Criticality safety of fuel debris, particularly MCCI(Molten-Core-Concrete-Interaction) products, is one of the major safety issues for decommissioning of Fukushima Daiichi Nuclear Power Station. Criticality or subcriticality condition of the fuel debris is still uncertain; its composition, location, neutron moderation, etc. are not yet confirmed. | Progress in Nuclear Energy 101 2017 321e328 Contents lists available at ScienceDirect Progress in Nuclear Energy journal homepage locate pnucene Study of experimental core configuration of the modified STACY for measurement of criticality characteristics of fuel debris Satoshi Gunji a Kotaro Tonoike a Kazuhiko Izawa b Hiroki Sono b a Japan Atomic Energy Agency Nuclear Safety Research Center Shirakata 2-4 Tokai-mura Ibaraki Japan b Japan Atomic Energy Agency Department of Fukushima Technology Shirakata 2-4 Tokai-mura Ibaraki Japan a r t i c l e i n f o a b s t r a c t Article history Criticality safety of fuel debris particularly MCCI Molten-Core-Concrete-Interaction products is one of Received 26 August 2016 the major safety issues for decommissioning of Fukushima Daiichi Nuclear Power Station. Criticality or Received in revised form subcriticality condition of the fuel debris is still uncertain its composition location neutron moderation 10 February 2017 etc. are not yet confirmed. The effectiveness of neutron poison in cooling water is also uncertain for use Accepted 1 March 2017 Available online 13 April 2017 as a criticality control of fuel debris. A database of computational models is being built by Japan Atomic Energy Agency JAEA covering a wide range of possible conditions of such composition neutron moderation etc. to facilitate assessing criticality characteristics once fuel debris samples are taken and Keywords Fuel debris their conditions are known. The computational models also include uncertainties which are to be clar- MCCI product ified by critical experiments. These experiments are planned and will be conducted by JAEA with the Modified STACY modified STACY STAtic experiment Critical facilitY and samples to simulate fuel debris compositions. Fukushima Daiichi nuclear power station Each of the samples will be cladded by a zircalloy tube whose outer shape is compatible with the fuel rod Critical experiment of STACY and loaded into an array
