The development of thermal and mechanical cutting technology for the dismantlement of the internal core of Fukushima Daiichi NPS

The cutting technologies for removing the fuel debris and the internal core structure in Fukushima Daiichi Nuclear Power Plant are needed in consideration of the situation in the core and so on. On the other hand, Japan Atomic Energy Agency (JAEA), which has been carrying out the decommissioning of the nuclear facilities ending the R&D, has several technologies and knowledge to dismantle the nuclear facilities. In particular, the cutting technologies of the plasma arc, the laser, and the abrasive water jet (AWJ) - which are used for dismantling the reactor of N.P.S. (FUGEN), a heavy water-moderated, light water cooled, pressure-tube-type reactor - and the plasma jet for dismantling the nuclear fuel facilities have been developed. Therefore, based on the above, JAEA has carried out the cutting test for investigating the applicability of those cutting technologies to propose the method for removing the fuel debris and the internal core structure to the national project. This paper outlines the test results of the plasma arc and the AWJ cutting technologies, and the future plan of the test of those technologies and the plasma jet cutting technology.