Applicability examination and evaluation of reactor dismantlement technology in the Fugen; Examination of double tubes cutting by abrasive water jet

Nakamura, Yasuyuki ; Kikuchi, Koichi; Morishita, Yoshitsugu ; Usui, Tatsuo*; Ogane, Daisuke*

It is necessary to clarify the dismantlement method of 224 double tubes arranging both pressure and calandria tubes concentrically in the reactor as a peculiar problem of Fugen, in the case of phased dismantlement of the reactor. The machine type cutting is desirable, considering the influence on the atmospheres because the double tubes consist of the zirconium alloy and zircalloy material radio activated highly. Besides, Cutting method has long standoff to cut the double tubes at a time for to be short the term of dismantlement. is desirable. Therefore, it was examined to confirm the applicability to the double tubes cutting by abrasive water jet (hereinafter referred to as AWJ) as the machine type cutting method that can take the standoff comparatively longer. As a result, We confirmed for possibility of cutting the double tubes at a time from inside and outside tube, and cutting thick slab by abrasive water jet. Besides, We confirmed for relationship of abrasive supply and cutting velocity, properties of secondly waste.