Japan Atomic Energy Agency (JAEA) has been developing a fuel disassembly system with reliability for FBR fuel reprocessing. Laser technology has a high cutting performance and stable operation and was apply to disassembly system in our previous studies. However, it was hard to produce the impeccable disassembly system, because it was occurred the problems, such as pin damage and dross adhesion between a wrapper tube and fuel pins.After that, the advance of the laser cutting technology has recently attracted a great deal of attention from industry. In particular, single mode fiber laser (SMFL), which has a small beam size and high beam quality, has been reported as a new oscillator. Then, it was presumed that SMFL might provide a possible to prevent the original matters in the disassembly.The main purpose of this study is to reevaluate an applicability of laser for the wrapper tube cutting by the basic cutting tests. Concretely, the authors researched whether every cutting condition such as SMFL etc, has the effects on the original matters or not. This experimental results show that the kerf width of SMFL is still narrower than that of multi mode fiber laser (MMFL). It is an important phenomenon to decrease the amount of dross. Therefore, the authors confirmed that SMFL is suitable for prevention of the original matters and the new feasibility method of wrapper tube cutting.© 2012 ASME