Modelling of Heat Flow in Fukushima Wasteforms
Researcher: Dr. Michael Rushton
One of the main problems facing the remediation of the Fukushima Daiichi site is the treatment of the effluent cooling water from Units 1 – 3. Large volumes of water were injected into the reactor cores and the spent fuel pools which was subsequently treated in a series of sophisticated systems. These have left large quantities of highly contaminated adsorbents. These are termed High Dose Spent Adsorbents (HDSAs) and are currently stored on-site while a suitable method of long term disposal is developed. To this end, a low temperature processing route is being developed at Imperial College by which the HDSAs may be immobilised in a low melting point glass.
To support this activity, the current project aims to develop a model across finite element and microstructural length scales to help underpin the assessment of wasteform options, including the feasibility of using the decay heat to drive self vitrification. A radiolytic heat generation tool is being developed to calculate the temperature distributions in HDSA bearing wasteforms and to provide predictions for possible wasteform thermal/stress damage which will aid in the optimization of processing conditions. The project is in collaboration with the Immobilisation Science Laboratory at Sheffield University and with partners in Japan at the universities of Kyushu and Tohoku and at Hitachi-GE Nuclear Energy and is part of a recently-awarded EPSRC grant “Advanced Waste Management Strategies for High Dose Spent Absorbents”.