Surface removal of stainless steel using a single-mode continuous wave fiber laser to decontaminate primary circuits

다국어 초록 (Multilingual Abstract)

Removing radioactive contaminated metal materials is a vital task during the decommissioning of nuclear power plants to reduce the cost of the post-dismantling process. The laser decontamination technique has been recognized as a key tool for a successful dismantling process as it enables a remote operation in radioactive facilities. It also minimizes exposure of workers to hazardous materials and reduces secondary waste, increasing the environmental friendless of the post-dismantling processing. In this work, we present a thorough and efficient laser decontamination approach using a single-mode continuous-wave (CW) laser. We subjected stainless steels to a surface-removal process that repetitively exposes the laser to a confined region of ~75 mm at a high scanning rate of 10 m/s. We evaluate the decontamination performance by measuring the removal depth with a 3D scanning microscope and further investigate optimal removal conditions given practical parameters such as the laser power and scan properties. We successfully removed the metal surface to a depth of more than 40 mm with laser power of 300 W and ten scans, showing the potential to achieve an extremely high DF more than 1000 by simply increasing the number of scans and the laser power for the decontamination of primary circuits.

참고문헌 (Reference)

1 R.L. Demmer, "Testing and Evaluation of Light Ablation Decontamination" Idaho National Engineering Laboratory 1994

2 G. Guerrero-Vaca, "Stripping of PFA Fluoropolymer Coatings Using a Nd:YAG Laser (Q-Switch) and an Yb Fiber Laser (CW)" 11 : 1738-, 2019

3 P.J. Maziasz, "Properties of Austenitic Steels for Nuclear Reactor Applications" Elsevier 267-283, 2012

4 L. Carvalho, "Metal decontamination by high repetition rate nanosecond fiber laser : application to oxidized and Eu-contaminated stainless steel" 526 : 146654-, 2020

5 K. H. Leong, "Laserbased Characterization and Decontamination of Contaminated Facilities" Argonne National Lab 1996

6 G. Greifzu, "Laser-based decontamination of metal surfaces" 117 : 293-298, 2019

7 J. P. Nilaya, "Laser-assisted decontaminationda wavelength dependent study" 254 : 7377-7380, 2008

8 L. Li, "Laser removal of surface and embedded contaminations on/in building structures" 1994

9 A. J. Potiens Jr., "Laser decontamination of the radioactive lightning rods" 95 : 188-190, 2014

10 E. J. Minehara, "Laser cleaning trials for the heavily radioisotopecontaminated stainless-steel samples in the primary cooling loop of the nuclear reactor" 48 : 47-55, 2013

11 A. Kumar, "Laser assisted removal of fixed radioactive contamination from metallic substrate" 320 : 183-186, 2017

12 L. Carvalho, "Growth of micrometric oxide layers to explore laser decontamination of metallic surfaces" 3 : 3-, 2017

13 Ph Delaporte, "Dry excimer laser cleaning applied to unclear decontamination" 208 : 298-305, 2003

14 L.E. Boing, "Decommissioning of nuclear facilities decontamination technologies" 2006

15 V. Kumar, "Chemical, biological, radiological, and nuclear decontamination: recent trends and future perspective" 2 : 220-238, 2010

16 J. Min, "Application of laser ablation in adhesive bonding of metallic materials : a review" 128 : 106188-, 2020

17 E. J. Minehara, "A new laser decontamination device" 40 : 165-170, 2011

18 Y. Lin, "A compact and portable laser radioactive decontamination system using passive Q-switched fiber laser and polygon scanner" 153 : 108835-, 2019