In nuclear fuel fabrication facilities, gloveboxes are typically dismantled manually. The integration of remotely controlled equipment, comprising a robot arm and a size reduction tool, can enhance work efficiency and mitigate radiation exposure risks in dismantling operations. The hydraulic cutter is regarded as a highly effective tool for reducing the size of steel frame structures, which are commonly composed of gloveboxes. However, when an object is severed by a hydraulic cutter fixed to a robot arm, the resultant reaction force may compromise the integrity of the robot arm or nearby structures. Consequently, in this study, we designed and manufactured a buffer device that can loosely hold the cutter to automatically align the object and absorb the reaction force. Furthermore, a visual support system was developed to assist the operator in performing remote dismantling operations. This system utilized a 3D viewer to project the robot arm, the buffer device, and the working environment. The functionality of the buffer device and 3D viewer was evaluated for the glovebox test bed. The experimental results satisfactorily confirmed the functionality of the buffer device to self-align the object and absorb sudden movements of the hydraulic cutter. Moreover, the 3D viewer provided the robot arm operator with an unobstructed perspective of the work environment, thereby confirming the efficacy of the visual support system in facilitating remote dismantling operations.

1. [1] K. Tesch, M. W. Collins, T. G. Karayiannis, M. A. Atherton, and P. Edwards, “Heat and mass transfer in air-fed pressurized suits,” Applied Thermal Engineering, Vol.29, No.7, pp. 1375-1382, 2009. https://doi.org/10.1016/j.applthermaleng.2008.03.045
2. [2] A. Kitamura, H. Hirano, M. Yoshida, and K. Takeuchi, “Experiences in dismantlement of gloveboxes for wet recovery and other use that are contaminated with nuclear fuel materials,” Japanese J. of Health Physics, Vol.58, No.2, pp. 76-90, 2023 (in Japanese). https://doi.org/10.5453/jhps.58.76
3. [3] L. Hao, J. Qi, R. Wang, Y. Yi, and J. Wu, “Protective performance test and safety risk evaluation of a powered air-purifying suit,” Biosafety and Health, Vol.1, No.2, pp. 91-97, 2019. https://doi.org/10.1016/j.bsheal.2019.08.002
4. [4] J. Wang et al., “Control strategy of master-slave manipulator based on force feedback for decommissioning of nuclear facilities,” Mathematical Problems in Engineering, Vol.2022, Article No.9945758, 2022. https://doi.org/10.1155/2022/9945758
5. [5] N. Mizuno, Y. Tazaki, T. Hashimoto, and Y. Yokokohji, “A comparative study of manipulator teleoperation methods for debris retrieval phase in nuclear power plant decommissioning,” Advanced Robotics, Vol.37, No.9, pp. 541-559, 2023. https://doi.org/10.1080/01691864.2023.2169588
6. [6] T. Hashimoto et al., “Experimental evaluation of manipulator teleoperation system based on trajectory planning for obstacle removal task in nuclear plant decommissioning,” J. Robot. Mechatron., Vol.36, No.1, pp. 49-62, 2024. https://doi.org/10.20965/jrm.2024.p0049
7. [7] A. Kitamura, H. Hirano, and M. Yoshida, “Comparative study of a glovebox dismantling facility for manual and remote glovebox dismantlement activities,” Nuclear Engineering and Design, Vol.411, Article No.112435, 2023. https://doi.org/10.1016/j.nucengdes.2023.112435
8. [8] G.-R. Lee, B.-J. Lim, D.-W. Cho, and C.-D. Park, “Selection methodology of the optimal cutting technology for dismantling of components in nuclear power plants,” Annals of Nuclear Energy, Vol.166, Article No.108808, 2022. https://doi.org/10.1016/j.anucene.2021.108808
9. [9] M.-G. Choi, D.-H. Lee, S.-M. Jeong, D. Figuera-Michal, and J.-H. Seo, “A hybrid cutting technology using plasma and end mill for decommissioning of nuclear facilities,” Nuclear Engineering and Technology, Vol.54, No.3, pp. 1145-1151, 2022. https://doi.org/10.1016/j.net.2021.09.012
10. [10] J. S. Shin et al., “Cutting performance of thick steel plates up to 150 mm in thickness and large size pipes with a 10-kW fiber laser for dismantling of nuclear facilities,” Annals of Nuclear Energy, Vol.122, pp. 62-68, 2018. https://doi.org/10.1016/j.anucene.2018.08.029
11. [11] A. Kitamura, K. Nakai, T. Namekawa, and M. Watahiki, “In-cell maintenance by manipulator arm with 3D workspace information recreated by laser rangefinder,” Nuclear Engineering and Design, Vol.241, No.7, pp. 2614-2623, 2011. https://doi.org/10.1016/j.nucengdes.2011.04.044
12. [12] K. Nagatani et al., “Emergency response to the nuclear accident at the Fukushima Daiichi Nuclear Power Plants using mobile rescue robots,” J. of Field Robotics, Vol.30, No.1, pp. 44-63, 2013. https://doi.org/10.1002/rob.21439
13. [13] I. Kim, D. Hyun, S. Joo, and J. Lee, “A methodology for digital mockup update based on the 3D scanned spatial information for the automated dismantling of nuclear facilities,” Annals of Nuclear Energy, Vol.139, Article No.107238, 2020. https://doi.org/10.1016/j.anucene.2019.107238
14. [14] A. K. Sleiti, J. S. Kapat, and L. Vesely, “Digital twin in energy industry: Proposed robust digital twin for power plant and other complex capital-intensive large engineering systems,” Energy Reports, Vol.8, pp. 3704-3726, 2022. https://doi.org/10.1016/j.egyr.2022.02.305
15. [15] T. Inamura, “Digital twin of experience for human–robot collaboration through virtual reality,” Int. J. Automation Technol., Vol.17, No.3, pp. 284-291, 2023. https://doi.org/10.20965/ijat.2023.p0284
16. [16] P. Satu et al., “Virtual-reality training solutions for nuclear power plant field operators: A scoping review,” Progress in Nuclear Energy, Vol.169, Article No.105104, 2024. https://doi.org/10.1016/j.pnucene.2024.105104
17. [17] B. Nash, A. Walker, and T. Chambers, “A simulator based on virtual reality to dismantle a research reactor assembly using master-slave manipulators,” Annals of Nuclear Energy, Vol.120, pp. 1-7, 2018. https://doi.org/10.1016/j.anucene.2018.05.018
18. [18] K. Jeong et al., “The digital mock-up system to simulate and evaluate the dismantling scenarios for decommissioning of a NPP,” Annals of Nuclear Energy, Vol.69, pp. 238-245, 2014. https://doi.org/10.1016/j.anucene.2014.02.020
19. [19] D. Hyun, I. Kim, S. Joo, J. Ha, and J. Lee, “Remote dismantling system using a digital manufacturing system and workpiece localization for nuclear facility decommissioning,” Annals of Nuclear Energy, Vol.195, Article No.110182, 2024. https://doi.org/10.1016/j.anucene.2023.110182
20. [20] I. Szőke, M. N. Louka, T.-R. Bryntesen, S.-T. Edvardsen, and J. Bratteli, “Comprehensive support for nuclear decommissioning based on 3D simulation and advanced user interface technologies,” J. of Nuclear Science and Technology, Vol.52, No.3, pp. 371-387, 2015. https://doi.org/10.1080/00223131.2014.951704
21. [21] M. Yoshida, S. Iguchi, H. Hirano, and A. Kitamura, “Development of plutonium fuel facility decommissioning technology to accelerate glovebox dismantling and reduce air-fed suits based operations,” Nuclear Engineering and Design, Vol.431, Article No.113691, 2025. https://doi.org/10.1016/j.nucengdes.2024.113691
22. [22] S. Sivčev, J. Coleman, E. Omerdić, G. Dooly, and D. Toal, “Underwater manipulators: A review,” Ocean Engineering, Vol.163, pp. 431-450, 2018. https://doi.org/10.1016/j.oceaneng.2018.06.018
23. [23] K. Jeong et al., “An evaluation on the cutting technologies for decommissioning of the tube bundles in the RPV of NPPs,” Annals of Nuclear Energy, Vol.83, pp. 342-345, 2015. https://doi.org/10.1016/j.anucene.2015.03.038
24. [24] Y. Mori and M. Wada, “Development of 3D digital-twin system for remote-control operation in construction,” Proc. of the 41st Int. Symp. on Automation and Robotics in Construction, pp. 958-964, 2024. https://doi.org/10.22260/ISARC2024/0124
25. [25] H. Kikuchi, H. Hirano, and A. Kitamura, “Safety improvements in demolition and removal activities with air-fed suit for plutonium fuel facility decommissioning,” Trans. of the Atomic Energy Society of Japan, Vol.21, No.1, pp. 50-63, 2022 (in Japanese). https://doi.org/10.3327/taesj.J20.035