposed core catcher designs. It is concluded that none of the previously existing core catcher designs is completely satisfactory for barge use, primarily due to the excessive weight/volume required, metallurgical and thermophysical uncertainties, cost and complexity, and the potential for steam explosions. The graphite pebble bed is shown to circumvent these problems, freezing the debris almost immediately upon its entry into the bed, and providing a grace period of several hours to initiate active cooling, which can be readily effected using a water spray and flood system.

  • Corporate Authors:

    Massachusetts Institute of Technology

    Department of Ocean Engineering, 77 Massachusetts Avenue
    Cambridge, MA  United States  02139
  • Authors:
    • Bowman, F L
  • Publication Date: 1973-5

Subject/Index Terms

Filing Info

  • Accession Number: 00048363
  • Record Type: Publication
  • Source Agency: Massachusetts Institute of Technology
  • Report/Paper Numbers: MS Thesis
  • Files: TRIS
  • Created Date: Nov 14 1973 12:00AM